Search

• Ethephon and NAA applications resulted in dense bisexual flowers within the first four weeks of the flowering period. • NAA applications improved yield and fruit size. • Applications during the 'green leaf' stage increased the yield per tree and fruit size. • A positive correlation was observed between the number of bisexual flowers and yield per tree. The study aimed to determine the effects of ethephon (150 μL/L, 200 μL/L, and 250 μL/L) and 1-naphthalene acetic acid (NAA; 50 μL/L, 100 μL/L, and 150 μL/L) applications at 'red leaf' and 'green leaf' stages on bisexual flower, fruit yield and quality characteristics of 'Hicaznar' cultivar. These results showed that ethephon and NAA applications increased the bisexual flower and fruit set ratios, depending on the used dose. The applications formed dense bisexual flowers in the first four weeks of the flowering period. The highest yield per tree and hectare was obtained from applying 50 μL/L NAA at the 'green leaf' stage for two consecutive years. Pomegranates harvested from ethephon and NAA-treated plants exhibited increased fruit size and seed percentage compared to those from control plants. Overall, this study demonstrated the potential of ethephon and NAA treatments to improve fruit yield and quality in pomegranate. [ABSTRACT FROM AUTHOR]

The hormonal variation essential for fruit set differs regarding crop species. Parthenocarpy is a key trait to reduce the climate dependency of fruit crops. Two distinct molecular mechanisms lead to a gibberellin-induced fruit setting. Transcription factors and miRNA interactions control parthenocarpy in several species. Fruit development is essential for flowering plants' reproduction and a significant food source. Climate change threatens fruit yields due to its impact on pollination and fertilization processes, especially vulnerable to extreme temperatures, insufficient light, and pollinator decline. Parthenocarpy, the development of fruit without fertilization, offers a solution, ensuring yield stability in adverse conditions and enhancing fruit quality. Parthenocarpic fruits not only secure agricultural production but also exhibit improved texture, appearance, and shelf life, making them desirable for food processing and other applications. Recent research unveils the molecular mechanisms behind parthenocarpy, implicating transcription factors (TFs), noncoding RNAs, and phytohormones such as auxin, gibberellin (GA), and cytokinin (CK). Here we review recent findings, construct regulatory models, and identify areas for further research. [ABSTRACT FROM AUTHOR]

Backcrossing between Sikitita and its male parent Arbequina, offers the possibility to check the suitability of different self-incompatibility models proposed for olive. To determine Sikitita's response to self- and cross-pollination treatments, including pollination with its father Arbequina, we compared the parameters following pollen–pistil interaction, the resulting initial and final fruit set, and the paternity of the seeds produced under different crosses. The results showed that Sikitita behaves as a self-incompatible cultivar due to the inhibition of pollen tube growth in the pistil of self-pollinated flowers. This incompatibility reaction led to a significant reduction of self-fertilization and fruit set. Seed paternity analyses confirmed the self-incompatibility response of Sikitita. A similar incompatibility response was observed in Sikitita flowers when hand-pollinated with pollen of Arbequina and Koroneiki. On the contrary, cross-pollination with Arbosana gave excellent results, with analyses showing that pollen of Arbosana is largely preferred by Sikitita to father its seeds more than the pollen of other cultivars presented in the orchard. The backcross failure of Sikitita with Arbequina pollen suggests that the self-incompatibility system in olives is not of the gametophytic type. In contrast, pollination tests fit features of previously reported sporophytic self-incompatibility systems. However, some amendments are proposed, among them the incompatibility groups for Sikitita and Koroneiki. [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]

The complex processes of pollen germination and pollen tube elongation are important events in the sexual reproduction of flowering plants and are essential to the success of seed formation. However, unfavourable environmental and climatic conditions affect pollen performance negatively. Integrating the application of various biostimulants represents one of the most innovative and promising strategies to improve crop productivity. Biostimulants are known to sustainably improve pollen viability, germination and elongation. However, there is limited information on the effects of biostimulants on pollen grains. The present review investigates the potential of biostimulants (such as seaweed extracts, smoke–water, polyamines, amino acids, melatonin, carbohydrate-based biostimulants and inorganic biostimulants) as signaling molecules that can improve crucial stages of pollen growth in a range of crops, both in optimal and suboptimal environments. Furthermore, this review investigates the stages of pollen development, including uninucleate microspores and different stages of mature pollen, following various biostimulant treatment during the flowering period. Regulation of biostimulant-induced pollen germination and elongation has also been discussed along with recent developments regarding the mechanism of action of biostimulants in various growth aspects of pollen. This review not only summarizes what is known currently, but it also lays the groundwork for future investigations to clarify the complex physiological and molecular processes involved in pollen performance as well as the regulatory systems that are impacted by biostimulants. [ABSTRACT FROM AUTHOR]

Phytohormones promote growth in the vegetative phase, flowering and fruit development. A novel class of PGR comprises brassinosteroids (BRs) and polyamines (PAs). In fruit crops, fruit drop at the maturity stage is controlled by the external application of BRs and PAs. BRs such as brassinolide, 24-epibrassinolide and 28-homobrassinolide and PAs such as putrescine, spermidine and spermine play significant roles in plant growth and development. Brassinolide provides tolerance against biotic and abiotic stresses. 24-Epibrassinolide promotes blossoming, fruit retention, fruit set and fruit growth. 28-homobrassinolide promotes cell division and cell elongation. Putrescine enhances seed germination and adventitious root formation in seedlings. Moreover, spermidine provides tolerance against drought and salinity. Furthermore, spermine promotes flowering and fruiting and competes with ethylene precursors. It would be beneficial to apply plant growth regulators such as BRs and PAs to increase fruit yield and quality. This review discusses how phytohormone (BR and PA) application can improve the productivity, quality, physiological, biochemical and postharvest aspects of some tropical, subtropical and temperate fruits and focuses on research areas such as the mode of action and stage of application of BRs and PAs which enhance the yield and quality of these perishable fruit crops. Article highlights: The newly emerged plant growth hormones brassinosteroids and polyamines are vital PGRs for the cultivation of horticulture commodities. BRs and PAs are environmentally safe phytohormones that improve the yield and quality of fruits. These materials are effectively utilized in both fruit production and postharvest management. [ABSTRACT FROM AUTHOR]

