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High temperatures (HTs) and high vapor pressure deficits (VPDs) have significant impacts on maize yields, partly due to the high sensitivity of maize tassels. However, there are few studies quantifying the impacts of HTs and VPDs on maize tassel performance under changing environments. Therefore, we carried out a two-year field experiment that included 20 inbred lines and four sowing dates. Compared with the first sowing date, the seed set in the second sowing date decreased by ~80% in both years. The opened spikelet ratio (OSR) and pollen viability (PV) were the key determinants of seed set, and their respective correlation coefficients with seed set were 0.58 and 0.90. The OSR and PV decreased by ~20% and ~50%, respectively, under high-temperature stress. When Tmax exceeded 32.5 °C or the VPD exceeded 0.91 KPa, PV began to decline; when Tmax exceeded 33.8 °C or VPD exceeded 1.10 KPa, the OSR began to decline. The OSR was more dependent on genotypic background than PV (28.4% vs. 19.7%). The maize tassel water content was significantly correlated with the OSR and PV. Based on the OSR and PV values, the 20 genotypes were divided into three different groups, namely the high H, middle M, and low L groups. The H group, on average, had the highest kernel number per ear and seed set, followed by the M and L groups. The average seed sets of the H, M, and L genotypes under the second sowing date were 17.4%, 10.9%, and 0%, respectively, in 2019 and 13.8%, 7.9%, and 0.6%, respectively, in 2020. The present results indicate that selecting maize varieties with a high OSR is an effective approach for improving maize yield under heat stress. [ABSTRACT FROM AUTHOR]

Lamiaceae is one of the most economically important plant families based on their aromatic, medicinal, and industrial significance. In the present study three species of the Lamiaceae subfamily, Nepetoideae (Ocimum basillicum, Nepeta cateria, Leucas aspera) and one species from Lamioideae (Rosmarinus officinalis) were selected to document the pollinator bee diversity, foraging behavior, and their role on seed set. Thirty-two species of bees representing three families of Hymenoptera, (Apidae (94.87%) followed by Megachilidae (3.74%) and Halictidae (1.40%) were observed in all four plant species. Non-Apis bees were more abundant (69.35%) than Apis species (30.65%). The species-level variation in pollinator bees was observed in each plant species irrespective of space, time, and environmental conditions. O. basillicum attracted the maximum number of pollinator species (22) followed by R. officinalis (14) and L. aspera (10) and N. cataria (5). In O. basillicum, Ceratina species were major flower visitors, whereas R. officinalis was mainly visited by both Ceratina and Apis sp. L. aspera was dominated by Amegilla species and N. cataria mostly visited by the Apis bee species. However, irrespective of the diversity, the abundance of pollinator activity mainly contributed to enhancing the maximum number of seeds set in each species up to 64% overall increase under open pollination compared to bagged conditions. Also, a significant reduction in the seed set percentage was observed in R. officinalis and L. aspera under bagged pollination conditions. This indicates the high dependency of Lamiaceae plants on bee pollinators to maintain their reproduction and regeneration activities. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim Location Taxon Methods Results Main Conclusions The evolutionary history of European alpine plant species with medium to large geographical ranges is relatively well explored. Here, we investigate the genetic structure and diversity of an extremely narrow endemic and one of the world's rarest plants.Eastern Carpathians, Romania.Andryala laevitomentosa (Asteraceae), an evolutionarily isolated herb species with a worldwide range limited to five micropopulations distributed along a 1.8 km long mountain ridge.We used three plastid loci, nuclear ribosomal ITS and genome‐wide, mostly nuclear 26,272 Single‐Nucleotide Polymorphism (SNPs) obtained from RAD‐seq data. We assessed haplotype and genotype diversity, dated the resulting phylogeographic structure, quantified seed production and inferred vegetative propagation.Maternally inherited plastid markers and nuclear genomic data revealed a concordant pattern: (i) limited genetic diversity, with seven cpDNA haplotypes and 11 RAD‐seq multilocus genotypes; (ii) a strong geographic structure corresponding to spatially isolated genets (clones). The species is likely of early Pleistocene origin (c. 2 Mya), and the estimated age of individual clones varied from c. 24 to 64 Kya. The average seed set assessed over 3 years was only 0.4%. However, the species reproduces veg by axillary and adventitious rosettes formed on rhizomes and roots, respectively.The strong trade‐off between sexual and vegetative reproduction explains not only a deep and ancient phylogeographic structure but also the rarity of the species. Its survival depends almost entirely on vegetative reproduction. The genets of A. laevitomentosa are amongst the oldest clones ever documented in angiosperms. The persistence of these clones in situ for tens of thousands of years suggests an exceptional ability of this species to adapt to major climatic oscillations throughout the Pleistocene and Holocene and challenge our perception of the extent of resilience in plants. [ABSTRACT FROM AUTHOR]

Premise: In plants, within‐individual trait variation might result from mechanisms related to ontogenetic contingency, i.e., to the position of a particular structure within the plant, previous developmental events, and/or the developmental environment. Flower position within inflorescences as well as inflorescence position within plants can influence resource provisioning, phenology, biotic interactions, and reproductive success. Despite the potential implications of within‐individual variation in plant reproductive phenotypes, its causes and effects on reproductive success are still little explored. Methods: We assessed how reproductive success, in terms of fruit and seed set, and seed predation of 5883 flowers in Lathyrus vernus were influenced by their position within and among racemes, to what extent relationships between flower position and reproductive success and seed predation were mediated by phenology, and if positional effects on reproductive success depended on the external environment. Results: In three years, basal flowers and racemes opened earlier and had higher fruit set than distal. Basal flowers also experienced higher seed predation. Differences among racemes in fruit and seed set were largely related to phenology, while differences in fruit set, seed set, and seed predation within racemes were not. In one year, differences in fruit set among flowers at different positions depended on flowering duration. Conclusions: Our results highlight the important role of ontogenetic contingency for within‐individual variation in phenology and reproductive success. As the spatial distribution of reproductive structures affects both within‐plant trait distributions and fitness, it is a likely target for natural selection. [ABSTRACT FROM AUTHOR]

Heat stress will be an increasing problem for plants and pollinators. Some Romneya coulteri flowers self-shade reproductive parts with vertically oriented petals; this keeps pistils 3–8 °C cooler. A previous study conducted outside of the plant's native range found that self-shading flowers experienced higher seed set than flowers with petals that were experimentally forced to all be horizontal (open) or vertical (shaded). Hand-pollinated flowers had higher seed set which negated the effect of petal orientation, suggesting that insect pollination may have driven seed set. In this study, we observed insect visitors and their effects on seed set in R coulteri's native range. Plant performance was again limited by pollen such that experimentally adding outcross pollen increased seed set. Native and introduced bees showed no proclivity toward either petal orientation. However, the most common visitor, a native beetle (Lytta auriculata), was strongly biased toward approaching and ultimately accepting flowers with vertical petals that provided shade. Beetles were covered with R. coulteri pollen. Flowers bagged with only beetles for 24 h produced as many seeds as controls left open to all visitors. However, beetles also consume pollen and chew petals. Flowers with vertical petals received more beetle damage and damaged flowers produced 35% fewer seeds than those without chewed petals. Despite the potential role of beetles as pollen vectors, flowers with vertical petals did not experience higher seed production. The outcome of beetle visitation on seed set is likely context-dependent. Petals that affected microclimate were attractive to at least one potential pollinator. [ABSTRACT FROM AUTHOR]

