scholarly journals Pollination and Plant Reproductive Success of Two Ploidy Levels in Red Clover (Trifolium pratense L.)

2021 ◽  
Vol 12 ◽  
Author(s):  
Shuxuan Jing ◽  
Per Kryger ◽  
Bo Markussen ◽  
Birte Boelt
Keyword(s):  
Reproductive Success ◽  
Honey Bee ◽  
Red Clover ◽  
Flower Head ◽  
Seed Number ◽  
Bee Pollination ◽  
Ploidy Levels ◽  
Plant Reproductive Success ◽  
Visitation Rates ◽  
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.

scholarly journals Role of insect visits on cucumber (Cucumis sativus L.) yield

2018 ◽  
Vol 4 (2) ◽  
pp. 81-88
Author(s):  
MS Hossain ◽  
F Yeasmin ◽  
MM Rahman ◽  
S Akhtar ◽  
MA Hasnat
Keyword(s):  
Cucumis Sativus ◽  
Honey Bee ◽  
Foraging Behaviour ◽  
Apis Cerana ◽  
Bee Pollination ◽  
Cucumis Sativus L ◽  
M 10 ◽  
Hand Pollination ◽  
Insect Visitors

The foraging activities of insect visitors on cucumber (Cucumis sativus L.) were studied. The insect visitors in decreasing order of abundance were: Formica sp.>Apis mellifera>Apis cerana>syrphids≥Apis dorstata. The activity of insects was peaked at 08.00-09.00 am. The foraging behaviour of A. mellifera was also studied. The bees spent significantly more time per flower during morning hours (sec/flower) and foraged significantly fewer flowers (7.9 flowers/min) compared to evening hours. There were significantly more nectar foragers (6.03/m²/10 min) than pollen foragers (5.16/m²/10 min). Most pollen foragers were observed during morning hours (6.59/m²/10 min) whereas nectar foragers were most active during noon hours (6.63/m²/10 min). Highest fruit set was observed in hand pollination (70.68%). Percentage of misshapen fruits was maximum in without honey bee pollination (24.35%). Without honey bee pollination resulted in significantly lowest percentage of healthy fruits (75.25%). Hand pollination ranked highest among the three forms of pollination in respective of fruits (985.13 g), number of seeds per fruit (425.22), fruit diameter (27.1 cm), fruit length (26.7 cm) and weight of 1000-seeds (28.64 g). J. Biodivers. Conserv. Bioresour. Manag. 2018, 4(2): 81-88

scholarly journals Honey Bee Activity in Northern Highbush Blueberry Differs across Growing Regions in Washington State

HortScience ◽  
2016 ◽  
Vol 51 (10) ◽  
pp. 1228-1232
Author(s):  
Lisa W. DeVetter ◽  
Sean Watkinson ◽  
Ramesh Sagili ◽  
Timothy Lawrence
Keyword(s):  
Honey Bee ◽  
Washington State ◽  
Highbush Blueberry ◽  
Seed Number ◽  
Bee Colony ◽  
Visitation Rates ◽  
Berry Size ◽  
Northern Highbush Blueberry ◽  
Western Washington ◽  
Eastern Washington

Commercial production of northern highbush blueberry (Vaccinium corymbosum) is dependent upon rented colonies of honey bees (Apis mellifera) for meeting pollination requirements. Despite the prevalent use of honey bees, growers in Washington State and the greater Pacific Northwest (PNW), particularly those located in the western regions, claim pollination is limited and yield potential is subsequently reduced due to pollination deficits. However, there have been no studies or surveys that document this occurrence for this economically important region of blueberry production. The objective of this study was to survey honey bee activity in commercial plantings of ‘Duke’ highbush blueberry in western and eastern Washington and to assess the relationship between honey bee activity, growing region, and select yield components. Honey bee colony strength was also assessed to evaluate this variable’s relationship to honey bee activity and measured yield components. Sixteen and 18 commercial ‘Duke’ blueberry fields across Washington State were surveyed in 2014 and 2015, respectively. Average number of honey bee visitations per plant and honey bee colony strength were determined to evaluate overall honey bee activity. Estimated yield, berry number per plant, berry size (mass), and seed number per berry were also determined and analyzed to determine their relationship to honey bee activity through regression analysis. Honey bee visitation rates differed between western and eastern Washington, with western Washington sites consistently below recommended honey bee densities. Colony strength was also below recommended levels, but was lower for western Washington relative to eastern Washington. Estimated yield and berry number differed across sites and years, but were not related to honey bee visitation rates. Regression analysis revealed few significant relationships, although honey bee visitation rates were positively related to seed number per berry and seed number was positively related to berry size (R2 = 0.25 and 0.16, respectively). Berry size was also positively related to colony strength (R2 = 0.63). This study demonstrates that honey bee activity is limited in Washington blueberry production, particularly in western Washington, when compared with recommendations for optimal honey bee activity in blueberry. However, yields were unaffected between the compared regions. The lack of a relationship between honey bee visitation rates and yields suggests that pollination is sufficient for ‘Duke’ blueberry in Washington State and pollination deficits do not limit yield for this cultivar under the conditions of the study.