Increasing ant abundance associated with climate warming has been observed in temperate ecosystems. However, how enhanced ant activity affects plant development and phenology remains unclear. In this study, individuals of a perennial forb (Potentilla tanacetifolia) during flowering with and without an ant (Proformica) nest were marked to explore the impacts of ant nests on plant growth and phenology in a temperate steppe on the Mongolian Plateau. Ant nests delayed the start and end flowering dates simultaneously and, consequently, had no effect on flowering duration. However, presence of an ant nest postponed the fruiting date of individuals. Nests further increased numbers of aborted flowers and thus decreased fruit set. These observations suggest that the delayed flowering phenology disrupted synchrony between plant reproduction and pollinators and thus reduced pollination efficiency under ant nests. Given the increasing abundance of ants with rising temperatures under climate warming, plant delayed reproductive phenology and reduced reproductive output will potentially have negative consequences for plant fitness and plant–arthropod interactions, with consequent impacts on resistance and resilience of perennial species in temperate steppes under climate change. [ABSTRACT FROM AUTHOR]

Olive is one of the important plants worldwide in terms of economic and cultural conditions. It is used in fresh consumption, olive oil, cosmetic and pharmaceutic fields and unique numinous plants. Olive can maintain its life for many years even in barren conditions but for an economic cultivation, fertile and preferred cultivars should be used in orchards and optimum maintenance conditions should be provided. At the same time the climate change is also convert the usual behavior of the plants. This study aims to determine the effects of classic and organomineral fertilizers on pollen quality and quantity parameters. In this study, classical fertilizers like Urea+MgSO4 and KNO3+H3BO3+ZnSO4 with Raykat Start, Raykat Growth and Fitomare organomineral fertilizers were sprayed foliarly before flowering on Gemlik olive cultivar and pollen studies were conducted on the flowers formed at full flowering. Within the study, effects of the treatments were evaluated on pollen viability and germination levels, the amount of pollen produced in one flower and the normally developed pollen ratio. As a result of this study, fertilization treatments positively affected pollen quality and quantity with regard to control treatment. In this context, the pollen viability level differed between 74.15% and 89.92%, the pollen germination level between 45.48% and 70.35% and pollen per flower was between 307.238 and 446.761. The lowest data were obtained from control treatments, while the highest were from Raykat group fertilizers. Especially, the 54% increase in pollen germination level with Raykat growth fertilization was one of the most important results of this study. In conclusion, it was determined that the foliar spray of organomineral fertilizers enhanced the pollen properties. Raykat Start, Raykat Growth and Fitomare organomineral fertilizers used in this study significantly increased pollen quality and quantity. [ABSTRACT FROM AUTHOR]

Enhalus acoroides (L.f.) Royle is a large and important foundation seagrass species in the tropical Indo-Pacific. The northern marginal populations in China have been declining over the last decades. The reproductive phenology and fruit set of this dioecious seagrass were investigated from June 2017 to February 2018 in two areas in Li'an lagoon, Hainan Island, China. We found that E. acoroides flowered year-round. However, the flowering intensity varied among seasons and was highest in the summer and lowest in the winter. The shoot sex ratio was male-biased, and the pollen-ovule ratio was approximately 104: 1, based on the sex ratio and the number of male florets per inflorescence. Female and male plants flowered at the same time in this population. Despite the high reproductive investment in terms of flower formation observed throughout the year, the abundance of the mature fruits was low, possibly due to physical disturbance and cover by epiphyte and algae. This study provides insight into the reproductive ecology of E. acoroides, which will be useful for the future conservation of this threatened seagrass. [ABSTRACT FROM AUTHOR]

Self-fertile cultivars of sweet cherry (Prunus avium) produce heavy crop load that is often associated with small and poor-quality fruits. Therefore, a crop load-management strategy is required to improve the quality of the fruit. In this study, the effect of blossom thinners on fruit set, yield and quality of the fruits was evaluated. Three types of blossom thinners were used at three different concentrations viz., ammonium thiosulphate (ATS) (1, 1.5 and 2%), naphthaleneacetic acid (NAA) (20, 40 and 60 ppm) and corn oil emulsion (1, 2 and 3%). These were sprayed at 80% of the bloom stage. The vegetative, flowering, fruit set and yield parameters were observed and recorded. Fruit quality was evaluated by measuring the physical and chemical characteristics of the fruits at the harvest stage. Negative correlation was found between fruit set and quality of fruit. The reduction in the crop load was associated with enhanced vegetative growth, including higher leaf:fruit ratio, higher supply and availability of photosynthates to the remaining fruitlets and reduced fruit firmness and titratable acidity. Fruit size, weight, volume, hue value, chroma value, soluble solid content (SSC), total sugars, SSC/acid ratio, anthocyanin and ascorbic acid content were enhanced as a result of thinning. The foliar spray of ATS at 2% and NAA at 60 ppm, at 80% bloom proved to be the most effective in reducing crop load and enhancing the fruit quality.

Abstract Animal pollination is crucial for the reproduction and economic viability of a wide range of crops. Despite the existing data, the extent to which citrus crops depend on pollinators to guarantee fruit production still needs to be determined. Here, we described the composition of potential pollinators in citrus (Citrus spp.) from the main growing areas of Argentina; moreover, we combined Bayesian models and empirical simulations to assess the contribution of animal pollination on fruit set and yield ha−1 in different species and cultivars of lemons, grapefruits, mandarins, and oranges. Honeybee (A. mellifera L.) was the most commonly observed potential pollinator, followed by a diverse group of insects, mainly native bees. Regardless of citrus species and cultivars, the probability of flowers setting fruit in pollinated flowers was 2.4 times higher than unpollinated flowers. Furthermore, our simulations showed that about 60% of the citrus yield ha−1 can be attributable to animal pollination across all species and cultivars. Therefore, it is crucial to maintain environments that support pollinator diversity and increase consumer and to producer awareness and demand in order to ensure the significant benefits of animal pollination in citrus production.

