scholarly journals Light Quality Effects on Flower Sex Expression in Cucumber and Spinach

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 464D-464 ◽  
Author(s):  
Gary R. Bachman ◽  
Margaret J. McMahon
Keyword(s):  
Growth Regulators ◽  
Light Quality ◽  
Red Light ◽  
Female Flower ◽  
Sex Expression ◽  
Internode Elongation ◽  
Dioecious Species ◽  
Spectral Filters ◽  
Male Flowers

Using spectral filters to reduce the amount of far-red (FR) light perceived by plants has been shown to effectively reduce internode elongation of many floriculture crops. It is theorized that gibberellin (GA) function is inhibited in some way by the increase in the red: far-red light ratio. Sex expression of flowers are effected by exogenous applications of gibberellin and cause a shift in flower sex expression towards maleness. The use of growth regulators (GA inhibitors) have demonstrated a shift towards femaleness. Flowering of spinach, a dioecious species, and cucumber (staminate and pistillate lines), a monoecious species, were surveyed for shifts in flower sex expression, indicating a suppression of GA. Male: female flower ratio decreased from 7.6:1 to 4.06:1 when comparing the controls and –FR for the staminate cucumber line and 1:13 to 1:40 for the gynecious cucumber line. The decrease in male flowers on plants grown in a –FR environment are an indication that the function of GA is inhibited. There was no significant effect on the male: female flower ratios of the spinach.

scholarly journals The effect of growth regulators on sex expression in melon (Cucumis melo L.)

2013 ◽  
Vol 13 (3) ◽  
pp. 165-171 ◽  
Author(s):  
Zdenka Girek ◽  
Slaven Prodanovic ◽  
Jasmina Zdravkovic ◽  
Tomislav Zivanovic ◽  
Milan Ugrinovic ◽  
...  
Keyword(s):  
Gibberellic Acid ◽  
Growth Regulators ◽  
Cucumis Melo ◽  
Staminate Flower ◽  
Sex Expression ◽  
Male Flowers ◽  
Cucumis Melo L ◽  
Perfect Flower

Seven traits related to flowering and sex expression in melon were studied and their reaction to application of two growth regulators (ethrel and gibberellic acid) was observed. Four monoecious genotypes (Sesame, ED-3, ED-4, Pobeditel) and four andromonoecious genotypes (Chinese muskmelon, Anannas, Fiata, A2-3lb) had been used for experiments. According to the results, ethrel had higher effects on the investigated traits than gibberellic acid. Ethrel increased the number of perfect flowers per plant for 7.18 (31.42%), reduced the number of male flowers per plant for 21.47 (17.98%), affected earlier appearance of the first pistillate/perfect flower for 3.68 days, and delayed the appearance of the first staminate flower for 16.07 days. Changes in the last two traits caused an extension of the period from the emergence of the first pistillate/perfect to the first staminate flower from 0.1 to 21.57 days, which represents the strongest effect of ethrel. Gibberellic acid had generally opposite effects on the studied traits.

scholarly journals 263 Photoselective Films Influence Flowering of Photoperiodic Species

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 436E-436
Author(s):  
Teresa A. Cerny ◽  
Nihal C. Rajapakse ◽  
Ryu Oi
Keyword(s):  
Plant Species ◽  
Light Quality ◽  
Red Light ◽  
Photon Flux ◽  
Crop Species ◽  
Plastic Films ◽  
Spectral Filters ◽  
Short Day ◽  
Long Day ◽  
Air Temperatures

