scholarly journals Flowering biology, nectar production and insect visits in Cucurbita pepo L. flowers

2012 ◽  
Vol 59 (1) ◽  
pp. 183-197
Author(s):  
Marta Dmitruk
Keyword(s):  
Honey Bees ◽  
Cucurbita Pepo ◽  
Sugar Content ◽  
Nectar Production ◽  
The Mean ◽  
Male Flowers ◽  
Female Flowers

In 1998-2000 studies on length and abundance of flowering and on nectar productivity of zucchini and marrow (<i>Cucurbita pepo</i> L.) were carried out in Lublin area. Flowers visitors were also monitored. Flowering of plants lasted from the end of June till the end of September. The mean number of flowers per plant of zucchini reached: 31 (male flowers) and 26 (female flowers), and for marrow 226 and 22, respectively. Flowers lived, on average, for 5 hours. Female flowers of marrow secreted the highest amount of nectar - 1.354 g per 10 flowers, on average. Sugar content in nectar was 21.84%-27.31%. The mean total amount of sugars secreted by 10 flowers of <i>Cucurbita pepo</i> L. was 21.5-304.3 mg. Pollinators were mainly bumblebees and honey bees.

Differential nectar production between male and female flowers in a wild cucurbit: Cucurbita maxima ssp. andreana (Cucurbitaceae)

2002 ◽  
Vol 80 (11) ◽  
pp. 1203-1208 ◽  
Author(s):  
Lorena Ashworth ◽  
Leonardo Galetto
Keyword(s):  
Reproductive Output ◽  
Male Flower ◽  
Female Flower ◽  
Cucurbita Maxima ◽  
Nectar Production ◽  
Male And Female ◽  
Nectar Sugar Composition ◽  
Nectar Sugar ◽  
Male Flowers ◽  
Female Flowers

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.

scholarly journals Phenology, dichogamy, and floral synchronization in a northern red oak (Quercus rubra) seed orchard

2016 ◽  
Vol 46 (5) ◽  
pp. 629-636 ◽  
Author(s):  
Lisa W. Alexander ◽  
Keith E. Woeste
Keyword(s):  
Quercus Rubra ◽  
Seed Orchard ◽  
Absolute Number ◽  
Red Oak ◽  
Northern Red Oak ◽  
Spring Phenology ◽  
Clonal Seed Orchard ◽  
The Mean ◽  
Male Flowers ◽  
Female Flowers

We developed a novel scoring system to assess spring phenology in a northern red oak (Quercus rubra L.) clonal seed orchard. The system was used to score from 304 to 364 ramets for three reproductive seasons and to place clones into early, intermediate, and late phenology classes. Although the absolute number of clones in each phenological class changed from year to year, the overall order of clonal flowering was highly stable (rs = 0.67, p < 0.001). Early-flowering clones flowered significantly longer than later flowering clones in all 3 years. Dichogamy was present in the orchard, with male flowers of a clone emerging from 1.4 to 3.0 d sooner than its female flowers. Mean dichogamy values for individual clones ranged from 0.0 to 4.9 (± 1.3) d. Year strongly influenced a clone’s dichogamy value (F = 6.0, p = 0.004), whereas genotype had no influence. The mean overall phenological synchronicity for the 3 years of observations was 0.30 ± 0.01 or about 30% overlap between the time when females were receptive and males were shedding pollen. This study represents the first effort to quantify phenology in an artificial population of northern red oak, and it provides a snapshot of the current relationship between temperature, phenology, and floral synchronization.

scholarly journals Evaluation of Deutzia x carnea (Lem.) Rehd. as a food source to urban bees

2012 ◽  
Vol 65 (4) ◽  
pp. 29-38 ◽  
Author(s):  
Marzena Masierowska
Keyword(s):  
Honey Bees ◽  
Sugar Content ◽  
Weather Conditions ◽  
Flowering Phenology ◽  
Floral Display ◽  
Wild Bees ◽  
Enrich Food ◽  
Pollen Productivity ◽  
The Mean ◽  
Ornamental Shrub

This 3-year study examined the flowering phenology, to- tal floral display, nectar and pollen production as well as bee visitation to the ornamental shrub <em>Deutzia </em>x <em>carnea </em>(Lem.) Rehd. <br /><em>D. </em>x <em>carnea </em>bloomed from early June until the middle of July. The total flower display reached 47927 flowers per plant. The number of developed flowers strongly depended on weather conditions before and during the flowering period and fluctuated significantly during the years of study. The flower of <em>D</em>. x <em>carnea </em>lived 5 days and the persistence of an inflorescence was 11 days. <br />Nectar productivity per 10 flowers differed significantly between the years of study and ranged between 15.7 and <br />40.14 mg. Mean sugar content in nectar was 39.7%. The total sugar mass in nectar per 10 flowers averaged 9.91 mg (range: <br />3.81 – 18.91 mg). Pollen mass per 10 flowers was 16.89 mg. The estimated sugar and pollen productivity per plant was 36.8 g and <br />40 g, respectively. <br />Among bees (Apoidea), honey bees were principal visitors on <em>Deutzia </em>flowers. The peak of daily activity of honey bees and bumblebees occurred between 11.00 and 15.00 hrs, whereas the presence of other wild bees was noted in the morning and in the late afternoon. All bees gathered mainly nectar, but pollen collectors were also noted. The mean daily visiting rate was 0.0809 visits per flower × min<sup>-1</sup>. <br />The use of this shrub in gardens and parks should be encouraged in order to enrich food pasture for urban Apoidea. However, its cultivation is limited to areas of mild climate and adequate water supply.