Fruit drop from pear trees causes serious losses in income. However, the application of plant bio-regulators improves the internal physiology of developing fruit by ensuring that they receive an adequate supply of water, nutrients, and other compounds necessary for their proper growth and development, which leads to improved size, quality, and ultimately better yield in a variety of fruit crops. This study investigated the foliar application of three plant growth regulators: CPPU at 10, 15, and 20 ppm, GA3 at 25, 50, and 75 ppm and NAA at 25, 50, and 75 ppm. The pear trees were sprayed four times: before flowering, full bloom, after three weeks, and after six weeks. The results showed that the spray of GA3 at 50 and 75 ppm gave the highest effect in increasing the shoot length, shoot thickness, leaf area, and leaf total chlorophyll. The spraying of NAA at 50 and 75 ppm was the best treatment in increasing the fruit set percentages, fruit yield, fruit weight, and fruit dimensions as well as the fruit content from soluble solids, and fruit sugars, while they reduced the fruit drop percentages comparing with the other applied treatments.

A lucrative and delicious nonclimacteric tropical fruit, rambutan, has disadvantages of inadequate fruiting, low yield, and inferior edibility at farm level that need to be addressed. Moreover, unstable tropical temperatures and humidity threaten poor fruit set and insufficient rambutan yields. Therefore, the study revealed the effectiveness of gibberellic acid (GA3) on fruit set and retention, fruit size and yield, shelf life, and postharvest properties of rambutan under these atmospheric conditions. GA3 at concentrations of 50, 100, 200, 300, 400, and 500 ppm, apart from the control (without GA3), was applied to panicles twice in the early flowering and the early fruiting stages (thirty days after the first spraying). The results showed that maximum fruit set (223.2 per panicle), retention (13.2 per panicle, 5.9%), and yield (714.0 g per panicle) were obtained by GA3 treatment at 300 ppm. In addition to increasing fruit size (54.1 g) and pulp weight (31.3 g), GA3 at a dose of 300 ppm significantly reduced seed weight by 27.5% and increased the edible portion by 26.6% compared to the control. Notably, preharvest GA3 treatment increased TSS content (19.0%), total sugar (4.5%), and shelf life (11.5 days), while it decreased titratable acidity (0.4%) of rambutan. GA3 doses from 200 to 500 ppm had similar effects in terms of affecting the edible properties and shelf life of rambutan. However, fruit set, retention, and yield exhibited distinct dose-dependent responses, with 300 ppm being the best and 200 ppm consistent with the best, with some differences. Regression analysis showed a skewed curve explaining higher yield and better fruit quality at the medium GA3 treatment level (250–350 ppm). In comparison, lower (< 200 ppm) and higher (> 400 ppm) doses resulted in worse results in most cases. Therefore, regulated use of GA3 is necessary to improve rambutan yield and fruit quality.

Parthenocarpic fruits, known for their superior taste and reliable yields in adverse conditions, develop without the need for fertilization or pollination. Exploring the physiological and molecular mechanisms behind parthenocarpic fruit development holds both theoretical and practical significance, making it a crucial area of study. This review examines how plant hormones and MADSbox transcription factors control parthenocarpic fruit formation. It delves into various aspects of plant hormones-including auxin, gibberellic acid, cytokinins, ethylene, and abscisic acid--ranging from external application to biosynthesis, metabolism, signaling pathways, and their interplay in influencing parthenocarpic fruit development. The review also explores the involvement of MADS family gene functions in these processes. Lastly, we highlight existing knowledge gaps and propose directions for future research on parthenocarpy. [ABSTRACT FROM AUTHOR]

In recent years, many farmers use new types of fertilizers to enhance fruit set and development and enhance the resilience of olive trees to climate change. In parallel, NO3− leaching in the soil and water threat the environment pointing toward a more sustainable nutrient management. This study investigated the effect of AMINO-16©, a commercial product derived from hydrolysis/extraction of protein-rich plant material and contains sixteen L-amino acids, on vegetative growth, flowering, nutritional status, yield, and oil qualitative characteristics of 'Koroneiki' olives on the Mediterranean island of Crete in Greece. We conducted a field experiment with amino acid foliar sprays for two growing seasons in a commercial irrigated olive grove. Treatments comprised (a) no amino acid application (Control), (b) three applications (summer 2014, winter 2015, and spring 2015) of AMINO-16 (A16-A), and (c) one application (winter 2015) of AMINO-16 (A16-B). The A16-A treatment (three sprays) significantly increased the number of inflorescences, the fruit set, and the number of fruits per shoot. Fruit yield and olive oil yield were higher than those of the control by 10.6 and 18%, respectively. In addition, leaf nutrient levels and the quality characteristics of olive oil in both treatments were not differentiated from the control. Overall, foliar fertilization with amino acids could enhance plant growth. Future research using amino acids at different reproductive and vegetative stages of olive trees is likely to further improve olive oil yield and quality. [ABSTRACT FROM AUTHOR]

Olive (Olea europaea L.) is an important Mediterranean tree species with a longstanding history of cultivation, boasting a diverse array of local cultivars. While traditional olive orchards are valued for their cultural and aesthetic significance, they often face economic sustainability challenges in the modern context. The success of both traditional and newly introduced cultivars (e.g. those obtained by cross-breeding) is hindered by self-incompatibility, a prevalent issue for this species that results in low fruit set when limited genetic diversity is present. Further, biological, environmental, and agronomic factors have been shown to interlink in shaping fertilization patterns, hence impacting on the final yield. Climatic conditions during pollination, such as excessive rainfall or high temperatures, can further exacerbate the problem. In this work, we provide an overview of the various factors that trigger the phenomenon of suboptimal fruit set in olive trees. This work provides a comprehensive understanding of the interplay among these factors, shedding light on potential mechanisms and pathways that contribute to the observed outcomes in the context of self-incompatibility in olive. [ABSTRACT FROM AUTHOR]

