scholarly journals Use of video surveillance to measure the influences of habitat management and landscape composition on pollinator visitation and pollen deposition in pumpkin (Cucurbita pepo) agroecosystems

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1342 ◽  
Author(s):  
Benjamin W. Phillips ◽  
Mary M. Gardiner

Pumpkin (Cucurbita pepo) production relies on insect-mediated pollination, which is provided by managed and wild pollinators. The goals of this study were to measure the visitation frequency, longevity and temporal activity patterns of pumpkin pollinators and to determine if local habitat management and landscape composition affected this pollination service. We used video surveillance to monitor bee acitivty within male and female pumpkin flowers in 2011 and 2012 across a pollination window of 0600–1200 h. We also quantified the amount of pollen deposited in female flowers across this time period. In 2011,A. melliferamade significantly more floral visits than other bees, and in 2012Bombus spp. was the dominant pumpkin pollinator. We found variation in visitation among male and female pumpkin flowers, withA. melliferavisiting female flowers more often and spending longer per visit within them than male flowers in both 2011 and 2012. The squash beeP. pruinosavisited male flowers more frequently in 2012, but individuals spent equal time in both flower sexes. We did not find variation in the timing of flower visitation among species across the observed pollination window. In both 2011 and 2012 we found that the majority of pollen deposition occurred within the first two hours (0600–0800 h) of observation; there was no difference between the pollen deposited during this two-hour period and full pollination window (0600–1200 h). Local additions of sweet alyssum floral strips or a field buffer strip of native wildflowers did not have an effect on the foraging activity of bees or pollen deposition. However, semi-natural and urban habitats in the surrounding landscape were positively correlated with the frequency of flower visitation by wild pollinators and the amount of pollen deposited within female flowers.


2002 ◽  
Vol 80 (11) ◽  
pp. 1203-1208 ◽  
Author(s):  
Lorena Ashworth ◽  
Leonardo Galetto

In dioecious and monoecious plants that depend on animal vectors for reproduction, pollinators have to be attracted to male and female flowers for pollination to be effective. In the monoecious Cucurbita maxima ssp. andreana, male flowers are produced in greater quantity, are spatially more exposed to pollinators and offer pollen in addition to nectar as floral rewards. Nectar traits were compared between male and female flowers to determine any differences in the characteristics of the main reward offered to pollinators. Nectar chemical composition and sugar proportions were similar between flower types. Total nectar sugar production per female flower was threefold higher than per male flower, and nectar removal did not have any effect on total nectar production in both flower morphs. Pollinators reduced nectar standing crops to similar and very scarce amounts in both flower types. Results indicate indirectly that pollinators are consuming more nectar from female flowers, suggesting that the higher nectar production in female flowers may be a reward-based strategy to achieve the high female reproductive output observed in this species.Key words: Cucurbitaceae, Cucurbita maxima ssp. andreana, nectar production, nectar sugar composition, removal effects, standing crop.



2020 ◽  
Vol 17 (2) ◽  
pp. 81
Author(s):  
Van Basten Tambunan ◽  
Bandung Sahari ◽  
Damayanti Buchori ◽  
Purnama Hidayat

<p>The African oil palm weevil,<strong> </strong><em>Elaeidobius kamerunicus</em> is an effective pollinator of oil palm. Each individual palm produces exclusively male or female inflorescence so that the success of pollination depends on the ability of the pollinator to transfer pollen from male to female flowers. The objective of this research was to study the amount of pollen carried by <em>E. kamerunicus</em> between male and female inflorescences (pollen load) and the amount of pollen carried on each part of the weevil’s body (pollen distribution). Fifty each of male and female  <em>E. kamerunicus</em> individuals were collected from male and female flowers on trees in 3 locations: Siantar (North Sumatra), Dramaga (West Java), and Morowali (Central Sulawesi). Data on pollen load and pollen distribution on the weevil’s body were analyzed using <em>ImageJ</em> software. Results show that <em>E. kamerunicus</em> individuals collected more pollen from male flowers than from female flowers. In addition, male insects carried more pollen on their bodies than female insects. Pollen distribution on weevil body parts was highest on the elytra, followed by the thorax, abdomen, legs, and head respectively.</p>