Plant reproduction in alpine environments is affected by climate both directly through climate impacts on growth and phenology, and indirectly through impacts on the biotic interactions affecting pollination success. These effects can be highly variable in time and space. In this study we investigated how different abiotic and biotic factors influence reproductive investment and success in populations of Ranunculus acris across an alpine landscape over a two-year period. In an alpine area at Finse, southern Norway, we measured reproductive investment (total seed mass) and reproductive success (seed-set rate) in 38 sites differing in temperature (related to elevation) and length of the growing season (related to time of snowmelt). To assess biotic interactions, we measured floral density and pollinator visits and conducted a supplemental pollen experiment. Reproductive investment and success increased with temperature, but only when floral density and/or number of pollinator visits was high, and only in the warmer year (2016). Reproduction in R. acris was pollen-limited in both years, especially at warmer temperature and in sites with early snowmelt. Pollinator visits increased with temperature and with higher floral density, suggesting a shift in relative importance of the biotic factors (from plants to pollinators) in limiting reproduction with increasing temperature. Our study shows that reproductive investment and success in R. acris is affected by climate through the interactive effects of abiotic and biotic processes. These effects vary between years and across the landscape, suggesting a potential for larger-scale buffering of climate change effects in heterogeneous landscapes. [ABSTRACT FROM AUTHOR]

Given a social network of users with selection cost, the Budgeted Influence Maximization Problem (BIM Problem in short) asks for selecting a subset of the nodes (known as seed nodes) within an allocated budget for initial activation to maximize the influence in the network. In this paper, we study this problem under the co-operative game theoretic framework. We model this problem as a co-operative game where the users of the network are the players and for a group of users, the expected influence by them under the Maximum Influence Arborences diffusion model is its utility. We call this game as BIM Game and show this is 'non-convex' and 'sub-additive'. Based on the proposed game-theoretic model and using the solution concept called 'Shapley Value', we propose an iterative algorithm for finding seed nodes. The proposed methodology is divided into mainly two broad steps: the first one is computing the approximate marginal gain in Shapley Value for all the nodes of the network, and the second one is selecting seed nodes from the sorted list until the budget is exhausted. We also show that the proposed methodology can even be more effective when the community structure of the network is exploited. The proposed methodologies have been implemented, and an extensive set of experiments have been conducted with three publicly available social network datasets. From the experiments, we observe that the seed set selected by the proposed methodologies lead to more number of influence nodes compared to many standard and baseline methods from the literature with a reasonable computational overhead. In particular, if the community structure of the network is exploited then there is an increase upto 2 % in number of influenced nodes. [ABSTRACT FROM AUTHOR]

Flowers of Salvia are characterized by a diversity of staminal lever types mediating pollen transfer. In the East Asian subgenus Glutinaria, species have been categorized based on their distinct flower and stamen morphologies. A hypothesized advantage of degraded-lever types suggests they may optimize pollinator foraging time, increase visitation rates, and potentially trigger autonomous self-pollination. However, this hypothesis remains untested. Here, Salvia castanea, S. miltiorrhiza, and S. liguliloba were selected as test species representing the three major flower and stamen types of the East Asian sages. We compared the species with regard to their inflorescence architecture, floral display, nectar reward, pollinator efficiency, and seed set. We found that S. liguliloba had a degraded-lever type that significantly reduced pollinator foraging time did not significantly increase pollination efficiency. These species have a mixed mating pattern with high seed set, no pollen- or pollinator limitation, and no inbreeding depression. We conclude that the diversity of floral traits is addressed to pollinators, whereas reproductive success emerges from a complex interplay of factors encompassing floral characteristics, pollination efficiency, plant life history, or/and other biotic and abiotic factors. For this reason, the link between floral morphological traits and mating systems should not overestimated. [ABSTRACT FROM AUTHOR]

Previous studies on the mountain plant Ranunculus kuepferi concluded that apomictic self-compatible tetraploids have experienced a niche shift toward a colder climate during the Holocene, which suggests a fitness advantage over the sexual, self-sterile diploid parents under cold and stressful high-mountain conditions. However, there is still a lack of information on whether reproductive development would be advantageous for tetraploids. Here, we report on microsporogenesis, megagametogenesis, the dynamics of flower and seed development, and the consequences for reproductive success in a common garden experiment along a 1000 m climatic elevation gradient and in natural populations. Flower buds were initiated in the year preceding anthesis and passed winter in a pre-meiotic stage. Flower morphology differed in the known cytotype-specific way in that tetraploid flowers produced about twice as many carpels and fewer petals, stamens, and pollen grains than diploid flowers. Tetraploids developed precociously aposporous embryo sacs and showed a high rate of developmental disturbances. Sexual seed formation prevailed in diploids and pseudogamous apomixis in tetraploids. Along the elevation gradient, stigma pollen load, pollen performance, and seed output decreased. Combinations of reproductive traits, namely, bypass of meiosis irregularities and uniparental reproduction, might have promoted the vast expansion of apomictic R. kuepferi lines across the European Alps. [ABSTRACT FROM AUTHOR]

The cherry laurel (Prunus laurocerasus) is a very popular garden plant and has been widely reported as a garden escape in Central Europe. However, it is still considered an unestablished neophyte in Germany. Few critical data are available on local population sizes, life history or reproductive biology outside its natural range. We carried out a study with 24 transects of 500 m × 6 m in the Kottenforst near Bonn, western Germany to fill these knowledge gaps. Along these transects we recorded the plant number and plant sizes and analysed their age structure. We found Prunus laurocerasus along 19 of 24 transects with up to 63 individual per transect. The largest plants covered areas of up to 50 m2 and were up to 30 years old. However, most of the plants were less than 20 years old and established since 2000. Since we observed high fruit set and old plants surrounded by many seedlings we conclude that Prunus laurocerasus has to be considered as an established neophyte in our study area and has invasive potential. [ABSTRACT FROM AUTHOR]

The escalation in the intensity, frequency, and duration of high-temperature (HT) stress is currently unparalleled, which aggravates the challenges for crop production. Yet, the stage-dependent responses of reproductive organs to HT stress at the morphological, physiological, and molecular levels remain inadequately explored in pivotal staple crops. This review synthesized current knowledge regarding the mechanisms by which HT stress induces abnormalities and aberrations in reproductive growth and development, as well as by which it alters the morphology and function of florets, flowering patterns, and the processes of pollination and fertilization in maize (Zea mays L.). We identified the stage-specific sensitivities to HT stress and accurately defined the sensitive period from a time scale of days to hours. The microspore tetrad phase of pollen development and anthesis (especially shortly after pollination) are most sensitive to HT stress, and even brief temperature spikes during these stages can lead to significant kernel loss. The impetuses behind the heat-induced impairments in seed set are closely related to carbon, reactive oxygen species, phytohormone signals, ion (e.g. Ca2+) homeostasis, plasma membrane structure and function, and others. Recent advances in understanding the genetic mechanisms underlying HT stress responses during maize sexual reproduction have been systematically summarized. [ABSTRACT FROM AUTHOR]