The contribution of insects to pollination constitutes a globally important ecosystem service. Due to the increasing demand for entomophilous crops, the nutritional and economic importance of insect‐pollinated crops and the inability of managed pollinators (Apis mellifera L) to meet the high demand for their services indicate that agriculture heavily relies on wild pollinators. Almonds are an economically valuable crop in Morocco. Therefore, it is essential to understand the fundamental pollination requirements of major almond varieties to promote their production. The main objectives of this study were to assess the dependency of three almond cultivars (Espoir, Largueta and Planeta) on insect pollination, and then to evaluate the pollination deficit resulting from the lack of these pollinators. For this purpose, we used insect‐proof net bags constructed around branches of almond trees to compare fruit set and yield with open and open + hand‐pollinated flowers. The results of the fruit set experiment confirmed that all three varieties require insect pollination, as fruit set and yield were significantly higher in insect‐pollinated than insect‐isolated trees. All three almond varieties were categorized as obligatory dependent on biotic pollinators. In addition, two out of the three studied almond varieties showed high pollination deficit resulting from the lower abundance and/or diversity of pollinating insects. The results of the current study highlights the important role of insect pollinators for almond crops and the urgent need for the implementation of sustainable strategies to preserve pollinators within agricultural ecosystems. [ABSTRACT FROM AUTHOR]

Fruit drop from pear trees causes serious losses in income. However, the application of plant bio-regulators improves the internal physiology of developing fruit by ensuring that they receive an adequate supply of water, nutrients, and other compounds necessary for their proper growth and development, which leads to improved size, quality, and ultimately better yield in a variety of fruit crops. This study investigated the foliar application of three plant growth regulators: CPPU at 10, 15, and 20 ppm, GA3 at 25, 50, and 75 ppm and NAA at 25, 50, and 75 ppm. The pear trees were sprayed four times: before flowering, full bloom, after three weeks, and after six weeks. The results showed that the spray of GA3 at 50 and 75 ppm gave the highest effect in increasing the shoot length, shoot thickness, leaf area, and leaf total chlorophyll. The spraying of NAA at 50 and 75 ppm was the best treatment in increasing the fruit set percentages, fruit yield, fruit weight, and fruit dimensions as well as the fruit content from soluble solids, and fruit sugars, while they reduced the fruit drop percentages comparing with the other applied treatments. [ABSTRACT FROM AUTHOR]

Trendy high-density olive fields are often monovarietal orchards, mostly using the cultivar Arbequina. However, Arbequina shows a strong self-incompatibility response, and its yields depend on wind cross-pollination, which is not always available. With the aim of finding suitable self-compatible cultivars that can replace Arbequina, we evaluated pollen–pistil interaction, fruit set and seed paternity in Arbosana under different pollination treatments: self-pollination, open-pollination and three cross-pollination treatments: × Arbequina, × Sikitita and × Koroneiki. All these cultivars are low-vigor cultivars suitable for high-density orchards, making them potential pollinizers for Arbosana. The results show that Arbosana is also self-incompatible with a strong reduction in fruit set due to a lower fertilization level caused by a strong inhibition of pollen tube growth in self-pollinated flowers. Seed-paternity analyses confirmed the self-incompatibility response of Arbosana and suggest that some fruit obtained in bagged shoots under self-pollination were, in fact, a product of cross-fertilization. In conclusion, we recommend against the use of Arbosana in large monovarietal orchards. On the contrary, good results were obtained under cross-pollination with Sikitita, Arbequina and Koroneiki pollen, allowing us to recommend them as pollinizers for Arbosana in appropriate pollination designs. This is the first time Arbosana self-incompatibility has been reported. [ABSTRACT FROM AUTHOR]

Inadequate lateral branch development can lead to decreased apple (Malus ×domestica Borkh.) orchard productivity and profitability in modern high-density orchard systems. Although plant growth regulator applications are used to increase lateral branching on leaders of young apple trees, inconsistent responses have been observed in the southeastern United States. In North Carolina and Washington, three experiments were conducted to identify effective leader management strategies to increase lateral branching. Effects and interactions of leader bagging, 6-benzyladenine (6-BA), and 6-BA + gibberellic acid (GA4+7) on lateral branch development of 1-year-old leaders were evaluated. Across all experiments, leader bagging was an influential factor. When compared with unbagged trees, leader bagging increased lateral branch number (20% to 48%), number of feathers (74% to 125%), average branch length (28% to 34%), and total linear bearing surface (428%) of the treated section of the leader. Blossom cluster density and final fruit set were increased in bagged trees, 65% and 36%, respectively. At the rates and timings tested, 6-BA and 6-BA + GA4+7 were generally ineffective in stimulating lateral branching and interactions among the factors evaluated were not influential. Leader bagging was an effective lateral branch induction strategy, although the mechanism of action is poorly understood. Future research to characterize the bagged environment and/or physiological responses to bagging may aid in the development of future environmentally sustainable technologies to stimulate lateral branching of apple trees. [ABSTRACT FROM AUTHOR]

Honey bee colonies rapidly decline when confined to greenhouses, increasing pollination rental costs as they need to be replaced frequently. We tested a hive system with entrances that can be manipulated to direct bees inside or outside greenhouses containing a zucchini crop. In one greenhouse, the bees could only forage inside for 15 days; in another, bees were directed to the inside from 5 to 9 a.m., after which they only foraged outside. This procedure was repeated two more times in each greenhouse with new hives. Data were collected on how the number of bee flower visits affected fruit production, the frequency of flower visits, and the amount of bee brood and food in the hives. Flowers visited by bees four times or more set more and larger fruit. The frequency of flower visits by bees from the hives confined to the greenhouse was reduced after eight days; it was not reduced in the greenhouse with bees that could forage outside. The bee brood area was reduced in the colonies that were confined to the greenhouse, while it was maintained in the semi-confined hives. The hives with controllable entrances proved effective for pollination, while causing less damage to the bees. [ABSTRACT FROM AUTHOR]