2004 ◽  
Vol 20 (3) ◽  
pp. 307-316 ◽  
Author(s):  
Nina Farwig ◽  
Emile F. Randrianirina ◽  
Friederike A. Voigt ◽  
Manfred Kraemer ◽  
Katrin Böhning-Gaese

In dioecious plant species differences in morphology and resources between female and male flowers can have consequences for flower visitation rates. Female flowers sometimes lack pollen and can be less attractive to pollinators than male flowers. We studied the pollination ecology of the dioecious tree Commiphora guillauminii in a dry deciduous forest in western Madagascar. We recorded floral display, visiting insect species and visitation rates for female and male trees. The results showed that female trees produce significantly larger but fewer flowers per inflorescence than male ones. Number of flowers per tree did not differ between the sexes. During 270 observation-hours we observed 17 insect and two bird species visiting the flowers. Mean visitation rates of male flowers were 6.1 times higher than those of female flowers (1.07 vs. 0.18 visitors per flower h−1). Visitation rates to female and male trees showed similar daily and seasonal patterns. Fruit set (2.9%) was low, which could have been caused by pollinator or pollen limitation. This study suggests that dioecy may pose a risk for fruit set and, potentially, reproductive success for plant species with depauperate pollinator faunas on islands such as Madagascar.



PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12328
Author(s):  
Baiting Qin ◽  
Xiujun Lu ◽  
Xiaomei Sun ◽  
Jianguo Cui ◽  
Jifeng Deng ◽  
...  

Juglans mandshurica Maxim is a hermaphroditic plant belonging to the genus Juglans in the family Juglandaceae. The pollination period of female flowers is different from the loose powder period of male flowers on the same tree. In several trees, female flowers bloom first, whereas in others, male flowers bloom first. In this study, male and female flower buds of J. mandshurica at the physiological differentiation stage were used. Illumina-based transcriptome sequencing was performed, and the quality of the sequencing results was evaluated and analyzed. A total of 138,138 unigenes with an average length of 788 bp were obtained. There were 8,116 differentially expressed genes (DEGs); 2,840 genes were upregulated, and 5,276 genes were downregulated. The DEGs were classified by Gene Ontology and analyzed by Kyoto Encyclopedia of Genes and Genomes. The signal transduction factors involved in phytohormone synthesis were selected. The results displayed that ARF and SAUR were expressed differently in the auxin signaling pathway. Additionally, DELLA protein (a negative regulator of gibberellin), the cytokinin synthesis pathway, and A-ARR were downregulated. On April 2nd, the contents of IAA, GA, CTK, ETH and SA in male and female flower buds of two types of J. mandshurica were opposite, and there were obvious genes regulating gender differentiation. Overall, we found that the sex differentiation of J. mandshurica was related to various hormone signal transduction pathways, and hormone signal transduction plays a leading role in regulation.



