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SUMMARY The pollen viability directly affects the pollination process and the ultimate grain yield of rice. Here, we identified that the MORN motif‐containing proteins, OsMORN1 and OsMORN2, had a crucial role in maintaining pollen fertility. Compared with the wild type (WT), the pollen viability of the osmorn1 and osmorn2 mutants was reduced, and pollen germination was abnormal, resulting in significantly lower spikelet fertility, seed‐setting rate, and grain yield per plant. Further investigation revealed that OsMORN1 was localized to the Golgi apparatus and lipid droplets. Lipids associated with pollen viability underwent alterations in osmorn mutants, such as the diacylglyceride (18:3_18:3) was 5.1‐fold higher and digalactosyldiacylglycerol (18:2_18:2) was 5.2‐fold lower in osmorn1, while the triacylglycerol (TG) (16:0_18:2_18:3) was 8.3‐fold higher and TG (16:0_18:1_18:3) was 8.5‐fold lower in osmorn2 than those in WT. Furthermore, the OsMORN1/2 was found to be associated with rice cold tolerance, as osmorn1 and osmorn2 mutants were more sensitive to chilling stress than WT. The mutants displayed increased hydrogen peroxide accumulation, reduced antioxidant enzyme activities, elevated malondialdehyde content, and a significantly decreased seedling survival rate. Lipidomics analysis revealed distinct alterations in lipids under low temperature, highlighting significant changes in TG (18:2_18:3_18:3) and TG (18:4_18:2_18:2) in osmorn1, TG (16:0_18:2_18:2) and PI (17:2_18:3) in osmorn2 compared to the WT. Therefore, it suggested that OsMORN1 and OsMORN2 regulate both pollen viability and cold tolerance through maintaining lipid homeostasis. [ABSTRACT FROM AUTHOR]

The present study was carried out to investigate the physio-biochemical and molecular responses of two rice genotypes (Noichi and N22) under drought, heat and combined drought/heat stress conditions. The antagonistic stomatal activity was found under the combined stress conditions; stomata were open under control and heat stress, conversely, stomata remained closed under drought and combined stress levels. Photosynthetic activity and chlorophyll content are decreased by the overproduction of reactive oxygen species and increased lipid peroxidation in both rice genotypes. To prevent oxidative damage, many antioxidant enzymes like catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD) are produced in both genotypes under these conditions. Under the single stress conditions, CAT activity were increased in N22, whereas combined stress levels, SOD and APX activity were higher for both genotypes. Proline accumulation was also increased under single as well as combined stress conditions for both genotypes to combat stress injuries. Pollen viability was lost under all stress levels but severe loss was found under combined stress levels, which causes spikelet sterility leading to yield losses for both genotypes. As evident from transcript levels, HSP71.18 and HSP71.10 expressions were higher under single and combined conditions, butHSP72.57 gene expression increased only by individual stress levels. WRKY11, WRKY 55, DREB 2A, LEA3 and DHN1 were positively expressed under all stress levels. Conversely, expression of DREB2B genes was higher only under single stress levels. In summary, these results suggest that the effect of combined stress is different from the single stress and it is more severe than the individual stress. [ABSTRACT FROM AUTHOR]

East African diploid cooking bananas, commonly called Mchare, are a staple crop for millions of subsistence farmers in Tanzania, particularly in the Pangani region in northern Tanzania. Several pathogens constrain Mchare production significantly and threaten food security. Sources of resistance to these pathogens have been identified; however, partial male and female sterility impedes successful resistance introgression, complicating the breeding process. Mchare cultivars are also the only known surviving representatives of a diploid banana subgroup that contributed unreduced gametes to many of the most widely grown and successful triploid dessert bananas (‘Cavendish’, ‘Gros-Michel’, ‘Silk’, and ‘Prata’). As such, they represent an essential intermediate step in the conventional improvement of bananas worldwide. We assess the amount and viability of pollen among Mchare and wild genotypes to identify the most fertile Mchare cultivars that can be used in conventional banana improvement. Pollen was collected from 14 banana genotypes for quantification and viability testing over 7 months, and the optimal time for pollen collection was determined to be 0800 HR. Significant variation among banana genotypes in terms of both overall pollen production and percentage of pollen viability was observed. The wild-type bananas ‘Calcutta 4’ (International Musa Germplasm Transit Center (ITC) 0249] and ‘Borneo’ (ITC0253) had the greatest overall pollen production (> 31,000 pollen grains/anther) and viability (~74%), whereas ‘Ijihu Inkundu’ (ITC1460; Mchare genotype) was the least productive (almost completely sterile), with an average pollen production of a few hundred grains per anther and a viability of 7%. There were significant differences among months in terms of pollen viability, with the greatest average viability observed in May, April, and February (> 51%), and the lowest average pollen viability in July (41%). Significant differences were observed among the Mchare genotypes, with ‘Huti-White’, ‘Huti green bell’ (ITC1559), and ‘Mchare Laini’ consistently producing more substantial amounts of total pollen and an overall more significant proportion of viable pollen. This information is vital to improve Mchare bananas and the global breeding of dessert bananas. The choice of Mchare banana used in improvement programs could affect fertility and the likelihood of breeding success. [ABSTRACT FROM AUTHOR]

Fig types such as "Smyrna" and "San Pedro" require pollination (called caprification in fig cultivation) to produce a commercial crop, based on the crop and pollination characteristics of figs. Caprification is the process of hanging caprifig (male fig) fruits on female fig trees to ensure the transfer of pollen from the female fig to the caprifig by a wasp (Blastophaga psenes) that lives within the caprifig. It is necessary to extend the caprification period by using caprifig genotypes that ripen at different times, as female fig fruits ripen gradually. However, as caprifigs may not be continuously available for pollinating female figs, storing suitable caprifigs is necessary. The aim of this study was to assess changes in Blastophaga psenes, the duration of Blastophaga's exit, and the viability of pollen from caprifigs of different genotypes (16 08 05, 16 08 09, 16 08 10, 16 09 10, and 16 ZF 08) stored for caprification. These stored caprifig genotypes were subsequently used for pollination three times at 8-day intervals, after which their impact on the set and quality of the edible fig fruits was evaluated. According to the average data, at the end of storage, the least B. psenes loss was obtained from the 16 08 05 (61.03%) genotype, and the highest was obtained from the 16 09 10 (67.00%) genotype. Pollen germination tended to increase with the storage of caprifig fruits, but this increase was not linear. After storage, the 16 08 09 and 16 09 10 genotypes exhibited greater pollen germination. The highest fruit set and quality were obtained when the 16 08 09 and 16 09 10 genotypes were used as pollen sources. Furthermore, since the 16 08 10 genotype is the latest ripening caprifig genotype, it has been determined that it can pollinate late-ripening "Bursa Siyahı" fruits. Principal component and path analysis demonstrated that pollen viability and germination rate were crucial in selecting caprifig genotypes for fruit set and quality. [ABSTRACT FROM AUTHOR]

Cytoplasmic male-sterility (CMS) is the primary source for the production of commercially viable onion F1 hybrids. The molecular interplay of the cytoplasmic-nuclear genes propels the restoration of fertility in the CMS system, making it cost-effective and stable. The use of the molecular markers that can determine the cytoplasm type and nuclear genotype reduces the amount of time and labour required. This study characterized the morphology of male sterile and fertile plants based on anther colour and pollen viability. Additionally, the molecular characterization of the organellar DNA differentiating cytoplasm and nuclear genotypes in 35 commercially grown open-pollinated varieties of Indian short-day onion was attempted. Our results revealed that morphological and microscopic observations for the identification of male sterile and fertile plants were not 100% corroborative. Markers located in the chloroplast (accD) and mitochondrial DNA (MKFR) revealed that Indian cultivars exhibited a greater frequency of N (normal) cytoplasm, lower frequency of S (sterile) cytoplasm and no occurrence of T (sterile) cytoplasm. All three markers viz., AcPMS1, AcSKP1, and jnurf13 revealed that 93 to 99% of the plants of all the varieties had homozygous recessive (msms) alleles at the Ms locus. The OPT marker classified the plants as having 38% msms, 39% Msms and 21% MsMs genotypes and needs further investigation. This underscores the pressing need for additional markers to precisely discern the Ms locus, facilitating the identification of male sterile and maintainer plants within open-pollinated populations of Indian short-day onions. Notably, male sterile cytoplasm was identified in eight commercial varieties, marking a pioneering revelation in Indian onion cultivation. [ABSTRACT FROM AUTHOR]

Hybridization and polyploidy are currently known as exponential factors for biodiversity. Some Paspalum species can hybridize and originate viable allopolyploids with possible agronomic use. We collected a frost resistance hybrid in north–western Misiones and determined its ploidy level, meiotic behavior, pollen viability, cytoembryology, and seed production in open and self-pollination. To elucidate its origin, we conducted a phenotypic and geographical analysis using herbarium specimens to establish its putative parental species. The hybrid was triploid, exhibiting irregular meiosis with the formation of non-viable pollen and undeveloped embryo sacs, resulting in very low seed production under both pollination conditions. Through morphological analysis, we identified Paspalum urvillei Steud. and the Paniculata group, i.e. Paspalum juergensii Hack., Paspalum umbrosum Trin., and Paspalum paniculatum L., as the putative parental species. Geographic distribution patterns suggested a possible hybridization event between P. urvillei and P. umbrosum, though further investigation is needed to precisely identify which species from the Paniculata group hybridized with P. urvillei. Future studies will help to unravel the complex genetic interactions underlying hybridization in Paspalum species and contribute to our understanding of biodiversity dynamics. [ABSTRACT FROM AUTHOR]

