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Globally, agricultural crops are often dependent on insect pollination. Blueberries are an example of such a crop and owing to their proposed health benefits they are grown around the world, including locations where their native bumble bee pollinators do not occur. In the absence of bumble bees, blueberry pollination in South Africa and many other parts of the non-native, commercial range is performed primarily by honey bees. Despite this, the effectiveness of honey bee pollination on blueberries remains understudied. This study determined the effect of honey bee pollination on components of fruit yield (fruit set and mass) of five blueberry varieties that are extensively planted in South Africa. For each variety, two metrics were calculated: 1) the benefit of bees — a comparison of fruit yields after exposure to honey bees and fruit yields after honey bee exclusion, 2) the pollination deficit — the difference in yield between hand pollination (maximum yield potential) and yields after exposure to honey bee pollinators. Honey bee pollination consistently resulted in improved yields, although the magnitude of this improvement (i.e., the benefit of bees) was dependent on the variety considered. Similarly, the pollination deficit also varied considerably across varieties and while some varieties appeared to perform close to maximum potential (small pollination deficit), others yielded well below their maximum potential under honey bee pollination. This study demonstrates that honey bees are functional pollinators of blueberries in areas where native blueberry pollinators are absent. However, in such areas, it is important that special focus be given to selecting blueberry varieties that perform well with honey bees as their sole pollinator. Further research is necessary to determine how the pollination deficit of blueberry varieties can be decreased as well as how to increase the effectiveness of honey bee pollination.

Sterility and low seed set in bananas is the main challenge to their conventional genetic improvement. The first step to seed set in a banana breeding program depends on pollination at the right time to ensure effective fertilization. This study aimed at determining bract opening time (BOT) to enhance efficient pollination and seed set in bananas. A Nikon D810 digital camera was set-up to take pictures of growing banana inflorescences at five-minute intervals and time-lapse movies were developed at a speed of 30 frames per second to allow real-time monitoring of BOT. Genotypes studied included wild banana (1), Mchare (2), Matooke (4), Matooke hybrid (1), and plantain (1). Events of bract opening initiated by bract lift for female flowers (P P P P

Passion fruit plants are self-incompatible and fruiting is exclusively dependent on cross-pollination, which in nature is performed by carpenter (mamangava) bees, especially Xylocopa spp. (family Apidae). To ensure satisfactory productivity, daily manual pollination is a common practice among passionflower growers. Therefore, we studied whether manual pollination mechanically transmits the cowpea aphid-borne mosaic virus (CABMV), the causal agent of the passion fruit woodiness disease. None of the eight healthy passion fruit plants manually pollinated with pollen from CABMV field-infected plants were infected, as confirmed by PTA-ELISA and RT-PCR. Healthy passion fruit plants mechanically inoculated with extracts of pollen collected from flowers of CABMV field-infected plants were not infected. CABMV was only detected by RT-PCR in groups of three anthers, and in pollen from groups of 20 anthers collected from flowers of infected passion fruit plants. RT-qPCR conducted with different amounts of pollen grains and anthers indicated extremely low virus titers. In addition to low virus titers, transmission failure may be associated with an absence of virus particles outside the pollen grains and/or absence of enough wounding produced on the stigmas by the fingertips. The improbability of CABMV transmission via pollen during manual pollination showed that this widely used cultural practice is a negligible factor in the epidemiology of passion fruit woodiness disease.

Interspecific hybrids between pearl millet (Pennisetum glaucum) and napier grass (Pennisetum purpureum) give rise to perennial fodder crops characterized by high biomass, broad clumps and good palatability. These hybrids are triploid and developed by hand pollination of napier grass pollen on pearl millet panicles. The progeny shows a high percentage of pearl millet genotype due to self-pollination in the female parent. Identification of hybrids at a young stage based on morphological characters is difficult. DNA-based molecular markers have high discriminating power and were used to assess genetic differences between hybrids and their parents. Genetic diversity was studied in 18 pearl millet × napier grass hybrids along with their parents and two released national checks using inter simple sequence repeat (ISSR) markers. Eight ISSR primers gave rise to 125 bands, of which 120 bands were polymorphic. Polymorphic information content and ISSR primer index ranged from 0.40 to 0.49 and 8.88 to 11.14, respectively. The hybrids showed the presence of unique bands, besides those shared with male and female parents. Female (pearl millet) parents formed a separate group in the dendrogram constructed based on ISSR polymorphism. The male (napier grass) parents formed a separate group along with hybrids, indicating a higher similarity of hybrids with the male parents. Principal component analysis and STRUCTURE analyses showed a similar grouping. The close resemblance of hybrids to the male parents confirmed their interspecific origin. The study revealed that ISSR marker analysis could be a quick and reliable method to identify interspecific hybrids at an early stage of growth.

Animal-mediated pollination is an essential ecosystem service on which over a third of the world's agricultural crops depend. Blueberry fruit production is highly dependent on animal pollination and although visited by a range of bee species in their native range and agricultural settings, bumble bees are thought to be their primary native pollinators. Demand for blueberries has increased in recent years due to their perceived health benefits. Consequently, blueberry cultivation has expanded well beyond their native and original agricultural range, including several regions where bumble bees are not present. In South Africa, like many areas in the world, honey bees are the only commercially available pollinators for blueberries because many countries ban the importation of bumble bees. This study aimed to determine the benefits of honey bee pollination on blueberry fruit yield for the variety Ventura by comparing yields of honey bee-pollinated flowers to flowers where pollinators were excluded. Our results show that honey bees significantly increased berry mass and diameter. We conclude that Ventura in South Africa can be pollinated by honey bees, and that honey bee pollination can be an effective substitute for bumble bees in areas where bumble bees are unavailable. We also determined the extent to which blueberry yields could be improved by comparing fruit yield under honey bee pollination to fruit yield achieved through hand pollination. We found that honey bee pollinated blueberry yields were lower than yields achieved through hand pollination, suggesting that there is potentially room to improve honey bee pollination. Furthermore, we offer a conceptual figure to demonstrate how yield obtained through pollinator exclusion, open pollination, and hand pollination relate to each other. Additional research is required to study how beneficial honey bees are to fruit yield on other blueberry varieties as the benefits of honey bees are likely to vary depending on the variety.

The present study was carried out on eleven year old vines of Hayward (female cultivar) and Tomuri and Matua (male cultivars) at Zangam orchard of Department of Horticulture (J&K) trained on T bar trellis system. The fruit set and yield characteristics of Hayward were signifcantly infuenced by the pollen source. Among the various treatment combinations irrespective of the source of pollen, hand pollination at 90% bloom + spray of 0.1% borax (Na2B4O7.10H2O) and 0.4% ZnSO4 enhanced both fruit set and yield characteristics. Tomuri cultivar proved to be a good pollen source for desired fruit characteristic, and hand pollination supplemented with boron and zinc exhibited benefcial effects on all the afore-mentioned parameters of pistillate cv. Hayward.

The importance of wild insects as pollinators of tropical tree crops has rarely been tested. Across 18 small-scale lychee orchards in northern Thailand, we evaluated the roles of different wild insects as pollinators and predators of pests in fruit production. Quantitative assessments showed that bees (Family Apidae) were strongly dominant (83%) among insect flower visitors, comprising four species in tribes Apini and four in Meliponini. Experimental manipulations of inflorescences showed that fruit production in these orchards was: (1) dependent on flower visits by wild insects because enclosure of inflorescences in mesh bags decreased fruit set (to one-fifth) and (2) not greatly limited by pollinator deficiencies, because hand pollination of unbagged flowers did not enhance fruit set. Pollination success, as indicated by the proportion of unmanipulated flowers setting fruit, correlated positively across orchards with the abundance of large-bodied Apidae (>7 mm; most were Apis species) and of Apini, and negatively with abundance of small-bodied Apidae and of all Meliponini, despite the latter being the commonest flower visitors. We conclude that larger-bodied bees are most likely to travel sufficiently far to import genetically diverse pollen, in this landscape-scale mosaic where non-orchard habitats (both agriculture and treed patches) were sufficient to sustain wild pollinators.

