Maximum Positive Direct Effect Research Articles

Selection parameters for the improvement of seed yield and attributes in cowpea (Vigna unguiculata L. Walp.)

The present investigation was carried out with 53 genotypes of cowpea to study association among yield contributing traits. The genotypes were sown in a randomized block design replicated with three replications at the National Pulse Research Centre, TNAU , Vamban, Pudukkottai, during Kharif,2022. Observations on ten traits were recorded and subjected to statistical analysis. The coefficient of phenotypic differences was substantially greater than the genotypic variation for all the characters under study, showing that the prevailing variation is mainly governed by the genotypic factor and substantial environmental factors. High heritability and genetic advance as percentage of mean were observed for the traits seed yield and 100 seed weight. This showed the role of additive gene action in the inheritance of these traits which gives the best chance of their improvement through simple selection. Association analysis revealed that number of cluster/plant and number of pods/plant had a significant and positive correlation on seed yield. Yield component traits viz., plant height, number of branches/plant, number of pods/cluster, number of pods/plant, 100 seed weight and seed yield were high inter-correlated among themselves. Furthermore, it was observed that the number of pods/plant, pod length, and 100 seed weight had the maximum positive direct effects on seed yield. So direct selection for these three traits could help to improve the seed yield potential of cowpea. Keywords: Cowpea, heritability, genetic advance, association analysis.

Assessing the genetic diversity and character association of yield components in litchi (litchi chinensis sonn.)

Eighteen litchi genotypes were evaluated in this study for genetic advancement, heritability, variability, and association studies. The genotype ‘CHL-4’ exhibited maximum fruit weight (28.12 g), aril weight (14.00 g), aril thickness (9.65 mm) and seed weight (4.86 g). Fruit length (10.70 and 10.46%), panicle width (10.61 and 10.37%), and panicle length (15.75 and 15.45%) all had substantial phenotypic and genotypic coefficients of variation. All the metrics, with the exception of fruit diameter, aril thickness, seed weight, and number of fruits/panicle, showed higher heritability estimations with substantial genetic advances. In addition to being negatively correlated with fruit weight, aril weight, seed weight and pulp thickness, yield also showed a strong positive correlation with the number of fruits/panicle and aril percentage. Path analysis made the impact of different components on yield very evident. The maximum positive direct effect on yield at genotypic level was through fruit weight (10.120) followed by seed weight (4.070), panicle length (1.550), panicle girth (1.170) and negative direct effect via aril weight (-0.12.860) followed by panicle width (-11.830), fruit length (-6.290). In order to select a diverse parent for a subsequent breeding effort, cluster analysis assists in classifying comparable objects into appropriate categories. Therefore, the goal of the study was to confirm the genetic variability across genotypes of litchi and identify prospective features for the selection of genotypes that are superior. Bangladesh J. Bot. 53(3): 465-473, 2024 (September)

Genetic Variability and Character Association Studies in Diverse Rice (Oryza sativa L.) Genotypes for Agro-Morphological Traits in Terai Region of West Bengal

Aims: The study aims to analyze the genetic variability in diverse rice genotypes and establish correlations with grain yield and its attributes. By identifying and quantifying the genetic elements influencing grain yield and associated traits, the research intends to offer insights for developing high-yielding and resilient rice varieties, ultimately enhancing food security and agricultural sustainability. Study Design: The experiment was set up in a randomized complete block design (RCBD) with two replications, using a spacing of 20 cm × 15 cm. Place and Duration of Study: The experiment was conducted at the Instructional Farm of Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal during the Kharif season (the period from June to October) of 2019 and 2020. The duration of the study encompassed the entire Kharif seasons of both years. Methodology: The study evaluated forty-two diverse rice genotypes based on nine agro-morphological traits. The methodology encompassed the utilization of ANOVA to evaluate significant differences in trait means and discern genetic variability among rice genotypes. Central tendency and variability were assessed through the calculation of mean, range, and standard deviation to gain insights into genetic variation. Furthermore, variation among traits was quantified using phenotypic and genotypic coefficient of variation to aid in understanding genetic variability. Heritability in broad sense was estimated to ascertain the genetic contribution to the observed variation, while the identification of traits with potential for improvement was achieved through the analysis of genetic advance as percent of mean. Furthermore, correlation and path coefficient analyses were conducted to comprehend the connections between the agro-morphological traits and grain yield, offering insights into the genetic relationships among the traits and their direct and indirect impacts on grain yield patterns. Results: The analysis of variance results confirmed the presence of significant differences among the evaluated genotypes. The phenotypic coefficient of variation displayed elevated values, closely associated with the genotypic coefficient of variation for all traits. Both phenotypic and genotypic coefficient of variation values were observed to be low to moderate for all the nine traits. Furthermore, specific traits such as grain breadth, panicles plant-1, and grain L/B ratio exhibited high heritability and high genetic advance percentage of mean, indicating their potential for selection and improvement in breeding programs. Additionally, the correlation study at the genotypic level revealed positive and significant correlations between grain yield plant-1, test weight, and spikelet fertility. Moreover, the path coefficient analysis showed that grain length had the maximum positive direct effect on grain yield plant-1. Conclusion: In conclusion, the analysis revealed significant genotype variations across multiple traits, indicating potential for targeted breeding improvements. Traits like grain breadth, panicles plant-1, and grain L/B ratio showed promising heritability and genetic advancement, emphasizing their value for selection in breeding programs. Correlation and path coefficient analyses highlighted interrelationships and direct effects on yield, underlining the importance of genetic factors in trait expression.

