Number Of Female Flowers Research Articles

Effect of Drought Stress on Agronomic Traits and Total Leaf Proteins in Different Bottle Gourd [<i>Lagenaria siceraria</i> (Molina) Standl.] Genotypes

Breeding drought-tolerant genotypes using genetic and biochemical tools is an important mitigation strategy to improve stress response and yields in bottle gourd [<em>Lagenaria siceraria</em> (Molina) Standl.]. This current study evaluated the variations among bottle gourd genotypes for potential breeding purposes by establishing the relationship between agronomic traits and the protein profile required for the plants’ resilience against drought stress. The study assessed 12 bottle gourd accessions grown under non-stressed (NS) control conditions and different levels of drought stress (DS) induced by withholding irrigation for 7, 14, and 21 days, using a 12 × 2 × 3 factorial experiment in a randomized complete block design with 3 replicates. Agronomic traits such as the total number of male and female flowers per plant, sex ratio, fruit number and fruit yield per plant (FYPP), and total protein analysis were determined in bottle-gourd plants immediately after the period of stress. Results showed significant differences (<em>p</em><em> </em>< 0.001) among the genotypes × environmental effect for most agronomic traits except the number of days to first flower (DTFF). Among the genotypes, BG-70 and BG-78 recorded the highest FYPP under drought stress conditions, with BG-70 showing similar results even under NS conditions. A positive correlation was found among all the agronomic traits and the total protein contents of the genotypes, especially after 14 days of drought stress. Overall, the results implied that the significant improvements in agronomic traits and unique protein expressions observed in BG-70 and BG-78 potentially confer tolerance to drought stress. Moreover, the high and unique proteins found in all genotypes (BG-48, BG-58, BG-52, BG-70, BG-78, and BG-81) warrant further research on their interaction with the stress, especially when coupled with improved agronomic traits, which could assist in identifying drought stress tolerant genotypes.

Natural and anthropogenic factors influence flowering synchrony and reproduction of a dominant plant in an inter-Andean scrub.

Agriculture expansion, livestock, and global change have transformed biological communities and altered, through aerosols and direct deposition, N:P balance in soils of inter-Andean valleys, potentially affecting flowering phenology of many species and thereby flowering synchrony and plant reproduction. We evaluated the influence of variation in temperature and moisture along the local elevational gradient and treatments with the addition of N and P and grazing on flowering synchrony and reproduction of Croton, a dominant shrub of the inter-Andean dry scrub. Along the elevational gradient (300 m difference between the lowest and highest site), we set up plots with and without grazing nested with four nutrient treatments: control and addition of N or P alone or combined N + P. We recorded the number of female and male flowers in bloom monthly from September 2017 to August 2019 to calculate flowering synchrony. We assessed fruiting, seed mass, and pre-dispersal seed predation. Higher growing-season soil temperatures, which were negatively associated with local elevation and higher nitrogen availability promoted flowering synchrony of Croton, particularly among larger plants. Greater flowering synchrony, high soil temperatures, and addition of N + P resulted in production of more fruits of Croton, but also intensified pre-dispersal seed predation. Temperature, availability of moisture throughout the elevational gradient, and nutrient manipulation affected flowering synchrony, which subsequently affected production of fruits in Croton. These results emphasize the critical role of current anthropogenic changes in climate and nutrient availability on flowering synchrony and reproduction of Croton, a dominant plant of the inter-Andean scrub.

Potential coconut (Cocos nucifera L.) genotypes for farmers: Evaluation of agronomic traits in a lethal yellowing disease endemic zone in Ghana