Growth chambers constructed from photoselective plastic films were used to investigate the effects of light quality on height manipulation and flowering of photoperiodic plant species. Three types of treatment films were used; control, a far-red light intercepting film (YXE-10) and a red light intercepting film (SXE-4). The red (600-700 nm):far-red (700-800 nm) ratios and phytochrome photoequilibrium estimates for the control, YXE-10 and SXE-4 films were 1.0 and 0.71, 1.5 and 0.77, and 0.71 and 0.67, respectively. The photosynthetic photon flux was adjusted to uniformity among chambers using neutral density filters. Spectral filters did not effect minimum and maximum air temperatures. Experiments were conducted using quantitative long day (Antirrhinum majus and Petunia × hybrida), quantitative short day (Zinnia elegans and Dendranthema × grandiflorum) and day-neutral (Rosa × hydrida) plant species under natural short-day conditions. Plants produced under the YXE-10 filters were significantly shorter than the control plants, while plants produced under the SXE-4 films had similar or increased height compared to the control plants. However, both height response and flowering times varied with the crop species. Flowering time of Rosa × hybrida plants was uniform among all treatments. Flowering of quantitative long-day plants was delayed by at least 10 days under the YXE-10 film and was most responsive to the filtered light. Flowering of quantitative short-day plants was delayed by 2 days under the YXE-10. Days to flower for plants produced under the SXE-4 film were similar to the control plants for all species tested.

scholarly journals Brassinosteriod-induced Femaleness in Cucumber and Relationship to Ethylene Production

HortScience ◽  
2005 ◽  
Vol 40 (6) ◽  
pp. 1763-1767 ◽  
Author(s):  
Ekaterina Papadopoulou ◽  
Rebecca Grumet
Keyword(s):  
Ethylene Production ◽  
Female Flower ◽  
Sex Expression ◽  
Bisexual Flower ◽  
Flower Production ◽  
Total Female ◽  
The Difference ◽  
Male Flowers ◽  
Cucurbitaceae Family

The Cucurbitaceae family is noted for a diversity of sex expression phenotypes. Typically, a phase of male flowers precedes either female or bisexual flower production. Sex determination of individual flowers is regulated by a combination of genetic, environmental, and hormonal factors. Ethylene, auxins, and gibberellins have all been shown to influence flower sex expression in cucurbits. Ethylene, which promotes femaleness, plays a predominant role. In this study, we tested whether brassinosteroids (BR), a more recently identified class of plant hormones, also influences cucurbit sex expression. Applied epi-brassinolide (epi-BL) caused a significant decrease in time of appearance of the first female flower on monoecious cucumber plants, and increased total female flowers on the main stem. Increasing concentrations had a stronger effect. Of the three species tested, cucumber, melon and zucchini, cucumber was the most responsive to BR. Application of epi-BL also caused an increase in ethylene production by cucumber and zucchini seedlings, suggesting that the BR effect may be mediated by ethylene. To investigate the possible relationship between BR and ethylene on sex expression, we identified the concentration of ethephon (5 ppm) that caused an increase in ethylene production comparable to that induced by 10 μm epi-BL (approximately two-fold). Treatment with 5 ppm ethephon was sufficient to increase femaleness of cucumber plants, but not zucchini plants, suggesting that the difference in response to epi-BL treatment may reflect differences in sensitivity to ethylene. Collectively, our results indicate that application of brassinosteroids to cucumber cause earlier and increased female flower production, and that the effects may be mediated, at least in part, by brassinosteroid-induced production of ethylene.

Ploidy and sex expression in monoecious hop (Humulus lupulus)

Botany ◽  
2012 ◽  
Vol 90 (7) ◽  
pp. 617-626 ◽  
Author(s):  
Suzana Skof ◽  
Andreja Cerenak ◽  
Jernej Jakse ◽  
Borut Bohanec ◽  
Branka Javornik
Keyword(s):  
Nuclear Dna ◽  
Flow Cytometric Analysis ◽  
Nuclear Dna Content ◽  
Female Flower ◽  
Sex Expression ◽  
Unreduced Gametes ◽  
Humulus Lupulus ◽  
Dna Amount ◽  
Perennial Plant ◽  
Male Flowers