Abstract: Letícia AF is a mutation of the plum cultivar Laetitia that confers self-compatibility. This work compared the Letícia AF mutant cultivar with the standard Laetitia regarding fruit set, self-compatibility, yield, and fruit quality traits during four growing seasons. The study was carried out in two plum orchards with the cultivar Letícia AF (orchard 1) and Laetitia plus pollinizers trees (orchard 2) and in an experimental unit with Letícia AF and Laetitia planted side by side. A self-compatibility test was performed on covered branches to prevent pollinating insects from reaching the flowers. Fruit set occurs in covered branches of Letícia AF, whereas it was rare in Laetitia. In commercial orchards, Leticia AF plums yield was higher than that of Laetitia over the years. The results suggest that the oscillation in productivity across the years, mainly due to unfavorable conditions for insect pollination, may be lower in the plum Leticia AF orchard. On the other hand, the requirement for fruit thinning may be greater in Leticia AF. No significant differences were found between the mutant and the standard cultivar regarding fruit quality at harvest and after 30 days of cold storage, indicating the mutation did not alter the fruit characteristics.

Domesticated honeybee management (Apis mellifera) could be a useful tool to supplement wild pollinators and increase crop productivity. However, it is necessary to know the optimal hive density for each particular crop. Sunflower (Helianthus annuus) is the third most produced oil seed crop in the world and is dependent on insect pollination to increase the number of seeds and oil content. We proposed quantifying the H. annuus dependency to pollinators and assessing the optimal hive density of honeybees to increase sunflower productivity in 2 ha plots immersed in an extensive soybean matrix in Argentina. We set up a field experiment of five plots with a different number of hives each one (0, 5, 10, 15, 20), assessed fruit set and crop yield of flower heads open and excluded from pollinators and insect abundance. The set and crop yield increased in the heads of open flowers. The crop yield did not present a linear response to the density of the hive, although there could be a positive effect of the intermediate densities. Crop yields were not explained by the abundance of the two most frequently pollinator species, Astylus atromaculatus (Coleoptera) and Apis mellifera, suggesting that sunflower productivity was limited by resources other than pollen (e.g., the low abundance of rains). Drought conditions could have limited the response of the crop to hive addition and also influenced the high A. atromaculatus abundance, which could play a pollinator role in this system. More repetitions (plots and years) are needed to get these results more robust.

Plant growth regulators (PGRs) are artificially synthesized substances that control growth, development, and other various physiological processes in plants. Synthesized auxins, ethylene, abscisic acid, cytokinin, and gibberellins are only a few of the key PGRs that have been studied and used for quite a long period of time. brassinosteroids, salicylic acid, jasmonic acid, CPPU (N-(2-chloro-4-pyridyl)-N'-phenylurea), putrescine, hexanal, triacontanol, melatonin, and other chemicals have been added to the list of PGRs. These PGRs can be considered the new generation of plant growth regulators. These relatively novel hormones are critical for a plant's growth and development. They aid in the increase of not only the quantity (fruit set, length, weight, yield, volume, pulp percentage, and so on) but also the quality of fruit crops (fruit colour, firmness, total soluble solids, total sugar, ascorbic acid content, etc). They also help to prolong the shelf life of certain fruits and minimize the losses after harvesting. As a result, these new-generation PGRs can be used to boost an orchard's productivity and income while minimizing pre and post-harvest losses to the greatest extent possible. Hence, this extensive review discusses the impact of these new-generation PGRs on fruit crops.

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]

This study was carried out to investigate fruit yield and quality characteristics among new nectarine cultivars grown in the eastern Mediterranean region of Turkey. 'Gardeta', 'Gartario', and 'Garofa' nectarine cultivars were cultivated on 'GN15' rootstock. The flowering stage, fruit set percentage, yield, and fruit quality properties of these cultivars were investigated between 2018 and 2021. During the study, chill requirements ranged between 391 and 600 chilling hours and between 207 and 361 chill units in the area, and huge values were obtained for the average initial fruit set above 60% and the final fruit set above 45%. 'Gardeta' had the highest cumulative yield per tree (80.15 kg tree-1) and cumulative yield per hectare (133.04 tons ha-1). The fruit size, Total Soluble Solids (TSS) content, and fruit coloration were homogeneously distributed in all three cultivars. In addition, the Flowering (F) and Initial Fruit Set (IFS) characters were negatively correlated with Fruit Weight (FW), Fruit Length (FLE), and Fruit Diameter (FD). As a result, the 'Gardeta' was found remarkable with late flowering, the highest yield, and superior fruit quality characteristics such as size, red skin color, and high TSS/total acidity values in the eastern Mediterranean region of Turkey. In addition, the date of Full Flowering (FF) and Fruit Firmness (FF) were negatively correlated with fruit Skin color L* (SL), C (SC), and h° (SH) variables. The results demonstrated that the new nectarine cultivars used here showed changes in yield parameters and fruit quality attributes depending on the genotypic and environmental effects. [ABSTRACT FROM AUTHOR]

Tomato (Solanum lycopersicum) breeding for improved fruit quality emphasizes selecting for desirable taste and characteristics, as well as enhancing disease resistance and yield. Seed germination is the initial step in the plant life cycle and directly affects crop productivity and yield. ERECTA (ER) is a receptor-like kinase (RLK) family protein known for its involvement in diverse developmental processes. We characterized a Micro-Tom EMS mutant designated as a knock-out mutant of sler. Our research reveals that SlER plays a central role in controlling critical traits such as inflorescence development, seed number, and seed germination. The elevation in auxin levels and alterations in the expression of ABSCISIC ACID INSENSITIVE 3 (ABI3) and ABI5 in sler seeds compared to the WT indicate that SlER modulates seed germination via auxin and abscisic acid (ABA) signaling. Additionally, we detected an increase in auxin content in the sler ovary and changes in the expression of auxin synthesis genes YUCCA flavin monooxygenases 1 (YUC1), YUC4, YUC5, and YUC6 as well as auxin response genes AUXIN RESPONSE FACTOR 5 (ARF5) and ARF7, suggesting that SlER regulates fruit development via auxin signaling. [ABSTRACT FROM AUTHOR]