Multiple factors can affect the R1-nj purple kernel expression and seed set, reducing its efficiency in identifying haploids in maize. The complex interaction among the haploid inducer (HI), source germplasm (SG), and season (S) is inevitable in in vivo maize haploid induction but could be used through compatibility and stability tests. We tested five HI genotypes on 25 distinct source germplasm in two different seasons of tropical savanna in Thailand. The dry season was more suitable than the rainy season for haploid induction. We noticed varying degrees of R1-nj inhibition among the 25 tropical source germplasm, with some of them exhibiting significant issues with the R1-nj purple kernel expression. Therefore, using the R1-nj alone may not provide accurate ploidy identification in maize. Despite the intense R1-nj expression, haploid inducer BHI306 showed poor stability and compatibility with tropical source germplasm for pollination rate and seed set during the rainy season. The GGE biplot suggested KHI42 and KHI64 as the most compatible haploid inducers under their respective two different mega-source germplasm for the pollination rate and R1-nj seed set. These findings can guide breeders in selecting the most compatible and stable haploid inducers under varying conditions. [ABSTRACT FROM AUTHOR]

Climate change may disrupt plant-pollinator mutualisms by generating phenological asynchronies and by altering traits that shape interaction costs and benefits. Our knowledge is limited to studies that manipulate only one partner or focus on either phenological or trait-based mismatches. We assembled communities of three annual plants and a solitary bee prior to flowering and emergence to test how springtime warming affects phenologies, traits, interactions and reproductive output. Warming advanced community-level flowering onset, peak and end but did not alter bee emergence. Warmed plant communities produced fewer and smaller flowers with less, more-concentrated nectar, reducing attractiveness, and warmed bees were more generalized in their foraging, reducing their effectiveness. Plant-bee interactions were less frequent, shorter and peaked earlier under warming. As a result, warmed plants produced fewer, lighter seeds, indicating pollinator-mediated fitness costs. Climate change will perturb plant-pollinator mutualisms, causing wide-ranging effects on partner species and diminishing the ecosystem service they provide.

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]

Most banana improvement programs are restricted to using a sub-set of edible landraces for sexual hybridization as the majority are female sterile. This results from an array of factors that work in tandem and lead to sterility. Use of pollen germination media (PGM) during pollination significantly increases seed set, but it is a very small fraction compared to the potential seed set. This research therefore explored early pollination (a day before anthesis), evening pollination, saline treatment, plant growth regulators (PGRs) treatment, and ovule culture as potential techniques for overcoming sterility in bananas. Early and evening pollinations did not increase seed set because of immature flowers and a mismatch of male and female flower opening, respectively (t-prob. = 0.735 and 0.884). Immersion of bunches in a saline solution before pollination and ovule culture also did not overcome pollination barriers. Auxin antagonists (TIBA and salicylic acid) increased seed set, though their respective increases were not statistically significant (t-prob. = 0.123 and 0.164, respectively). The use of auxin antagonists shows great potential for overcoming pollination barriers in bananas. However, application rates and time of application have to be optimized and used holistically with other promising techniques, such as use of PGM. [ABSTRACT FROM AUTHOR]

High temperatures (HTs) and high vapor pressure deficits (VPDs) have significant impacts on maize yields, partly due to the high sensitivity of maize tassels. However, there are few studies quantifying the impacts of HTs and VPDs on maize tassel performance under changing environments. Therefore, we carried out a two-year field experiment that included 20 inbred lines and four sowing dates. Compared with the first sowing date, the seed set in the second sowing date decreased by ~80% in both years. The opened spikelet ratio (OSR) and pollen viability (PV) were the key determinants of seed set, and their respective correlation coefficients with seed set were 0.58 and 0.90. The OSR and PV decreased by ~20% and ~50%, respectively, under high-temperature stress. When Tmax exceeded 32.5 °C or the VPD exceeded 0.91 KPa, PV began to decline; when Tmax exceeded 33.8 °C or VPD exceeded 1.10 KPa, the OSR began to decline. The OSR was more dependent on genotypic background than PV (28.4% vs. 19.7%). The maize tassel water content was significantly correlated with the OSR and PV. Based on the OSR and PV values, the 20 genotypes were divided into three different groups, namely the high H, middle M, and low L groups. The H group, on average, had the highest kernel number per ear and seed set, followed by the M and L groups. The average seed sets of the H, M, and L genotypes under the second sowing date were 17.4%, 10.9%, and 0%, respectively, in 2019 and 13.8%, 7.9%, and 0.6%, respectively, in 2020. The present results indicate that selecting maize varieties with a high OSR is an effective approach for improving maize yield under heat stress.

Pollen allelopathy positively or negatively influences the fertilization of plants and has great significance from ecological perspectives. The release of allelochemicals from foreign pollen grains on the stigmatic surface obstructs the processes of fertilisation, seed establishment, tube formation, stigma receptivity, and pollen germination. So far, pollen allelopathy has received little attention and still a growing topic of ecological studies. Therefore, a literature review was undertaken to provide the valuable information regarding the ecological and reproductive implications of pollen allelopathy, heterospecific pollen transfer mechanisms of allelopathic anemophilous and entomophilous plants, and to shed light on the biochemistry and mode of action of allelochemicals. The majority of entomophilous plants share pollinators within communities, and heterospecific pollen transfer by both anemophilous and entomophilous plants causes a reduction in their reproductive success, like pollen germination, tube development, ovule maturation and seed set. For detailed study of pollen allelopathy, a few factors should be considered like metrological parameters, distance travelled by pollen, pollen viability, and stigma receptivity during foreign pollen deposition. A thorough understanding of the biochemical and enzymatic processes that occur after foreign pollen is deposited on the native stigma will open up new perspectives on plant reproduction. Pollen allelochemicals, which have important significance as biocontrol agents for the maintenance of agroecosystems, need to be identified and characterised. The ecological aspects of pollen allelopathy may be well understood with the help of field studies. [ABSTRACT FROM AUTHOR]

Sucrose non-fermenting–1-related protein kinase–1 (SnRK1) is a highly conserved serine–threonine kinase complex regulating plants' energy metabolisms and resistance to various types of stresses. However, the downstream genes regulated by SnRK1 in these plant physiological processes still need to be explored. In this study, we found that the knockout of OsSnRK1a resulted in no obvious defects in rice growth but notably decreased the seed setting rate. The ossnrk1a mutants were more sensitive to blast fungus (Magnaporthe oryzae) infection and showed compromised immune responses. Transcriptome analyses revealed that SnRK1a was an important intermediate in the energy metabolism and response to biotic stress. Further investigation confirmed that the transcription levels of OsNADH-GOGAT2, which positively controls rice yield, and the defense-related gene pathogenesis-related protein 1b (OsPR1b) were remarkably decreased in the ossnrk1a mutant. Moreover, we found that OsSnRK1a directly interacted with the regulatory subunits OsSnRK1β1 and OsSnRK1β3, which responded specifically to blast fungus infection and starvation stresses, respectively. Taken together, our findings provide an insight into the mechanism of OsSnRK1a, which forms a complex with specific β subunits, contributing to rice seed set and resistance by regulating the transcription of related genes. [ABSTRACT FROM AUTHOR]