Character Association and Path Coefficient Analysis to Determine Interrelationships among Grain Yield and its Components in Maize Genotypes (Zea mays L.)

Aim: A study was carried out to evaluate the magnitude of correlation between grain yield and its various contributing characters.
 Methodology: 39 genotypes of maize, comprising 31 hybrids and 8 parents, were assessed using randomized block design with three replications. The data recorded on twelve quantitative characters including days to 50 percent tasseling, days to 50 percent silking, days to maturity, plant height (cm), ear height (cm), ear length (cm), ear diameter (cm), number of kernel rows per ear, number of kernels per row, 100 kernel weight, shelling percentage and grain yield per plant.
 Results: The results of this study showed higher genotypic correlation coefficient for all the characters studied compared to the corresponding phenotypic correlation coefficient. This suggests that, despite the strong inherent association between the traits under study, environments’ influence masked its expression. Ear diameter was found to have a strong and significant positive correlation with grain yield per plant at phenotypic (0.9016) and (0.9540) genotypic level followed by ear length (0.8976, 0.9360), number of kernels per row (0.8905, 0.9247), plant height (0.8399, 0.8697), 100 seed weight (0.8070, 0.8544), ear height (0.7170, 0.7550) and number of kernel rows per ear (0.3240, 0.3901). Days to 50% silking and days to 50% tasselling, however, exhibited significant negative association with grain yield, while days to maturity showed non-significant negative. In path coefficient analysis the maximum positive direct effect on grain yield per plant was found by the ear diameter (0.3505), followed by the 100 seed weight (0.2362), ear length (0.2273), number of kernels per row (0.1827), days to 50% silking (0.1269), and shelling percentage (0.1223).
 Conclusion: The strong correlation of ear diameter, 100 seed weight, ear length and number of kernels per row (0.2971) with grain yield per plant appears to be mostly due to their high direct effects. Therefore, improving yield could be achieved through direct selection for these attributes.

Genetic Variability, Heritability, Genetic Advance and Association Studies in Blackgram [Vigna mungo (L.) Hepper

Background: In Tamil Nadu blackgram is cultivated in 4.02 lakhs hectare with the production of 2.25 millon tonnes and productivity of 559 kg/ha. Even though it has great importance, blackgram cultivation is ignored as minimum attention is given towards its genetic improvement. There are various reasons for the low production of crop like lack of genetic variability, absence of suitable ideotype, susceptibility to biotic and abiotic stresses and planting in marginal areas of farming. Hence, it is important to improve the productivity of blackgram. Methods: The present investigation was carried out on 44 blackgram genotypes at field experimentation site of Regional Research Station, Tamil Nadu Agricultural University, Aruppukkottai, Virudhunagar District, to study genetic variability, heritability, genetic advance and correlation and path effects of seven important yield contributing traits including yield trait. Result: Highest GCV and PCV value observed for seed yield per plant and for plant height. High heritability coupled with high genetic advance as percent of mean were recorded for plant height and seed yield (kg/ha) and selection of these traits was useful for further improvement in plant breeding programme. Association analysis revealed that seed yield exhibited significant and positive correlated with plant height and number of pods/plant. Yield component traits viz., plant height, number of pods/plant, 100 seed weight and single plant yield were highly correlated among themselves. It was observed that plant height and number of pod/plant had the maximum positive direct effects on seed yield. The indirect effect of plant height on grain yield was positive through days to maturity, days to fifty percent flowering and number of pods per plant. Hence selection of plants based on plant height and number of pods/plant will help the improvement of seed yield in blackgram.

Amelioration of economically important traits through mutagenesis in spine gourd (Momordica dioica)

Mutation breeding can sometimes be endeavored along with conventional breeding efforts, resulting in the discovery of some economically useful genetic changes. Evaluation of 96 first-generation mutant germplasm lines of spine gourd (Momordica dioica Roxb.) was done through morphological descriptors and molecular makers. Correlation coefficient analysis, path analysis and cluster analysis supplemented by molecular marker-based population structure analysis helped in understanding the population behavior and identification of high-yielding lines. The yield was found to be highly positively correlated with days to first flowering, leaf width, single fruit weight and number of fruits per plant. Also, the maximum positive direct effect on yield was shown by single fruit weight followed by the number of fruits per plant and leaf width. The population structure analysis revealed 4 clusters of population. Few high-yielding lines were identified which approximately yielded 1.5 times more than the checks. Further refinement in these mutant lines through breeding programs coupled with in-depth molecular analysis can lay the foundation of the release of some excellent spine gourd varieties in the future.