The genus Dyckia (Bromeliaceae) is endemic to South America, and its species show important ecological roles in xeric environments. The flowering phenology as well as floral and reproductive biology were monitored monthly in Dyckia dissitiflora at two sites (Bela Vista: 11°42′03.4″ S 39°05′21.7″ W and Barra do Vento: 11°37′58.1″ S 39°03′33.7″ W) in the municipality of Serrinha, Bahia, Brazil. Flowering occurs in the early austral summer with a peculiar time of beginning of anthesis (10:00–11:00), offering resources 18 h after the first petal movements. Pollen viability was 98%, with a high production of pollen grains. Stigma receptivity is continuous from flower opening to senescence, and nectar production initiates at 04:00 and extends until 18:00. The species is self‐compatible and autogamous, but not agamospermic. Pollen tubes developed and reached the micropyle within 24 h in all of the reproductive tests. The hummingbird Chlorostilbon lucidus was the only floral visitor and pollinator (frequency = 0.82 ± 0.02). Fruiting occurs 3 days after anthesis, and the seeds are wind‐dispersed. Self‐compatibility and autogamy are essential strategies for the reproductive success of D. dissitiflora in light of the low number and visit frequency of its pollinators, and it is favored by slow floral movements and the position of the stigmas in relation to stamens. [ABSTRACT FROM AUTHOR]

Cryptangieae has recently been revised based on morphology and molecular phylogeny, but cytogenetic data is still scarce. We conducted this study with the aim of investigating the occurrence of holocentric chromosomes and pseudomonads, as well as understanding the mode of chromosomal evolution in the tribe. We performed analyses of meiotic behavior, chromosome counts, and reconstruction of the ancestral state for the haploid number. We present novel cytogenetic data for eight potentially holocentric species: Cryptangium verticillatum, Krenakia junciforme, K. minarum, Lagenocarpus bracteosus, L. griseus, L. inversus, L. rigidus, and L. tenuifolius. Meiotic abnormalities were observed, with parallel spindles being particularly noteworthy. Intra-specific variations in chromosome number were not found, which may indicate an efficient genetic control for the elimination of abnormal nuclei. The inferred ancestral haploid number was n = 16, with dysploidy being the main evolutionary mechanism. At least five chromosomal fissions occurred in Krenakia (n = 21), followed by a further ascending dysploidy event in Lagenocarpus (n = 17). As proposed for Cyperaceae, it is possible that cladogenesis events in Cryptangieae were marked by numerical and structural chromosomal changes. [ABSTRACT FROM AUTHOR]

Flowers of most Piperales do not reward pollinators. However, a few mutualistic pollination relationships have been proposed among the perianth-bearing species. To test the hypothesis of a mutualistic relationship between Prosopanche and beetle pollinators, we studied the pollination biology of three species (P. americana , P. bonacinae , P. panguanensis). For all three species, we recorded flower visitors and flower volatile organic compounds (VOCSs). In addition, for P. americana we investigated flower phases, thermogenesis, visitors' behaviour, and viability of transported pollen. Using a behavioural experiment, we identified the role of flower heat and fragrance in pollinator attraction. We recorded Neopocadius nitiduloides and Lasiodactylus sp. sap beetles (Nitidulidae) as main pollinators and Hydnorobius hydnorae and H. helleri weevils (Belidae) as occasional pollinators. Thermogenic female flowers heat up to 8°C above the ambient temperature. Flowers only trap the small-sized sap beetles. Methyl-3-methyl-2-butenoate dominated the VOC profile. This was a powerful attractant for sap beetles in controlled bioassays. We conclude that pollination in Prosopanche is mutualistic. This was observed through a pollinator-size-based access limit to the stigmatic chamber and a strong olfactory attractant. Mutualism in Prosopanche therefore contrasts with that of most perianth-bearing Piperales, suggesting it is a novel pollination relationship in early-diverging angiosperms. [ABSTRACT FROM AUTHOR]

The production of melons (Cucumis melo L.) in greenhouses relies on pollination. Extreme temperature and insufficient light reduce not only flower visitation by pollinators but also pollen viability, resulting in inefficient pollination. In this study, we investigated the effects of forchlorfenuron [(N-(2-chloro-4-pyridyl)-N0-phenylurea (CPPU)] on the fruit setting and growth of oriental melons (C. melo L. var. makuwa Makino). The primary objective was to devise a new strategy for the management of oriental melons. Treatment with 5 mg·L21 CPPU a day before flowering (T1), on the day of flowering (T2), and a day after flowering (T3) increased the fruit setting rate (by 20.1% to 30%) in melons subjected to artificial pollination (AP) or no pollination (NP) compared with the rate in those subjected to only artificial pollination without CPPU (CK). CPPU treatment induced unfertilized seeds; in addition, a tendency toward parthenocarpy was noted. The highest fruit setting rate (~95%) was noted in plants subjected to the following treatments: AP+T1 and NP+T3. The rates of abnormal fruit formation decreased from 45.2% of CK group to 9.4% in plants subjected to AP+T1 and to 19.4% in those subjected to NP+T3. Elevated exogenous concentrations of CPPU markedly increased fruit weight. Plants subjected to NP+10 mg·L21 CPPU bore the heaviest fruits (541.0 g), which were heavier than those borne by plants subjected to AP+10 mg·L21 CPPU. CPPU treatment reduced the fruit cavity ratio in a concentration-dependent manner from 47.3% to 33.6% and increased the pulp thickness from 1.5 to 2.5 cm. Notably, supplementary CPPU treatment exerted no significant effects on fruit traits. Regarding taste, inconsistent results were obtained for sugar accumulation. Although the content of cucurbitacin B increased immediately after the initial CPPU treatment, it markedly decreased after 15 days of CPPU treatment. Therefore, mature melons did not have a bitter taste. [ABSTRACT FROM AUTHOR]

Brinjal hybrid seed production primarily utilizes the seed-to-seed method. Optimal results require synchronized stigma receptivity and pollen viability, timing of emasculation and pollination along with the appropriate quantity of pollen on the female parent's stigma. With this perspective, the research was carried out, employing the parents of the GJBH 4 brinjal hybrid. The study involved 18 experiments, considering two emasculation options namely emasculation on same day as flower opening, emasculation on a day prior to flower opening, three pollination times namely 8-9 am, 9-10 am and 10-11 am and three cross-pollination ratios namely two female flowers per male flower, four female flowers per male flower, six female flowers per male flower. The results revealed that for better hybrid seed yield, emasculation on the day prior to flower opening, pollination between 9-10 am and using one male flower to pollinate four female flowers could be adopted. [ABSTRACT FROM AUTHOR]

Rising temperature affects agricultural production, causing food insecurity. Thus, the objective of this study was to evaluate how increased temperature influences pollen viability, photosynthetic and enzymatic responses, and their consequences on the final yield of cowpea cultivars. The cultivars BRS Acauã, BRS Guariba, BRS Gurguéia, and BRS Pajeú were used, kept in growth chambers under two temperature regimes: 24.8–30.8–37.8 °C and 20–26–33 °C. The cultivars BRS Acauã, BRS Guariba, and BRS Pajeú showed prolonged flowering and greater flower abortion, at 23.58%, 34.71%, and 25.55%, respectively, under an increase of 4.8 °C in temperature. This increase also reduced the viability of BRS Acauã and BRS Pajeú pollen by 34 and 7%, respectively. Heating increased stomatal opening and transpiration but reduced chlorophyll content. The enzymatic response varied according to cultivars and temperature. Changes in photosynthetic and enzymatic activities contribute to reducing pollen viability and productivity. BRS Acauã was the most affected, with an 82% reduction in the number of seeds and a 70% reduction in production. BRS Gurguéia maintained its production, even with an increase of 4.8 °C, and can be selected as a cultivar with the potential to tolerate high temperatures as it maintained pollen viability, with less flower abortion, with the synchrony of physiological and biochemical responses and, consequently, greater production. [ABSTRACT FROM AUTHOR]

Reproductive barriers are the single largest impediment in breeding of Solanum aethiopicum (Shum and Gilo cultivars). Knowledge of these barriers is important for prudent germplasm utilization and genetic improvement of the species. This study investigated compatibility barriers between S. aethiopicum and its relatives. A randomized complete block design and a full diallel mating method were used to evaluate crossability and floral traits of six genotypes of four different species (S. aethiopicum, S. macrocarpon, S. anguivi and S. incanum) across two seasons. Parameters assessed were petal opening time, stigma receptivity, anther dehiscence, pollen quantity, pollen viability and crossing success. Most flowers for all parental genotypes were opened by 08:00 am. Mean number of open flowers was higher (12 ± 6) for S. aethiopicum Shum (N11) and lowest (n = 3 ± 1) for S. macrocarpon (E12; (p < 0.001), with other genotypes being intermediate. Stigma receptivity differed (p < 0.001) among genotypes and seasons and was highest for N11 at 3.31 ± 1.32 and lowest for S. incanum (In1) at 2.24 ± 1.27; other genotypes were intermediate. All genotypes possessed high pollen viability (µ > 80%) though species differed (p < 0.01). All genotypes exhibited self-compatibility to varying degrees with N11 showing the highest fruit success (67.9 ± 15.6%), seeds per fruit (82 ± 51), and F1 germination rate (79 ± 18%). Interspecific crosses using S. macrocarpon, S. anguivi and S. incanum as females showed poor or no fruit and seed. N11 (S. aethiopicum Shum) was the top performer as a female; crosses with S. macrocarpon (N11xE12) showed highest fruit success (65.9 ± 26.5), with S. anguivi (N11xA1) showing the highest seed set (n = 56 ± 34) and S. incanum (N11xIN1) showing the highest F1 germination (64 ± 19). The F1 intraspecific cross between S. aethiopicum Shum (N4) and S. aethiopicum Gilo (G4) did not germinate. Female parent functioning may be a key feature for the failure of interspecific crosses where S. aethiopicum is a donor as observed by the unilateral incompatibility. [ABSTRACT FROM AUTHOR]