We investigated the fruit set and quality of yellow passion fruit subjected to hand and natural pollination by carpenter bees (Xylocopa spp.) in the Philippines. We also recorded the foraging behav...

The production of fruits and seeds of many crops is increased when external pollination occurs. Although self pollination is a widespread biological process in cultivated grapevines, there are still some uncertainties about the consequences of cross fertilization regarding productivity and quality of grapevines. Fertilization biology of grapevines becomes an essential issue when protected cultivation in particular is considered. The present investigations were therefore performed to clarify the possible effects of different pollination treatments on the agronomic features of 'Perle de Csaba' and 'Trakya Ilkeren' table grape cultivars. Before the anthesis, clusters of self-pollination treatment were enclosed within cheesecloth frames to avoid extraneous pollination. For the free pollination group, flowers of twelve similar clusters were allowed to bloom and pollinate spontaneously, while hand pollination was performed by transporting the mixture of external pollens gathered from different cultivars at bloom stage. In 'Perle de Csaba' cultivar, hand pollination and free pollination treatments significantly increased the overall agronomic parameters on berry set rate, berry development, cluster size, seed weight and seed size in comparison to self pollination. Treatments had similar effects in 'Trakya Ilkeren', except for a few parameters such as cluster length, berry diameter and seed thickness. Overall results indicated that cross pollination would considerably increase the quantity and quality of table grapes when cultivated under protected conditions such as glass or greenhouses.

Sinocalycanthus chinensis Cheng et S. Y. Chang (Calycanthaceae), which has a unique systematic status, is listed as a national second‐class protected plant of China. In this study, the genetic diversity, performance, and fitness of F1 progeny from crosses between the Damingshan (DMS) population of S. chinensis and pollen parents from the Daleishan (DLS) and Longxushan (LXS) populations were examined. The DLS population has a relatively small population size, low genetic diversity, and considerable geographical and genetic distances from the DMS population relative to the LXS population. Compared with naturally occurring seeds, DLS‐sired seeds had the highest thousand‐seed weight, starch content, fat content, germination rate, germination index, and emergence rate, but the lowest protein content. Naturally occurring, open‐pollinated seeds had the lowest thousand‐seed weight, starch content, and fat content, but the highest protein content. Compared with natural F1 progeny, DMS × DLS seedlings had the highest genetic diversity, photosynthetic parameters, and growth characteristics, except for leaf mass ratio and stem mass ratio. Under strong light, DMS × DLS seedlings exhibited a Fv/Fm value of 0.75, while the other two seedling types exhibited Fv/Fm values of 0.65. DLS‐sired seeds had the most vigorous growth characteristics except for leaf mass ratio and stem mass ratio. These results suggest that genetic rescue by transplanting seedlings from the DLS population or hand pollination with pollen from the DLS population would be effective methods to reduce inbreeding depression and obtain strong offspring with high genetic diversity and fitness in the DMS population.

A study was conducted in a yard long bean (Vigna unguiculata sup/ssp. sesquipedalis) hybrid VS 50 (Kakkamoola Local) x VS 26 (Vellayani Jyothika) to assess the percentage fruit set at two time intervals and to identify the best time interval for pollination in yard long bean hybrids. Hand pollination was done using VS 50 as female parent and VS 26 as male parent for seven consecutive days at two time intervals, 6.30 – 7.30 am and 7.30 – 8.30 am. Higher percentage of fruit set (36.8 %) was observed between 6:30 – 7:30 a.m. as compared to the time interval 7:30 – 8:30 am. (23.8%). Pollen viability was determined for the parents VS 50 (Kakkamoola Local) and VS 26 (Vellayani Jyothika) at 6.30, 7.30 and 8.30 am. Highest pollen viability for both the parents VS 50 and VS 26 was observed during 7.30 am. The present study shows that the best time interval for crossing in yard long bean is 6.30- 7.30 a.m.

Aims: This field experiment was conducted to determine if hand and open pollination methods affected performances of Musa progenies from 4x - 2x crosses and to identify promising progenies for recurrent selection. Study Design: The experimental design was a randomized complete block design with two replications of 6 plants per genotype. Place and Duration of Study: International Institute of Tropical Agriculture (IITA) High Rainfall Station, Onne (4º51’N, 7º03’E, 10 m above sea level), in Rivers State, South-south Nigeria for 24 months. Methodology: Two-month old seedlings of hand pollinated (6 diploid, 6 tetraploid) and open pollinated (6 diploid, 6 tetraploid) progenies, along with parental clones (2x) and (4x) of each genotype were planted at 3 m x 2 m spacing. Data on phenology, vegetative growth, yield and yield characters were collected at flowering and harvest over three crop cycles. Genotypes were partitioned into 5 clusters assayed by means of orthogonal contrasts to compare the performance of progenies from both pollination methods. Results: Pollination methods produced no significant (P = .05) differences, unfavourable effects or reduction in performance of economically important yield and yield components of 4x and 2x progenies of similar genotype. Some significant (P = .05) linear correlations and relationships between phenological and vegetative traits; and yield and yield components changed with pollination methods and ploidy levels but did not affect final outcomes. Promising open pollinated diploids include the early maturing TMP2x 2829-62OP; and for high yield and yield components measured, TMB2x 8084-2OP and TMP2x 1448-1OP. Promising open pollinated tetraploids include TMP4x 7002-1OP and TMP4x 2796-5OP. Conclusion: Open pollination did not result in unfavorable effects or reduction in performance of economically important yield and yield components in progenies of similar genotypes. Therefore, open pollination could be considered for Musa breeding. This will reduce cost, labour, time and stress involved in Musa improvement.

In the intense solar radiation of an alpine climate, small black bees often experience extremely high thoracic temperatures when they are foraging on flowers, but flies forage at lower temperatures. To explore the hypothesis that seed set could be depressed by transient dehydration of pollen at the high temperatures reached by hot bees foraging in sunshine, we compared the effectiveness of single visits by different pollinators to a bowl-shaped flower Potentilla lancinata in alpine meadows, SW China. The ratio of seed set to pollen transferred in individual flowers was monitored over 2 years, indicating that pollen deposited on stigmas by halictid bees produced lower seed set than pollen carried by flies. Scopal pollen applied to stigmas by hand gave good seed set, but in germination tests it burst more frequently than pollen from anthers, implying dehydration. Pollen grains freshly taken from the scopae of solitary bees foraging in sunshine were smaller than those taken from anthers or foraging bees in early-morning overcast conditions, implying dehydration. The effect was reversible: hand pollination showed that scopal pollen was no less effective than fly pollen after removal from the bee. Pollen carried by such bees foraging in intense sunlight in flowers became dehydrated, causing an osmotic mismatch between the pollen and the stigmas. Transient heat-induced dehydration of pollen represents a novel pathway by which climate warming may disrupt plant reproduction, and helps us understand why flies could be more effective pollinators than bees in cool, high-radiation arctic or high-altitude sites.

Premise Most plants interact with mycorrhizal fungi and animal pollinators simultaneously. Yet, whether mycorrhizae affect traits important to pollination remains poorly understood and may depend on the match between host and fungal genotypes. Here, we examined how ericoid mycorrhizal fungi affected flowering phenology, floral traits, and reproductive success, among eight genotypes of highbush blueberry, Vaccinium corymbosum (Ericaceae). We asked three overarching questions: (1) Do genotypes differ in response to inoculation? (2) How does inoculation affect floral and flowering traits? (3) Are inoculated plants more attractive to pollinators and less pollen limited than non-inoculated plants of the same genotype? Methods To examine these questions, we experimentally inoculated plants with ericoid mycorrhizal fungi, grew the plants in the field, and measured flowering and floral traits over 2 years. In year 2, we conducted a hand-pollination experiment to test whether plants differed in pollen limitation. Results Inoculated plants had significantly higher levels of colonization for some genotypes, and there were significant floral trait changes in inoculated plants for some genotypes as well. On average, inoculated plants produced significantly larger floral displays, more fruits per inflorescence, and heavier fruits with lower sugar content, than non-inoculated, control plants. Hand pollination enhanced the production of fruits, and fruit mass, for non-inoculated plants but not for those that were inoculated. Conclusions Our results demonstrate that inoculation with ericoid mycorrhizal fungi enhanced flowering and altered investment in reproduction in genotype-specific ways. These findings underscore the importance of examining belowground symbionts and genotype-specific responses in their hosts to fully understand the drivers of aboveground interactions.