A four-year study was conducted to evaluate selected vegetative and reproductive characteristics in four coconut genotypes namely: Niu Leka Dwarf (NLD), New Guinea Brown Dwarf (NGBD), Malayan Green Dwarf (MGD), Indonesian Brown Dwarf (IBD), and a hybrid between Sri Lankan Green Dwarf and Vanuatu Tall (SGDVTT), which was used as a control. The study was located at Anwea in the Western Region of Ghana, an endemic zone to the lethal yellowing disease. This experiment was laid out in a randomized complete block design (RCBD) in three replications. Results showed a significant higher growth for NGBD, IBD, and NLD in stem girth, leaf length, petiole length, and number of leaflets. NGBD, IBD, and SGDVTT also recorded significantly higher reproductive characteristics. Time taken for first flowering was noticed in IBD (41.30 months). NGBD recorded the highest number of female flowers (27.80), number of spikelets with female flowers (17.20), and total number of spadix (12.50) seasonally. Significant and positive correlations were observed between the number of leaves emitted, and the number of female flowers produced in the coconut genotypes except for MGD. The highest correlation between these vegetative and reproductive characteristics was expressed in IBD while the least was observed in the MGD genotype. MGD also recorded the least number of spikelets with female flowers, suggesting that this genotype is not likely to produce high number of fruits and should not be included in future breeding programs. Low and less robust characteristics were expressed in both SGDVTT, and MGD in the growing period, which could be ascribed to the rather low number of leaflets observed in these genotypes. Conclusions from this study suggest that NGBD, IBD, and NLD are potential genotypes to be integrated into further breeding programs across coconut-growing regions in Ghana.

Pengaruh Pupuk ‘Mutiara’ dan Giberelin Terhadap Pertumbuhan dan Produksi Tanaman Semangka Partenocarpi

Watermelon production is influential in supporting the increase of income of the farm. Watermelon production tends to decline at present, so that efforts need to be carried out to optimize the growth and yield of watermelon plants. One of the important nutrients source for watermelon plants is ‘Mutiara’ fertilizer and the plant growth regulator (PGR) gibberellin. This study aimed to determine the right combination of ‘Mutiara’ fertilizer dosage and gibberellin concentration on the growth and yield of parthenocarpic watermelon plants. This research was conducted from September to December 2023 at Pattimura Mutiara Farm of Pattimura University, in Rumahtiga Village, Teluk Ambon Subdistrict, Ambon City. This research was an experimental study that used a Factorial Randomized Group Design (RAK) consisting of two treatment factors, i.e.: ‘Mutiara’ fertilizer with 4 levels and the dose of gibberellin with 4 levels, with replications, so that there was a total of 48 treatment combinations. The observed variables included plant height, number of leaves, number of female flowers formed, fresh fruit weight, fruit diameter, and number of seeds. The results showed that the interaction between the dose of ‘Mutiara’ fertilizer 6 g/plant and the concentration of gibberellin 6 mL/L was the best treatment combination and could increase plant length and number of leaves. The combination of 2 g of ‘Mutiara’ fertilizer and 2 mL/L gibberellin concentration was the best combination for fresh fruit weight

Efficacy of Ethephon Doses on Vegetative and Reproductive Attributes of Watermelon [(Citrullus lanatus (Thunb.) Matsum. & Nakai

Watermelon is a widely cultivated cucurbitaceous crop with economic and dietary significance. The plant's ability to reproduce effectively relies on the harmonious growth and maturation of both its male and female flowers. At the farm level, determining the exact amount of ethylene required to regulate the development and sexual expression of individual floral buds remains uncertain, despite the known influence of exogenously applied ethylene on these processes. The goal of the research was to explore how the ethephon doses influence vegetative characteristics, sex expression, and watermelon yield. The experiment, employing a one-factorial Randomized Complete Block Design (RCBD) comprising five treatments and four replications, was conducted in a farmer's field in Buttabari, Jhapa. Using R-stat software, the data were analyzed at a 5% level of significance. Treatment consisted of Ethephon with four doses namely; 100ppm, 200ppm, 300ppm, 400ppm, and a control. Ethephon application was done twice, once at the two true-leaf stages and another at four true-leaf stages. The study revealed that plant height decreased with ethephon compared to the control, reaching a minimum of 280.1 cm at 400 ppm and a maximum of 307.1 cm in the control. Additionally, the highest branch numbers were observed with ethephon at 200 ppm. The plot treated with 200ppm ethephon was found to be more effective than alternative doses at increasing the total number of female flowers, bearing 15.25 female flowers per plant. Control (166.50 per plant) and 400 ppm (150.00 per plant) had the highest and lowest male flower counts per plant, respectively. A maximum yield of 25.12 t/ha and a minimum yield of 19.1 t/ha were determined at 200 ppm and control, respectively. Hence, farmers are found to benefit from ethephon doses of 200 ppm.