The evolution of postzygotic isolation is thought to be a key step in maintaining species boundaries upon secondary contact, yet the dynamics and persistence of hybrid incompatibilities in naturally hybridizing species are not well understood. Here, we explore these issues using genetic mapping in three independent populations of recombinant inbred lines between naturally hybridizing monkeyflowers, Mimulus guttatus and Mimulus nasutus, from the sympatric Catherine Creek population. We discover that the three M. guttatus founders differ dramatically in admixture history, with nearly a quarter of one founder's genome introgressed from M. nasutus. Comparative genetic mapping in the three RIL populations reveals three new putative inversions, each one segregating among the M. guttatus founders, two due to admixture. We find strong, genome‐wide transmission ratio distortion in all RILs, but patterns are highly variable among the three populations. At least some of this distortion appears to be explained by epistatic selection favouring parental genotypes, but tests of inter‐chromosomal linkage disequilibrium also reveal multiple candidate Dobzhansky‐Muller incompatibilities. We also map several genetic loci for hybrid pollen viability, including two interacting pairs that coincide with peaks of distortion. Remarkably, even with this limited sample of three M. guttatus lines, we discover abundant segregating variation for hybrid incompatibilities with M. nasutus, suggesting this population harbours diverse contributors to postzygotic isolation. Moreover, even with substantial admixture, hybrid incompatibilities between Mimulus species persist, suggesting postzygotic isolation might be a potent force in maintaining species barriers in this system. [ABSTRACT FROM AUTHOR]

Pollen viability, dispersion ability and longevity during deep-freezer storage were studied in three Juniperus taxa distributed in Slovakia. All these characteristics of pollen are closely related to the pollination and/or fertilization success of the junipers in nature. Pollen viability varied considerably between the three populations of J. communis and one population of each, J. sibirica and J. communis var. intermedia. Pollen germination rate ranged between 40.75% and 75.06%, and pollen tube length between 30.32 and 40.41 µm. A clear tendency indicates a higher germination rate of J. communis pollen from lower altitudes and reduced germination of J. sibirica and J. communis var. intermedia pollen from higher altitudes. The dispersion potential of the J. communis pollen during its shedding seems relatively low. In 2021, pollen cloud density was diluted at 68.1% at the 4 m distance from the test shrub, in 2022 of 52.1% at the 17 m distance from the pollen source. A deep-freezer storage of juniper pollen in a double-walled polyethylene bag with silica gel was not efficient enough, as indicated by the drop of pollen germination rate of 31.2% in J. communis and of 79.4% in J. sibirica during a 1-year storage period at − 81 °C. [ABSTRACT FROM AUTHOR]

Identifying tomato genotypes that can thrive and produce abundantly under arid climatic conditions and addressing the growing food demand caused by population growth are pressing concerns for food security. This research aimed to assess the growth, physiological, phenological, fruit yield, and postharvest quality of tomato genotypes cultivated in an organic hydroponic system in Qatar, where abiotic stress conditions prevail. Ten different tomato genotypes were carefully evaluated, and comprehensive data regarding their growth and development were collected and analyzed. The performance of these tomato genotypes across all traits related to yield and quality showed significant variations. Notably, the 'Velocity' and 'Sigma' genotypes consistently exhibited robust vegetative growth and improved phenological characteristics compared with the other tomato cultivars. Specifically, 'Velocity' and 'Sigma' displayed increased leaf assimilation rates (35% and 32%), stomatal conductance (14% and 11%), and reduced transpiration loss (50% and 44%) compared with 'SV4129TH'. These genotypes also showed lower electrolyte leakage (32% and 28%) and maintained higher intercellular CO2 concentrations. Furthermore, 'Velocity' exhibited an accelerated flowering pattern, with the first flowering occurring 4 days sooner and 50% flowering occurring 5 days sooner than that of 'SV4129TH'. 'Velocity' also demonstrated superior fruit set (14%), pollen viability (24%), and fewer incidences of flower drops (36%) compared with 'SV4129TH'. Notably, 'Velocity' outperformed 'SV4129TH' in terms of marketable fruit yields, with a 32% higher yield. In addition to its impressive yield, 'Velocity' exhibited superior postharvest quality, including firmness, Brix level, acidity, and color. Therefore, overall, 'Velocity' and 'Sigma' emerged as promising genotypes with strong abiotic stress tolerance capabilities. The correlation analysis of these traits provided valuable insights into the selection and breeding of genotypes that can withstand abiotic stress conditions, laying the foundation for effective comparisons and selections of genotypes suitable for organic hydroponic cultivation in stressful environments. [ABSTRACT FROM AUTHOR]

Pollen cells require large amounts of sugars from the anther to support their development, which is critical for plant sexual reproduction and crop yield. Sugars Will Eventually be Exported Transporters (SWEETs) have been shown to play an important role in the apoplasmic unloading of sugars from anther tissues into symplasmically isolated developing pollen cells and thereby affect the sugar supply for pollen development. However, among the 17 CsSWEET genes identified in the cucumber (Cucumis sativus L.) genome, the CsSWEET gene involved in this process has not been identified. Here, a member of the SWEET gene family, CsSWEET5a, was identified and characterized. The quantitative real-time PCR and β-glucuronidase expression analysis revealed that CsSWEET5a is highly expressed in the anthers and pollen cells of male cucumber flowers from the microsporocyte stage (stage 9) to the mature pollen stage (stage 12). Its subcellular localization indicated that the CsSWEET5a protein is localized to the plasma membrane. The heterologous expression assays in yeast demonstrated that CsSWEET5a encodes a hexose transporter that can complement both glucose and fructose transport deficiencies. CsSWEET5a can significantly rescue the pollen viability and fertility of atsweet8 mutant Arabidopsis plants. The possible role of CsSWEET5a in supplying hexose to developing pollen cells via the apoplast is also discussed. [ABSTRACT FROM AUTHOR]

With global warming, the impact of high‐temperature stress on crop production is one of the major issues facing agriculture. Combining a series of field and controlled environment experiments, the current study aimed at understanding causes of yield loss due to heat stress in lima bean (Phaseolus lunatus L.) in order to guide breeding for heat tolerance. A growth‐stage analysis of multi‐year field trials suggested that yields were reduced by sensitivity to heat during floral transition. High nighttime temperatures during this period were also associated with delayed pod set and subsequent harvest. These effects were validated in controlled environments, with additional tests revealing how nighttime heat stress generally reduces seeds per pod but can also reduce the number of pods set. Using an intra‐plant dual temperature treatment design for vegetative and reproductive organs, it was determined that effects on pollen viability and release are primary factors underlying heat stress‐associated yield losses in lima bean. Elevated nighttime temperatures did not reduce aboveground biomass, indicating the physiological basis for temperature sensitivity was not driven by a photosynthate deficit, but instead could be attributed to changes in source–sink dynamics. Still, the basis for sensitivity to heat differed among genotypes, opening new targets for a multi‐mechanistic breeding approach for heat tolerance. Core Ideas: Seed yield in lima bean is reduced when heat stress occurs during reproductive phase.Sensitivity to heat stress is greater during the night.High nighttime temperatures affect multiple physiological mechanisms of reproduction.Genotypes show mechanism‐specific sensitivities to high nighttime temperature.Multiple physiological mechanisms may be targeted for breeding heat tolerance in lima bean. [ABSTRACT FROM AUTHOR]

Wheat pollen, which is characterized by its short lifespan, exhibits rapid germination after anthesis. The preservation of wheat pollen is contingent upon environmental factors including temperature, relative humidity, light, and wind. The aim is to explicate the process for efficiently storing wheat pollen, particularly with regard to breeding. The short longevity of wheat pollen grains renders it impractical to conduct tests for pollen viability and in vitro germination on a large scale. Herein, the impact of storage temperatures and duration was assessed on pollen viability and in vitro germination in order to optimize storage conditions for preserving pollen viability. Pollen grains from 50 diverse spring wheat genotypes, each with three replicates, were harvested and stored at temperatures of 22 °C, −20 °C, and 4 °C. Subsequently, pollen viability and in vitro germination rates were determined after storage for 1, 3, and 6 days. The results revealed that storage temperatures, durations, genotypes, and their interactions had a statistically significant impact on both pollen viability and in vitro germination. Notably, when pollen was kept at 22 °C, almost all genotypes exhibited a loss of pollen viability and in vitro germination after 1, 3, and 6 days of storage. Likewise, storage at −20 °C failed to extend pollen germination. However, at a storage temperature of 4 °C, the pollen of 36 wheat genotypes exhibited a range of 6–14% for in vitro pollen germination and even remained viable for 6 days. The ANOVA revealed a substantial variation in grain number per spike between wheat genotypes, thereby highlighting the significant influence of genetic variations on grain yield. Moreover, a slight positive association between the viability of wheat pollen and the number of grains was found in the current study, suggesting that a variety of factors affect the number of grains produced. Simple linear regression analysis further revealed a significant negative correlation between pollen viability, in vitro germination, and storage time and temperature. In conclusion, our findings underscore that 4 °C is the optimal temperature for preserving pollen viability and in vitro pollen germination in spring wheat for up to 6 days. The results of the present study suggests that the pollen viability of wheat is dependent on genotype, storage temperature, and storage duration. Thus, the 36 wheat genotypes identified during the present work could be efficiently maintained at 4 °C for short-term storage (6 days) and could be further used for genetic and breeding purposes. [ABSTRACT FROM AUTHOR]