The main aim of the peach breeding program in the Steppe branch of Nikitsky Botanical Gardens developed in 1975 was to obtain new adapted cultivars, which combine most valuable biological and economic traits. Standard breeding techniques such as crossing, hand pollination, self-pollination and open pollination, were employed. Best foreign and domestic cultivars were used as parents. Mother cultivars were ‘Valiant’, ‘Veteran’, ‘Laureate’, ‘Red Haven’, ‘Santarine’, ‘Start’, and ‘9251’, fathers cultivars were: ‘Cardinal’, ‘Kudesnik’, ‘Miryanin’, ‘Sanrise’, ‘Favourite Morettiny’ and ‘Kievskiy Ranniy’. A large hybrid fund was created and studied. As a result distinguished peach hybrids were identified and selected. This paper focuses on some biological and economic features of 42 selected elite forms of 12 peach hybrid combinations of F1 and F2. They are characterized by high productivity, good quality of fruits and excellent taste. Some of these elite forms are superior to existing national standards by crop yield, winter hardiness, appearance and fruit quality. So they were registered as cultivars, such as: ‘Vavilovskiy’, ‘Demerdzhinskiy’, ‘Kandidatskiy’, ‘Posol Mira’, ‘Osvezhayuschiy’ and ‘Jubilejnyiy Ranniy’. Some biological and economic characteristics (fruit size, skin, colour and over colour, flesh firmness, taste of the fruit, yield, etc.) of these cultivars are presented.

Experiment was conducted in the rainforest agro-eco-zone of Southeastern Nigeria under rain fed condition at the sweet potato breeding ground of National Root Crops Research Institute, Umudike, Nigeria to generate 10,000 botanical seeds for further evaluation for high root yield, dry matter and micro-nutrient content, to identify high flowering parent(s) and to select compatible parent(s) for further genetic recombination. The treatment which consisted of 14 parents of bi-parental crossing was laid out in a randomized complete block design with seven parents, each per plot per block and replicated three times while the other seven parents were maintained in different plots as pollen donors. Data collected were on: total number of emerged flowers visually counted, total number of flowers covered, total number of flowers pollinated, total number of capsules formed, total number of flowers aborted, total number of seeds obtained from crosses, number of good seeds, number of unfilled seeds, percentage of good seeds. Data collected were statistically analyzed using Statistical Package for Social Sciences (SPSS, version 15.0). Differences between means were tested using analysis of variance (ANOVA) while means separation was done using standard error of difference means at 5% probability. The results obtained showed that despite the seemingly high total number of flowers produced from the controlled crosses (14520), only 17.4% of this figure yielded good seeds. The objective of realizing 10,000 botanical seeds through the hand pollination was not achieved as a result of high flower abortion arising probably from moisture stress which was severe during seed filling. The variety Tio-joe gave the highest flower production of 2334. The relatively high number of capsules of 347obtained from the cross between UMUSPO 3 and NRSP/2 indicated high compatibility between the two parents which suggested that the two parents could be used for further recombination for micro-nutrient enhancement.

Pollination is the process by which pollen grains are exchanged in plant flowers to allow for fertilisation and production to take place. However, challenges occur when crops are grown under protected structures where there are minimal activities of natural pollination agents such as wind and animals which are responsible for transferring pollen grains from the anther to the stigma. Therefore, the study objective was to determine the effect on hand pollination on the yield of African horned cucumber grown under greenhouse and shade net environment. A factorial experiment with two factors (hand pollinated and non-hand pollinated/control) was conducted under two different growing environments (greenhouse and shade net). African horned cucumber plants were hand self-pollinated in the morning. Pollen were manually transferred with a hand using the new earbud from the male to the female flowers on the same plant (selfing). Results showed that hand pollinated African horned cucumber plants increased total biomass from 0.93 to 2.23 kg under greenhouse environment. Hand pollinated plants increased harvest index from 0.07 to 0.35 under shade net environment. It can thus, be deduced that hand pollination increases African horned cucumber yield in the greenhouse and shade net environments.

During the breeding program studies, the pollen donor parents (pollinizers) were observed to be characterized by a strong flowering rate and very low fruit set, even after hand pollination. Then the notion of pollinizers in the argane species was born, first mentioned, checked, documented and confirmed like other conventional tree species. Since the argane tree is completely self-incompatible, the presence of compatible pollinizers is necessary for the fruit set. Indeed, pollinizers need to be selected accurately based on the synchronization of bloom periods and compatibility to receiver trees (female). The pollinizer is essential in any breeding program and for new orchard plantations. The current study was conducted on 13 argane genotypes including two pollinizers. The flowering period, bloom phenology, floral structure and fruit set of crossed genotypes were monitored, illustrated and a season phenogram was established. The pollen viability and germination were also evaluated. In order to test compatibility, the hand pollination using two selected pollinizer pollens was compared to open pollination. Then, the compatibility system was monitored and evaluated through analysis of crossing diallel programs and through the index of self-incompatibility. The flowering periods are genotype depending and one to three blooms have been observed during the two years study (2018-2019) and the argane tree is a tristylous species (Mesostylous, brevistylous and longistylous flowers). Thein vitrotests showed that the pollen originated from crossed genotypes were viable and able to germinate. The cross-compatibility rate depends on cross associations and it varies from 39 to 84 %. In fact, this study showed that the effect of pollen-parent (xenia) occurs in all fruit components of argane tree. It was observed, for the first time, that both compatible pollinizers and xenic effects of pollen on argane fruit have occurred. Artificial pollination is currently feasible for breeding programs and the screening of elite genotypes. Then the selected pollinizer is quite required for the development of argane tree cropping.HighlightsPollinizers in the argane species first mentionedPollinizer is essential in any breeding program and for new orchard plantationsArgane tree is self-incompatiblePollen-parent effect, (xenia) occurs in all fruit components of argane tree

Cassava breeding is hampered by high flower abortion rates that prevent efficient recombination among promising clones. To better understand the factors causing flower abortion and propose strategies to overcome them, we 1) analyzed the reproductive barriers to intraspecific crossing, 2) evaluated pollen-pistil interactions to maximize hand pollination efficiency, and 3) identified the population structure of elite parental clones. From 2016 to 2018, the abortion and fertilization rates of 5,748 hand crossings involving 91 parents and 157 progenies were estimated. We used 16,300 single nucleotide polymorphism markers to study the parents’ population structure via discriminant analysis of principal components, and three clusters were identified. To test for male and female effects, we used a mixed model in which the environment (month and year) was fixed, while female and male (nested to female) were random effects. Regardless of the population structure, significant parental effects were identified for abortion and fertilization rates, suggesting the existence of reproductive barriers among certain cassava clones. Matching ability between cassava parents was significant for pollen grains that adhered to the stigma surface, germinated pollen grains, and the number of fertilized ovules. Non-additive genetic effects were important to the inheritance of these traits. Pollen viability and pollen-pistil interactions in cross- and self-pollination were also investigated to characterize pollen-stigma compatibility. Various events related to pollen tube growth dynamics indicated fertilization abnormalities. These abnormalities included the reticulated deposition of callose in the pollen tube, pollen tube growth cessation in a specific region of the stylet, and low pollen grain germination rate. Generally, pollen viability and stigma receptivity varied depending on the clone and flowering stage and were lost during flowering. This study provides novel insights into cassava reproduction that can assist in practical crossing and maximize the recombination of contrasting clones.