The Effect of Foliar Application with Naphthalene Acetic Acid and Potassium Nitrate on the Growth, Sex Ratio, and Productivity of Cucumbers (Cucumis sativas L.) under High Temperatures in Semi-Arid Areas

High temperatures in late spring, summer, and autumn are one of the main elements limiting cucumber production. Heat stress in cucumber plants leads to significant changes in sex expression and negative effects at the physiological stage, including decreased absorption of water and nutrients, decreased photosynthetic functions, and increased respiration, which in turn affects growth and production. Therefore, it is very difficult for cucumber plants exposed to heat stress to improve their productivity, especially in arid and semi-arid regions. Cucumber plants bear a variety of flower forms, including staminate, pistillate, and hermaphrodites that occur in different arrangements. In addition, maleness is considered the main problem in cucumber production, as it significantly reduces fruit yield. Recently, the growth, flowering, and productivity of plants have been controlled with the help of growth-regulating substances, and one of these substances is naphthalene acetic acid (NAA), which is of great importance in modifying sex in cucumber and various cucurbit crops. Two experiments were conducted during 2022 and 2023 during the summer season to study the effect of foliar spraying of two levels of potassium nitrate, 500 mg/L and 1000 mg/L, and two levels of NAA, 50 mg/L and 100 mg/L, individually and together, and the comparison treatment in nine treatments on growth traits, sex ratio, fruit traits and yield of cucumber (Cucumis sativas L.) plants in three replicates in a completely randomized block design. The results indicated that applying the treatment containing 1000 mg/L KNO3 + 100 mg/L NAA led to obtaining the highest value in most vegetable growth, flowering, and production parameters, with a significant increase compared to the control and all other treatments. Followed by treatments consisting of potassium nitrate and NAA, which gave high values in the traits of sex ratio %, fruit setting %, fruit yield, and most other traits. This study showed the importance of spraying with both NAA and potassium nitrate, individually or in combination, and the high combined effect of both in the treatments that contained each of them in the vegetative growth traits and floral traits such as the number of female flowers, the sexual ratio, fruit set percentage, weight fruit, length fruit, and the fruit yield in cucumber plants grown in the summer season with high temperatures

Study On The Growth, Yield And Yield Attributes Of Eight Varieties Of Bitter Gourd (Momordica Charantia L.)

Seeds of eight varieties of bitter gourd (V1, V2, V4, V5, V6, V7, V9 and V10) were sown in the experimental field and their growth, yield and yield attributes were studied. The length, number of nodes and leaves and number of branches per plant were highest in V1. The number of female flowers, number of fruits and yield per plant were found maximum in V4. Chlorophyll a and total pigment contents of leaves were highest in V2. Total NPK and Vitamin C contents of fruits were found highest in V6. The Chittagong Univ. J. B. Sci.,Vol. 7(1 &2):167-174 , 2012

Effects of Addition of Humic and Fulvic Acids on Soil Properties and Germination Percentage of Cucurbit Plants (Zucchini and Cucumber)

This research was conducted to study the effect of adding humic and fulvic acids to the irrigation water on soil properties and germination percentage of two cucurbit plants: zucchini and cucumber. The study was conducted in an open field in Sokhna District in the governorate of Zarqa (Jordan). The field soil was transported to calcareous sandy soil. In the beginning, the weeds and stones were removed, and the land was smoothed and plowed. Effort was made to control weeds and insects at all stages of plant growth. Then, an irrigation network was installed. The fulvic acid-humic acid (FA-HA) biostimulant mixture was incorporated with the irrigation water, and irrigation was practiced three days per week for four weeks. During this period, every irrigation round lasted for two to three hours. A mixture of humic acid (8.0%) and fulvic acid (8.0%) was added to the irrigation water. Three treatments were considered, corresponding to three acid mixture concentrations: 0.50 mL.L-1, 1.00 mL.L-1, and 1.50 mL.L-1. The acid mixtures were added continuously at all stages of plant growth until plant maturity and harvest. Four replicates of the experiment were made. The plant growth variables of interest were germination percentage, number of leaves, date of fruition, size of fruit, and overall mass of fruits. Meanwhile, the soil parameters of interest were soil pH and soil salinity (electric conductivity (EC)) before and after adding the FA-HA mixture. The study found that the 0.5 mL.L-1 acid mixture treatment led to the early growth of the zucchini plant seeds and that fruition took place 12 days after planting. In addition, the results showed an increase in plant germination under the 0.5 mL.L-1 acid mixture treatment in light of the increase in the number of male and female plant flowers, with fruiting taking place on time. In conclusion, the relationship between zucchini growth and yield with FA-HA mixture concentration is non-linear. It is also concluded that the optimum acid mixture concentration and application rate are crop-specific. Hence, for each crop, the most appropriate acid mixture concentration should be determined first before the broad-scale application of amendments to the soil to ensure the contribution of this environmentally friendly practice to sustainable agriculture.