• Significant morphological diversity exists amongst the species- C. annuum, C. frutescens, C. chinense for all the characters studied. • Interspecific hybridization in Capsicum species is possible despite hindered by pre- and post-fertilization barriers. • Amongst the successful crosses made in the present study, Mem x King chilli-A5 had the highest fruit set (60 %), while C. annuum (Capsicum) x C. chinense (King chilli-A18) and King chilli-A18 x Krishna had the lowest fruit set (20 %). • It was found Capsicum x King chilli-A18(19.10 %) had the lowest pollen sterility and was the most desirable hybrid in terms of pollen fertility. • Estimation of the Usual Euclidean distance amongst the parents and their F 1 s revealed that Mem and F 1 of C. chinense (King chilli-A5) x C. frutescens (Mem) had the minimum distinction (94.39) amongst them, supporting that King chilli is the natural hybrid of C. chinense and C. frutescens. The present study explores the potentiality of interspecific crosses using three different Capsicum species, comprising of two C. annuum (Krishna and Capsicum) , five C. chinense (King chilli A1, A5, A18, A19, A20) and one C. frutescens (Mem) genotypes, with the objective to identify the incompatibility barriers, accomplish the morpho-molecular characterization of parents and hybrids and assess the genetic relatedness between the genotypes. Amongst the three species used for the crossing programme, 'Krishna' (C. annuum) and 'Mem' (C. frutescens) are local cultivars of Assam (India) and possess excellent adaptability. Guinness World Records certified King chilli, or 'Bhut Jolokia' (C. chinense), as the world's hottest chilli (10,001,304 SHU) in September 2007. King chilli has tremendous export potential but is prone to viral diseases, thereby necessitating the transfer of desirable disease resistance from local cultivars. It was observed from the study that the reciprocal crosses involving C. chinense and C. frutescens were compatible, but C. frutescens (Mem) was crossable with only accession A5, suggesting genotype specificity in the interspecific crosses. The usual Euclidean distance between Mem and A5 was 716.605 Similarly reciprocal crosses involving C. annuum and C. chinense were partially incompatible. Both the C. annuum (Krishna, Capsicum) genotypes successfully crossed with King chilli accession A18 thereby exhibiting genotype specificity. It was observed that in the cross A18 x Krishna the F 1 seeds failed to germinate and in the cross A18 x Capsicum the F 1 plants exhibited dwarfism. Hence, unilateral incompatibility was observed when King chilli accession A18 was used as the female parent. In the reciprocal crosses, germination and plant development was normal. The pollen viability ranged from 72.64 to 94.92 % for parents and 23.55 to 81.02 % for the hybrids. Thus, hybrids exhibited lower pollen viability compared to their parents. Significant morphological differences were visible between the parents and their combinations; some features were similar to the male or female parent, and others were either intermediate or novel. Parental polymorphism was detected using thirty random SSR primers, and the markers showing polymorphic bands were used to confirm the hybridity of F 1 s. Therefore, an attempt was made in this study to assess the possibility of interspecific crosses to transfer disease resistance from the related species to enhance the quality of King chilli, thus improving its commercial valve. [ABSTRACT FROM AUTHOR]

Occurrence of male and bisexual flowers (andromonoecy) in a species is thought to be an adaptation to enhance reproductive success through increasing male function or by diverting resources otherwise used for the formation of pistils. Commelina diffusa Burm. f. is a pantropical, herbaceous, and andromonoecious species from the family Commelinaceae. A typical inflorescence comprises male and bisexual flowers enclosed within a spathe. Morphology of the different floral types, floral phenology, pollen viability, pollen production, and mating system were studied in this annual, bearing small fruits. Being nectarless, pollen is the only reward for the pollinators in this species. The number of fruits developing was found to influence the gender of the subsequent flowers within the spathe. The floral visitors, including members of Diptera and Hymenoptera, facilitate outcrossing and may mediate geitonogamous selfing as well. Delayed selfing takes place when floral organs intertwine as the flower fades. Andromonoecy in itself does not promote outcrossing, but it may be advantageous to present pollen in more flowers, thereby attracting and feeding more insects and potentially increase male function. [ABSTRACT FROM AUTHOR]

Exacum bicolor (Roxb.) is an herbaceous perennial endemic to peninsular India and enlisted as an endangered plant species. Since a thorough insight into the reproductive biology of a species is necessary to aid conservation and crop improvement, the present study was formulated to assess the floral biology and reproductive behaviour of the plant. It was found that the bisexual flowers of this plant possess pollen grains that remain viable for nine days after anthesis exhibiting maximum viability on the first day of anthesis (84.61%) and 84.18 per cent viability on the previous day of anthesis. Stigma was found to be receptive upto four days after anthesis. Maximum seed weight per capsule (17.21 mg) was realised from flowers pollinated on the third day of flower opening. There was 100 per cent fruit set in flowers that were open pollinated as well as in the flowers which were either controlled out-crossed or self-pollinated under control. Fruit set was not observed on bagging the flowers to avoid natural out-crossing, and on open pollination. Hence, it became evident that Exacum bicolor (Roxb.) is primarily a cross-pollinated species, although no self-incompatibility mechanism operates in the species. Also, natural self-pollination is not favoured for procreation; reproduction via apomixis is absent in the species. [ABSTRACT FROM AUTHOR]

Interspecific hybridization has long been used to produce Phalaenopsis hybrids with superior traits such as flower size, color, lip morphology, heavy pigmentation spots, spike number, plant height, floret number and size, inflorescence angle, and branching. For a successful breeding program, superior parents with desirable horticultural traits must be selected for hybridization based on market preferences. However, many existing hybrids produce triploids or aneuploids and are almost completely sterile. A database of the cytogenetic backgrou nds of species and cultivars is essential for formulating systematic breeding programs. However, this information is limited to the Phalaenopsis cultivars. Therefore, chromosome composition, pollen viability, and meiotic abnormality of two Phalaenopsis yellow cultivars, namely Phalaenopsis ‘Fuller’s Sunset’ and Phalaenopsis ‘Geumgongju,’ were analyzed in this study. Cytogenetic analyses revealed that both cultivars had hypotetraploid and asymmetrical chromosomes. Assessment of pollen viability using the 2,3,5-triphenyl tetrazolium chloride (TTC) staining test and in vitro pollen germination in five flower developmental stages demonstrated that P. ‘Fuller’s Sunset’ pollinia were viable because it were stained in all stages with pollen tube growth. In contrast, unstained pollinia and the absence of pollen tubes were observed in P. ‘Geumgongju.’ Sporad stage analysis showed that P. ‘Geumgongju’ contained predominantly abnormal sporads with micronuclei compared to those of P. ‘Fuller’s Sunset.’ The results of this study provide vital information for breeding programs for Phalaenopsis cultivars and emphasize the importance of selecting appropriate parents for hybridization. [ABSTRACT FROM AUTHOR]

In vitro pollen germination is considered the most efficient method to assess pollen viability. The pollen germination frequency and pollen tube length, which are key indicators of pollen viability, should be accurately measured during in vitro culture. In this study, a Mask R-CNN model trained using microscopic images of tree peony (Paeonia suffruticosa) pollen has been proposed to rapidly detect the pollen germination rate and pollen tube length. To reduce the workload during image acquisition, images of synthesized crossed pollen tubes were added to the training dataset, significantly improving the model accuracy in recognizing crossed pollen tubes. At an Intersection over Union threshold of 50%, a mean average precision of 0.949 was achieved. The performance of the model was verified using 120 testing images. The R 2 value of the linear regression model using detected pollen germination frequency against the ground truth was 0.909 and that using average pollen tube length was 0.958. Further, the model was successfully applied to two other plant species, indicating a good generalizability and potential to be applied widely. [ABSTRACT FROM AUTHOR]

Due to global climate change, heat stress is increasingly harming the growth, development, overall biomass, and grain yield of numerous crops. Heat stress impairs pollen development and thus reduces seed set in Sorghum bicolor (L.) Moench; however, the effects of heat stress on anther development at specific stages and tiller formation remain incompletely understood. Here we report that exposure to heat stress [42°C/32°C (day/night)] at pollen mother cell (PMC) and booting stages profoundly disrupts tapetum and pollen development, resulting in a significant decrease in grain yield in sorghum. Sorghum plants subjected to 9 days or less of heat stress at the PMC stage exhibited normal pollen viability, but 12 days of heat stress caused almost complete loss of grain yield and the formation of nonviable pollen grains. Similarly, sorghum plants that were heat‐stressed for 3 days at the booting stage produced few seeds. Further analysis revealed that aberrant tapetum and pollen development contributed to the sterility of pollen in these heat‐stressed plants. Notably, in addition to inhibiting plant height, a 12‐day heat stress at the PMC stage promoted the formation of basal tillers, whereas a 3‐day heat stress at the booting stage stimulated the formation of apical tillers, which helped salvage seed yield under heat stress conditions. Moreover, the application of exogenous auxin promoted the formation of apical tillers and leaf numbers per apical tiller. Collectively, our findings suggest that sorghum is susceptible to heat stress during both early and late anther development, and auxin might be involved in governing the formation of apical tillers. [ABSTRACT FROM AUTHOR]