Humulus lupulus L. is a dioecious perennial plant, cultivated for its female inflorescences. Spontaneously arising monoecious hop plants, carrying male and female flower types on a specific plant, occasionally occur in the progeny of certain hop crosses. We assessed the ploidy of 58 monoecious plants, progenies of various crosses of diploid parents, to provide additional data on hop monoeciousy. Flow cytometric analysis revealed that a high percentage (41.4%) were triploid. An inheritance analysis of parental alleles using six codominant SSR markers demonstrated a primarily paternal origin (84.2%) of unreduced gametes as the cause of triploidy in monoecious plants. All triploids had predominantly male flowers with a few female cones; this phenotype was found only within this ploidy group. All other monoecious plants were diploid, except for one genotype with the highest nuclear DNA content, which showed an aneuploidic number of chromosomes (21). Male hops showed the lowest nuclear DNA amount, as measured by DAPI and propidium iodide fluorochromes. The estimated AT frequency placed hop among species with a high AT content, which was slightly higher in male than in female plants (63.0% vs. 62.5%). The results are discussed in relation to the occurance of ploidy and sex expression in monoecious hop.

scholarly journals Influence of plant growth regulators on vegetative growth, sex expression and yield of summer bottle gourd

2020 ◽  
Vol 44 (4) ◽  
pp. 577-590
Author(s):  
M Moniruzzaman ◽  
R Khatoon ◽  
M Moniruzzaman ◽  
AKM Qamruzzaman
Keyword(s):  
Sex Ratio ◽  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Female Flower ◽  
Sex Expression ◽  
Fruit Weight ◽  
Bottle Gourd ◽  
Male And Female ◽  
Female Flowers

Field experiments on bottle gourd variety ‘BARI Lau -4’ were conducted at the Plant Physiology field of Horticulture Research Center, Bangladesh Agricultural Research Institute, Gazipur during two consecutive summer seasons of 2015 and 2016 to investigate the effect of plant growth regulators on growth, sex expression, yield and yield components of the crop. The experiment consisted of different concentrations of Gibberellic acid (GA3), Naphthalene acetic acid (NAA), Maleic hydrazide (MH) and single concentration of cycocel (CCC) viz., GA3 @ 10 ppm, GA3 @ 30 ppm, NAA @100 ppm, NAA @ 150 ppm, MH @ 50 ppm, MH @ 150 ppm and CCC @ 500 ppm along with distilled water considered as control. All growth regulators were sprayed to the seedlings at two-leaf stage and 4 days after the first spray. Growth regulator treatments had significant effect on primary branches/plant, node number of 1st male and female flower appearance, number of days to 1st male and female flower appearance, number of male and female flowers, sex ratio (male:female flower) number of fruits/plant, individual fruit weight and fruit yield. Spraying of MH @ 150 ppm gave the highest primary branches/plant (17.0 and 18.0 in first and 2nd year, respectively) and induced maximum female flowers (37.3 and 40.0 in first and 2nd year, respectively) at lower nodes followed by CCC @ 500 ppm (36.3) in the first year and MH @ 50 ppm (40.0) in the 2nd year. Application of MH @ 150 ppm caused early appearance of female flowers on the nearest node (from bottom). Application of MH @ 150 ppm gave the lower number of male flowers (81.7 and 96.0 in first and 2nd year, respectively) and the highest number of female flowers/plant, thereby producing lower male:female sex ratio (2.2 and 2.5 in first and 2nd year, respectively) and the maximum number of fruits/plant (12.0 and 14.0 in first and 2nd year, respectively). The maximum fruit weight/plant was obtained from the application of MH @ 150 ppm (29.3 and 35.8 in first and 2nd year, respectively) followed by CCC @ 500 ppm (26.0 in the 1st year and 29.0 in 2nd year). The highest fruit yield per hectare was recorded significantly with the application of MH @ 150 ppm (97.6 t/ha and 89.6 t/ha in first and 2nd year, respectively) closely followed by CCC @ 500 ppm (88.5 t/ha in 2015) and GA3 @ 30 ppm (75.3 t/ha in 2016), as compared to other treatments. The highest mean yield over the years was also recorded at MH @ 150 ppm (93.6 t/ha) followed by CCC @ 150 ppm (80.6 t/ha) and GA3 30 (74.1). Application of MH @ 150 ppm gave the maximum gross return and net return with the highest BCR of 5.24 followed by CCC 500 ppm (4.15) and GA3 30 ppm (3.86). Bangladesh J. Agril. Res. 44(4): 577-590, December 2019