Low female fertility in bananas is the biggest hurdle for banana breeding. The aim of this study was to determine seed set patterns in East African Highland Cooking bananas (EAHBs) to inform future decisions on a more targeted approach of increasing seed set and subsequently banana-breeding efficiency. Matooke (AAA) and Mchare (AA) bananas are genetically distinct but belong to the same genetic complex, referred to as EAHBs. Seed set patterns in “Enzirabahima” (AAA), “Mshale” (AA), and “Nshonowa” (AA), all with residual fertility, were examined after hand pollination with a highly male fertile wild banana “Calcutta 4” (AA). Seed set in “Enzirabahima” is predominant in distal hands. Mchare cultivars have a slightly more even distribution of seeds in their hands compared to “Enzirabahima”. There is a gradual increase in seed set from proximal to distal hands with a slight drop in the last hand. This pattern is more definite in “Enzirabahima” and “Mshale”, while “Nshonowa” has a somewhat inconsistent pattern. There is also a drop in seed set per 100 fruits per hand from small to larger bunches. However, larger bunches have a higher pollination success compared to smaller bunches. They therefore set more seed on 100 fruits per hand and per bunch basis, if bunches without seed are accounted for. Pollination success rate increases from smaller to larger bunches of EAHBs. Seed set is biased toward the distal third part of fruits of examined EAHBs, as well as tetraploid Matooke hybrid “401K-1” (AAAA), and improved diploid “Zebrina” GF (AA) that were used for comparison. In comparison, in the highly female fertile “Calcutta 4”, seed set is along the entire length of the fruit. Seed set bias in the distal hands and distal end of fruits suggests a systematic mechanism rather than a random occurrence. It is expected that this information will provide a foundation for increased crossbreeding efficiency in bananas.

Gac is valued for the nutritious aril surrounding its seed. When pollinators are limited or when flower sex expression is female-biased, hand pollination is necessary. Here, female flowers were hand pollinated with male flowers or pollen stored for up to 84 days at 4 or &minus, 20 &deg, C, and fruit set and some qualities of mature fruit were evaluated. Cool storage reduced pollen viability (germinability and pollen tube length) and compromised fruit set (10&ndash, 87%) compared with fresh pollen (97%). Fruit weight was also reduced at least by 8%, and oil concentration in aril by 40%. However, the lycopene and &beta, carotene concentrations in aril were largely uncompromised, and some fruits were of a marketable weight (&gt, 1.2 kg) and quality. Cool storage is a low-cost method for the short-term storage of Gac pollen. However, methods for drying pollen to an inactive state need investigation for a storage protocol, and for improvements in fruit set and fruit physicochemical qualities using hand pollination.

Plant reproduction in red clover requires cross-fertilization via insect pollination. However, the influences of visitation rate and timing on maximizing ovule utilization are yet to be determined. We aimed to study the influences of visitation rate, flowering stage, and self-incompatibility on reproductive success. We applied hand and honey bee pollination in the study of eight red clover cultivars with two ploidy levels released between 1964 and 2001. In hand pollination, increasing the visitation rates (from 10 to 80 pollinated florets per flower head) increased the seed number per flower head but reduced the seed number per pollinated floret. Different flowering stages (early, middle, and full flowering) did not influence the seed number per pollinated floret significantly. There was a marked difference in reproductive success depending on the ploidy level, with 0.52 seeds per pollinated floret in diploid and 0.16 in tetraploid cultivars. During the cultivar release history, seed number per pollinated floret seemed to decrease in diploid cultivars, whereas it increased in tetraploids. In honey bee pollination, diploid cultivars had more two-seeded florets than tetraploids. Different visitation rates and the stochastic nature of pollen transfer resulted in difficulties when the plant reproductive success between hand and bee pollination was compared. A maximum of 0.27 seeds per pollinated floret were produced in hand pollination compared to the 0.34 in honey bee pollination. In spite of this, hand pollination provided a valuable method for studying the pollination biology and reproduction of red clover. Future studies may employ hand pollination to unravel further aspects of the low reproductive success with the future perspective of improving seed number per pollinated floret in tetraploid red clover.

Kiwifruit is a new emerging crop for the southeastern United States that requires cross-pollination to set fruit. However, the pollination requirements for varieties grown in the southeastern United States are unknown. Through insect surveys and a bagging experiment, we assessed the pollination requirements of two female kiwifruit cultivars (Actinidia chinensis var. chinensis ‘AU Golden Sunshine’ and A. chinensis var. chinensis ‘AU Gulf Coast Gold’). For each, fruit quantity (fruit set) and fruit quality (weight, size, seed count, firmness, soluble solid content, and dry matter) were compared among three pollination treatments (wind, insect, and artificial pollination). Low abundances of insects were observed visiting female flowers of both kiwifruit cultivars, and therefore likely minimally influenced kiwifruit pollination. Artificial pollination resulted in the greatest percentages of fruit set and marketable fruits, followed by insect and wind pollination. Artificial pollination resulted in fruits that were greater in weight, size, and contained more seeds, than insect- and wind-pollinated fruits. Firmness and soluble solid content did not vary greatly between pollination treatments, yet were greater in ‘AU Golden Sunshine’. Dry matter content did not vary greatly between pollination treatments or between each cultivar. To maximize yields and optimize fruit quality, these results suggest that kiwifruit producers should place more effort into artificial pollination compared to wind and insect pollination. Future research should explore the use of managed bees (e.g., honey bees and bumble bees) within kiwifruit orchards to determine ways to utilize them as a secondary source for pollination needs.

Self-incompatibility in Rosaceae is determined by a Gametophytic Self-Incompatibility System (GSI) that is mainly controlled by the multiallelic locus S. In apricot, the determination of self- and inter-(in)compatibility relationships is increasingly important, since the release of an important number of new cultivars has resulted in the increase of cultivars with unknown pollination requirements. Here, we describe a methodology that combines the determination of self-(in)compatibility by hand-pollinations and microscopy with the identification of the S-genotype by PCR analysis. For self(in)compatibility determination, flowers at balloon stage from each cultivar were collected in the field, hand-pollinated in the laboratory, fixed, and stained with aniline blue for the observation of pollen tube behavior under the fluorescence microscopy. For the establishment of incompatibility relationships between cultivars, DNA from each cultivar was extracted from young leaves and S-alleles were identified by PCR. This approach allows establishing incompatibility groups and elucidate incompatibility relationships between cultivars, which provides a valuable information to choose suitable pollinizers in the design of new orchards and to select appropriate parents in breeding programs., Ministerio de Ciencia, Innovacion y Universidades-European Regional Development Fund, European Union: AGL2016-77267-R, AGL2015-74071-JIN, Instituto de Investigacion Agropecuaria (INIA): RFP2015-00015-00, RTA2017-00003-00, Gobierno de Aragon-European Social Fund, European Union: A12_17R, Fundacion Biodiversidad, Agroseguro S.A.

Bee-pollinated crops in landscapes with a low abundance of bees suffer from insufficient pollination. The present study investigates the effect of wild bee pollination on fruit and seed production in okra, Abelmoschus esculentus (L.) Moench. The study was conducted in a home garden, where an okra field was established for three pollination trials each to include 40 okra plants. For each trial, three sets of 25 flower buds were selected and tagged. One set was covered to deter bees, another set was kept open to enable bee visits and the other set was cross-pollinated by hand. Of the two species of bees, Tetragonula iridipennis (Smith) visited flowers for nectar while Lithurgus atratus Smith collected and carried pollen grains. The period of stigma receptivity and pollen availability coincided with the highest activity of L. atratus from 10.00 a.m. to 12.20 p.m. Bee-pollinated flowers had significantly enhanced okra pod length and diameter, seed number and seed germinability compared to the trial with flowers covered to deter bees. Hand pollinated flowers also produced significantly longer pods and a higher number of seeds with higher germinability. Although there was no significant difference in pod length and diameter and seed number between hand pollination trial and bee-pollinated trial, germinability of bee-pollinated seeds was significantly higher. Present study highlights the importance of the wild bee, L. atratus to enhance pod size, seed number and seed germinability in okra in Kurunegala, Sri Lanka.