Most plants produce floral nectar to attract pollinators that impact pollination and seed production; some of them also secrete extrafloral nectar harvested by insects that may influence the plant reproductive success. The aim of this study was to analyze the effects of excluding pollinators and/or ants on the per-plant reproductive success in two species (Dyckia floribunda Griseb. and Dyckia longipetala Baker, Bromeliaceae) that produce floral and extrafloral nectar. The hypothesis states that both ecological processes (pollination and ant defense) involving nectar-mediated animal–plant interactions are beneficial for plant reproductive success. We expected the highest decrease in the plant fruit and seed sets when the pollinators and ants were excluded, and a moderate decrease when solely ants were excluded, compared to the control plants (those exposed to pollinators and ants). In addition, a lower natural reproductive success was also expected in the self-incompatible D. longipetala than in the self-compatible D. floribunda, as the former totally depends on animal pollination for seed production. D. floribunda and D. longipetala presented similar trends in the response variables, and the expected results for the experimental treatments were observed, with some variations between species and among populations. The ecological function of nectar is important because these two plant species depend on pollinators to produce seeds and on ants to defend flowers from the endophytic larvae of Lepidoptera. The study of multispecies interactions through mechanistic experiments could be necessary to clarify the specific effects of different animals on plant reproductive success. [ABSTRACT FROM AUTHOR]

Thiamethoxam (TMX) is one of the most widely used neonicotinoid insecticides. However, it is unclear how TMX alters the flower-visiting behavior and seed production of Apis cerana in sunflowers. We conducted cage experiments to study the impact of chronic exposure (10 days) to TMX at sublethal concentrations of 2.4 μg/kg and 10 μg/kg on the number of flower visits per minute, seed setting percentage, 100-seed weight, and seed yield in sunflowers. Bees treated with TMX demonstrated a significantly lower number of flower visits per minute compared with the control group. Although we did not observe a significant difference in yield parameters between TMX treatments and the control group, a positive correlation was observed between yield and the bees’ flower visitation rate. Our study highlights the concern that exposure to field-level concentrations of TMX could pose a threat to the pollination services provided by A. cerana for other crops and wildflowers. [ABSTRACT FROM AUTHOR]

Premise of the study: On islands, flowering plants tend to be more generalist in their pollination needs, as insects (the main pollinators of flowering plants) are underrepresented in these ecosystems compared to the mainland. In addition, some vertebrate species that are typically insectivorous or granivorous on the mainland are forced to broaden their diet and consume other resources such as nectar or pollen on the islands. The shrub Malva arborea , with its large and colourful flowers, attracts different groups of potential pollinators. This study aimed to compare the effectiveness of vertebrates versus insects in an insular population of M. arborea and to investigate its reproductive system. Methods: For three groups of taxa (insects, birds and lizards), we assessed the two components of pollination effectiveness: (i) the quantitative component (i.e. number of visits and number of flowers contacted) through direct observations of flowers; and (ii) the qualitative component (fruit and seed set, number and size of seeds and proportion of seedling emergence) through pollinator exclusion experiments. Key results: Vertebrates (birds and lizards) were quantitatively the most effective pollinators, followed by insects. However, when all three groups visited the flowers, fruit and seed set were higher than when any of them were excluded. We also found that M. arborea has hermaphrodite flowers and is able to reproduce by autogamy, although less efficiently than when pollinated by animals. Conclusions: Both vertebrates and insects play an important role in the reproduction of M. arborea. Although the plant does not need pollinators to produce seeds, its reproductive success increases when all pollinators are allowed to visit the flowers. Besides providing new information on M. arborea, these findings may help to better understand the role of different pollinator groups in the reproduction of other plant species, especially on islands where the co-occurrence of vertebrate and invertebrate pollination in the same plant species is usual. [ABSTRACT FROM AUTHOR]

Context. Reproductive success in dioecious plant species may be limited by severe pollen limitation owing to their separate sexes and pollination barriers. Aims. Dodonaea viscosa subsp. angustifolia (Jacq.) (Sapindaceae) is a dioecious and wind-pollinated species that has a long flowering period. This study sought to determine the relationship between its reproductive behaviour and pollen availability during different flowering phases. Methods. Extra-stigmatic pollen germination and reproductive performance during different phases of flowering were investigated and correlated with pistil elongation under natural conditions. Results. The species offers whole stigmatic and stylar surfaces for pollen to land and germinate under natural conditions. During pollen-limiting conditions, the length of the pistil increases significantly to enhance pollen capture. Depending on where on the pistil pollen lands, the timing of pollen tube arrival at the ovary varies. Conclusions. Dodonaea viscosa subsp. angustifolia is the first reported wild species in the Sapindaceae where pistil elongation is regulated by pollination conditions and extra-stigmatic pollen germination ensures reproduction during phases of differing pollen availability. Our results indicated that the flexibility of female function and reproductive behaviour in Dodonaea viscosa subsp. angustifolia adds to the evolutionary possibilities to overcome pollination constraints. Implications. This unique strategy for increasing female fitness through pollen presentation in D. viscosa subsp. angustifolia could be explored in other subspecies of D. viscosa on the Australian subcontinent. [ABSTRACT FROM AUTHOR]

Cassava breeding faces obstacles due to late flowering and poor flower and seed set. The acceleration of breeding processes and the reduction in each cycle's duration hinge upon efficiently conducting crosses to yield ample progeny for subsequent cycles. Our primary objective was to identify methods that provide tools for cassava breeding programs, enabling them to consistently and rapidly generate offspring from a wide array of genotypes. In greenhouse trials, we examined the effects of the anti-ethylene silver thiosulfate (STS) and the cytokinin benzyladenine (BA). STS, administered via petiole infusion, and BA, applied as an apical spray, combined with the pruning of young branches, significantly augmented the number of flowers. Controls produced no flowers, whereas treatments with pruning plus either BA or STS alone produced an average maximum of 86 flowers per plant, and the combination of pruning, BA and STS yielded 168 flowers per plant. While STS had its primary effect on flower numbers, BA increased the fraction of female flowers from less than 20% to ≥87%, thus increasing the number of progeny from desired parents. Through field studies, we devised an optimal protocol that maintained acceptable levels of phytodamage ratings while substantially increasing seed production per plant compared to untreated plants. This protocol involves adjusting the dosage and timing of treatments to accommodate genotypic variations. As a result, cassava breeding programs can effectively leverage a diverse range of germplasm to develop cultivars with the desired traits. [ABSTRACT FROM AUTHOR]