scholarly journals Bees biodiversity, forage behavior and fruit production in gherkin crop (Cucumis anguria L.)

2019 ◽  
Vol 42 ◽  
pp. e47421
Author(s):  
Darclet Teresinha Malerbo-Souza ◽  
Milena Oliveira de Andrade ◽  
Rodrigo Alves de Siqueira ◽  
Núbia Maria Guedes de Medeiros ◽  
Lucas Rodrigues de Farias ◽  
...  
Keyword(s):  
Honey Bees ◽  
Fruit Production ◽  
Native Bees ◽  
Africanized Honey Bees ◽  
Africanized Honey Bee ◽  
University Center ◽  
Number Of Visits ◽  
Male Flowers ◽  
The University ◽  
Female Flowers

The objectives were to evaluate the biodiversity of bees, forage behavior and their effect on fruit production in the gherkin crop (Cucumis anguria L.) in the campus of the University Center Moura Lacerda in two years. The frequency and type of collection of the insects in the flowers was observed by counting from 8:00 a.m. to 5:00 p.m., in the first 10 minutes of each time, for three distinct days in each year. The percentage of fruiting was quantified in 25 female flowers covered with nylon compared to the 25 female flowers uncovered in the two years. The flowers were visited by the Africanized honey bees Apis mellifera and the native bees Plebeia sp., Exomalopsis sp. and Melissodes sp., and the Africanized honey bees presented higher frequency and constancy with a higher number of visits in the male flowers compared to the female ones and these visits occurred between 8:00 a.m. and 3:00 p.m. Without the visitation of the bees there was no fruit production, and both the Africanized honey bee and the native ones when collecting nectar and pollen, visited both female and male flowers, carrying pollen in their body, being considered important pollinators of this culture.

Evaluation of the apicultural value of sunflower hybrids

2008 ◽  
Vol 56 (1) ◽  
pp. 91-97 ◽  
Author(s):  
E. Zajácz ◽  
T. Szalai ◽  
G. Mészáros
Keyword(s):  
Honey Bees ◽  
Sugar Content ◽  
Nectar Production ◽  
Honey Production ◽  
Partial Data ◽  
High Sugar Content ◽  
Nectar Sugar ◽  
Production Value ◽  
The Individual ◽  
Selection Of

Sunflower is one of the most important bee-pasture crops and the leading oil crop plant in Hungary. There are very few studies concerning the nectar production of the plant, most of which consist only of partial data that show the apicultural value of sunflower under intensive cultivation conditions.The nectar production and nectar sugar concentration of six sunflower hybrids, Arena, Alexandra, Cledor, Coriste, Hysun 321 PR and Louidor, were examined in Mezőhegyes (south-east Hungary) from 2002 to 2004. The aim was to determine the nectar production and overall apicultural value of the hybrids. In the experiment the agroecological conditions were also examined and recorded. These agroecological conditions showed a distinctive effect on the consistency of the apicultural values of the hybrids.It can be determined from the results that the nectar production and its sugar content can be modified measurably by external factors. The nectar quantity was measurably increased by abundant precipitation during flowering, while an increase in the nectar sugar content was caused by excessively low air temperature. During these three years the average nectar production of the hybrids was 0.147 mg/floret, with a sugar content of 48.8%. Significant differences were found between the hybrids in nectar production and in the nectar sugar concentration.Averaged over three years Coriste displayed the best apicultural value. Its nectar production was stable and high (0.167 mg/floret). Its high sugar content (49.1%) also proved to be attractive to honey bees (sugar value 0.082). The lowest apicultural value was displayed by the hybrid Alexandra, with a sugar value of 0.059. This suggests that the honey production value of the individual hybrids should be taken into consideration during the selection of bee pastures.

scholarly journals The morphology and ultrastructure of the nectaries of marrow (Cucurbita pepo L. convar. giromontiina)

2013 ◽  
Vol 66 (3) ◽  
pp. 11-22 ◽  
Author(s):  
Marta Dmitruk ◽  
Elżbieta Weryszko-Chmielewska
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cucurbita Pepo ◽  
Female Flower ◽  
Transmission Electron ◽  
Parenchyma Cells ◽  
Male Flowers ◽  
Nectariferous Tissue ◽  
Female Flowers ◽  
Size And Structure