A large suite of floral signals, and environmental and biotic characteristics influence the behavior of pollinators, affecting the female success of food‐deceptive orchids. In this study, we examined the many factors shaping the reproductive output of three orchid taxa: Dactylorhiza majalis, D. incarnata var. incarnata, and D. fuchsii. We applied a statistical model to correlate female success (number of fruit sets) with individual characteristics (plant and inflorescence height, number of flowers, and spur length), number of pollinaria removed, flowering time, and density of floral units of co‐flowering rewarding plants. Our findings suggested that the broad spectrum of variations in Dactylorhiza's morphological traits, floral display, and flowering phenology within different environmental contexts has a significant impact on their reproductive success. The number of fruits increased with an increase in the number of pollinaria removed in the studied Dactylorhiza taxa. In contrast, a higher number of flowers per inflorescence and higher inflorescences in relation to individual height always decreased fruit set. We observed that low number of co‐flowering rewarding plants in populations could affect the Dactylorhiza reproductive output as magnets and competitor plants. The synchronization of flowering, or lack thereof, between Dactylorhiza and rewarding plants can limit reproductive success. This demonstrates that the food deception strategy is multidirectional, and reproductive output can vary considerably both spatially and temporally within the context of this strategy. [ABSTRACT FROM AUTHOR]

Lowbush blueberry is a mass-flowering plant species complex that grows in both unmanaged wild landscapes and managed agricultural fields in northeastern regions of both the USA and Canada. During pollination, more than 120 native bee species are associated with lowbush blueberry ecosystems in Maine, USA, in addition to three commercially managed bees. Over a 29-year period, we sampled 209 lowbush blueberry fields using quadrat and transect sampling, recording both native bee and honey bee densities, honey bee hive stocking density, and native bees as a proportion of total bees. These data were used to simulate economic uncertainty in pollination. We developed a novel algorithm, the Economic Pollinator Level (EPL), to estimate bee densities that economically warrant pollination investments such as rented hives and planting bee pastures. Statistical modeling indicated both native bee and honey bee activity density predicted proportion fruit set in fields. Honey bee activity density was well predicted by hive stocking density. Proportion fruit set adequately predicted yield. EPL was most sensitive to fruit set/m2/bee and less dependent on berry weight, rented hive stocking density, hive rental cost, lowbush blueberry price, and the annual cost of planting/maintaining pollinator pastures. EPL can be used to sustainably balance economical pollination investments/decisions with bee conservation in lowbush blueberry crops and potentially other pollinator-dependent crops. [ABSTRACT FROM AUTHOR]

Parthenocarpy allows fruit set independently of fertilization. In parthenocarpicprone tomato genotypes, fruit set can be achieved under pollen-limiting environmental conditions and in sterile mutants. Parthenocarpy is also regarded as a quality-related trait, when seedlessness is associated with positive fruit quality aspects. Among the different sources of genetic parthenocarpy described in tomato, the parthenocarpic fruit (pat) mutation is of particular interest because of its strong expressivity, high fruit set, and enhanced fruit quality. The complexity of the pat "syndrome" associates a strong competence for parthenocarpy with a complex floral phenotype involving stamen and ovule developmental aberrations. To understand the genetic basis of the phenotype, we mapped the pat locus within a 0.19-cM window of Chr3, comprising nine coding loci. A non-tolerated missense mutation found in the 14th exon of Solyc03g120910, the tomato ortholog of the Arabidopsis HD-Zip III transcription factor HB15 (SlHB15), cosegregated with the pat phenotype. The role of SlHB15 in tomato reproductive development was supported by its expression in developing ovules. The link between pat and SlHB15 was validated by complementation and knock out experiments by cosuppression and CRISPR/Cas9 approaches. Comparing the phenotypes of pat and those of Arabidopsis HB15 mutants, we argued that the gene plays similar functions in species with fleshy and dry fruits, supporting a conserved mechanism of fruit set regulation in plants. [ABSTRACT FROM AUTHOR]

Introduction: Inbreeding depression (ID) in food-deceptive plants have been reported previously, however, it has not been often proven that selfed seeds germinate better than outbred ones or that selfing affects ID. To resolved these issues, food-deceptive related Dactylorhiza majalis, D. incarnata var. incarnata and D. fuchsii orchids were investigated. Methods: Hand pollination treatments and control pollination were conducted. Fruit set, number of seeds per fruit, seed length, number of well-developed seeds per fruit, and proportion of in vitro asymbiotic germination seeds, were analyzed in relation to inflorescence levels and used as fitness indicators for these orchids. The ID and pollen limitation were measured. Results: The lowest ID (d = -1.000) was in D. majalis, and present in combination with a high pollen limitation in its populations. D. fuchsii showed higher ID (d = 0.366), and D. incarnata var. incarnata weak ID (d = 0.065), although ID varied between its fitness components. The seed number per fruit differed significantly between the treatments and the inflorescence levels in treatments. Discussion: This study emphasizes that the breeding system rather than the flower position on the inflorescence shaped the quality and quantity of reproductive output. The ID and its effect on germination of food-deceptive orchid seeds undoubtedly played an important role. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the impact of variety factor on the physiological characteristics and growth curve of date palm fruits in a private orchard in the Hartha district of Al-Masheeb, north of Basrah province. Two date palm varieties, Barhi and Zamli, were selected and antioxidants tocopherol and Glutathione were used at three concentrations (0, 75, 150 mg/L) for each. The interaction between these factors was studied in terms of physiological characteristics and growth curves. Results showed no significant differences between the varieties' physiological characteristics, but the spray treatments had a significant effect on the percentage of fruit set. The Glutathione spraying treatment had the highest rate of fruit set (86.60%), while the comparison treatment had the lowest drop rate (77.55%). The interaction treatments also had significant differences in drop rate and non-set fruit percentages. The Zamli variety showed the highest growth curve of physical traits (6 and 12 weeks after pollination), while antioxidant spray treatments had significant differences in the rate of physical characteristics. The interaction had a significant effect on the studied characteristics during the two growth periods. [ABSTRACT FROM AUTHOR]