The stability of ecological communities over time, often quantified using their aggregated abundance or biomass, is thought to be influenced by species richness and the asynchrony of species abundance fluctuations. However, the relationship between community stability and the stability of ecosystem functioning provided by this community has been little explored, especially for functions involving several trophic levels such as plant pollination. Understanding the mechanisms driving community stability and how this should be related to the stability of ecosystem functions is important to predict the resilience of communities in front of the increasing threats to biodiversity.Using a 5‐year dataset across 13 Mediterranean shrublands and 12 plant species, we assessed the effect of pollinator richness and asynchrony as drivers of stability in plant visitation rates and plant reproductive success. Additionally, we analysed whether the effects of species richness and visitation rate on plant reproductive success were consistent over the years.The stability of plant visitation rates is driven by the asynchrony of pollinator species abundances, but the effect of pollinator species richness is only indirect, as richer communities also tend to have more asynchronous populations. In contrast, the stability of plant reproductive success is not related to the stability of pollinator visitation rates. A year‐by‐year analysis reveals that plants in the studied system are unlikely to be limited by pollinator abundance except in specific years, blurring any potential effect of visitation rate stability on reproductive success stability.Synthesis: We highlight the importance of asynchronous fluctuating species that are redundant in their function as an important factor for the stability of ecosystems. This is particularly important for pollinators with diverse responses to environmental fluctuations, as their asynchrony between years ensures stable levels of flower visitation rates. However, we warn that final ecosystem functions such as plant reproductive success, which depends not only on pollinators but on plant competition or resource availability, might be decoupled from first order ecosystem functions (i.e. visitation rates and pollen deposition) when pollination is not a limiting factor. [ABSTRACT FROM AUTHOR]

An increasing number of recent studies show that nectar-inhabiting microorganisms influence plant fitness by mediating interactions between plants and pollinators. However, whether the effects of nectar microbes extend beyond pollination to affect subsequent stages of plant reproduction remains largely unknown. This study aims to explore whether nectar microbes can indirectly affect fruit consumption by birds, which can be essential for seed dispersal and germination. Wild flowers of Eurya japonica trees were experimentally inoculated with the nectar-inhabiting yeast Metschnikowia reukaufii and the nectar-inhabiting bacterium Acinetobacter boissieri, both of which had been previously isolated frequently from E. japonica flowers. In this experiment, I examined whether these microbes changed female reproductive success of the understory tree. Experimental inoculation of flowers with yeasts decreased fruit and seed set compared to those inoculated with bacteria, and the control. Furthermore, fruits with higher seed set tended to be larger, and larger fruits were more likely to be consumed by seed-dispersing birds, including the Japanese white-eye Zosterops japonica, the brown-eared bulbul Hypsipetes amaurotis, and the Daurian redstart Phoenicurus auroreus. These results suggest that nectar-inhabiting microorganisms have the potential to affect plant reproduction by influencing not only plant-pollinator interactions, but also by indirectly modifying plant-frugivore interactions via changes in plant-pollinator interactions.

The present study reports the chromosome number, meiotic behavior and its relation with pollen fertility and seed set of Arnebia euchroma (Royle ex Benth.) I.M.Johnst. The species shows a chromosome count of 2n = 2x = 14. The meiotic abnormalities such as chromatin stickiness, cytomixis, laggard formation, chromosomal bridges, were also observed in the Pollen Mother Cells (PMCs) of the target plant species. The linear model of regression showed a significant reduction of seed set with increasing meiotic abnormality and correlation analysis highlighted positive relationship between pollen viability and seed set. Meiotic abnormalities within the species hinder its reproductive process, causing a decline in reproductive efficiency. This study highlights the importance of addressing these intrinsic factors in future conservation programs to prevent a decline in the species population in nature.

Roses are known for their low pollen quality. It remains unclear how many days of pollen should be used in order not to reduce crossbreeding success. The study was conducted to determine whether short-term pollen storage is effective on the crossing success of roses comparatively in vivo and in vitro. The study was conducted in a greenhouse and a cytology laboratory at Ankara University, Turkey. The 'Avalanche' rose variety was used as the seed parent, and 'Magnum' was the pollen parent. A total of 210 crosses were made. Pollens were used immediately (day 0) and stored at +4°C for 6 days after collection. The pollen viability by IKI and the germination rates by the petri dish method, the fruit and seed set, the fruit and seed weight, and the seed germination rate were recorded. All examined traits showed a decreasing trend as the storage time increases. The pollen germination rates were recorded at 1.63% for stored pollen at six days and 15.27% for fresh pollen. The highest fruit and seed set rates were obtained from crossing with pollen stored for one day. The fruit set decreased below 10% as of the 5th day, and the seed numbers decreased 1.8 times compared to one day of storage. No germination was observed in seeds obtained from crosses with pollen stored for 5 or 6 days. A positive correlation was found between seed number and pollen germination rate. The study concluded that successful crossing could be made with pollen stored at +4°C for up to 3 days. [ABSTRACT FROM AUTHOR]

Highbush blueberry production has expanded worldwide in recent decades. To safeguard future yields, it is essential to understand if insect pollination is limiting current blueberry production and which insects contribute to pollination in different production regions.We present a systematic review including a set of meta‐analyses on insect‐mediated pollination in highbush blueberry. We summarize the geographic distribution of research, the abundance of different pollinator taxa and their relative pollination contributions. Using raw data from 21 studies, totalling 496 site replicates, we determine the degree of pollination service and pollen limitation (i.e. combining open pollination levels with experimental bagged and/or hand pollination treatments), as well as the contribution of honeybees and wild bees to pollination (i.e. observational, open pollination).Most studies originate from North America, focusing on only a few cultivars. Honeybees are the dominant pollinator, and wild bees are occasionally abundant. Wild bees are more efficient pollinators on a single‐visit basis compared to honeybees, which increases their relative pollination contribution compared to their relative abundance.Insect‐mediated pollination services increased blueberry fruit set, berry weight and seed set (R2 values: 64.8%, 75.9% and 75.2% respectively). We often detected pollen limitation, indicated by an increase in fruit set, berry weight and seed set (R2: 10.1%, 18.2% and 21.5%, respectively), with additional hand pollination. Increasing visitation of honeybees and wild bees contributed to blueberry pollination by increasing fruit set (R2: 5.4% and 3.5%), berry weight (R2: 6.5% and 2.8%) and seed set (R2: 6.4% and 3.8%) respectively. Bee contributions to fruit set and berry weight were variable across regions.Synthesis and application: A diverse community of insects, primarily bees, contributes to highbush blueberry pollination and yield. However, pollination deficits are common. The finding that both honeybees and wild bees enhance pollination highlights the possibility of adopting different management strategies that utilize honeybees, wild bees or both depending on the specific context and region. This further emphasizes the general importance of conserving pollinator health and diversity. Our synthesis highlights data gaps and areas for future research to better understand the pollination contribution of different pollinators to crops that are expanding globally. [ABSTRACT FROM AUTHOR]

Climate change is likely to alter both flowering phenology and water availability for plants. Either of these changes alone can affect pollinator visitation and plant reproductive success. The relative impacts of phenology and water, and whether they interact in their impacts on plant reproductive success remain, however, largely unexplored. We manipulated flowering phenology and soil moisture in a factorial experiment with the subalpine perennial Mertensia ciliata (Boraginaceae). We examined responses of floral traits, floral abundance, pollinator visitation, and composition of visits by bumblebees vs. other pollinators. To determine the net effects on plant reproductive success, we also measured seed production and seed mass. Reduced water led to shorter, narrower flowers that produced less nectar. Late flowering plants produced fewer and shorter flowers. Both flowering phenology and water availability influenced pollination and reproductive success. Differences in flowering phenology had greater effects on pollinator visitation than did changes in water availability, but the reverse was true for seed production and mass, which were enhanced by greater water availability. The probability of receiving a flower visit declined over the season, coinciding with a decline in floral abundance in the arrays. Among plants receiving visits, both the visitation rate and percent of non-bumblebee visitors declined after the first week and remained low until the final week. We detected interactions of phenology and water on pollinator visitor composition, in which plants subject to drought were the only group to experience a late-season resurgence in visits by solitary bees and flies. Despite that interaction, net reproductive success measured as seed production responded additively to the two manipulations of water and phenology. Commonly observed declines in flower size and reward due to drought or shifts in phenology may not necessarily result in reduced plant reproductive success, which in M. ciliata responded more directly to water availability. The results highlight the need to go beyond studying single responses to climate changes, such as either phenology of a single species or how it experiences an abiotic factor, in order to understand how climate change may affect plant reproductive success.