In most parts of the world pepper has become a popular spice that makes food hot in addition to its much needed nutrients of carotenoids and vitamins. This report has its objective to evaluate the parents and hybrid of three Nigerian pepper genotypes (Shombo, Tatase and Nsukka yellow pepper) for growth and yield; and to estimate their genetic parameters. Conventional breeding by hand pollination was adopted. The mean performance of the parents and hybrids for morpho-agronomic characters were evaluated. Heterosis and inbreeding depression were estimated. The F1 hybrids showed superiority over the parental genotypes with Sho x Nsky-rw having significantly (P ≤ 0.05) the highest value in most of the traits. In morphological traits, Sho x Nsky-rw hybrid had highest values in canopy diameter, number of leaves, number of nodes and number of branches per plant, while in fruit traits, it also had significantly the highest values in the number of fruits, fruit length and weight of fruits per plant. Sho x Nsky – rw had positive heterobeltiosis over the better parent in most of the yield and yield component characters. While Sho x Nsky – rw had the highest yield, Tat x Sho had the highest fruit wall thickness. The combinations of these traits are important to both the farmers and consumers. Having appropriate parents with genetic variability F1 pepper plants having distinct superiority above the mid and better parents could be developed. Key words: Capsicum annuum, chili pepper; heterosis, hybrid, inbreeding depression.

Field observations suggest high air temperatures during bloom decrease fruit set of many sweet cherry (Prunus avium L.) cultivars. We investigated the role of temperature on stigma receptivity and ovule viability in four sweet cherry cultivars that exhibit variability in productivity and fertility: ‘Sweetheart’ (self-fertile, high productivity), ‘Benton’ (self-fertile, low productivity), ‘Rainier’ (self-sterile, high productivity), and ‘Tieton’ (self-sterile, low productivity). The development of the stigmatic surface, and pollen hydration, germination and tube growth in vivo, were evaluated by hand pollination and used as proxies for stigma receptivity. In addition, the senescence of primary and secondary ovules was analyzed with fluorescence microscopy. The stigmatic papillae began deteriorating by the second day after anthesis and had collapsed by the sixth day post-anthesis across cultivars. Pollen hydration exhibited 5 stages related to the length-width ratios of 2.5:1, 2:1, 1.75:1, 1.5:1 to 1:1. Maximum pollen hydration and pollen germination occurred on the stigmas within 2 days of bloom, depending on cultivar and air temperature. Pollen hydration and germination, and ovule senescence accelerated under warmer temperatures. At 7 days post-anthesis and under 24 °C approximately 80% of ‘Rainier’ ovules were viable compared to 30% in the three other cultivars. Under moderate temperature (18 °C) which mimicked the field average flowering temperature, ovule of the two high productivity cherry cultivars, ‘Rainier’ and ‘Sweetheart’, kept full viabilities for 3–4 days post-anthesis while only 1 day for the two low productivity cultivars ‘Benton’ and ‘Tieton’. These results reveal that low commercial productivity of sweet cherry cultivars in the Pacific Northwest (PNW) of U.S. is likely due to rapid ovule senescence, a condition exacerbated in warm conditions.

Reproductive ecology studies of rare species can provide information pertinent to population growth and persistence. One rare species confined to two disjunct localities, one on private land located in Florida and the other one that is composed of two subpopulations on public land in South Carolina, is the federally threatened Miccosukee gooseberry, Ribes echinellum. Studies were carried out in the Florida population to determine change in abundance between 1992 and 2012 and to understand the lack of seedling recruitment in the wild. In Florida, the number of patches increased in the northern part of the study area but decreased in the southern part. Hand pollination experiments indicate Ribes echinellum exhibits a mixed mating system. Although autogamous pollination occurred, it did not result in fruit production. Reduced seed set of selfed flowers and seedling size provided some support for inbreeding depression, yet small sample sizes precluded full evaluation. No asexual seed production was d...

'Forelle' pear fruit is prone to mealiness. The aim of this study was to establish whether pollination and seed development influence the mealiness and tissue structure by characterising microstructural differences using X-ray computed tomography (CT). Flowers of five mature 'Forelle' trees were emasculated and hand cross-pollinated with 'Early Williams Bon Chretien' pollen. Another five trees were emasculated without hand pollination. After harvesting and storage for 8 weeks at -0.5°C and subsequent ripening for 7 d at 20°C, nine pollinated and nine unpollinated pears were subjected to X-ray CT. A non-destructive X-ray micro-CT was used to visualise the internal structure of the whole fruit and to investigate seed development and density variations in regions next to viable or aborted seeds. A source voltage of 100 kV and electron current of 100 μA resulted in a resolution of 75 μm. Additional high resolution (3 μm) scans were performed on a section of the neck and equator, respectively. Nano-CT allowed for characterisation and quantification of microstructural parameters at cellular level. Fruits without viable seeds was more prone to mealiness compared to fruit with viable seeds. Differences in tissue density next to viable and aborted seeds were observed, with the region next to viable seeds being denser. Pollinated fruit had a lower porosity, indicating that these fruits may have a better source of hormones due to the viable seeds, resulting in lower mealiness incidence. Mealiness is associated with a high porosity and larger cells. Although not significant (P>0.05), fruit from unpollinated flowers was associated with larger cells, higher porosities and low connectivity between cells. This study demonstrated that X-ray CT is useful for characterising and quantifying microstructural differences related to mealiness in seeded and parthenocarpic 'Forelle' pears.

Fresh market demands high quality fruit and, therefore, citrus growers and researchers are constantly looking for solutions to avoid seed presence. Current horticultural techniques have low effectiveness or high cost. The objective of this study is to evaluate the inhibition effect of seven products on the in vivo pollen tube growth in Nadorcott mandarin, which is a high-value seedy variety. To achieve this main objective, three inorganic fertilizers (ammonium nitrate, potassium nitrate, sulfur), and four saccharides (saccharose, methyl cellulose, callose, chitosan) were applied to Nadorcott stigmas 24 h before and after hand pollination. Pollen tubes were counted 1, 3, and 5 days after treatment in longitudinal blue violet autofluorescence-stained sections. Of the seven evaluated products, only sulfur had a strong inhibitory effect. Elemental sulfur (S8) inhibited pollen tube growth by 94-100%. This strong effect was observed regardless of sulfur being applied 24 h before or after pollination, and on fixed flowers 1, 3 or 5 days after applications. Saccharose treatment seemed to have the opposite effect: stimulated pollen tube growth, but the difference with the positive control was small and non-significant. The sulfur effect could be useful for designing agronomic applications capable of preventing seed presence in Nadorcott mandarin.

Recent declines in wild pollinators represent a significant threat to the sustained provision of pollination services. Insect pollinators are responsible for an estimated 45% of strawberry crop yields, which equates to a market value of approximately £99 million per year in the UK alone. As an aggregate flower with unconcealed nectaries, strawberries are attractive to a diverse array of flower-visiting insects. Syrphine hoverflies, which offer the added benefit of consuming aphids during their predatory larval stage, represent one such group of flower visitor, but the extent to which aphidophagous hoverflies are capable of pollinating strawberry flowers remains largely untested. In replicated cage experiments we tested the effectiveness of strawberry pollination by the aphidophagous hoverflies Episyrphus balteatus and Eupeodes latifasciatus, and a mix of four hoverfly taxa, when compared to hand pollination and insect pollinator exclusion. Hoverflies were released into cages, and the strawberry fruits that resulted from pollinated flowers were assessed for quality measures. Hoverfly visitation increased strawberry yields by over 70% and doubled the proportion of marketable fruit, highlighting the importance of hoverflies for strawberry pollination. A comparison between two hoverfly species showed that Eupeodes latifasciatus visits to flowers produced marketable fruit at nearly double the rate of Episyrphus balteatus, demonstrating that species may differ in their pollination efficacy even within a subfamily. Thus, this study offers compelling evidence that aphidophagous syrphine hoverflies are effective pollinators of commercial strawberry and, as such, may be capable of providing growers with the dual benefit of pollination and aphid control.