Lily (Lilium spp.) is a popular ornamental plant. Traditional genetic transformation methods have low efficiency in lily, thus development of a high-efficiency genetic transformation system is important. In this study, a novel transient transformation method involving pollen magnetofection was established and optimized pollen viability, and exogenous gene expression in magnetofected pollen and that of different germplasm were assessed. The highest germination percentage of Lilium regale pollen was 85.73% in medium containing 100 g/L sucrose, 61.5 mg/L H3BO3, and 91.5 mg/L CaCl2. A 1:4 ratio of nanomagnetic beads to DNA plasmid and transformation time of 0.5 h realized the highest transformation efficiency (88.32%). The GFP activity in transformed pollen averaged 69.66%, while that of the control pollen was 0.00%. In contrast to the control, transgenic seedlings obtained by pollination with magnetofected pollen showed strong positive GUS activity with 56.34% transformation efficiency. Among the lily germplasm tested, 'Sweet Surrender' and L. leucanthum had the highest transformation efficiency (85.80% and 54.47%), whereas L. davidii var. willmottiae was not successfully transformed. Transformation efficiency was positively correlated with pollen equatorial diameter and negatively correlated with polar axis/equatorial diameter ratio. The results suggest that pollen magnetofection-mediated transformation can be applied in Lilium but might have species or cultivar specificity. [ABSTRACT FROM AUTHOR]

The rice GA biosynthetic gene OsGA3ox1 has been proposed to regulate pollen development through the gametophytic manner, but cellular characterization of its mutant pollen is lacking. In this study, three heterozygotic biallelic variants, "-3/-19", "-3/-2" and "-3/-10", each containing one null and one 3bp-deletion allele, were obtained by the CRISPR/Cas9 technique for the functional study of OsGA3ox1. The three homozygotes, "-19/-19", "-2/-2" and "-10/-10", derived from heterozygotic variants, did not affect the development of most vegetative and floral organs but showed a significant reduction in seed-setting rate and in pollen viability. Anatomic characterizations of these mutated osga3ox1 pollens revealed defects in starch granule accumulation and pollen wall development. Additional molecular characterization suggests that abnormal pollen development in the osga3ox1 mutants might be linked to the regulation of transcription factors OsGAMYB, OsTDR and OsbHLH142 during late pollen development. In brief, the rice GA3ox1 is a crucial gene that modulates pollen starch granule accumulation and pollen wall development at the gametophytic phase. [ABSTRACT FROM AUTHOR]

• Comprehensive phenology from the onset of the primordial bud to the senescence phase, is documented for Macrotyloma uniflorum. • Floral organs exhibits ultrastructural variation in Macrotyloma uniflorum. • Macrotyloma uniflorum accessions from Republic of Benin are non-echinate; other accessions exhibit spinuliferous pollen. • There is a positive correlation between days to flowering and most floral traits. • Pollens of Macrotyloma uniflorum are viable during the day. The absence of information on the reproductive biology of some nutritive legumes has been an obstacle to their genetic improvement. Gathering information on reproductive biology contributes significantly to the interest of breeders to have adequate tools for initiating the improvement program through crosses among high performing genotypes. To contribute to this, we examined the flowering phenology, pollen biology, stigma receptiveness at bud dehiscence and anthesis phases, and the in-vitro germination of the pollens in horsegram (Macrotyloma uniflorum). Pollens of horsegram were found to be either tricolporate or triporate, echinates in all accessions except in the collections from Benin. Ovaries in horsegram showed great variation in the number of ovules and activities of peroxidase indicated the receptiveness of stigma at bud dehiscence phase and during anthesis. A high number of ovules per ovary was found in accessions from Australia (Leichardt 1 and 2), Mali (LeichardtMali) and India (CPI22679). Pollen viability analysis implies the possibility of better results when pollinating during the day and immediately after the flower opens. The study provides information on the reproductive biology of horsegram for future hybridization program in order to enhance the performance of the crop and increase production. It also reveals differences in accessions from Benin compared with all other accessions from Mali, India or Australia. [ABSTRACT FROM AUTHOR]

The genus Sphaeralcea belongs to the Malvaceae family and has native species from South America. Their attractive morphological characteristics with ornamental value have not yet been explored. The objective of this work was to know the viability of pollen, stigma receptivity, type of pollination and combining ability of four Sphaeralcea species (S. australis, S. bonariensis, S. crispa and S. mendocina), with the aim to develop new ornamental varieties. Fructification, fertility, seed germination and survival seedlings on intraspecific and reciprocal interspecific offspring were assessed. The highest values of stigma receptivity and pollen viability were obtained at 2:00 PM for the four species. S. mendocina also showed high values of pollen viability at 4:00 PM. The species proved to be self-incompatible and allogamous, with different degrees of reproductive compatibility. The interspecific crosses of S. mendocina and the intraspecific of S. crispa did not produce descendants. The crosses between S. australis and S. bonariensis as maternal parent presented the best combining ability with good fruit production, seed germination and survival. This research provides useful information for the formulation and implementation of breeding strategies, to improve pollination efficiency, and to breed new Sphaeralcea varieties with ornamental potential. [ABSTRACT FROM AUTHOR]

Hot and humid conditions create challenges for tomato production under a controlled environment. Low tomato productivity is related to the lack of stress tolerance of existing cultivars and their ability to maximize fruit set and yield. The aim of this study was to evaluate the effectiveness of three management strategies, cultivar selection, grafting, and plant density, for the growth and production efficiency of organically grown hydroponic tomatoes under adverse environmental conditions in Qatar. The experiment used a split-split plot design with 'Velocity F1' and 'Sigma F1' as the main plot treatments and a factorial arrangement of grafting combinations and planting densities (3.5 and 5.5 plants/m2) as subplots. Tomato cultivar Velocity F1 grafted on Maxifort F1 resulted in greater vegetative growth and improved phenological attributes than nongrafted Velocity F1. Grafted 'Velocity F1' plants grown at 3.5 plants/m2 had an increase in leaf photosynthetic rates (18%), less transpiration loss (16%), and less electrolyte leakage (15%) while maintaining stomatal conductance and intercellular CO2 concentrations. At 9 weeks after transplanting, canopy growth was higher (24%) and flowering occurred earlier (3 days) with grafted 'Velocity F1' transplants than with nongrafted transplants. Higher fruit sets (20%), pollen viability (22%), and fewer flower drops (17%) were also observed for grafted 'Velocity F1' transplants than for nongrafted transplants. Marketable fruit yields were higher (26%) with grafted 'Velocity F1' grown at 3.5 plants/m2 than with nongrafted 'Velocity F1'. Both grafted 'Velocity F1' and 'Sigma F1' fruits retained acceptable fruit color (L*, a*, b*, C*, °h), firmness, °Brix, titratable acidity, weight, and prolonged shelf life by 4 additional days than nongrafted ones. We conclude that grafted tomato 'Velocity F1' grown at a plant density of 3.5 plants/m2 was the best management strategy for enhancing seedlings quality, plant growth, and postharvest quality and alleviating abiotic stresses under this protected environment and hydroponic system. [ABSTRACT FROM AUTHOR]

Pollen hydration on dry stigmas is strictly regulated by pollen–stigma interactions in Brassicaceae. Although several related molecular events have been described, the molecular mechanism underlying pollen hydration remains elusive. Multiple B‐class pollen coat proteins (PCP‐Bs) are involved in pollen hydration. Here, by analyzing the interactions of two PCP‐Bs with three Arabidopsis thaliana stigmas strongly expressing S‐domain receptor kinase (SD‐RLK), we determined that SD‐RLK28 directly interacts with PCP‐Bβ. We investigated pollen hydration, pollen germination, pollen tube growth, and stigma receptivity in the sd‐rlk28 and pcp‐bβ mutants. PCP‐Bβ acts in the pollen to regulate pollen hydration on stigmas. Loss of SD‐RLK28 had no effect on pollen viability, and sd‐rlk28 plants had normal life cycles without obvious defects. However, pollen hydration on sd‐rlk28 stigmas was impaired and pollen tube growth in sd‐rlk28 pistils was delayed. The defect in pollen hydration on sd‐rlk28 stigmas was independent of changes in reactive oxygen species levels in stigmas. These results indicate that SD‐RLK28 functions in the stigma as a PCP‐Bβ receptor to positively regulate pollen hydration on dry stigmas. [ABSTRACT FROM AUTHOR]