Identifying the resources that limit bee populations is essential for both bee conservation and pollination management in agroecosystems. Land‐use change typically leads to decreased habitat availability for wild pollinators, including loss of nesting habitat, which is an essential but often‐overlooked resource for wild bees. Cavity‐nesting bees, such as many Osmia spp. (Hymenoptera: Megachilidae), occupy holes in wood or reeds to build their nests; due to their nesting habits, they are frequently scarce in agricultural settings. Nevertheless, under the right circumstances, these bees can be ideal pollinators of apple and other orchard crops. Artificial nesting structures ('bee hotels' or 'trap‐nests') are often used to study cavity‐nesting bees and have been proposed as tools for bee conservation.To evaluate the effects of additional nesting habitat on the local abundance of pollinators, we selected 24 sites in apple orchards in eastern Canada in 2021 and 2022. Each site comprised two study plots: one in which we installed artificial nesting structures for cavity‐nesting bees, and one without added nesting habitat (control).Pollinator surveys were conducted in both plot types to measure pollinator visits to apple blossoms and, after apple bloom, to flowers in the undergrowth and/or in shrubs. Numbers and size of developing fruit were also recorded. Both Osmia bees and overall pollinator numbers were significantly higher in the treatment with trap‐nests (respectively, 33% and 22% higher during the 2021 growing season, and 113% and 30% higher during apple bloom across the 2 years of the study); however, there was no consistent difference in apple size or fruit set between the two treatments. Thus, trap‐nests locally increased the numbers of cavity‐nesting bees as well as total pollinator numbers, but they had little effect on apple yield, likely because apple production was not pollinator limited in the years of this study.Synthesis and applications. These findings suggest that bee populations in apple orchards can be limited by nesting resources such that addition of constructed nesting habitat could be an effective means of increasing pollinator numbers in orchards, and potentially, supporting bee conservation. [ABSTRACT FROM AUTHOR]

Gametophytic self-incompatibility (GSI) has been mainly described in species-rich clades within Orchidaceae. We report GSI for a genus within Maxillariinae, one of the most conspicuous and diverse subtribes of neotropical orchids. Here, we describe the reproductive system of Brasiliorchis picta, B. phoenicanthera, and B. porphyrostele. Anatomical studies of fruit development showed that pollen tubes of aborted, self-pollinated flowers degenerate half-way in the stylar channel and never reach the ovules. Spontaneous self-pollination and emasculation set no fruits for none of the sampled species, thus supporting the hypothesis that these three species studied rely on the agency of pollinators and pollinator-mediated cross-pollination to set fruit. Fruit set from cross-pollinations ranged from 33.4 to 77.5%. One self-pollinated fruit of B. porphyrostele developed to completion. All other fruits aborted between 10 and 21 days after pollination. These data support previous evidence of variable strength GSI being exhibited in orchid species. Additional studies of self-incompatibility systems are needed to evaluate their role in species diversification and evolution of reproductive strategies in Maxillariinae and to allow for effective conservation strategies of threatened orchid species. [ABSTRACT FROM AUTHOR]

Nitrogen is the most commonly managed mineral nutrient in olive groves because it is essential for plant growth. The precise management of N fertilization in olive cultivation is still not fully clarified, but it is essential for providing sustainable production. A nitrogen fertilizer experiment with olive trees (cv. Kalinioti) was carried out over a six-year period. Seven levels of nitrogen fertilizer given as ammonium nitrate (control, 1, 2, 3, 4, 5, and 6 kg/tree) were annually applied in order to determine the effect of nitrogen on vegetative growth, fruit set, fruit weight, yield, maturation index, and leaf N, P, and K concentrations. The results indicate that, under these conditions, application of up to 4 kg NH4NO3/tree significantly increased yield to 62.5 kg/tree compared to the control (37.09 kg/tree). The positive effect was attributed to the initial and final fruit set increases (7.63 and 3.73%, respectively at 4 kg NH4NO3/tree). However, the weight of 100 olives (W100 = 331 g) at 4 kg NH4NO3/tree obtained during harvest was considerably lower compared to the control (W100 = 384 g). Higher nitrogen rates decreased yield while increasing overall shoot growth. Nitrogen fertilization did not significantly influence the oil content of olive fruit. Fruit weight, maturation index, and concentration of oil reached maximum levels in the beginning of December, indicating a suitable start to olive harvesting. The concentration of N in olive leaves increased from 1.23% to 2.38% as fertilizer levels increased from 0 to 6 kg NH4NO3. Maximum yield was achieved at a level of 6 kg NH4NO3/tree, which corresponded to 2.01% N in leaves. The results suggest that application of 3 kg NH4NO3/tree can be recommended for table olive production, due to the fact that fruit weight was not decreased, while fertilization with 4 kg NH4NO3/tree was suitable for oil olives. [ABSTRACT FROM AUTHOR]

IntroductionHabitat loss and fragmentation have negative impacts on pollinator populations and thus on the pollination services they provide. Negative effects can be lessened by the presence of forest remnants that serve as refuges and sources of food for pollinators. However, few studies have analyzed the influence of highly heterogeneous agricultural landscapes (as commonly found in many developing countries), on pollination services.MethodsWe compared native bee diversity, pollination visitation, and fruit set of Brassica rapa L. between two land use conditions (sites maintaining more than 15% of the original forest coverture [Moderately Modified], and sites with less of 10% [Highly Modified]) in the highlands of Guatemala.ResultsNative bee diversity was higher in HM areas, although social bees were more abundant in MM sites. We did not find differences in pollinator visitation rate between conditions. HM sites were mainly visited by honeybees (Apis mellifera Linnaeus), while native bees and syrphid flies were more frequent in the MM condition. Fruit set was significantly higher in MM sites and was positively affected by natural forest areas. Experiments on pollen limitation and on pollinator efficiency stressed the importance of native pollinators in fruit production, especially in moderately modified areas.DiscussionOur results highlight the role of forest remnants for the provision of pollination services in tropical agricultural highlands and underline the relevance of appropriate management of introduced bees such as A. mellifera.