Most banana improvement programs are restricted to using a sub-set of edible landraces for sexual hybridization as the majority are female sterile. This results from an array of factors that work in tandem and lead to sterility. Use of pollen germination media (PGM) during pollination significantly increases seed set, but it is a very small fraction compared to the potential seed set. This research therefore explored early pollination (a day before anthesis), evening pollination, saline treatment, plant growth regulators (PGRs) treatment, and ovule culture as potential techniques for overcoming sterility in bananas. Early and evening pollinations did not increase seed set because of immature flowers and a mismatch of male and female flower opening, respectively (t-prob. = 0.735 and 0.884). Immersion of bunches in a saline solution before pollination and ovule culture also did not overcome pollination barriers. Auxin antagonists (TIBA and salicylic acid) increased seed set, though their respective increases were not statistically significant (t-prob. = 0.123 and 0.164, respectively). The use of auxin antagonists shows great potential for overcoming pollination barriers in bananas. However, application rates and time of application have to be optimized and used holistically with other promising techniques, such as use of PGM.

Asteraceae (synonym as Compositae) is one of the largest angiosperm families among flowering plants comprising one-tenth of all agri-horticultural species grown across various habitats except in Antarctica. These are commercially utilized as cut and loose flowers as well as pot and bedding plants in landscape gardens due to their unique floral traits. Consequently, ineffective seed setting and presence of an intraspecific reproductive barrier known as self-incompatibility (SI) severely reduces the effectiveness of hybridization and self-fertilization by traditional crossing. There have been very few detailed studies of pollen-stigma interactions in this family. Moreover, about 63% of Aster species can barely self-fertilize due to self-incompatibility (SI). The chrysanthemum (Chrysanthemum × morifolium) is one of the most economically important ornamental plants in the Asteraceae family which hugely shows incompatibility. Reasons for the low fertility and reproductive capacity of species are still indefinite or not clear. Hence, the temporal pattern of inheritance of self-incompatibility and its effect on reproductive biology needs to be investigated further to improve the breeding efficiency. This review highlights the self-incompatible (SI) system operating in important Astraceous (ornamental) crops which are adversely affected by this mechanism along with different physiological and molecular techniques involved in breaking down self-incompatibility. [ABSTRACT FROM AUTHOR]

Drought is an increasingly important consequence of climate change. Drought often causes plants to alter patterns of resource allocation, which in turn can affect how plants interact with other species. How these altered interactions subsequently influence plant reproductive success remains incompletely understood and may depend on the degree of specialization exhibited by antagonists and mutualists. Specialist pollinators, for example, are dependent on floral resources from their obligate hosts and under drought conditions may thus indiscriminately visit these hosts (at least in certain circumstances). Generalist pollinators, in contrast, may only forage on host plants in good condition, given that they can forage on other plant species. We tested this hypothesis and its consequences for plant reproduction in squash (Cucurbita pepo) grown along an experimental moisture gradient ranging from dry (growth and flowering compromised) to wet conditions. Floral visitation increased with plant soil moisture for generalist honey bees but was independent of plant soil moisture for specialist squash bees. Pollen production increased with plant soil moisture, and fluorescent pigments placed on flowers revealed that pollinators primarily moved pollen from male flowers on well‐watered plants to the stigmas of female flowers on well‐watered plants. Seed set increased with increasing plant soil moisture but, notably, was higher in bee‐pollinated plants compared to plants pollinated by hand with an even mix of pollen from plants grown at either end of the experimental moisture gradient. These results suggest that superior pollen rewards, perhaps combined with selective foraging by generalists, enhanced reproductive success in C. pepo when plant soil moisture was high and more generally illustrate that pollinator behavior may contribute to how drought conditions affect plant reproduction. [ABSTRACT FROM AUTHOR]

An increasing number of recent studies show that nectar-inhabiting microorganisms influence plant fitness by mediating interactions between plants and pollinators. However, whether the effects of nectar microbes extend beyond pollination to affect subsequent stages of plant reproduction remains largely unknown. This study aims to explore whether nectar microbes can indirectly affect fruit consumption by birds, which can be essential for seed dispersal and germination. Wild flowers of Eurya japonica trees were experimentally inoculated with the nectar-inhabiting yeast Metschnikowia reukaufii and the nectar-inhabiting bacterium Acinetobacter boissieri , both of which had been previously isolated frequently from E. japonica flowers. In this experiment, I examined whether these microbes changed female reproductive success of the understory tree. Experimental inoculation of flowers with yeasts decreased fruit and seed set compared to those inoculated with bacteria, and the control. Furthermore, fruits with higher seed set tended to be larger, and larger fruits were more likely to be consumed by seed-dispersing birds, including the Japanese white-eye Zosterops japonica, the brown-eared bulbul Hypsipetes amaurotis , and the Daurian redstart Phoenicurus auroreus. These results suggest that nectar-inhabiting microorganisms have the potential to affect plant reproduction by influencing not only plant-pollinator interactions, but also by indirectly modifying plant-frugivore interactions via changes in plant-pollinator interactions. [ABSTRACT FROM AUTHOR]

In hybrid sunflower, bee pollination can improve productivity, but the contribution of bees to productivity may be over or underestimated. To estimate bee effects (seed trait gains from exposure to bees during anthesis), single capitula are commonly covered with a porous material to exclude bees. However, depending on the exclosure porosity, estimates of the magnitude of bee effects will vary. In two studies, porosity size and bee effect gains in two sunflower types were tested. In the exclosure study, Delnet exclosures severely reduced seed set and exclosures with larger porosities and had smaller and similar effects. However, since a few small bees penetrated the largest porosity size tested, exclosures with porosity sizes < 7 mm are recommended. With an exclosure porosity of 5 X 5 mm, the estimated bee effect contribution to the yield was 323 kg per hectare. Effects of exclosures on seed traits were similar in the oilseed and confectionary hybrids tested. Insecticide use did not affect seed traits but did lower insect damage to seeds. Bees from three families, mostly Apidae, were collected while foraging on sunflower. In summary, we recommend the use of exclosures with porosities of about 3 to 5 mm to avoid over or underestimating bee effects. And we recommend holistic insect management for sunflower cropping systems that balances the benefits of bee effects on seed traits with management of pest insects. [ABSTRACT FROM AUTHOR]