Inter-parent distance affects reproductive success in two clonal dwarf shrubs, Vaccinium myrtillus and Vaccinium vitis-idaea (Ericaceae)

2002 ◽  
Vol 80 (8) ◽  
pp. 875-884 ◽  
Author(s):  
Carolin Nuortila ◽  
Juha Tuomi ◽  
Kari Laine
Keyword(s):  
Reproductive Success ◽  
Natural Populations ◽  
Vaccinium Myrtillus ◽  
Seed Number ◽  
Genetic Population ◽  
Pollen Donor ◽  
Hand Pollination ◽  
Population Structures ◽  
Limited Dispersal ◽  
Vaccinium Myrtillus L

Clonal propagation and limited dispersal of seeds lead to genetic population structures in which most potential mates are relatives. If the species suffers from inbreeding depression or is self-incompatible, the number of seeds matured per fruit may be limited by the lack of outcrossing by unrelated pollen. We tested for distance-related genetic structure by hand-pollinating plants at increasing distances and measuring fruit set (berries/pollinated flowers) and seed number per fruit in natural populations of bilberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.). Bagging of the flower buds without natural (pollination by insects) or hand-pollination yielded almost no fruit or seed, suggesting that the species are obligately insect pollinated. Self-pollination led to a significant reduction in seed number per fruit and increased seed abortion compared with cross-pollination. Moreover, seed number increased with increasing distance between the pollen donor and pollen recipient. Flight distances of bumblebees were estimated for bilberry by monitoring between-flower and, for lingonberry, between-inflorescence flight distances. About 90% of all flights were at distances of less than 1 m. At this distance, we observed less than the maximum seed number per fruit in hand-pollinations in both study species. Consequently, clonal growth is likely to be an important factor that constrains fruit and seed number in these species.Key words: bumblebee forage distance, clonal, hand-pollination, inter-parent distance, reproductive success, Vaccinium.

scholarly journals Assessing the effectiveness of honey bee pollinators for cultivated blueberries in South Africa

2021 ◽  
Author(s):  
Keanu Martin ◽  
Bruce Anderson ◽  
Corneile Minnaar ◽  
Marinus L de Jager
Keyword(s):  
South Africa ◽  
Honey Bee ◽  
Honey Bees ◽  
Maximum Yield ◽  
Yield Potential ◽  
Special Focus ◽  
Bee Pollination ◽  
Hand Pollination ◽  
Pollination Deficit ◽  
The Difference

AbstractGlobally, 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.

scholarly journals Honey bees, Apis mellifera, are important pollinators of the highbush blueberry variety Ventura despite the inability to sonicate

2019 ◽  
Author(s):  
Keanu Martin ◽  
Bruce Anderson ◽  
Corneile Minnaar ◽  
Marinus de Jager
Keyword(s):  
Honey Bee ◽  
Fruit Quality ◽  
Honey Bees ◽  
Fruit Production ◽  
Bumble Bees ◽  
Highbush Blueberry ◽  
Agricultural Crops ◽  
Native Range ◽  
Bee Pollination ◽  
Hand Pollination

AbstractAnimal-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.

Factors affecting pollinator visitation and reproductive success in Sonneratia caseolaris and Aegiceras corniculatum in a mangrove forest in India

2001 ◽  
Vol 17 (3) ◽  
pp. 431-447 ◽  
Author(s):  
SHALINI PANDIT ◽  
B. C. CHOUDHURY
Keyword(s):  
Reproductive Success ◽  
Mangrove Forest ◽  
Time Of Day ◽  
Pollinator Visitation ◽  
Aegiceras Corniculatum ◽  
Factors Affecting ◽  
Plant Reproductive Success ◽  
Sonneratia Caseolaris ◽  
Exclusion Experiments ◽  
Selfing Species