scholarly journals Influence of Spectral Filters on Height, Leaf Chlorophyll, and Flowering of Rosa × hybrida ‘Meirutral’

1990 ◽  
Vol 8 (4) ◽  
pp. 209-211
Author(s):  
M.J. McMahon ◽  
J.W. Kelly
Keyword(s):  
Light Quality ◽  
Red Light ◽  
Rosa Hybrida ◽  
Photon Flux ◽  
Textile Dye ◽  
Photosynthetic Photon Flux ◽  
Flower Buds ◽  
Spectral Filters ◽  
Leaf Chlorophyll ◽  
Growth Chambers

Abstract Growth of Rosa × hybrida ‘Meirutral’ under different spectral filters was evaluated. Two filters that altered far-red (730 nm)/red (660 nm) light (FR/R) were developed. One, a blue textile dye, increased FR/R by filtering out a portion of red light. The second, a salt (copper sulfate) decreased FR/R by filtering out a greater portion of far-red than red light. A third filter that did not alter light quality was the control. The filters were installed in specially built growth chambers. Photosynthetic photon flux (PPF) was adjusted to equal values in each chamber. Plants were significantly shorter and had higher leaf chlorophyll when grown under the reduced FR/R filter. The number of flower buds and number of buds showing color at termination of the experiment was not affected by light quality treatments.

scholarly journals INFLUENCE OF END OF DAY FAR-RED LIGHT ON HEIGHT OF CHRYSANTHEMUM PLANTS UNDER CuSO4 SPECTRAL FILTERS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 649a-649
Author(s):  
Nihal C. Rajapakse ◽  
Margaret J. McMahon ◽  
John W. Kelly
Keyword(s):  
Weight Reduction ◽  
Red Light ◽  
Plant Morphology ◽  
Dry Weight ◽  
Internode Length ◽  
Internode Elongation ◽  
Additional Mechanism ◽  
Spectral Filters ◽  
Reduced Height ◽  
Stem Internode

The response of `Bright Golden Anne' and `Spears' chrysanthemum plants to EOD-R or FR light was evaluated to determine the involvement of phytochrome in regulation of plant morphology under CuSO4 filters. Light transmitted through the CuSO4 filter significantly reduced height, internode length and stem dry weight of `BGA' and `Spears' chrysanthemum plants. However, the degree of response varied with the cultivar. Exposure to EOD-FR reversed the reduction of plant height, internode length and the stem dry weight caused by the light transmitted through CuSO4 filters to a level comparable with control plants. Exposure to EOD-FR did not significantly alter height and stem dry weight under control filter Exposure to EOD-R light reduced the height and stem dry weight of `BGA' plants grown under control filter but EOD-R had no effect under CuSO4 filters. In `Spears' plants, EOD-R caused stem dry weight reduction under control filters, but did not reduce stem or internode elongation. The results suggest phytochrome may be involved in controlling plant response under CuSO4 filters. However, there are evidence to indicate that an additional mechanism may be acting on stem/internode elongation.

scholarly journals (214) Brassinosteroid-induced Femaleness in Cucumber and Relationship to Ethylene Production

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1057C-1057
Author(s):  
Ekaterina Papadopoulou ◽  
Rebecca Grumet
Keyword(s):  
Ethylene Production ◽  
Female Flower ◽  
Sex Expression ◽  
Predominant Role ◽  
Flower Production ◽  
Total Female ◽  
The Difference ◽  
Male Flowers ◽  
Female Flowers