An analysis of sex ratio value, fruit set and fruit to bunch of palm oil Socfindo MT Gano variety on mature plants (MP1, MP2, MP3)

Several studies in managing fruit sets and fruit to bunch are needed to get an ideal concept of treatment for varieties, one of which is the technical culture to explore the production potential of cultivated varieties. Therefore, this research aims to determine the sex ratio, fruit set, and fruit to bunch of palm oil bunch of Socfindo MT Gano variety on mature plants. This research was conducted using the survey method, object of research namely the 2019 planting year (3 years old), the 2018 planting year (4 years old), and the 2017 planting year (5 years old). The data collected were the number of male flowers, female flowers, stalk weight, stalk diameter, fruit, and parthenocarpy fruit, then calculated the sex ratio, fruit set, and fruit to bunch, analyzed by Analysis of Variance at a 5% level. The results indicated that the sex ratio and fruit to bunch were significantly different between MP1, MP2, and MP3, but the fruit set presented no significant difference between MP1, MP2, and MP3. The sex ratio is negatively correlated with fruit set and fruit to bunch, while the fruit set is positively correlated with fruit to bunch with an exceptional relationship.

Correlation and Path Coefficient Analysis in Bitter Gourd (Momordica charantia L.) Genotypes

Correlation of various characters with yield is useful and provides criteria for direct selection of component characters. The other genetic parameter commonly used is the path analysis as given by Dewey and Lu, 1959. It critically breaks up different direct and indirect effects which finally add upto the correlation coefficient. The present investigation was undertaken at the Experimental field of Urban Technological Park Habbak, Srinagar, Jammu and Kashmir during kharif-2022. The experiment was laid out in Randomized Block Design with three replications and plant spacing of 2×1 m for thirty genotypes in order to study the association among yield and yield components, their direct and indirect influence on total marketable fruit yield. Observations were recorded on various growth and yield traits and seed traits. Positive and significant correlation was noted for fruit yield ha-1 with number of male flowers plant-1, number of female flowers plant-1, vine length (m), number of fruits, average fruit weight (g), leaf area (cm2), number of seeds fruit-1, seed weight fruit-1 and fruit yield plant-1 both at genotypic and phenotypic levels. Path coefficient analysis disclosed that traits such as number of fruits per plant, vine length (m), number of female flowers, average fruit weight(g) and number of seeds per fruit should be given due importance by selection for breeding of new cultivars as they exhibited the highest direct effects on the fruit yield ha-1.

Respon Pertumbuhan dan Produksi Labu Madu (Cucurbita moschata) Keturunan Keempat (F4) Hidroponik Sistem NFT pada Konsentrasi Nutrisi AB Mix yang Berbeda