Both drought and high temperature can influence the antioxidant metabolism of crop reproductive organs in different ways, affecting the fertility of reproductive organs and yield formation. However, the combined effects of drought stress and high temperature on the crop reproductive physiology have not yet been widely considered. In order to broaden our understanding of this mechanism of influence, a pond experiment was conducted using a cotton variety Yuzaomian 9110 divided into four treatment groups: control (CK), drought stress (DS), high temperature (HT), and drought stress coupled with high temperature (DS+HT). Results showed a significant negative correlation between pollen viability and superoxide anion (O2−) content, as well as hydrogen peroxide (H2O2). Compared with CK, DS did not alter O2− content in anthers, but HT treatment resulted in higher anther O2−. Compared with single-stress groups, DS+HT further promoted the formation of O2− in anthers, leading to more malondialdehyde in anthers. Moreover, a higher H2O2 content in anthers was found in DS and HT than in CK. DS+HT did not show altered H2O2 content relative to HT treatment, although its H2O2 was higher than in DS. Further analyses of the antioxidant enzyme system showed that DS had no significant effect on superoxide dismutase gene (GhCu/ZnSOD) expression, but HT and DS+HT significantly downregulated its expression. The expression of GhCu/ZnSOD was lower under DS+HT than HT, which might be why O2− content was not altered under DS treatment compared with CK and was higher in DS+HT than HT. DS and HT significantly downregulated the expression of the peroxidase gene (GhPOD) and catalase gene (GhCAT), which should be the main reason for the larger accumulation of H2O2 under drought stress and high-temperature conditions. Compared with single-stress groups, DS+HT had lower expression of GhCAT, resulting in a larger H2O2 content. Regarding the ascorbic acid–glutathione (AsA–GSH) cycle, DS and HT significantly downregulated the expression of monodehydroascorbate reductase gene (GhMDHAR) to hinder the production of AsA and upregulated the expression of ascorbate oxidase gene (GhAAO) to promote the oxidation of AsA, which was theoretically detrimental to AsA accumulation. However, HT downregulated the expression of the ascorbate peroxidase gene (GhAPX), hindering the reduction of H2O2 by AsA, which was the reason for AsA and H2O2 accumulation. Moreover, DS also significantly upregulated the expression of the dehydroascorbate reductase gene (GhDHAR2) to enhance the reduction of dehydroascorbate to form AsA, leading to a higher content of AsA under DS than HT. The combined stress significantly downregulated the expression of GhAAO to inhibit the oxidation of AsA but significantly upregulated the expression of GhMDHAR and GhDHAR2, promoting the AsA production, and downregulated the expression of GhAPX, hindering the reduction of H2O2 by AsA. All these resulted in increased AsA content under combined stresses. In addition, HT significantly downregulated the glutathione reductase gene (GhGR) expression, hindering the reduction of oxidized glutathione (GSSG), which led to the reduction of GSH. However, DS and DS+HT significantly downregulated the glutathione peroxidase gene (GhGPX) expression, resulting in the accumulation of GSH. Overall, compared with single-stress treatments, the effects of DS+HT on cotton pollen fertility and peroxide accumulation were more significant. The effects of DS+HT on the antioxidant enzyme system were mainly caused by high temperature, while the mechanism of abnormal accumulation of AsA and GSH caused by DS+HT was different from those of single-stress groups. [ABSTRACT FROM AUTHOR]

Cannabis sativa is a widely studied species and is currently accepted worldwide due to its medicinal properties, especially those conferred to the CBD phytocannabinoid, which is synthesized mainly in the globular trichomes of female flowers. Males are undesirable and rare in commercial plantations; however, they are necessary for breeding programs. This research aimed to evaluate sexual reversion methods in female cannabis plants as a preliminary stage of a plant breeding program. A completely randomized design with eight treatments and four repetitions was used. The treatments consisted of protocols for the sexual reversion of female plants through drip application and foliar spraying of Silver Thiosulfate (STS), Aminoethoxy-vinyl-glycine (AVG), 1-Methylcyclopropene (1-MCP), and Gibberellic acid (AG3), plus a control treatment without application. Male flower production was evaluated in female cannabis plants, and pollen viability in male flowers was determined. The AVG treatments applied to the apex by dripping, and the AG3 applied to the foliage in the form of a spray influenced the sexual reversion of female plants and produced a total of 132 and 32 male flowers, respectively, without difference between them (P=0.08383). For AVG dripping, only male flowers were observed at the apex, where the application was made directly. Moreover, STS and 1-MCP did not induce the production of male flowers. The pollen from male plants treated with AG3 in spray, and AVG dripping showed high viability (>50%), contrary to the low viability observed in plants treated with AGC applied in spray. The plants treated with AG3 (spray) were higher due to the elongation of the internodes. The AVG and AG3 compounds are effective in the sexual reversion of female cannabis and generate male flowers with viable pollen. [ABSTRACT FROM AUTHOR]

Summary: Global nocturnal temperatures are rising more rapidly than daytime temperatures and have a large effect on crop productivity. In particular, stomatal conductance at night (gsn) is surprisingly poorly understood and has not been investigated despite constituting a significant proportion of overall canopy water loss.Here, we present the results of 3 yr of field data using 12 spring Triticum aestivum genotypes which were grown in NW Mexico and subjected to an artificial increase in night‐time temperatures of 2°C.Under nocturnal heating, grain yields decreased (1.9% per 1°C) without significant changes in daytime leaf‐level physiological responses. Under warmer nights, there were significant differences in the magnitude and decrease in gsn, values of which were between 9 and 33% of daytime rates while respiration appeared to acclimate to higher temperatures. Decreases in grain yield were genotype‐specific; genotypes categorised as heat tolerant demonstrated some of the greatest declines in yield in response to warmer nights.We conclude the essential components of nocturnal heat tolerance in wheat are uncoupled from resilience to daytime temperatures, raising fundamental questions for physiological breeding. Furthermore, this study discusses key physiological traits such as pollen viability, root depth and irrigation type may also play a role in genotype‐specific nocturnal heat tolerance. [ABSTRACT FROM AUTHOR]

The success of rose breeding programs is low due to poor seed set and germination rate. Determining the combining ability of parents might increase breeding programs’ success. The study was conducted to determine the crossing success of ‘pot miniature rose × cut rose’ combinations. Four different pot miniature rose varieties as the seed parents, and four different cut roses as pollen parents were used as plant material. Eight cross combinations were formed, and 30 crosses were made in each combination. Pollen viability and germination rate, fruit set, seed number per fruit, fruit and seed weight, and seed germination rate were recorded. The pollen germination rate varied between 14.09% (‘Moonlight’) and 31.25% (‘Golden Gate’). Among cross combinations, the fruit set rate ranged from 0% to 83.33%, while the seed number was between 0 and 6.14, and the seed germination rate ranged from 0% to 47.5%. The best combinations were ‘Rosa Bling Love Star × Golden Gate’, ‘Rosa Bling Love Star x Magnum’, ‘Rosa Bling Love Star × Inferno’, and ‘Rosa Shining Star × Inferno’. Except for Hot Jewel as the seed parent, low values were obtained from the traits examined in all combinations where Moonlight was used as the pollen parent. There was a positive correlation between seed number, seed weight and fruit weight. There may be prepollination barriers in ‘pot miniature rose × cut rose’ crosses, but productive seeds and progenies are obtainable. The miniature roses can be successfully used as seed parents when combined with cut roses. [ABSTRACT FROM AUTHOR]

Bdallophytum americanum (Cytinaceae) is an endoparasitic plant species, meaning only the flowers emerge from the host during the reproductive season. Reports on the pollination biology of this species state that its primary pollinators are carrion flies attracted by the smell of the flowers and nectar as a reward. However, the functional role of one of the most outstanding attributes of B. americanum has been neglected. These are the staminal appendages formed by the apical overgrowth of connective tissue during anther development. To determine whether these staminal appendages play a role in pollination, we monitored a nectarless population of B. americanum. We described the inflorescence emergence, floral movements, and pollination and performed field experiments to test whether the absence of the staminal connective appendages affected the visitation frequency. Male inflorescences emerge early, and both male and female flowers open during the day and do not close. Hoverflies are the most frequent visitors to both floral sexes and carry the most pollen. Moreover, the movement of staminal appendages matching the pollen viability changes is reported for the first time. The staminal appendages are the structures where pollinators land before foraging. The field experiments showed that the visitation frequency decreased sharply without staminal appendages. As a landing platform, the staminal connective appendages in B. americanum are crucial for pollinator positioning and collecting viable pollen. [ABSTRACT FROM AUTHOR]

Background: Sweetpotato is an important vegetable and food crop that is bred through sexual crosses and systematic selection. The use of in vitro germination of sweetpotato pollen to test its viability has important theoretical and practical implications for improving the efficiency of sweetpotato crossbreeding by controlling pollination and conducting research on sweetpotato pollen biology. Results: In this study, we observed the morphological structure of sweetpotato pollen under a scanning electron microscope (SEM), developed an effective method for the in vitro germination of sweetpotato pollen, and examined the viability of sweetpotato pollen after treating plants at different temperatures before blossoming. Sweetpotato pollen grains are spherical, with an average diameter of 87.07 ± 3.27 μm (excluding spines), with multiple germination pores and reticulate pollen surface sculpture. We applied numerous media to sweetpotato pollen germination in vitro to screen the initial medium and optimised the medium components through single-factor design. The most effective liquid medium for in vitro sweetpotato pollen germination contained 50 g/L Sucrose, 50 g/L Polyethylene glycol 4000 (PEG4000), 100 mg/L Boric acid and 300 mg/L Calcium nitrate, with a pH = 6.0. The optimum growth temperature for pollen development in sweetpotato was from 25 to 30 °C. Neither staining nor in situ germination could accurately determine the viability of sweetpotato pollen. Conclusions: In vitro germination can be used to effectively determine sweetpotato pollen viability. The best liquid medium for in vitro germination of sweetpotato pollen contained 50 g/L Sucrose, 50 g/L Polyethylene glycol 4000 (PEG4000), 100 mg/L Boric acid and 300 mg/L Calcium nitrate, with the pH adjusted to 6.0. This study provides a reliable medium for the detection of sweetpotato pollen viability, which can provide a theoretical reference for sweetpotato genetics and breeding. [ABSTRACT FROM AUTHOR]