2021 ◽  
Author(s):  
Julissa Rojas-Sandoval

Abstract Genetics: The chromosome number reported for Cucumis anguria is 2n=24 (Ramachandran and Narayan, 1990; Flora of North America Editorial Committee, 2020). Reproductive Biology: Cucumis anguria is a monoecious species, with individual male and female flowers appearing on both plants, that depends of pollinators to transfer pollen grains in order to produce fruits. Although self-fertile, a degree of outcrossing results from insect pollination. Zagorcheva (1988) has suggested that C. anguria may also be a facultative apomict. The flowering season is of about 55-58 days. Male flowers appear before female flowers and both male and female flowers remain open for one day (from 7:30 am to 4:00 pm). The relationship between male and female flowers is on average 5.5 male flowers for each female flower. The greater number of male flowers compared to female flowers produces a greater flow of pollen in the crop and ensures pollination. Flowers are visited and pollinated by insects. In a study in Brazil, the most important visitor was Apis mellifera (72% of all visits) followed by native bees from the genera Plebeia sp. (16.7%), Exomalopsis sp. (8.3%) and Melissodes sp. (2.8%). Flowers are also visited by butterflies (Malerbo-Souza et al., 2020). Physiology and Phenology: Cucumis anguria is an annual species. Early growth is upright, followed by branching at the base to produce several trailing stems. Within its native distribution range, this species germinates in a few days during the summer rains when night temperatures are above 12°C and the soil is sufficiently wet. When plants are about 2-3 m length, they start to develop flowers. Fruits are often produced within 60 days after germination. Plants may produce up to 50 fruits per stem. Fruits remain attached to the withered annual stems long after these have died back at the end of the growing season (Wilkins-Ellert, 2004). Photoperiod is important and longer days coupled with higher temperatures confines plants to the production of male flowers. Shorter days and a drop in temperature stimulate the production of female flowers. Fruiting occurs within 60 days of planting and fruit are produced continuously, with as many as 50 fruits per plant produced during the growing season (Wilkins-Ellert, 2004). Environmental Requirements: Cucumis anguria prefers to grow in tropical and subtropical climates. It grows best in areas with mean annual temperatures ranging from 15°C to 28°C (tolerates 8°C-35°C) and mean annual rainfall between 800 mm-1000 mm (tolerates 300 mm-1700 mm). It is well adapted to soils with low fertility and is adapted to grow in a wide range of soil types, including Kalahari sands (regosols), red clays and black cotton soils (vertisols) with pH in the range 6-7.5 (tolerates 5.5 - 8.3), but it grows best on well drained sandy soils (Fernandes, 2011). This species is sensitive to cold and does not tolerate frost (Wilkins-Ellert, 2004; Useful Tropical Plants, 2020).



1982 ◽  
Vol 30 (3) ◽  
pp. 251 ◽  
Author(s):  
CA McConchie ◽  
SC Ducker ◽  
RB Knox

Floral development of male and female flowers in Amphibolis antarctica and A. griffithii was followed from the initiation of the floral meristem to the mature flower. In A. antarctica the flowers form on lateral branches, while in A. griffithii they may also develop terminally on an upright branch from the rhizome. A. griffithii and. to a lesser extent, A. antarctica, show sympodial branching from the floral axis. The female flower develops from a pair of primordia; in A. griffithii these primordia each develop three stigmas, which in A. antarctica subsequently may form secondary branches. The. ovary wall bears the initials of the future grappling apparatus, comprising four comb initials in A. grijjjthii and a further inner set of horns in A. antarctica. The female flowers of Amphibolis are unique amongst the members of the Cymodoceaceae in being subtended by a bract or perianth, similar to the male flowers. Differences between the floral vasculature and intravaginal squamulae are presented for both species.



2007 ◽  
Vol 62 (2) ◽  
pp. 49-51 ◽  
Author(s):  
Leman Tarhan ◽  
Hulya Ayar Kayali ◽  
Raziye Ozturk Urek


2013 ◽  
Vol 66 (3) ◽  
pp. 11-22 ◽  
Author(s):  
Marta Dmitruk ◽  
Elżbieta Weryszko-Chmielewska

The present study investigated the size and structure of the nectaries in flowers of marrow – <em>Cucurbita pepo </em>convar.<em> giromontiina </em>cv. ‘Weiser Busch’. The diameter and thickness of nectariferous layer were compared in female and male flowers of this taxon. The micromorphology as well as the anatomical and ultrastructural characters of the nectary from the female flower were observed using light, scanning and transmission electron microscopy. The density and size of stomata of the nectary epidermis from both types of flowers were examined using light microscopy. The nectaries in female flowers were found to have a larger size than in male flowers. The stomata occurring in the nectary epidermis of both types of flowers have a similar size and density. We observed that nectar was released onto the surface of the nectary not only via the stomata, but also through the walls of the epidermal cells. In TEM examination, large nuclei, different-shaped plastids, ER tubules, dictyosomes, and ribosomes were observed in the nectariferous tissue cells. A large number of mitochondria accompanying the plastids were found in the parenchyma cells of the nectary. The degradation of the nectary parenchyma cells in the flowers living for about 6 hours was asynchronous.



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