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.

scholarly journals Pollination and Fruit Set of Pumpkins in Growers' Fields in New York's Capital District

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 462D-462
Author(s):  
H. Chris Wien ◽  
Dale Riggs
Keyword(s):  
Apis Mellifera ◽  
Cucurbita Pepo ◽  
Fruit Set ◽  
Rating Scale ◽  
Female Flower ◽  
Stigmatic Surface ◽  
Black Light ◽  
Pollen Removal ◽  
Male Flowers ◽  
Female Flowers

Reports of sharply reduced feral bee populations (Apis mellifera) due to harsh winters and prevalence of several bee diseases have raised concerns that pollination and fruit set in pumpkin fields will be adversely affected. In 1995 and 1996, five and eight pumpkin (Cucurbita pepo) fields, respectively, were inventoried on three occasions per season for pollinator activity and percent fruit set. Pollen removal from male flowers was determined visually using a rating scale, while deposition of pollen on stigmata of female flowers was judged by rating fluorescence of pollen on the stigmatic surface under a “black light.” Samples were taken from 15 to 30 locations in each field, and female flowers tagged. These were considered set if they had enlarged to fist size within 14 days. In both years, the amount of pollen remaining on male flowers was negatively correlated with female flower fluorescence ratings. Neither pollen on male flowers nor stigma fluorescence were significantly correlated with percent fruit set. Fifty-two percent of tagged flowers set fruit in both years, with a range of 24% to 84%, and 17% to 78% in 1995 and 1996, respectively. Presence of bee hives in or near the fields had no effect on fruit set. The results indicate that the pollen removal and deposition ratings used were not reliable for predicting fruit set in farmers' fields. In these 2 years, bee hives were not needed in the sampled fields.

scholarly journals Nectar defense and hydrogen peroxide in floral nectar of Cucurbita pepo

2015 ◽  
Vol 68 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Daniele Nocentini ◽  
Massimo Guarnieri ◽  
Chiara Soligo
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Cucurbita Pepo ◽  
Defense Mechanism ◽  
Starch Accumulation ◽  
Floral Nectar ◽  
Male Flowers ◽  
Female Flowers

This study was carried out to investigate some similarities between the nectaries of <em>Nicotiana</em> sp. and <em>Cucurbita</em> pepo, such as starch accumulation in the nectary parenchyma, changes in nectary color during maturation, and the production of a large quantity of sucrose-dominant nectar. The concentration of hydrogen peroxide in <em>C. pepo</em> floral nectar was determined in order to verify the presence of a defense mechanism similar to that found in <em>Nicotiana</em> sp. which protects nectar from yeast and bacteria proliferation. We also tested the eventual accumulation of antioxidants in the nectary of <em>C. pepo</em> as a protection against oxidative stress caused by hydrogen peroxide. The level of hydrogen peroxide found in the floral nectar of <em>C. pepo</em> was much lower than that found in <em>Nicotiana</em> sp. and the male flowers of <em>Cucurbita</em> had a higher concentration than the female flowers. The low oxidative stress induced by this level of hydrogen peroxide caused the accumulation of a low amount of lutein inside the plastoglobules which were contained in amyloplasts. Plastids of the <em>C. pepo</em> nectary are specialized in the accumulation of starch rather than antioxidants.

scholarly journals The ecological features of flowers and inflorescences of two species of the genus Petasites Miller (Asteraceae)

2012 ◽  
Vol 65 (2) ◽  
pp. 37-46 ◽  
Author(s):  
Weronika Haratym ◽  
Elżbieta Weryszko-Chmielewska
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Structural Features ◽  
Pollination Ecology ◽  
Nectar Production ◽  
Ecological Features ◽  
Male Flowers ◽  
Female Flowers ◽  
Scanning Electron

The structural features of flowers and inflorescences of <i>Petasites hybridus</i> and <i>P. albus</i> were compared. Only individuals producing flower heads with male flowers and few female flowers were found in the studied populations. Light microscopy (LM) and scanning electron microscopy (SEM) were used for examination. The present study shows that the stems of the above- -mentioned species differed in height and number of flower heads, but the number of flowers per head was similar. Larger flowers were found on the stems of <i>P. albus</i>. The following features has been found to play an important role in pollination ecology: the strongly contrasting colours of the floral parts; on the petals, the occurrence of several types of cells which can increase the attractiveness of the flowers by refracting sunlight in a different way; production of odorous oils by the petal cells; production of significant amounts of pollen offered to insects by the well-developed pollen presenters; the development of nectaries and nectar production by the male flowers as well as the development of colour attractants by the corolla, anthers, and bracts.

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
Keyword(s):  
Video Surveillance ◽  
Habitat Management ◽  
Cucurbita Pepo ◽  
Landscape Composition ◽  
Pollen Deposition ◽  
Male And Female ◽  
Flower Visitation ◽  
Visitation Frequency ◽  
Male Flowers ◽  
Female Flowers

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.

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