Social media needs social networks to disseminate information among the people who like to interact with each other. Identification of the most prominent influencers is a crucial problem for influence diffusion in applications like viral marketing. Most of the previous works on influence diffusion studied the topological nature of the users but ignored the effects of communities within a network. This paper proposes a new method called the TSGC method, where the whole graph is divided into different non-overlapping communities. Each of the communities is taken as a subgraph by ignoring the connecting links between them. The most influential users are identified by using each node's local and global centrality measures in the given subgraph of a graph. Finally, the ranking of each node is performed by calculating the I s c o r e p of each node within a whole network. Experimental results on six datasets confirm that the proposed TSGC method outperforms many well-known existing methods in terms of influence diffusion phenomenon under both the LT and IC models. This paper also proposes a new model where an active promoter may lose his influencing potential over time, go to a recovered state where he is no longer active or can activate others, and then go to a susceptible state where he is prone to getting influenced in the future. A user who is influenced by an active user can also become an active user. We termed this model the ICIRS model. This model undergoes influence diffusion in continuous time, unlike discrete-time steps as focused in most of the existing papers. Our experimental evaluations on the datasets reveal that the ICIRS model performs non-progressive influence diffusion. [ABSTRACT FROM AUTHOR]

Premise: Co‐flowering species that have not evolved an avoidance mechanism may have tolerance to heterospecific pollen (HP) deposition as an adaptive strategy to minimize any deleterious effects of HP transfer, but empirical evidence for the tolerance hypothesis remains scarce. Methods: To estimate the potential effects of heterospecific pollen deposition (HPD) on female reproductive success, we counted conspecific (CP) and HP pollen grains deposited on stigmas and assessed subsequent seed set of both open‐ and hand‐pollinated flowers in three co‐flowering Silene species with exposed stigmas that usually received numerous HP grains on the elongated receptive area. Results: The percentage of HP grains per flower (HP%) varied from 16.6% to 43.0% among three species. Silene chungtienensis had lower HP%, and the CP‐HP relationship was neutral; S. gracilicaulis and S. yunnanensis had a relatively higher HP% with a positive CP‐HP relationship. The effects of CP and HP number on natural seed set were positive for all three species, but HP% had stronger negative effects in S. chungtienensis and S. gracilicaulis. In hand‐pollinated flowers of the three Silene species, seed set did not decrease with HP whether CP was in excess or insufficient, indicating no negative effects of HPD on seed production. Conclusions: Consistent with the tolerance hypothesis, our results indicated that species with higher HP interference are likely to be tolerant to an increase in HP%. These species with generalist‐pollinated flowers and exposed large stigmas may benefit from an increase of conspecific pollen deposition, despite the associated increase in heterospecific pollen deposition. [ABSTRACT FROM AUTHOR]

Mulberry is a fast growing woody perennial tree that maintains high heterozygosity due to the out-breeding reproductive system. The success of breeding programme mainly depends on availability of genetic variability and selection of superior progenies. Polyclonal seed orchard is one of the sources for creating huge desirable genetic variability using natural hybridization with minimum effort for improvement of leaf yield and quality in mulberry. High bush polyclonal seed orchard was established using twenty nine parents (16 female & 13 male) at CSR&TI Berhampore. Morphological assessment of hybrid fruits and seeds were performed for two successive years (2020 & 2021). The results showed that significant differences among polycross hybrids in most of the fruit & seed traits. Fruit weight varied from 0.63g (T-13) to 2.27g (Berhampore-A); fruit length varied from 1.58cm (T-13) to 2.65cm (CSRS-1); fruit width varied from 0.86cm (Matigera-black) to 1.32cm (Berhampore-A); seeds per fruit varied from 25 (C-2038) to 47 (Berhampore-A) and test weight varied from 1.25g (China-white) to 2.20g (C-2045). The highest seed set was recorded in C-2045 (91.95%) followed by Sujanpur-5 (88.70%). Highly significant positive correlation was observed between fruit weight & fruit width (0.87); fruit weight & fruit length (0.84); achenes per fruit & seeds per fruit (0.72). A significant difference was recorded for seed germination among 16 polycross & it varied from 70 per cent (China-white & S-30) to 99 per cent (C-2038). After 60 days, germination was reduced more in Sujanpur-5 (92.5%) and Bogura-4 (90.40%). The information may be useful for the breeders to identify superior seedlings and creating heterozygous hybrid progenies in mulberry. [ABSTRACT FROM AUTHOR]

Sucrose non-fermenting–1-related protein kinase–1 (SnRK1) is a highly conserved serine–threonine kinase complex regulating plants’ energy metabolisms and resistance to various types of stresses. However, the downstream genes regulated by SnRK1 in these plant physiological processes still need to be explored. In this study, we found that the knockout of OsSnRK1a resulted in no obvious defects in rice growth but notably decreased the seed setting rate. The ossnrk1a mutants were more sensitive to blast fungus (Magnaporthe oryzae) infection and showed compromised immune responses. Transcriptome analyses revealed that SnRK1a was an important intermediate in the energy metabolism and response to biotic stress. Further investigation confirmed that the transcription levels of OsNADH-GOGAT2, which positively controls rice yield, and the defense-related gene pathogenesis-related protein 1b (OsPR1b) were remarkably decreased in the ossnrk1a mutant. Moreover, we found that OsSnRK1a directly interacted with the regulatory subunits OsSnRK1β1 and OsSnRK1β3, which responded specifically to blast fungus infection and starvation stresses, respectively. Taken together, our findings provide an insight into the mechanism of OsSnRK1a, which forms a complex with specific β subunits, contributing to rice seed set and resistance by regulating the transcription of related genes.

Cassava breeding faces obstacles due to late flowering and poor flower and seed set. The acceleration of breeding processes and the reduction in each cycle’s duration hinge upon efficiently conducting crosses to yield ample progeny for subsequent cycles. Our primary objective was to identify methods that provide tools for cassava breeding programs, enabling them to consistently and rapidly generate offspring from a wide array of genotypes. In greenhouse trials, we examined the effects of the anti-ethylene silver thiosulfate (STS) and the cytokinin benzyladenine (BA). STS, administered via petiole infusion, and BA, applied as an apical spray, combined with the pruning of young branches, significantly augmented the number of flowers. Controls produced no flowers, whereas treatments with pruning plus either BA or STS alone produced an average maximum of 86 flowers per plant, and the combination of pruning, BA and STS yielded 168 flowers per plant. While STS had its primary effect on flower numbers, BA increased the fraction of female flowers from less than 20% to ≥87%, thus increasing the number of progeny from desired parents. Through field studies, we devised an optimal protocol that maintained acceptable levels of phytodamage ratings while substantially increasing seed production per plant compared to untreated plants. This protocol involves adjusting the dosage and timing of treatments to accommodate genotypic variations. As a result, cassava breeding programs can effectively leverage a diverse range of germplasm to develop cultivars with the desired traits.

The influence maximization (IM) problem asks for a group of seed users in a social network under a given propagation model, so that the information spread is maximized through these users.Existing algorithms have two main problems.Firstly, these algorithms were difficult to be applied in large-scale social networks due to limited expected influence and high time complexity.Secondly, these algorithms were limited to specific propagation models and could only solve the IM problem under a single type of social network.When they were used in different types of networks, the effect was poor.In this regard, an efficient algorithm (MTIM) based on two classic propagation models and reverse influence sampling (RIS) was proposed.To verify the effectiveness of MTIM, experiments were conducted to compare MTIM with greedy algorithms such as IMM, TIM and PMC, and heuristic algorithms such as OneHop and Degree Discount on four real social networks.The results show that MTIM can return a ( 1− 1 e −ε ) approximate solution, effectively expand the expected influence and significantly improve the efficiency.