Abortion of fertilized ovaries at the tip of the ear can generate significant yield losses in maize crops. To investigate the mechanisms involved in this process, 2 maize hybrids were grown in field crops at 2 sowing densities and under 3 irrigation regimes (well-watered control, drought before pollination, and drought during pollination), in all possible combinations. Samples of ear tips were taken 2-6 days after synchronous hand pollination and used for the analysis of gene expression and sugars. Glucose and fructose levels increased in kernels with high abortion risk. Several FASCICLIN-LIKE ARABINOGALACTAN PROTEIN (FLA) genes showed negative correlation with abortion. The expression of ZmFLA7 responded to drought only at the tip of the ear. The abundance of arabinogalactan protein (AGP) glycan epitopes decreased with drought and pharmacological treatments that reduce AGP activity enhanced the abortion of fertilized ovaries. Drought also reduced the expression of AthFLA9 in the siliques of Arabidopsis thaliana. Gain- and loss-of-function mutants of Arabidopsis showed a negative correlation between AthFLA9 and seed abortion. On the basis of gene expression patterns, pharmacological, and genetic evidence, we propose that stress-induced reductions in the expression of selected FLA genes enhance abortion of fertilized ovaries in maize and Arabidopsis.

In a previous work, it was found that ‘Spadona’ the main European pear cultivar grown in Israel, is semi-compatible with each of its three pollinators ‘Gentile’,‘Coscia’ and ‘Spadochina’. Thus, the full yield potential of these cultivars is not being realized. The Japanese pear (Pyrus pyrifolia) can fertilize European pears. In Israel, the environmental conditions for growing pears are sub-optimal for most pear cultivars. However, the Japanese pear ‘Hosui’ is well adapted to these conditions; moreover, it is fully compatible and flowers simultaneously with the cultivated European pears. In this work, we report on a 10-year evaluation of pollination of ‘Spadona’ and ‘Coscia’ pollinated by ‘Hosui’. The experiments were conducted in three stages: hand pollination; ‘bouquet insertion’; and a combined European-Asian pear orchard. The results indicate that this is a beneficial means for significantly improving fruit quality and quantity.

Background In a breeding program, usually only superior parents are chosen for cross hybridization. Pollens of elite cultivars may not be available at hand. Properly stored pollens provide an opportunity for cross hybridization at unavailable time. Results Pollen of a Phalaenopsis hybrid was evaluated for the storage ability at different temperatures, including room temperature, 4, − 20, and − 80 °C for up to 96 weeks. The viability of pollen was assessed by TTC staining, in vitro germination and hand pollination during and after storage. Pollen stored at all temperatures for 4 weeks remained viable and capable of successful pollination. Pollen lost its viability after 4 weeks at room temperature. Pollen remains viable after 40 weeks at 4 °C, and after 96 weeks at both − 20 and − 80 °C of storage. Viable pollen could be successfully pollinated to the female parent at all effective storage conditions and produced seeds. Conclusions Our results indicate that Phalaenopsis pollen can be stored at 4 °C up to 40 weeks for short-term purpose. For long-term storage, pollen can be kept at both − 20 and −80 °C.

Seed production is the key factor for maintaining plant population renewal and development. Because of pollination limitations and other factors, orchids, especially rewardless ones, generally have low fruit set rates. In Rhomboda tokioi, however, the natural fruit setting rate is very high, more than 90%. Common reasons for such a high natural fruit setting rate include high pollinator efficiency, autonomous selfing, seed formation through apomixis and so on. To test these possibilities, we carried out field observations, morphological examinations, and breeding system experiments. The results showed no migration of pollinia into or out of flowers and suggested that the structure of the floral organs hinder autonomous selfing. Interestingly, the fruit setting rate of this orchid was still higher than 90% when the gynostemium was removed prior to flowering. Additionally, after hand pollination, the pollen tube stopped growing at a late stage and could not enter the ovule, indicating the seeds were produced by obligate apomixis. Morphological experiments showed that a megasporocyte first forms a chain tetrad and then develops into a mature embryo sac, while the embryo of the offspring developed from unfertilized egg cells. More interestingly, the offspring had the same number of chromosomes as the female parent. According to the existing theory of apomixis, we can infer that the reproductive model of R. tokioi is Allium-type apomixis.

Twenty seven pigeonpea [Cajanus cajan (L.) Millsp.] hybrids were developed by hand pollination using three CMS lines (A lines) and nine testers (R lines). These hybrids along with their parents and two standard checks (VL Arhar1 and ICPL 161) were evaluated in a randomized block design with three replications during kharif 2016-17 for the heterosis studies. Results indicated that the crosses ICPA 2039 x ICPL161 and ICPA 2039 x ICPL 90048 had manifested significant heterobeltiosis and standard heterosis over two checks viz., VL Arhar1 and ICPL 161 for grain yield per plant and yield contributing characters. The stability of these promising crosses can be studied across the different environments and feasibility for their commercial utilisation could be tested in further generations.

Breeding mango is a long-term commitment, and from time of pollination to release of a new variety can take at least 20 years. Currently, in Australia, hand-pollination is used to target traits of known parents. Field assessment of hybrid progeny currently occurs without confirmation that the progeny are from the desired selected parents. Open pollination is a more cost-effective alternative to hand pollination; however, ensuring the desired parentage and, therefore, the inheritance of targeted traits is problematic. The use of molecular markers can confirm the parentage of the hybrids, with rogues eliminated at an early stage of the assessment. In this study, 12 microsatellite markers were used to determine parentage in hand- and open-pollinated mango hybrid progeny. Over 80% of hand-pollinated hybrid individuals were successfully identified for the most likely candidate father using a strict (95%) confidence level. In open-pollinated individuals, parentage was assigned with 95% confidence to 15 samples and to almost half the population with 80% confidence or more, assuming 75% of the candidate pollen donor population had been sampled. The result indicates that simple sequence repeat (SSR) analysis is an efficient method for cultivar identification. Although marker selection will not shorten the time to evaluate hybrid progeny, it can improve breeding efficiency by allowing the culling of unwanted hybrids prior to field evaluation. Development of additional molecular markers directly associated with traits of interest will allow further selection of hybrid populations for desirable traits prior to field planting.

One of the aims of the Australian Mango Breeding Program is to breed low-vigour, short-statured trees suitable for high-density production systems. The program has employed four strategies towards this goal: (a) controlled hybridisation using hand pollination, (b) genetic analyses of progeny and families, (c) rootstock selection to induce dwarfing in scion cultivars and (d) molecular marker development for marker-assisted selection of low-vigour breeding progeny. Full-sib families in the breeding population have enabled breeding values to be calculated and superior parents to be selected. The same families have also facilitated the identification and development of markers associated with low vigour in mango.

We conducted a hand pollination experiment to test the effects of supplemental pollen and pollen identity on subsequent reproductive success in three American wildflower species: Chamaecrista fasciculata, Gaillardia pulchella and Salvia coccinea. These species are commonly used in ecological restoration plantings and vary in pollination syndrome and compatibility system. We hypothesized that for all three species, treatments that supplemented pollen would yield greater fruit and seed set. Plants were germinated in a closed greenhouse until flowering, then divided into three treatments: “control”, with no supplemental pollen added; “self”, with supplemented self-pollen; and “outcross”, with supplemented outcross pollen. Treated flowers were bagged and allowed to develop to mature fruit stage, and any resulting fruits and seeds were counted and weighed. Results varied between species. Outcross C. fasciculata flowers had significantly higher fruit set than self or control treated flowers, whereas S....

The development of resistant varieties can be done according to a genetic approach. Estimation of genetic parameters for the quantitative traits of cocoa genotypes (Theobroma cacao L.) was made from a 5 × 5 diallel mating design. The objective of this study was to identify tolerant genotypes to black pod disease (BPD) through genetic analyzes. The inoculation of the leaves of parental cocoa genotypes and their offsprings with Phytophthora megakarya was performed in the nursery for two seasons (dry and rainy). Percentage success for crosses made using hand pollination was low (31.22%) and fair for grafting (60.68%). Observations made on necrosis length on the 2nd, 4th and 6th days after inoculation showed increasing sensibility of the clones to BPD in the order SNK 413E‚T 79/467E‚T 79/501E‚SNK 16E‚SCA 12. 84.37 and 76.04% of hybrid genotypes exhibited positive heterosis (hybrid vigor) in dry and rainy seasons respectively. Narrow sense (h²) and broad-sense (H²) heritabilities was high in two reciprocal crosses [F30 (h²= 0.699 and H²=0.624) and F70 (h²= 0.601 and H²=0.643)]. Key words: Theobroma cacao, Phytophthora megakarya, tolerant, heterosis, heritability.