This study aims to obtain the best concentration of AB Mix nutrients for the growth and production of four (4) phenotypes of honey gourd (Cucurbita moschata) hydroponic NFT system, as well as determine the growth and production of four (4) phenotypes of honey gourd hydroponic NFT system at different AB Mix nutrient concentrations. This research was carried out at Greenhouse DnR Hydroponic Farm Housing Pondok Bedadung Indah Block AA.01. Sumbersari District, Jember Regency, East Java with an altitude of 70 meters above sea level from November 2022 to January 2023. This study was conducted using a Complete Randomized Design (RAL) factorial 3 x 4 with 3 repeats. The first factor is the concentration of AB Mix (N) nutrients consisting of three (3) levels, namely: 700 – 1400 ppm (N1), 900 - 1700 ppm (N2), 1100 - 2000 ppm (N3) and the second factor: phenotype (B) consists of four (4) phenotypes, namely: Flat round (B1), Round oval (B2), Long-necked (B3), Notched (B4). The parameters observed in this study include plant height, number of leaves, number of male flowers, number of female flowers, fruit diameter, fruit length, fruit weight, sweetness content. The observed data were analyzed with the F test to determine the effect of treatment. Different results were marked, followed by a level of 0.05. Using Duncan software test with SPSS 26 for windows. The results showed that AB Mix nutrition with a concentration of N3 (1100-2000) ppm resulted in the highest growth and production of F4 honey pumpkin on the parameters of plant height, number of leaves, number of male flowers, fruit diameter, fruit length, fruit weight, sweetness content, The influence of F4 honey pumpkin phenotype causes fruit shape diversity on the parameters of fruit diameter, fruit length, fruit weight. F4 seeds are heterozygous.

Association studies on Yield and Yield Components in Snap Melon (Cucumis Melo. Var. Momordica)

An experiment was carried out at Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore to study the correlation analysis in snap melon. The study revealed that the traits fruit girth, fruit weight, number of primary branches, flesh thickness, number of female flowers per plant, fruit length, fruit girth, fruit weight, days to first harvest, number of fruits per plant, vine length, TSS, protein, carbohydrate, calcium, iron showed high positive significant correlation with fruit yield per plant. The traits such as days to first male flower appearance, node at which first female flower appearance and days to first harvest registered negative significant association with yield

Assessment of growth characteristics and yield of different cucumber cultivars

A field experiment was carried out to determine the performance of different cucumber varieties. The research was carried out in Randomized Complete Block Design (RCBD) with 4 treatments and 6 replications. The varieties used are Bhaktapur local, Kamini, Ragini, and Ranjha. Data were collected on the following parameters such as stem length, plant height, number of leaves, number of branches, number of male flowers, number of female flowers, days to first flowering, male to female flower ratio, days to first male flowering, days to first female flowering, fruit weight, fruit length, number of fruits per plant and yield. It is found that among the performance of different varieties, Kamini was the best high yielding variety for this locality with a yield of 58.93 ton ha-1 followed by Ranjha. Kamini exhibited a greater count of female flowers and fruits. In comparison, Bhaktapur local outperformed other varieties in various aspects such as plant height (193.37 cm), number of leaves (42.39), number of branches (7.13), and male to female ratio (2.63).

The Effect of Applying Cow Dung Manure on Plant Growth and Yield Honey Gray (Cucurbita moschata L.)

This study aims to examine the effect of cow manure on the growth and yield of pumpkin honey (Cucurbita moschata L.). This research has been carried out in the Experimental Garden of the Faculty of Agriculture, Tridinanti University located in Pulau Semambu Village, North Indralaya District, Ogan Ilir Regency, South Sumatra Province. The study has been conducted from April 2023 to July 2023. The method used in this study is an experimental method, using Randomized Block Design (RBD) with 5 (five) treatments and 5 (five) repeats. Each unit consists of 20 plants so that the plants studied are 500 plants. The treatment in this study was P0 (without cow dung manure), P1 (10 tons of cow dung manure per hectare equivalent to 300 g per plant), P2 (20 tons of cow dung manure per hectare equivalent to 600 g per plant) P3 (30 tons of cow dung manure per hectare equivalent to 900 g per plant) and P4 (40 tons of cow dung manure per hectare equivalent to 1,200 g per plant). Based on the results of the study, it can be concluded that the application of cow dung manure has a good effect on the growth and yield of honey gourd plants. The application of cow dung manure P2 (20 tons/ha) resulted in the main length of the 1st month as high as 187.62 cm, the length of the main stem of the 2nd month as high as 327.16 cm, the length of the main trunk of the 3rd month as high as 367.36 cm, the number of primary branches 2.33 branches, flowering age 37 hst, the number of female flowers 63.30%, dry weight of plants 53.09 g, the number of fruits per plant 1.18 pieces, Fruit weight per plant 1.12 kg and fruit weight per plot 12.71 kg.

