scholarly journals Reproductive biology in monoecious and gynoecious cucumber cultivars as a result of IBA application

2008 ◽  
Vol 26 (1) ◽  
pp. 30-34
Author(s):  
Valdir Diola ◽  
Afonso I Orth ◽  
Miguel P Guerra

The understanding of both the reproductive biology and the regulation of the sexual expression of cucumber flowers (Cucumis sativus) makes crop management easier and can improve fruit yield and quality. The objective of this study was to evaluate the physiological answer of cucumber floral verticils to the application of IBA. The experiment was carried out in a greenhouse, in completely randomized blocks, with four replications of 4-plant plots, and treatments applied to a 5 x 2 factorial (0, 50, 100, 200, and 500 µmol of IBA, and two cultivars: Wisconsin MR28, gynoecious, and Caipira, monoecious). Cultivar Wisconsin MR28 produced in average 7,636 pollen grains (PG) per flower, with a positive linear response to the increase in IBA concentration. Instead, in cultivar Caipira (5,160 PG) all IBA concentrations reduced PG production. Cultivars did not differ from each other in relation to PG viability (average in vitrogermination of 75.4 and 79.9% to cultivars Wisconsin MR28 and Caipira, respectively) and in both PG viability increased linearly with the increase in AIB concentration. Cultivars Wisconsin MR28 and Caipira presented in average 71.6 and 70.6 seeds per fruit respectively, and responded with an increase in seed number and improvement in fruit general aspect to the rise in IBA concentration. The ratio male:female flowers was significantly different between cultivars (4.2:1 and 3.5:1, respectively to cultivars Wisconsin MR28 and Caipira) and responded in a distinct way to IBA concentrations. While in cultivar Caipira, IBA concentrations near to 100 µmol increased the number of male flowers; in cultivar Wisconsin MR28 the same IBA concentration reduced it. The two cultivars had a similar number of female flowers. However, whereas it remained relatively stable in cultivar Caipira in spite of the increase in IBA concentration, there was an increase in the number of female flowers in cultivar Wisconsin MR28, as a result of the rise in IBA concentration.

2011 ◽  
Vol 39 (1) ◽  
pp. 139 ◽  
Author(s):  
Deniz KARAKAYA ◽  
Hüseyin PADEM

This study was conducted to investigate the effects of silver nitrate (AgNO3) on the flower quantity of cucumbers. The seeds used in this study, which was carried out in a plastic greenhouse, in the Gazi village of Antalya Province (Turkey) the during spring and autumn 2005 breeding periods, were ‘Mostar F1’ (designated as ‘GND1’) and ‘Vesco Seeds Beith Alpha F1 (26.50 F1)’, designated as ‘GND2’ and those are the types having common production. The silver nitrate application was performed by the method of spraying on the growth tips of plants and 0, 250, 500, 750, and 1000 ppm silver nitrate doses were administered. The research was conducted with 4 repetitions having 5 plants in each repetition according to the Random Parcel Trial Pattern. In order to determine the effects of the applications, the effects of a number of female flowers and male flowers on generative characteristics of planting periods (spring and fall) were identified and the results were statistically evaluated. According to the results obtained in this research, AgNO3 has led to the formation of male flowers (no male flower formation in control), has increased the number of male flowers, and has led to a decrease in the number of female flowers. The increase in the number of male flowers varied according to the periods (in ‘GND2’).