Global climate changes have led to frequent and recurrent heat stress, which has seriously affected the world maize production. The experiment presented in this paper was carried out during the maize‐growing season in 2021 and 2022 at the Huang–Huai–Hai Region Maize Science and Technology Innovation Center (36°09′N, 117°09′E) in Tai'an, Shandong province, China. The test site is located in the semi‐humid warm temperate continental monsoon climate zone, soil is brown loam. We selected different heat‐sensitive maize varieties: heat‐tolerant variety Zhengdan 958 (ZD958) and heat‐sensitive variety Xianyu335 (XY335) to study the stress effects of high temperature on the development of tassel in the key stage of its differentiation (the 12‐leaf stage, V12). We found that exposure to heat stress during the V12 stage significantly reduced the tassel size and the anther dehiscence area, making it difficult to disperse pollen, thus effectively reducing pollen production. In addition, heat stress had significant negative effects on pollen development, resulting in deformed pollen and lower pollen viability and germination rate. Our results also showed that heat stress significantly increased the activities of key reactive oxygen species‐scavenging enzymes including superoxide dismutase, peroxidase and catalase, and that the malondialdehyde and H2O2 content in tassels exposed to heat stress were significantly higher than those control group, where it should be noted that for the XY335, these effects were more pronounced than for the ZD958. The endogenous hormone content of tassels exhibited a variety of responses. After heat stress, the zeatin and salicylic acid content in tassels of both maize varieties were significantly lower than those in the respective control groups, while the abscisic acid and gibberellin acid content were significantly higher. With respect to the jasmonic acid and 3‐indoleacetic acid content, the two maize varieties exhibited opposite responses: in tassels from ZD958 plants subjected to heat stress were higher than those in the respective control group, while in tassels from XY335 plants, they were lower. The observed changes in protective enzyme activities and endogenous hormone contents induced by heat stress significantly affected the development of maize tassels and significantly reduced the amount, activity and germination rate of pollen. [ABSTRACT FROM AUTHOR]

Ogura cytoplasmic male sterility (CMS) is one of the important methods for hybrid seed production in cruciferous crops. The lack of a restorer of fertility gene (Rfo) in Brassica rapa L. restricts the development and utilization of its germplasm resources. In this research, Brassica napus with the Rfo gene was used to restore the fertility of Ogura CMS B. rapa with the golden heart trait. Through the distant cross of two B. rapa and four B. napus, six interspecific hybrid combinations received F1 seeds. The six combinations were different in seed receiving. By morphological observation and molecular marker-assisted selection (MAS), in F1, individuals containing the Rfo gene all appeared fertile, while those without it remained male-sterile. The pollen viability of the fertile individuals was measured, and the fertile lines of the six interspecific hybrid combinations were different (40.68–80.49%). Three individuals (containing both Rfo and GOLDEN genes) with the highest pollen vitality (≥60%) were backcrossed with fertile cytoplasmic B. rapa, resulting in a total of 800 plants. Based on the MAS, a total of 144 plants with GOLDEN but no Rfo were screened (18%). Moreover, through morphological investigation, one individual with normal cytoplasm, stable fertility but without the restoring gene Rfo, the GOLDEN gene, and morphological characteristics similar to those of B. rapa was obtained. These results increased the diversity of B. rapa germplasm and provided a new method for the utilization of CMS germplasm in Brassica crops. [ABSTRACT FROM AUTHOR]

Prunus cerasoides have a high value in phytochemistry and pharmacology. It was classified as the Least Concern globally based on the IUCN red list due to its widespread distribution in eastern Asia. This research aims to evaluate the reproductive biology of P. cerasoides through the study of pollen morphology, pollen viability, stigma receptivity, and pollination in the Cibodas Botanical Garden, located in the Cibodas subdistrict of West Java, Indonesia. The pollen morphology was observed using SEM. Moreover, the pollen viability test was followed by the staining method (aceto-orcein 2%, I2KI 1%, TTC 1%) and in vitro pollen germination with thirteen treatments (aquadest [control]; 5-30% sucrose; and 5-30% sucrose + 5 ppm boric acid). Stigma receptivity was observed daily, from 7 days before anthesis until the anthesis stage. Furthermore, several types of pollination were evaluated, including open pollination, autogamy, geitonogamy, and allogamy. The results showed that the best staining method on P. cerasoides was aceto-orcein 2%, with pollen viability at 87.87%. The sucrose concentration of 25% at 72 hours of observation gave the highest pollen viability results, 52.48%. Stigma receptivity was optimal in the two days before anthesis until anthesis. The highest pollination efficiency was cross-pollination at 53.33%, with an average percentage of the total fruit set of 24.17%. [ABSTRACT FROM AUTHOR]

An experiment is conducted in bitter gourd cropping system at Coimbatore district in India, to study bitter gourd floral character, the foraging ecology of native pollinators and their modes of pollination. Bitter gourd is a monoecious plant bears separate male and female flowers. Male flower blooms early followed by female flowers. Stigma receptivity of pistillate flowers was confirmed on 4th day old flower showed yellowish-green stigma with shining stigmatic exudation. The stigma receptivity lasts up to 24 hours after anthesis. Pollen viability test done with 2 per cent acetocarmine solution indicated that pollen collected during morning hours (06:00 h) were more viable and were deeply stained, whereas pollens collected at evening hours (17:00 h) remained unstained and considered as nonviable. The foraging activities of Apis cerana indica Fabricius and Tetragonula iridipennis begin at 06:00 h and 06:30 h respectively and ceased by evening 17:00 h. T. iridipennis foragers spent more time in pollen collection (31.1 seconds/flower) and nectar collection (26.14 seconds/flower) whereas, A. cerana indica spent less time in pollen collection (8.62 seconds/flowers) and nectar collection (3.56 seconds/flower) respectively. A total of 17 pollinator species belongs to four orders viz., Hymenoptera, Diptera, Lepidoptera and Coleoptera have been documented and grouped based on their mode of foraging in bitter gourd flowers. [ABSTRACT FROM AUTHOR]

Summary: Sporopollenin is one of the most structurally sophisticated and chemically recalcitrant biopolymers. In higher plants, sporopollenin is the dominant component of exine, the outer wall of pollen grains, and contains covalently linked phenolics that protect the male gametes from harsh environments. Although much has been learned about the biosynthesis of sporopollenin precursors in the tapetum, the nutritive cell layer surrounding developing microspores, little is known about how the biopolymer is assembled on the microspore surface.We identified SCULP1 (SKS clade universal in pollen) as a seed plant conserved clade of the multicopper oxidase family. We showed that SCULP1 in common wheat (Triticum aestivum) is specifically expressed in the microspore when sporopollenin assembly takes place, localized to the developing exine, and binds p‐coumaric acid in vitro.Through genetic, biochemical, and 3D reconstruction analyses, we demonstrated that SCULP1 is required for p‐coumaroylation of sporopollenin, exine integrity, and pollen viability. Moreover, we found that SCULP1 accumulation is compromised in thermosensitive genic male sterile wheat lines and its expression partially restored exine integrity and male fertility.These findings identified a key microspore protein in autonomous sporopollenin polymer assembly, thereby laying the foundation for elucidating and engineering sporopollenin biosynthesis. [ABSTRACT FROM AUTHOR]

Androgenesis is reported in a few tree crops such as citrus and papaya; however, there is little information available about guava. Different modified Chu (N6) media and cold pretreatments of floral buds were tested to induce embryogenic calli in the anthers of two white flesh guava cultivars, 'Round' and 'Pyriform'. Four modified Chu (N6) media formulations, i.e., M1 (400 mgL-1 casein hydrolysate, 200 mgL-1 glutamine, 0.2 mgL-1NAA, 1.0 mgL-1 KIN, 0.5 mgL-1 6-BAP, 0.5 mgL-1 zeatin and 5% coconut water), M2 (400 mgL-1 casein hydrolysate, 200 mgL-1 glutamine, 0.2 mgL-1NAA, 1.0 mgL-1 KIN, 0.5 mgL-1 6-BAP), M10 (0.5 mgL-1 2,4-D), and M11 (0.5 mgL-1 2,4-D and 50 mgL-1 PVP) enhanced anther swelling and callus formation. Genotypic variability was found in pollen viability, phenolic exudation, and anther tissue browning after cold pretreatment for 0-72 hrs. intervals. Anthers of 'Round' showed more pollen viability across cold pretreatment intervals with less phenolic exudations and tissue browning than 'Pyriform'. On both M10 and M11 media, anthers with uni-nucleate microspores developed embryogenic calli; however, anthers of 'Pyriform' resulted in more calli induction (69.58%) on M10 media, whereas anthers of 'Round' developed more calli (66.60%) on M11 media. The proliferating calli in white flesh 'Round' and 'Pyriform' cultivars and pink flesh 'Round' cultivar formed more embryogenic masses upon transfer to growth hormone-free Chu (N6) media under light conditions; however, embryos showed delayed maturity with limited germination. More genotypes shall be explored to enhance embryo germination, and embryogenic media shall be further fine-tuned. This study provides the foundation for the generation of homozygous lines in guava using androgenesis. [ABSTRACT FROM AUTHOR]

Late blight disease caused by the fungus Phytophthora infestans is the main yield limiting factor amongst the diseases of potato in India and across the globe. Potato Cyst Nematode/PCN (Globodera spp.) is another biotic factor of economic importance and is a quarantine organism. Exploitation of genetic resistance is the most preferred management strategy. In the present study, indigenous potato genotypes collected from different parts of the country along with checks were evaluated for their resistance against late blight under natural epiphytotic field conditions and in laboratory under artificially inoculated conditions including detached leaf and tuber slice assays and PCN through Root ball technique during 2020-2023. The converted field scale values i.e. average AUDPC value ranged from 7 in highly resistant genotype Rangpuria to 1596 in susceptible accession AGR/56. The field blight response was comparatively more correlated (r =0.63) with susceptibility levels measured in the detached leaf assay compared to that with tuber slice assay (r =0.48). Genotypes Kanpuria Safed, JG-1, Rangpuria and Desi Aloo showed resistance to late blight both under laboratory and field conditions. For PCN, Garlentic, Jeevan Jyoti and JG-1 have combined resistance (0 female/root ball) over the years to both the species. Majority of the studied genotypes have medium to high pollen viability with desirable tuber traits and yield advantage. The identified resistant genotypes excel their usage as parental lines in breeding for biotic stress resistance specifically for late blight and PCN. [ABSTRACT FROM AUTHOR]