Pollinator visitation to, and the reproductive success of, Sonneratia caseolaris (Sonneratiaceae) and Aegiceras corniculatum (Myrsinaceae) was investigated in a mangrove forest in India. S. caseolaris was shown to be primarily outcrossed and A. corniculatum was shown to be a selfing species. The flowers of both plant species attracted several diurnal and nocturnal visitors. Earlier reports had indicated that S. caseolaris flowered for one night and was exclusively night-pollinated. But flowers of this species were found to be in bloom both at night and during the day, and diurnal visitors to the flowers were more diverse and frequent than nocturnal ones. This was related to the higher volume and energy value of nectar in the morning. The effects of time of day and temperature on visitation rates were quantified. The importance of visitors to plant reproductive success was investigated via controlled visitor-exclusion experiments. Pollinators were expected to be more important for the outcrossing species than for the selfing species, and this was confirmed by the results of the exclusion experiments. In S. caseolaris reproductive success was determined both by pollinator availability and the intensity of flower and fruit predation, while in A. corniculatum it is likely to be resource limited.

Reproductive success of wind, generalist, and specialist pollinated plant species following wildfire in desert landscapes

2017 ◽  
Vol 26 (12) ◽  
pp. 1030 ◽  
Author(s):  
Andrew H. Lybbert ◽  
Justin Taylor ◽  
Alysa DeFranco ◽  
Samuel B. St Clair
Keyword(s):  
Reproductive Success ◽  
Plant Species ◽  
Mojave Desert ◽  
Fruit Production ◽  
Native Plant ◽  
Pollination Services ◽  
Generalist Species ◽  
Plant Reproductive Success ◽  
Show Evidence ◽  
Specialist Species

Wildfire can drastically affect plant sexual reproductive success in plant–pollinator systems. We assessed plant reproductive success of wind, generalist and specialist pollinated plant species along paired unburned, burned-edge and burned-interior locations of large wildfires in the Mojave Desert. Flower production of wind and generalist pollinated plants was greater in burned landscapes than adjacent unburned areas, whereas specialist species responses were more neutral. Fruit production of generalist species was greater in burned landscapes than in unburned areas, whereas fruit production of wind- and specialist-pollinated species showed no difference in burned and unburned landscapes. Plants surviving in wildfire-disturbed landscapes did not show evidence of pollination failure, as measured by fruit set and seed:ovule ratios. Generalist- and specialist-plant species established in the interior of burned landscapes showed no difference in fruit production than plants established on burned edges suggesting that pollination services are conserved with increasing distance from fire boundaries in burned desert landscapes. Stimulation of plant reproduction in burned environments due to competition release may contribute to the maintenance of pollinator services and re-establishment of the native plant community in post-fire desert environments.

scholarly journals Do abundance and proximity of the alien Impatiens glandulifera affect pollination and reproductive success of two sympatric co-flowering native species?

2012 ◽  
Vol 10 ◽  
pp. 130-139
Author(s):  
Valérie Cawoy ◽  
Mathieu Jonard ◽  
Carolin Mayer ◽  
Anne-Laure Jacquemart
Keyword(s):  
Reproductive Success ◽  
Native Species ◽  
Natural Populations ◽  
Pollen Deposition ◽  
Impatiens Glandulifera ◽  
Insect Behaviour ◽  
Native Flora ◽  
Visitation Rates ◽  
Aconitum Napellus ◽  
Negative Effect

In invasion ecology, potential impacts of aliens on native flora are still under debate. Our aim was to determine the pollinator mediated effects of both proximity and abundance of an alien species on the reproductive success of natives. We chose the highly invasive Impatiens glandulifera and two native species: Epilobium angustifolium and Aconitum napellus ssp. lusitanicum. These species share characteristics allowing for pollination interactions: similar biotopes, overlapping flowering periods and same main pollinators. The effects of abundance (5, 25 and 100 individuals) and proximity (0 and 15 m) of the alien on visitation rate, insect behaviour, pollen deposition and reproductive success of both natives were investigated during 2 flowering seasons. We used centred visitation rates as they can be directly interpreted as a positive or negative effect of the invasive.Both abundance and proximity of the alien increased bumblebee visitation rates to both natives. On the other hand, abundance of the exotic species had a slight negative effect on honeybee visits to natives while its proximity had no effect. The behaviour of bumblebees changed as visitors left significantly more often the native plants for I. glandulifera when its abundance increased. As a consequence of this “inconstancy”, bees deposited considerable quantities of alien pollen on native stigmas. Nevertheless, this interspecific pollen transfer did not decrease seed set in natives. Self-compatibility and high attractiveness of both native species probably alleviate the risk of altered pollinator services and reproductive success due to the invader in natural populations.

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