The cucurbit family is noted for diversity in sex expression phenotypes. Typically, a phase of male flowers precedes the appearance of female or hermaphrodite flowers. Sex determination of individual flowers is regulated by genetic, environmental, and hormonal factors. Ethylene, auxins, and gibberellins all influence flower sex, with ethylene, which promotes femaleness, playing a predominant role. In this study, we tested whether brassinosteroids, a more recently identified class of plant hormones, also influence cucurbit sex expression. Applied epi-brassinolide (epi-BL) caused a significant decrease in time of appearance of the first female flower on monoecious cucumber plants, and increased total female flowers on the main stem. Increasing concentrations had a stronger effect. Of the three species tested, cucumber, melon, and zucchini, cucumber was the most responsive. Application of epi-BL also caused an increase in ethylene production by cucumber and zucchini seedlings, suggesting that the BR effect may be mediated by ethylene. To investigate the possible relationship between BR and ethylene on sex expression, we identified the concentration of ethephon (5 ppm) that caused an increase in ethylene production comparable to that induced by 10 μm epi-BL (about two-fold). Treatment with 5 ppm ethephon was sufficient to increase femaleness of cucumber plants, but not zucchini plants, suggesting that the difference in response to epi-BL may reflect differences in sensitivity to ethylene. Collectively, our results indicate that application of brassinosteroids to cucumber cause earlier and increased female flower production, and that the effects may be mediated, at least in part, by brassinosteroid-induced increased production of ethylene.

Response of snake cucumber (Cucumis melo var. pubescens) to some plant regulators

1982 ◽  
Vol 99 (3) ◽  
pp. 587-590 ◽  
Author(s):  
E. El-Kholy ◽  
H. Hafez
Keyword(s):  
High Temperature ◽  
Sex Ratio ◽  
Cucumis Melo ◽  
Total Yield ◽  
Female Flower ◽  
Sex Expression ◽  
Significant Suppression ◽  
Yield Production ◽  
Male Flowers ◽  
Fruit Characters

SUMMARYTrials were conducted during the summer seasons (1978 and 1979) at the Faculty of Agriculture, Elminia University, to evaluate the effect of some growth regulators on sex expression, sex ratio and yield production of snake cucumber. The results obtained showed that both sex expression and ratio could be modified with plant regulator sprays even under the long and high temperature conditions of Elminia governorate. All plant regulators induced the formation of the first female flower at lower nodes compared with the control. There was significant suppression of male flowers in plants sprayed with plant regulators. All the treatments gave an increase in total yield and improved fruit characters.

scholarly journals EFFECTS OF SPECTRAL FILTERS ON GROWTH OF ROSA × HYBRIDA AND EXACUM AFFINE.

HortScience ◽  
1990 ◽  
Vol 25 (8) ◽  
pp. 849a-849
Author(s):  
Margaret J McMahon ◽  
John W. Kelly
Keyword(s):  
Light Quality ◽  
Red Light ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Textile Dye ◽  
Light Spectrum ◽  
Spectral Filters ◽  
Leaf Chlorophyll ◽  
Exacum Affine

The growth of Rosa × hybrida and Exacum affine under different spectral filters was evaluated. Three filters that altered light quality were developed. One, a red textile dye, filtered out much of the blue/green portion of the light spectrum but did not change far-red to red (FR/R) light ratio. Another, a blue textile dye, raised FR/R by filtering out a portion of red light. The third, a salt (copper sulfate) lowered FR/R by filtering out a greater portion of far-red than red light. Two controls were used that did not alter light quality. The filters were installed in specally built growth chambers. Photosynthetic Photon Flux Density (PPFD) was adjusted to equal values in each chamber. Plants of both species were significantly shorter and had higher leaf chlorophyll, when grown under the low FR/R filter.

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