2013 ◽  
Vol 26 (1) ◽  
pp. 25-33 ◽  
Author(s):  
S. Akter ◽  
M. G. Rasul ◽  
A. K. M. Aminul Islam ◽  
M. M. Rahman

The experiment was conducted to study variability, correlation coefficient and path analysis for yield and quality related traits of 30 pumpkin genotypes. Significant variations were found among the genotypes for most of the characters studied. High genotypic coefficient of variation (GCV) and high heritability coupled with high genetic advance in percent of mean were observed for beta-carotene followed by non-reducing sugar, number of seeds per fruit, yield per plant, dry weight, flesh thickness, number of male flowers per plant and number of female flowers per plant which indicated that these characters were under additive gene control and selection for genetic improvement for these traits might be effective. Correlation co-efficient between yield per plant with number of primary branches, number of fruits per plant and single fruit weight were positive and highly significant. On the other hand, days to first female flower, number of male flowers per plant, ß- carotene and total sugar showed positive and insignificant correlation with yield per plant. But correlation between brix content and yield per plant were significantly negative. Path coefficient analysis revealed that the maximum direct contribution towards yield was obtained through number of fruits per plant followed by days to first female flower and single fruit weight indicated that these traits should be considered as primary components of yield. Negative direct effect on yield was exerted by total sugar followed by number of female flowers per plant, reducing sugar and brix content. Considering all the qualitative and quantitative traits ten genotypes as G7, G13, G14, G17, G18, G19, G20, G22, G27, G29 among thirty were selected and suggested to be selfed for the development of inbred line for use in future breeding programme.DOI: http://dx.doi.org/10.3329/bjpbg.v26i1.19981


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).


2019 ◽  
Vol 7 (3) ◽  
pp. 370-377
Author(s):  
Shiva Dhakal ◽  
Mahesh Karki ◽  
Pritee Subedi ◽  
Aarati GC

A study on the effect of ethephon doses on vegetative characters, sex expression and yield of cucumber (Cucumis sativus cv. Bhaktapur Local) was conducted in Gulmi, Nepal during 21st April to 24th August 2017.  The experiment was laid in single factor Randomized complete Block Design (RCBD) with 4 replication and 5 treatments. Four different doses of ethephon 100, 200, 300 & 400 ppm with control were applied. Two sprays of ethephon was made one at two true leaf stage and other at four true leaf stage. Ethephon was found to reduce the plant height compared to control, minimum (238.8 cm) with 400 ppm and maximum (310.4 cm) with the control. The number of nodes and branches per plant were found to be highest with 300 ppm. Ethephon was found to shift first male flowers and female flowers towards upper and lower nodes respectively. The plot treated with 300 ppm ethephon, bearing 20.31 female flowers per plant was found superior to other doses for increasing total female flowers. Maximum and minimum number of male flowers per plant was recorded with control(107 per plant) and 400 ppm (46.90 per plant) respectively. Similarly, 300 ppm of ethephon was found superior for reducing (male: female) sex ratio. Maximum yield 27.51 t/ha was recorded with 300 ppm and minimum yield of 17.48 t/ha with the control. 57% increment in the yield was observed with 300 ppm ethephon as compared to the control. Thus, proper use of ethephon is found to be beneficial to farmers. Int. J. Appl. Sci. Biotechnol. Vol 7(3): 370-377  


Author(s):  
P. M. Duarte ◽  
K. M. M. de Siqueira ◽  
N. C. da Silva ◽  
G. B. S. Silva ◽  
Í. L. S. Gomes