Size‐dependent clonal reproduction and sex allocation in the monoecious Begonia emeiensis

AbstractSize‐dependent clonal and sexual reproduction has been studied in many species. However, very few attempts have investigated size‐dependent resource allocation among clonal reproduction, female function, and male function within a species. Moreover, how clonal reproduction and sexual reproduction interact to influence size‐dependent sex allocation has not been explored. In this study, we investigated the size dependency of clonal reproduction and sex allocation and how clonal reproduction and sexual reproduction interact to influence size‐dependent female function, male function, and sex allocation in the monoecious Begonia emeiensis. Individuals with no reproduction, reproducing clonally through bulbils, reproducing sexually through flowers, and reproducing through both bulbils and flowers differed significantly from each other in terms of size (leaf area), suggesting a threshold size for clonal versus sexual reproduction. Bulbil number per individual increased with size regardless of flower production. In contrast, the relationship between size and female and male flower production per individual was influenced by bulbil production; both female and male flower numbers per individual increased with size at a slower rate for individuals reproducing clonally and sexually than for those reproducing only sexually. The ratio of female to male flowers per individual increased with size independent of bulbil production. Our study shows that the size dependency of clonal reproduction was unlikely to be influenced by sexual reproduction; however, the size dependency of female and male function was influenced by clonal reproduction.

Mutagenic effect of ultraviolet rays on sex expression in summer squash genotypes

The present study aimed to induce genetic variations within the control of sex expression in summer squash using ultraviolet rays (UV) as a physical source of mutations in plants. Because the sex expression in summer squash is fundamentally controlled mainly by genetics and partially by the environment. Therefore, this study tries to increase floral differentiation of female flowers, as well as decrease male flowers developed per plant, because summer squash usually exhibit more male flowers and lower female flowers. This will cause decreases in fruits yield per plant. This study was designed in a randomized complete block design with a factorial investigation. It was included four genotypes of summer squash subjected to four exposure periods of UV rays, with three repetitions for each experimental unit. The results showed that genotype number four increased the features of female flowers by 28% and 14% at 4 and 8 minutes of exposure period, respectively. The 12 – minute exposure period significantly increased floral differentiation among all genotypes toward male flowers developed per plant. Meanwhile, genotype number two enhanced floral differentiation toward female flowers by 14% at 8 minutes of exposure period, indicating that these few periods of exposure to UV irradiation may be responsible for induced benefit mutations in cucurbits affected on sex expression, as it induced high number of female flowers. The results indicated that UV irradiation had a direct role in promoting floral differentiation as it inducement higher female flowers in some genotypes leading to improve floral characteristics, as a consequence increased fruits yield per plant.

Bloom Performances during Rainy Season of Off-season Longan (Dimocarpus longan Lour. ‘Phuang Thong’) Grown at Samut Sakhon Province, Thailand

Rainy season is an obstruction for efficient off-season longan production in Thailand. In this experiment, the bloom performances of off-season 'Phuang Thong' longan as affected by microclimate in a private longan orchard at Ban Phaeo district, Samut Sakhon province was evaluated during the rainy season of 2020. This study focused on the reproductive development at four different times (plots) of potassium chlorate application: May, June, July, and August. Air temperature, relative humidity and light intensity at the canopy level were recorded. Rainfall data was obtained from the Meteorological Department of Thailand. The results showed that inflorescence length, female flower number, and sex ratio of female to male of the May plot were the highest compared to other plots, and it was associated with early rainfall occurrence during flower development and blooming time. The August plot had a low growing degree day and a short flowering period, which coincided with frequent rainfall during the flower development period. However, the pollen viability and female flower characters were unaffected by environment. In conclusion, flower induction in the early rainy season, especially in May, was an effective time for the production of off-season ‘Phuang Thong’ longan in Ban Phaeo district, Samut Sakhon province, Thailand. Keywords: Floral biology, Flower, Pollen, Microclimate, Heat unit

Flowering induction in cassava using photoperiod extension premature pruning and plant growth regulators.