N-(2-Chloro-4-pyridyl)-N′-phenylurea (CPPU) is a cytokinin-like plant growth regulator, which application in melon fruit set often produced bitter fruit caused by cucurbitacin B (Cu B) accumulation. However, more evidence is required to uncover the role of CPPU in regulating Cu B synthesis. In this study, two oriental melon cultivars ‘YMR’ (easy to present bitter fruit in maturation) and ‘HDB’ (hardly produce bitter fruit at maturity) were used. Four concentrations of CPPU (2.5, 5, 10 and 20 mg L−1) were set and hand pollination was used as control. Cu B accumulated in roots and fruit of 7 days after flower (7 DAF), which in ‘YMR’ was higher than those in ‘HDB’, and consistent with Cu B biosynthetic genes expression patterns. Furthermore, Cu B content in fruit significantly increased with CPPU concentrations and reached the highest level at 7 DAF, then decreased after 14 DAF, and which treated by 20 mg L−1 CPPU was always higher than that of controls and other low CPPU concentrations. Meanwhile, fruit bitterness evaluation suggested 20 mg L−1 CPPU increased the occurrence of bitterness during melon maturation. Transcription analysis suggested that the expression of Cu B biosynthetic genes (CmBi, Cm710, CmACT) and CmBt, the fruit-specific transcription factor, were significantly induced by 20 mg L−1 CPPU. Transient over-expression of CmBt in young fruit of ‘YMR’ increased Cu B biosynthetic genes (CmBi, CmACT, Cm710 and Cm890) expression and promoted Cu B accumulation. Taken together, this study demonstrates that 20 mg L−1 CPPU promotes Cu B accumulation in melon fruit by inducing CmBt and its biosynthetic genes.

Hand pollination is a necessary aiding method for pitaya ( Hylocereus undatus ) production to achieve a high yield. With the cultivated area of pitaya going up exponentially in the recent years, a systematic study was carried out to understand the mechanism behind the high yield. In this study, we first developed an optimal medium for the in vitro germination of pitaya pollen. Upon testing the activity of the pollen collected from or stored for different time, we observed that the relative high pollen germination rates (27.2–65.1%) were those collected at between 2 h before blooming and 6 h after blooming, the highest activity was at 2 h after blooming, and that storing them for 24 h at 4°C reduces their germination rate from 65.2% to 35.5% and their production to about 82%. Therefore, it is not appropriate to pollinate plants with pollen that have been stored for more than 24 h, without bringing a breakthrough in pollen storage. We also observed that stigma receptivity and pollen activity are synchronous, which together determine fruit setting rate and fruit size. Pollination within 6 h after blooming provides the best fruit setting percentage and fruit size, the other favorable option being pollination at 6:00 pm, that is, 2 h before blooming; however, pollination at 6:00 am the next morning is expected to lead to 23% reduction in the production. These results will be useful for reproductive biology studies in this species. Moreover, this work set an important foundation for collecting pollen and selecting the right time of hand pollination to improve the yield and breeding efficiency in pitaya.

Pollination techniques could affect fruit size, whereas optimal maturity stage during harvest could affect postharvest life and the eating quality of fruit. Therefore, the right pollination technique and timing to harvest fruit is an important factor in reducing postharvest losses. The objective of this study was to determine the physico-chemical changes of jackfruit harvested at four different maturity stages and produced from natural and assisted pollination. This study was conducted at a jackfruit commercial farm in Bukit Beruntung, Selangor, Malaysisa. For assisted pollination, the selected female inflorescences were covered with bags before anthesis. Hand pollination was performed by gently rubbing mature male inflorescences over the surface of receptive female inflorescences. For natural pollination, female inflorescences were left to develop into syncarps by themselves. Syncarps at the age of 12, 13, 14 and 15 weeks after anthesis (WAA) were used in this study. For each maturity stage, four syncarps were harvested and allowed to ripen naturally at 27±2 °C and 70−80% relative humidity until a sweet aroma was detected. Physico-chemical characteristics such as colour, firmness, pH, titratable acidity, β-carotene, lycopene content, sugars, organic acid content and antioxidant activity were evaluated. In this study, the pollination technique did not affect the eating quality of jackfruit flesh. However, the physico-chemical quality of jackfruit flesh was affected by ripening level and WAA. The initial stages of syncarp maturity, the L*, C* and ho values, remained unaffected. However, the L*, C* and ho decreased significantly from 14 WAA onwards when the syncarp rind turned fully yellow. This indicated that the rind and bulb colour became lighter and less intense with a green colour changing to yellow during ripening. Rind and flesh firmness decreased as ripening progressed due to cell wall modification and starch hydrolysis when ripening occurred. The β-carotene content of fleshy syncarps harvested at 14 and 15 WAA was higher than those harvested at 12 and 13 WAA. Sugar content such as glucose, fructose and sucrose increased as syncarps ripened. Total phenolic, flavonoid and antioxidant content were higher after syncarps ripened compared to before ripening. The ripe edible parts of jackfruit contain high levels of antioxidant and thereby signify the nutritional value of jackfruit for human health. In conclusion, harvesting stages affect the nutritional quality of jackfruit cv. Tekam Yellow, and it is recommended that the optimal harvesting stage of jackfruit is 14 WAA for local markets and 12 WAA for long-distance markets.

Introduction. Most commercial almonds are self-incompatible and growing these cultivars would increase orchard management costs. Self-compatible almond cultivar cultivation seems to be the solution to increase the yield and reduce the production costs. Materials and methods. In this study, the self–compatible almond cultivar Supernova was used as a seed parent and hand pollinated by the pollen of ‘Shahrood 21’, ‘Shahrood 12’, ‘Fra Giulio Grande’, ‘4–10’, ‘11–5’, and ‘Supernova’ itself. Also, two pollination methods were used, using ‘Supernova’ non–emasculated vs. emasculated flowers. Pollen tube growth of these pollinizers was studied by fluorescent microscopy at different times from flower samples harvested at 24, 48, 72, 96 and 120 h after hand pollination. The composition of fatty acids and the main characteristics of the fruit in the seed parent ‘Supernova’ were recorded after fruit harvest. Results and discussion . Although all pollens of the used pollinizers were compatible on ‘Supernova’ and had satisfied fruit set, significant differences were observed among pollinizers in stages 2 and 3. The highest fruit set was achieved when ‘Shahrood 21’ pollen was used, while the lowest fruit setting was recorded in ‘Supernova’ by self-pollination. Microscopic observation at 120 h after pollination revealed that pollen tubes of all pollinizers reached the ovary of ‘Supernova’. In this study, fatty acid content was varied with oleic acid between 70.11 to 77.76%, linoleic acid from 4.0% to 5.5%, palmitic acid from 6.17 to 6.73%, stearic acid from 1.50 to 1.91%, palmitoleic acid from 0.40% to 0.47%, arachidic acid from 0.1 to 0.4%, gadoleic acid from 0.05 % to 0.06% and total oil content was between 50.25 to 51.59%. Conclusion . This experiment revealed that different pollen sources had a significant effect on fruit setting, but not in the oil content and fatty acid composition of the seed parent kernels.

We developed an efficient method for inducing high-frequency in vitro flowering and fruiting in 10 cultivars (Cap-1 to -10) of three different species of Capsicum (C. annuum, C. chinense, and C. frutescens) collected from diverse geographical regions of India and Mexico. Shoot tips of in vitro germinated seedlings were cultured on MS media supplemented with different concentrations of 6-benzylaminopurine (BAP) alone or in combination with silver nitrate or silver thiosulphate. Low BAP concentration was a good inducer of flower buds in vitro. Synergism between silver ions and cytokinin improved flower induction. Flowering frequency improved significantly when silver nitrate or silver thiosulphate was supplemented with optimum BAP. Maximum responses, 7.5 ± 0.20 (in Cap-1) to 15.8 ± 0.27 (in Cap-5) flowers, were induced in the medium containing 0.75 mg l−1 BAP and 30 μM silver thiosulphate within 60 days of culture. Both in vitro hand-pollination and high sucrose concentration (5.0–6.0 %) in the medium improved fruit setting. In general, fruits were very small (mini-fruit) and seedless; however, three cultivars (Cap-3, -5, and -6) produced normal fruits with seeds. On an average, 144 days were required from seed implantation to fruit ripening. The frequency of meiotic abnormalities was higher in flowers produced in vitro than in those produced in vivo, and pollen viability was relatively lower in the in vitro flowers than in the in vivo flowers. The present protocol offers a repeatable system for studying the physiological mechanism of flowering and fruiting as well as providing the basis for further investigation for rapid in vitro cross-breeding programmes in Capsicum spp. for commercial hybrid production.