Nitrogen is the most commonly managed mineral nutrient in olive groves because it is essential for plant growth. The precise management of N fertilization in olive cultivation is still not fully clarified, but it is essential for providing sustainable production. A nitrogen fertilizer experiment with olive trees (cv. Kalinioti) was carried out over a six-year period. Seven levels of nitrogen fertilizer given as ammonium nitrate (control, 1, 2, 3, 4, 5, and 6 kg/tree) were annually applied in order to determine the effect of nitrogen on vegetative growth, fruit set, fruit weight, yield, maturation index, and leaf N, P, and K concentrations. The results indicate that, under these conditions, application of up to 4 kg NH4NO3/tree significantly increased yield to 62.5 kg/tree compared to the control (37.09 kg/tree). The positive effect was attributed to the initial and final fruit set increases (7.63 and 3.73%, respectively at 4 kg NH4NO3/tree). However, the weight of 100 olives (W100 = 331 g) at 4 kg NH4NO3/tree obtained during harvest was considerably lower compared to the control (W100 = 384 g). Higher nitrogen rates decreased yield while increasing overall shoot growth. Nitrogen fertilization did not significantly influence the oil content of olive fruit. Fruit weight, maturation index, and concentration of oil reached maximum levels in the beginning of December, indicating a suitable start to olive harvesting. The concentration of N in olive leaves increased from 1.23% to 2.38% as fertilizer levels increased from 0 to 6 kg NH4NO3. Maximum yield was achieved at a level of 6 kg NH4NO3/tree, which corresponded to 2.01% N in leaves. The results suggest that application of 3 kg NH4NO3/tree can be recommended for table olive production, due to the fact that fruit weight was not decreased, while fertilization with 4 kg NH4NO3/tree was suitable for oil olives.

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]

Plant reproductive ecology is one of the research hotspots in ecology. With the increasing attention paid to the conservation of plant diversity, the research on reproductive characteristics and flowering biological characteristics of more species has attracted more attention. However, plant reproduction is affected by multiple interacting factors such as pollen limitation and resource availability. Vitex negundo var. heterophylla (Franch.) Rehder (Lamiaceae) is a significant species for water and soil conservation. Previous studies have revealed its mating system by the biological characteristics of flowering and SSR markers, but its reproductive strategies remain to be further studied. We evaluated reproductive success through artificial pollination to explore the reproductive characteristics of V. negundo var. heterophylla for the first time. From the results of fruit set, there is a mixed mating system dominated by outcrossing in V. negundo var. heterophylla accompanied by self‐compatibility, and it cannot carry out autonomous selfing. Our data show the pollinator‐mediated interaction in the success of reproduction, whereas the effect of anemophily is very weak. And the seed germination rate of inbred line progenies was lower than that of hybrid progenies, which is suspected to be caused by inbreeding depression. The research will provide scientific information for the protection and conservation of V. negundo var. heterophylla from the point of view of reproduction. In sum, the results are necessary to protect animal vectors in the background of insect decline. [ABSTRACT FROM AUTHOR]

Avocado is an evergreen tree that exhibits protogynous dichogamy and displays a massive flower production, characterized by a high abscission of unfertilized flowers and developing fruitlets, ultimately leading to a low final fruit set. A common practice to improve avocado pollination involves introducing honey bee (Apis mellifera L.) hives during the flowering season. To evaluate the extent of inadequate pollination in avocado, the effect of different beehive densities on the percentage of flowers receiving pollen during the female flower stage was examined for seven years in an experimental orchard located in Southern Spain. A total of 17,288 flowers were observed under the microscope for this purpose. Additionally, pollen deposition was evaluated in five "Hass" avocado commercial orchards under different management strategies situated in the Malaga province (3960 flowers). The results obtained reveal that the percentage of flowers with pollen at the end of the female stage ranged from 2.85 (0.13% fruits retained at the end of June) in orchards without honey bee hives to 4.34 (0.11% fruits retained) in orchards in which 10 beehives per ha were placed. This percentage increased significantly to 13.79 after introducing 24 honey beehives per ha (0.21% fruits retained). Furthermore, the percentage of pollinated flowers in the commercial orchards remained below 15% even in those orchards in which pollen donors and honey bee hives were present. Thus, insufficient pollination could be considered as a primary limiting factor in avocado production under Mediterranean climates. Enhancing pollinator diversity and increasing their numbers could be a viable strategy to improve the percentage of avocado flowers receiving pollen during the female stage. [ABSTRACT FROM AUTHOR]

The tomato is a convenient object for studying reproductive processes, which has become a classic. Such complex processes as flowering and fruit setting require an understanding of the fundamental principles of molecular interaction, the structures of genes and proteins, the construction of signaling pathways for transcription regulation, including the synchronous actions of cis-regulatory elements (promoter and enhancer), trans-regulatory elements (transcription factors and regulatory RNAs), and transposable elements and epigenetic regulators (DNA methylation and acetylation, chromatin structure). Here, we discuss the current state of research on tomatoes (2017–2023) devoted to studying the function of genes that regulate flowering and signal regulation systems using genome-editing technologies, RNA interference gene silencing, and gene overexpression, including heterologous expression. Although the central candidate genes for these regulatory components have been identified, a complete picture of their relationship has yet to be formed. Therefore, this review summarizes the latest achievements related to studying the processes of flowering and fruit set. This work attempts to display the gene interaction scheme to better understand the events under consideration. [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]