<p>A melancieira apresenta comumente flores masculinas e femininas na mesma planta, necessitando assim dos serviços de polinização para a transferência dos grãos de pólen e consequente produção de frutos. A atratividade aos polinizadores está na dependência dos recursos florais oferecidos como recompensa durante as visitas, e como consequência a planta é beneficiada com a polinização. O objetivo desse trabalho foi registrar aspectos relevantes da floração incluindo a razão sexual e a descrição da morfologia floral de variedades de melancieira. As variedades demelancieira utilizadas foram, Congo, Elisa, Crimson super e Charleston super, em cultivo orgânico, com irrigação por gotejamento. Foram avaliados quatro tratamentos e quatro repetições, utilizando o delineamento experimental inteiramente casualizado. Para todas as variedades analisadas, foi registrada a emissão inicial de flores masculinas. Não foi registrada diferença significativa na emissão de flores femininas entre as variedades, porém para as flores masculinas a variedade Congo apresentou um maior número. Foi registrada diferença nas características da morfologia floral entre variedades e tipos florais em relação ao diâmetro e altura da flor. A presença de flores hermafroditas foi registrada com média de 1,45 (Crimson) a 0,15 flores por planta (Congo). A variedade Charleston apresentou a menor média de dias para a emissão da primeira flor feminina em relação a masculina (4,6±2,81) já a Congo apresentou a maior média (9,05±3,28). A menor razão sexual foi registrada para a variedade Elisa(1:13,32) e a maior para a Congo (1:24,05). Os menores períodos de floração foram registrados para as variedades Crimson e Elisa.</p><p> </p><p align="center"><strong><em>Flowering and floral morphology of watermelon varieties in Juazeiro-BA</em></strong></p><p><strong>Abstract-</strong> The watermelon commonly presents male and female flowers on the same plant, thus requiring the pollination services for the transfer of pollen grains and consequent production of fruits. The attractiveness to pollinators is dependent on the floral resources offered as a reward during visits and as a result the plant benefits from pollination. The objective of this study was to record important aspects of flowering including sex ratio and the description of floral morphology of varieties of watermelon. The varieties of watermelon were used, Congo, Elisa, super super Crimson and Charleston in organic farming, drip irrigation. Four treatments and four repetitions were performed using a completely randomized design. For all varieties analyzed, it was registered the initial issue of male flowers. It did not record significant difference in the issue of female flowers between varieties, but the male flowers to the Congo variety presented more. There was recorded differences in the characteristics of morphology flower varieties and types in relation to the height and flower diameter. The presence of hermaphrodite flowers was recorded with an average of 1.45 (Crimson) 0.15 flowers per plant (Congo). The Charleston variety had the lowest average number of days to issue the first female flower compared to males (4.6 ± 2.81) since the Congo had the highest average (9.05 ± 3.28). The lowest sex ratio was recorded for the variety Elisa (1: 13.32) and the highest for the Congo (1: 24.05). The smallest flowering periods were recorded for the Crimson and Elisa varieties. </p>


2016 ◽  
Vol 8 (4) ◽  
pp. 482-488
Author(s):  
Lawrence Stephen FAYEUN ◽  
Alexander Chukwunweike ODIYI ◽  
Ayodele Moruf ADEBISI ◽  
Lateef Akinkunle HAMMED ◽  
David Kolawole OJO

Knowledge of floral biology is essential to crop improvement. Ten genotypes of fluted pumpkin (Telfairia occidentalis) were observed for floral morphology, phenology and insect visitation for two consecutive years. Functional dioecy of fluted pumpkin was confirmed, whereas none of the studied genotypes was monoecious. Floral structures differed significantly among the genotypes. Both male and female flowers were symmetrical, pentasepalous, fimbriate and non-bright pentapetalous, but male flowers were more numerous. Male inflorescences emerged from 11 to 14 weeks after planting and the female flower buds appeared about 4 weeks later. The flowering period of the male flowers was longer than that of female flowers and both gender flowering periods coincided for a specific interval. It took between 11 to 14 days from bud initiation to anthesis and flowering ceased when there were occurrences of successful fruits set. In both gender flowers petals started unfurling at around 6.00 pm and full bloom was achieved by dawn, while petal shrivelled at sun set (between 6.30 pm to 7.30 pm). The anthers dehisced at anthesis of the male flowers; the pollen grains were whitish and sticky. Only the male flowers have nectar and pollen and this may explain infrequent female flowers visitation. Hover flies (Cheilosia species) were the major floral visitors observed. 