Corynespora Leaf Fall (CLF) disease is one of the serious diseases, caused by Corynespora cassiicola, affecting rubber (Hevea brasiliensis L) plantations. Clones rated as resistant to the disease under the polybag nurseries became susceptible at the field level causing major problems in clone recommendations. Therefore, it is of utmost importance to add new CLF resistant genotypes to the breeding pool. Therefore, the present study was carried out to attempt to validate the molecular screening by field screening results. The molecular screening was carried out using 35 genotypes from 2005 hand-pollinated progeny, their grandparents (RRIC 100 and RRIC 103), grate grandparents (RRIC 52 and PB 86), and two check clones (RRISL 201 and RRISL 208). The 2005 hand-pollinated progeny which has comprised with self progenies, raised at 1978 hand pollination by selfing at CLF susceptible clone RRIC 103 and CLF resistant clone RRIC 100. Four SSR Primers (HB 1, HB 11, HB 29, hmct 5) were selected based on polymorphism between the CLF free clone RRIC 100 and susceptible clone RRIC 103 for molecular screening. Field screening was done at polybag nursery, budwood nursery, and at field level in three locations viz., Nivithigalakale, Monaragala, and Gallewatta. Completely randomized design (CRD) was used with five to ten replicates. Disease assessment was carried out allowing plants for the natural infection based on the index developed for scoring of disease severity. Observations were taken three times during peak and off seasons of CLF disease occurrence and were assessed along with control clones. All primers generated two fragments for Hevea and built the genetic distance matrix using a power maker (V 3.0) computer program and a tree diagram was drawn using the Tree view computer program. Cluster analyses revealed four distinct clusters. Two primary clones, PB 86 and RRIC 52, and the clones RRIC 103 and RRIC 201 were grouped and another cluster was again grouped into three main sub-clusters. Around 40% of field screening results obtained agreed with molecular grouping whereas, 57% were not agreed and around 3% of genotypes did not show a clear correlation. However, further screening at the field level and molecular screening is needed.

Yield and quality of grapes are markedly enhanced by cross-pollination although self-pollination ensures some level of berry set. Cross pollination is also employed to breed a new fruitful genotype to sustain the food to feed the increasing world population on the face of climate change. The present investigations were performed to reveal the effects of diploid and tetraploid pollinizers on the agronomy of ‘Michele Palieri’ table grape cultivar. For cross pollinations, the flower buds of the maternal cultivar were emasculated 5–6 d before bloom, while the clusters belonging to self- or free pollination groups were not emasculated. All the clusters including the pollinizers, except for free pollination, were covered with cheesecloth bags to exclude random pollination. Hand pollination was carried out for each cross-combination with hairbrushes when the stigma attains peak receptivity. Pollination was carried out two times (morning in the following day), while the flowers of self-pollination group were allowed to bloom and self-pollinate in the bags. The clusters of free pollination were left after labeling without isolation. The pollinizers had remarkably different impacts on the agronomy of maternal cultivar. The highest values on berry set (20.22 %), seed size (7.18 mm) and soluble solid content (15.5°Brix) were achieved when ‘Crimson Seedless’ was used as pollinizer. The clusters set berries poorly when the pollen of interploid tetraploid ‘Kyoho’ (13.46 %) was used. However, berry color was markedly improved by ‘Kyoho’ pollens with darker and more intense skin color. Cluster mass was significantly improved by external pollens of diploid cultivars resulting from better berry set and berry development in comparison with self-pollination. Berry mass values of free pollination and ‘Michele Palieri’ x ‘Italia’ treatments were 26.6 % and 22.8 % higher than that of self-pollination. The highest values on berry detachment and skin rupture forces were detected in ‘Michele Palieri’ x ‘Italia’ combination, while the lowest measures were on both parameters were found in self-pollination berries. Finally, the use of pollinizer cultivars, instead of monovarietal vineyard establishment, could be recommended to improve berry set and quality under vineyard or protected cultivation conditions. Tetraploid ‘Kyoho’ could be used in an interspecific and interploid breeding study as donor for unique characters.

Pumpkins and winter squash require insect pollination to set fruit, but only three bee species are important pollinators of these crops in the Northeastern US. To determine if natural levels of pollen deposition are sufficient for full fruit production, open pollination was measured by counting pollen grains on stigmas, and open pollination was compared to supplemental hand pollination for fruit set, fruit size, and seed number. A threshold of 2300 pollen grains per stigma was sufficient for full pollination and fruit production. This threshold was met in 79 out of 80 combinations of site and sample date over four years on farms across Connecticut with a wide range of field sizes and pest management practices. Along with stigma collection, bees per flower were counted hourly on 100 flowers along a transect. Counts of bumble bees on female flowers were more closely related to the amount of pollen deposited than counts of bees on all flowers or counts of honey bees or squash bees on female flowers. There was tremendous variation in abundance of the three bee species on female flowers across farms within a year and even among years on a single farm.

Wild blueberry, Vaccinium angustifolium Aiton, is a native forest understory plant that is managed as a fruit crop. Over the past 51 years, experiments have been conducted to investigate its reproduction. A model was developed that predicts bloom to begin at 100&deg, days (base 4.4 &deg, C) after 1 April and to end at 500&deg, days for a period of three to four weeks. Flower stigmas are only receptive to pollen deposition for eight to 10 days, and the rate of fruit set declines rapidly after four days. Placement of pollen upon receptive stigmas suggests that fruit set occurs with as little as a single pollen tetrad. Twelve tetrads result in 50% fruit set. Several years of exploratory fruit set field experiments show viable seeds per berry, which result from pollination with compatible genotype pollen, is associated with larger berry mass (g). Decomposition of the total variance in fruit set shows that stem variation explains 65% to 79% of total variance in the fruit set. To a lesser extent, the field, year, and clone also explain the percent fruit set variation. Variation between stems may be due to variation in the number of flowers. Fruit set tends to decrease as the flower density increases, possibly due to the limitation of pollinators.

Animal-mediated pollination is an essential ecosystem service which over a third of the world’s agricultural crops depend on. Blueberry fruit production is highly dependent on pollinators and in their native range they are pollinated mostly by bumble bees (Bombus spp.). Demand for blueberries has increased in recent years due to their perceived health benefits. Consequently, blueberry cultivation has expanded well beyond their native range, including several regions where bumble bees are not present. In many areas, honey bees may be the only commercially available pollinators of blueberries because many countries ban the importation of bumble bees. This study aimed to determine the benefits of honey bee pollination on blueberry fruit quality and quantity for the variety Ventura by comparing yields of honey-bee-pollinated flowers to flowers where pollinators had been excluded. Honey bees significantly increased berry mass and diameter. Our results suggest that the presence of honey bee pollinators potentially increases revenue by approximately $864 501/ha in areas without bumble bees. We conclude that Ventura is reliably pollinated by honey bees, and that honey bee pollination may be a useful substitute for bumble bees in areas where bumble bees are absent. We also determined the extent to which blueberry yields could still be improved by comparing fruit quality and quantity under honey bee pollination to fruit quality and quantity achieved through ideal hand pollination. We found that blueberry yields may be still be significantly increased relative to ideal hand pollination and we discuss potential ways to improve the efficiency of honeybee pollination in the future. Additional research is required to study how beneficial honey bees are to fruit yield on varieties as the benefits of honey bees are likely to vary across different varieties.