Cassava (Manihot esculenta Crantz) is a vital crop for food and economic security in many regions of the world. Despite the economic and social importance of cassava, challenges persist in developing superior varieties that meet the needs of farmers in terms of agronomic performance, nutritional quality, and resistance to pests and diseases. One of the main obstacles for genetic improvement is the lack of synchronization in flowering and the abortion of young flowers, making planned crosses and progeny production difficult. Therefore, the aim of this study was to evaluate the effect of photoperiod, premature pruning, and growth regulators on cassava flowering under low-altitude conditions in Brazil. Eight cassava clones with contrasting flowering capacity were assessed in Cruz das Almas, Bahia, using two photoperiods (ambient condition and extended photoperiod with red light for 12 hours), premature pruning at the first and second branching levels (with and without pruning), and the application of growth regulators: 0.5 mM 6-benzyladenine (BA) and 4.0 mM silver thiosulfate (STS) (with and without). Plots were assessed weekly for the number of female (NFF) and male (NMF) flowers, height of the first branching (H1B, in cm), number of days to the first branching (ND1B), and the number of branching events up to 240 days after planting (NOB). The extended photoperiod did not promote an increase in the number of flowers but allowed for precocity in cassava flowering, reducing the onset of flowering by up to 35 days, and significantly increasing the number of branches, which is closely related to flowering. The use of pruning and plant growth regulators (PGR) resulted in an increase in NFF from 2.2 (control) to 4.6 and NMF from 8.1 to 21.1 flowers. Therefore, under hot and humid tropical conditions at low altitudes in the Recôncavo of Bahia, manipulating the photoperiod and using premature pruning and plant growth regulators can accelerate cassava flowering, benefiting genetic improvement programs.

INFLUENCE DES PARAMETRES DE REPRODUCTION SUR LA PRODUCTIVITE DES HYBRIDES F2 NAIN X NAIN

The objective of this study was to evaluate some production parameters for the identification of elite Nain. Twenty-seven coconut trees, spread over 2 plots, were selected. A control, Malay Yellow Dwarf (NJM), was added to each plot. The study of the relationship between five variables revealed highly significant correlations between them. The multivariate analyses made it possible to identify among the genotypes, the type 7 individuals as being the most efficient. Individuals of type 7 had the highest averages for number of flowers at bag laying (NFP), number of flowers at bag removal (NFE), number of knotted flowers (NFN) and number of nuts harvested (NNR) compared to types 4, 5 and 6. Pollen germination rates in type 1 (Control) individuals were significantly higher than those of the other four types that did not differ significantly between them. The tests for the prediction of the number of nuts harvested indicated that 48.31% of the fluctuations of seed nuts reaching maturity are attributable to the number of female flowers counted at the installation of the bag, that of the female flowers counted at the bag removal and that of the female flowers tied. The predicted values for the number of mature seed nuts are: Nnoirec = -1.12 – 0.007*Nflepose + 0.012*Nflenlev + 0.408*Nflnou +0.014TG. Individuals of type 7 likely to be elite broodstock can be used in programs of genetic improvement of the coconut for better performance.

JcSEUSS1 negatively regulates reproductive organ development in perennial woody Jatropha curcas.

Overexpression of JcSEUSS1 resulted in late flowering, reduced flower number, wrinkled kernels, and decreased seed yield in Jatopha curcas, while downregulation of JcSEUSS1 increased flower number and seed production. The seed oil of Jatropha curcas is suitable as an ideal alternative for diesel fuel, yet the seed yield of Jatropha is restricted by its small number of female flowers and low seed setting rate. Therefore, it is crucial to identify genes that regulate flowering and seed set, and hence improve seed yield. In this study, overexpression of JcSEUSS1 resulted in late flowering, fewer flowers and fruits, and smaller fruits and seeds, causing reduced seed production and oil content. In contrast, the downregulation of JcSEUSS1 by RNA interference (RNAi) technology caused an increase in the flower number and seed yield. However, the flowering time, seed number per fruit, seed weight, and size exhibited no obvious changes in JcSEUSS1-RNAi plants. Moreover, the fatty acid composition also changed in JcSEUSS1 overexpression and RNAi plants, the percentage of unsaturated fatty acids (FAs) was increased in overexpression plants, and the saturated FAs were increased in RNAi plants. These results indicate that JcSEUSS1 played a negative role in regulating reproductive growth and worked redundantly with other genes in the regulation of flowering time, seed number per fruit, seed weight, and size.