When the sexual system of a rare plant species is complex, characterizing floral development, plant morphology, and subpopulation structure is essential for assessing reproductive potential. Availability of pollinator rewards and positioning of sexual morphs within inflorescences relates to outcrossing potential. We studied the complex sexual system of the recently discovered Euphorbia rosescens E.L. Bridges & Orzell, a rare species occurring in a single Florida county. Euphorbia rosescens has both monomorphic subpopulations of female plants and mixed subpopulations with male and andromonoecious plants. Most data on cyathia sex, inflorescence architecture, floral visitors, and fruit set came from one female subpopulation and one mixed subpopulation. Cyathia longevity, flowering phase, nectar secretion, pollen production, and viability were measured in female, male, and hermaphrodite cyathia. Female plants had fewer inflorescence levels and cyathia and significantly smaller cyathia than male and andromonoecious plants. Andromonoecious plants were larger and produced more cyathia relative to male plants. Within mixed populations, sex switching occurred in both directions between male and andromonoecious plants. Female plants did not switch sexes. Proximal to distal inflorescence levels transitioned from hermaphrodite to male cyathia on andromonoecious plants. Nectar secretion corresponded to initiation of staminate flowering, but in female cyathia stigmas were receptive approximately a day before nectar secretion. Pollen production and viability were similar in male and hermaphrodite cyathia. Fruit maturation was minimal, primarily observed on andromonoecious plants. Nectar availability, pollen rewards, trimorphic inequalities in inflorescence display, and low fruit set suggest high geitonogamy, thus limiting outcrossing potential for this species. [ABSTRACT FROM AUTHOR]

Plants in the Gesneriaceae family are appreciated for their decorative leaves and flowers, ease of cultivation, and shade tolerance. Sexual hybridisation has long been carried out for producing novel hybrids. However, scientific knowledge is lacking on the correct timing of pollination in this family. This study was conducted to elucidate the optimal timing for pollination by screening pollen viability and stigma receptivity throughout the flowering period in eight gesneriad taxa. Pollen viability was evaluated by the in vitro germination test and stigma receptivity was based on stigma morphology and pistil length. The flowering duration varied from 10 days in Alsobia to 18 days in Streptocarpus. While the pollens of Episcia, Kohleria, Saintpaulia, Sinningia, and Smithiantha had totally lost viability 2–5 days before the flowers withered, a slightly contrasting situation was observed in the cases of Alsobia, Deinostigma, and Streptocarpus, where a small portion of pollen grains remained viable towards the end of the flowering period. The highest pollen germination rate was recorded from 1 day in Alsobia, Episcia, and Kohleria, to 9 days in Deinostigma. The reduction in pollen germination was rapid in Alsobia, Saintpaulia, and Smithiantha, and moderate in the remaining taxa. The greatest pollen tube growth occurred at 1–3 days after flower opening and decreased rapidly in all the taxa tested. The longest pistil of 2.03–3.50 cm was observed at 3–8 days of anthesis depending on the plant tested. The findings in this study suggest that higher pollination success may be achieved using pollen grains of newly opened flowers and stigmas of mature flowers in this family. [ABSTRACT FROM AUTHOR]

The nine Viola pilosa Blume populations studied from Pir Panjal contained 20 chromosomes. This count is not reported so far in Indian populations. Currently, comparison of tapetal and meiotic cells revealed the existence of synchrony in different developmental phases. Young tapetal cells at prometaphase co-occurred with the pollen mother cells (PMCs) at diakinesis to metaphase, mature tapetal cells with disintegrated chromatin material co-occurred with tetrads and no tapetal cells were found at mature pollen stage. Cytological studies in young tapetal cells revealed most of these to be endopolyploid, with each having 40 chromosomes. While outnumbering somatic cells contained clear 40 chromosomes which seemed to be the outcome of endomitosis, a sizeable number of cells possessed 40 sticky chromosomes at metaphase. Later chromosomes are likely to form restitution nucleus. Mature tapetal cells, occurring singly/cytomictically connected (3.2–26.31%) or showing coalescence (10.5–22.8%), did not contain recognizable chromosomes. Instead, they were characterized by disintegrated nuclear content. Further, meiotic studies revealed that the present population contained all/outnumbering euploid cells (2n=20); many of which exhibited nearly regular behaviour. However, 6.5–26.9% meiocytes of eight populations and 47% cells of P-Khe population depicted aneuploidy/contained quadri-octavalents, with per cent pollen viabilities of these ranging from 38.6 to 49.9. Going by the normal tapetal development in V. pilosa, existence of various chromosomal anomalies seems to have accounted for the reduction in gametic fertility of this taxon. [ABSTRACT FROM AUTHOR]

Rising daily temperatures and water shortage are two of the major concerns in agriculture.In this work, we analysed the tolerance traits in a tomato line carrying a small region of the Solanum pennellii wild genome (IL12‐4‐SL) when grown under prolonged conditions of single and combined high temperature and water stress.When exposed to stress, IL12‐4‐SL showed higher heat tolerance than the cultivated line M82 at morphological, physiological, and biochemical levels. Moreover, under stress IL12‐4‐SL produced more flowers than M82, also characterized by higher pollen viability. In both lines, water stress negatively affected photosynthesis more than heat alone, whereas the combined stress did not further exacerbate the negative impacts of drought on this trait. Despite an observed decrease in carbon fixation, the quantum yield of PSII linear electron transport in IL12‐4‐SL was not affected by stress, thereby indicating that photochemical processes other than CO2 fixation acted to maintain the electron chain in oxidized state and prevent photodamage. The ability of IL12‐4‐SL to tolerate abiotic stress was also related to the intrinsic ability of this line to accumulate ascorbic acid.The data collected in this study clearly indicate improved tolerance to single and combined abiotic stress for IL12‐4‐SL, making this line a promising one for cultivation in a climate scenario characterized by frequent and long‐lasting heatwaves and low rainfall. [ABSTRACT FROM AUTHOR]

Solanum melongena is susceptible to diverse diseases and parasites, in particular the wilts (bacterial, Fusarium and Verticillium), nematodes, and some insects. Solanum torvum is robust to Verticillium and some bacterial wilts and root-knot nematode. It was reported that interspecific hybrid plants originated out of the hybridization of these species were sterile. In our previous studies that have been carried out to overcome this interspecific hybridization barrier, only from Faselis F1 that was used as the female parent, many interspecific hybrid seeds were obtained and 9.07% of the seeds grew into plants in vitro. The percentage of pollen viability and germination of tetraploid interspecific hybrid (amphidiploid) genotypes that have been produced by in vitro colchicine treatment, were 6.8 and 3.4 fold of its source diploid genotype, respectively. However, the increment was not high enough to overcome the interspecific hybridization barrier between S. torvum and S. melongena. In this study, the changes in pollen fertility of diploid interspecific hybrids and tetraploid plants, which have grafted on Pala or Faselis F1, were investigated. Pollen viability and germination percentage in diploid genotypes were not affected by grafting, although they increased significantly (51.54% and 119.73%, respectively) in tetraploid genotypes by grafting. It was determined that the fertile diploid rootstock used for the tetraploid genotypes that produced by chromosome doubling from cultured eggplants could increase the number of seeds per fruit. It was concluded that some fertile diploid varieties can be used as rootstocks in order to increase pollen viability, germination rate and seed yield of tetraploid genotypes with low pollen yield obtained from cultivated eggplant by chromosome doubling. [ABSTRACT FROM AUTHOR]

Seventy four genotypes of the tomato (14 lines, four testers of ripening mutant and their 56 F1 crosses developed in line × tester mating fashion) were appraised under main (E1) and late (E2) planting season at Department of Vegetable Science, Punjab Agricultural University, Ludhiana, Punjab, India. To find out few general and specific combiners, if some, which might be utilized in furthermore breeding programmes to prolong the fruit harvesting span of tomato in the Punjab conditions. The findings hinted in general, the particular parent or hybrid could not be used to assess all examined characters with same efficiency. In main (E1) season line, FL-556 was found best general combiner for average fruit weight, locules number, pericarp thickness, P/E ratio, dry matter and lycopene content; PAU 114 for average fruit weight, lesser locules, pericarp thickness, TSS and dry matter. During late (E2) planting season line, Punjab Ratta found with good GCA values for average fruit weight, lesser locules number, pericarp thickness and TSS content; Roma for average fruit weight, locules number, pericarp thickness and P/E ratio. Similarly tester, alc-IIHR-2050 for pollen viability, minimum days from transplanting to first harvest, harvesting span, average fruit weight, pericarp thickness and P/E ratio in main (E1) season while, for pollen viability, average fruit weight, pericarp thickness and P/E ratio in late (E2) season. The received results furthermore illustrated the best combinations that possessed significant values of SCA which effectively combine to develop a cross with good performance. In main (E1) season from combinations, F1 hybrid SMZ-867 × rin-Rutgers were registered with best specific combiner for pollen viability, average fruit weight, lesser locules number, Pericarp thickness and P/E ratio; PAU 2381 × nor-RM-1 for harvesting span, average fruit weight, pericarp thickness, total fruit yield and lycopene content. Likewise, in late (E2) season cross, SMZ-867 × nor-RM-1 for pollen viability, minimum days from transplanting to first harvest, harvesting span and fruit yield; LT-44 × alc-IIHR-2050 for pollen viability, average fruit weight, lesser locules and pericarp thickness. [ABSTRACT FROM AUTHOR]