The seed yield in pea (Pisum sativum L.) depends on numerous environmental and genotypic factors. The ongoing climate changes draw one's attention to genetics and variation of underexplored reproductive traits. This study focuses on ovule number (ON) and flower size expressed as a length of flag petal (FL), in terms of their heritability, variability, and correlation with 1000 seed mass (TSM), seed number per pod, and seed/ovule ratio. A set of pea accessions was planted over several years in field conditions. Some of these accessions were also grown in a glasshouse. The chosen values were scored on living plants or while harvesting seeds. Nonparametric statistical methods were applied. Heritability of ON and FL was studied in five hybrid F1/F2 combinations. We found a relatively low (ca. 0.5) broad sense heritability of both ON and FL. Among other traits, TSM and ON reproduced best over the years. FL exhibited no reproducible correlations with other traits and cannot be used as a predictor of productivity. Water deficit and heat stress reduce seed yield in pea due to both seed abortion and development of fewer ovules. The differential and heritable ability to retain ON may become a basis for breeding pea cultivars adapted to changing climate. [ABSTRACT FROM AUTHOR]

The effectiveness of haploid induction systems is regarded not only for high haploid induction rate (HIR) but also resource savings. Isolation fields are proposed for hybrid induction. However, efficient haploid production depends on inducer traits such as high HIR, abundant pollen production, and tall plants. Seven hybrid inducers and their respective parents were evaluated over three years for HIR, seeds set in cross-pollinations, plant and ear height, tassel size, and tassel branching. Mid-parent heterosis was estimated to quantify how much inducer traits improve in hybrids in comparison to their parents. Heterosis benefits hybrid inducers for plant height, ear height, and tassel size. Two hybrid inducers, BH201/LH82-Ped126 and BH201/LH82-Ped128, are promising for haploid induction in isolation fields. Hybrid inducers offer convenience and resource-effectiveness for haploid induction by means of improving plant vigor without compromising HIR. [ABSTRACT FROM AUTHOR]

Generalized pollinators visit multiple co‐flowering plant species and may transfer heterospecific pollen grains. Recent studies have indicated that the effect of heterospecific pollen (HP) on reproduction success is variable and depends on the identity of donor and recipient species. However, few studies have documented variation in HP receipt and evaluated the reproductive effects of HP receipt across geographic locations under natural conditions. We investigated the spatial variation of pollen deposition across eight sites and how the pollen receipt related to the seed set of Salvia przewalskii, a subalpine perennial herb in Hengduan Mountain in southwest China. We found that stigmatic pollen loads substantially varied among sites for several metrics, including quantities of conspecific and heterospecific pollen, the proportion of HP, and species composition of HP donors. Five different plant families were the most common HP source at one or two sites, and the proportion of HP ranged from 3.4% to 51.3% across sites. The association of conspecific pollen with seed set was positive and variable among sites, whereas the association of HP receipt and seed set was negative and not significantly different among sites. Our results demonstrate variation in the quantity and fitness effect of pollen receipt across sites, which is a precondition for evolution of local adaptation. Further study of variation in patterns and effects of HP receipt for the same recipient species across natural communities would allow better understanding of the ecological and evolutionary consequences of HP receipt. [ABSTRACT FROM AUTHOR]

Climate change may disrupt plant–pollinator mutualisms by generating phenological asynchronies and by altering traits that shape interaction costs and benefits. Our knowledge is limited to studies that manipulate only one partner or focus on either phenological or trait‐based mismatches. We assembled communities of three annual plants and a solitary bee prior to flowering and emergence to test how springtime warming affects phenologies, traits, interactions and reproductive output. Warming advanced community‐level flowering onset, peak and end but did not alter bee emergence. Warmed plant communities produced fewer and smaller flowers with less, more‐concentrated nectar, reducing attractiveness, and warmed bees were more generalized in their foraging, reducing their effectiveness. Plant–bee interactions were less frequent, shorter and peaked earlier under warming. As a result, warmed plants produced fewer, lighter seeds, indicating pollinator‐mediated fitness costs. Climate change will perturb plant–pollinator mutualisms, causing wide‐ranging effects on partner species and diminishing the ecosystem service they provide. [ABSTRACT FROM AUTHOR]

The balance of pollination competition and facilitation among co‐flowering plants and abiotic resource availability can modify plant species and individual reproduction. Floral resource succession and spatial heterogeneity modulate plant–pollinator interactions across ecological scales (individual plant, local assemblage, and interaction network of agroecological infrastructure across the farm). Intraspecific variation in flowering phenology can modulate the precise level of spatio‐temporal heterogeneity in floral resources, pollen donor density, and pollinator interactions that a plant individual is exposed to, thereby affecting reproduction. We tested how abiotic resources and multi‐scale plant–pollinator interactions affected individual plant seed set modulated by intraspecific variation in flowering phenology and spatio‐temporal floral heterogeneity arising from agroecological infrastructure. We transplanted two focal insect‐pollinated plant species (Cyanus segetum and Centaurea jacea, n = 288) into agroecological infrastructure (10 sown wildflower and six legume–grass strips) across a farm‐scale experiment (125 ha). We applied an individual‐based phenologically explicit approach to match precisely the flowering period of plant individuals to the concomitant level of spatio‐temporal heterogeneity in plant–pollinator interactions, potential pollen donors, floral resources, and abiotic conditions (temperature, water, and nitrogen). Individual plant attractiveness, assemblage floral density, and conspecific pollen donor density (C. jacea) improved seed set. Network linkage density increased focal species seed set and modified the effect of local assemblage richness and abundance on C. segetum. Mutual dependence on pollinators in networks increased C. segetum seed set, while C. jacea seed set was greatest where both specialization on pollinators and mutual dependence was high. Abiotic conditions were of little or no importance to seed set. Intra‐ and interspecific plant–pollinator interactions respond to spatio‐temporal heterogeneity arising from agroecological management affecting wild plant species reproduction. The interplay of pollinator interactions within and between ecological scales affecting seed set implies a co‐occurrence of pollinator‐mediated facilitative and competitive interactions among plant species and individuals. [ABSTRACT FROM AUTHOR]

Locules are the seed‐bearing structure of fruits. Multiple locules are associated with increased fruit size and seed set, and therefore, control of locule number is an important agronomic trait. Locule number is controlled in part by the CLAVATA‐WUSCHEL pathway. Disruption of either the CLAVATA1 receptor‐like kinase or its ligand CLAVATA3 can cause larger floral meristems and an increased number of locules. In an EMS mutagenized population of Brassica rapa, we identified a mutant allele that raises the number of locules from four to a range of from six to eight. Linkage mapping and genetic analysis support that the mutant phenotype is due to a missense mutation in a CLAVATA 1 (CLV1) homolog. In addition to increased locule number, additional internal gynoecia are formed in brclv1 individuals, suggesting a failure to terminate floral meristem development, which results in decreased seed production. [ABSTRACT FROM AUTHOR]