HortScience ◽  
1991 ◽  
Vol 26 (6) ◽  
pp. 681A-681
Author(s):  
Hurriah H. AL-Juboory

Gibberellic acid (GA3) promoted maleness and 2-Chloroethyl phosphonic acid (ethephon) promoted femaleness in cucumber (Cucumis sativus L.) cv Regal 446 seedlings when treated with water, ethephon (250 or 350 ppm) or GA3 (1000 or 2000 ppm) at the l-, 2-, or 3-leaf stage. Seedlings treated with ethephon at all stages produced more female flowers than those with water or GA3 treatments. GA3-treated seedlings produced significantly more male flowers than water treatments, at all developmental stages. The differential response of cucumber seedlings treated at different stages indicated the importance of timing growth regulator applications.


2009 ◽  
Vol 276 (1665) ◽  
pp. 2147-2152 ◽  
Author(s):  
Nathan Muchhala ◽  
James D. Thomson

In a hypothesis that has remained controversial since its inception, Darwin suggested that long-tubed flowers and long-tongued pollinators evolved together in a coevolutionary race, with each selecting for increasing length in the other. Although the selective pressures that flowers impose on tongue length are relatively straightforward, in that longer tongues allow access to more nectar, selective pressures that pollinators impose on flower length are less clear. Here, we test for such selective pressures in the highly specialized mutualism between the nectar bat Anoura fistulata , which can extend its tongue twice as far as other nectar bats, and Centropogon nigricans , which has flowers of a similar length (8–9 cm). We used flight cage experiments to examine the effects of artificially manipulated flower lengths on (i) bat behaviour and (ii) pollen transfer. Increased length produced longer visits, but did not affect the force bats applied during visits. In the second experiment, flower length increased both the male and female components of flower function: long male flowers delivered more pollen grains and long female flowers received more pollen grains. However, pollen transfer was not correlated with visit duration, so the mechanism behind differences in pollen transfer remains unclear. By demonstrating that bats select for increasing flower length, these results are consistent with the hypothesis that A. fistulata evolved its remarkable tongue in a coevolutionary race with long-tubed flowers similar to that envisioned by Darwin.


Author(s):  
Gregory J Anderson ◽  
Julia Pérez De Paz ◽  
Mona Anderson ◽  
Gabriel Bernardello ◽  
David W Taylor

Abstract Island plants provide special opportunities for the study of evolution and ecology. In field and greenhouse studies we characterized a model reproductive system for Plocama pendula, endemic to the Canary Islands. This species has a complicated and not immediately obvious reproductive system. Pollination is biotic, and all flowers are morphologically hermaphroditic, but half of the plants characteristically bear flowers with nectar, pistils with reflexed stigmatic lobes and pollen-less anthers (i.e. they are functionally female flowers). The other half bear nectar-less flowers with abundant pollen and full-sized pistils that mostly have un-reflexed stigmatic lobes (i.e. they are hermaphroditic flowers functioning mostly as males). However, experiments show these pollen-bearing flowers to be self-compatible. Thus, the functionally male flowers have a breeding system that allows selfing in limited circumstances, but the functionally male flowers produce far fewer fruits than do functionally female flowers. With morphologically gynodioecious, functionally largely dioecious flowers, sometimes capable of selfing, the reproductive system of this species could be labelled as ‘leaky’ in many respects. Thus, we propose that P. pendula has colonized new habitats and persists in substantial populations at least in part because it manifests a reproductive system that is a model for successfully balancing the often-conflicting evolutionary demands of colonization, establishment and persistence.


1979 ◽  
Vol 1 (1) ◽  
pp. 113
Author(s):  
Amélia Moema Veiga Lopes ◽  
Vanoli José Xavier Lopes

The the external morphological features of a monoecious plant Cannabis sativa L. were studied. These features were compared with those of dioecious plant described by CARAUTA (1) and COSTA & JACCOUD (2) and the following conclusions were reached: 1) the monoecious plant presents external characteristics similar to the male dioecious plant; 2) in the monoecious plant do occur, aproximately in the same proportion, flowers with 2 and 3 stigmas, while the dioecious plant normally has 2 stigmas present; 3) in branches on which modified flowers occur, the general aspect of the flowers suggests that the male flowers give origin to female flowers.


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