Assessment of inter-relationships between yield and yieldattributes in safflower (Carthamus tinctorius L.)

Character association studies in 29 genotypes of safflower for seven characters conducted at Agricultural Research Station, Tandur revealed significant positive association of single plant yield with test weight, number of effective capitula per plant, plant height and number of seeds per capitulum. Estimates of direct and indirect effects of component characters on single plant yield at genotypic level revealed that test weight contributed for maximum positive direct effect on single plant yield followed by days to maturity, plant height and number of seeds per capitulum. Also, these traits had positive and significant association with grain yield. Critical analysis of character association and path analysis showed that these characters should be given importance to isolate superior lines with genetic potentiality for high grain yield.

Efforts to Stimulate Morpho-Physio-Biochemical Traits of Maize for Efficient Production under Drought Stress in Tropics Field

Maize, a major food source for the world’s tropical regions, is often impaired by droughts under a changing climate, which creates the importance of making efforts to improve the tolerance characteristics of maize under field conditions. The experiment was conducted during the dry season of the 2020–2021 period to investigate the stimulatory effects of plant growth regulator (PGR) ethephon (2-chloroethylphosphonic acid) on the morpho-physio-biochemical traits of maize and to identify suitable application approaches for efficient production under water stress. The factorial randomized complete block design was followed for the present experiment. Ethephon was applied at the vegetative 6 leaves (V6) and/or 10 leaves (V10) stages. Seven application approaches (doses in g a.i. ha−1) of ethephon, i.e., 281 at the V6 stage (E1), 281 at the V6 stage + 281 at the V10 stage (E2), 281 at the V10 stage (E3), 562 at the V6 stage (E4), 562 at the V6 stage + 562 at the V10 stage (E5), 562 at the V10 stage (E6), and no ethephon (E7), were used for maize production. Another factor was that three water levels were used, i.e., well-watered conditions (watering every week) (W1), short water stress (no watering during 48–69 days after planting) (W2), and prolonged water stress (no watering during 48–83 days after planting) (W3). Water stress negatively affected most of the morpho-physiological traits, and in W2 and W3 conditions, the grain yield was significantly lower, i.e., 4.82 and 4.27 t ha−1, respectively, compared to W1 (5.71 t ha−1). The plant height and leaf area index at the reproductive milk stage of maize (R3) were significantly reduced by all approaches of ethephon application compared to no ethephon. However, across the water levels, E3 performed better and produced a higher grain yield (5.11 t ha−1), which was mostly seen by a higher 100-grain weight (24.52 g) and a slightly higher grain number per plant (356.12). It was also positively supported by most of the physiological and biochemical traits, as they were especially higher in the relative growth rate (25.73 mg plant−1 day−1), net assimilation rate (0.79 mg cm−2 day−1) at V6-R3, heat use efficiency (3.39 kg ha−1 °C days−1), electrolyte leakage (5.69%), and proline (28.78 µmol g−1 FW). These traits, under prolonged stress, also gave the maximum drought tolerance index by E3, i.e., the relative growth rate (1.00) and net assimilation rate (1.00) at V6 to R3, heat use efficiency (1.06), relative water content (1.00), electrolyte leakage (1.65), proline (1.88), 100-grain weight (1.01), grain yield (1.11), and water productivity (1.53). A path analysis showed that the shoot weight at R3 (1.00), the stem diameter at the R3 stage (1.00), net assimilation rate (0.95), relative water content (0.95), 100-grain weight (0.90), grain number (0.76), proline (0.75), SPAD value (0.71), and total soluble sugar (0.57) were highly positive, and electrolyte leakage (−0.84) was negatively correlated with the grain yield under prolonged water stress. The maximum positive direct effect on the grain yield was found in the shoot weight (1.05), net assimilation rate (0.68), leaf area index at R3 (0.45), SPAD (0.22), and electrolyte leakage (0.21). The ethephon application as the E3 approach was more efficient in both short and prolonged stress, especially under prolonged stress, as it showed a higher energy use efficiency (1.55) and less CO2-eq emission (3603.69) compared to the other approaches of ethephon. The subsequent efficient ethephon approaches were E1 under short water stress, E6 under prolonged water stress, where E5 performed minimally, and no application of ethephon, which exhibited the worst efficiency under water stress.

Assessment of genetic variability, correlation and path analysis for yield and its components in groundnut (Arachis hypogaea L.)

Genetic variability, heritability, correlation and path analysis were carried out in 27 groundnut genotypes. Analysis of variance revealed significant differences among the genotypesfor all the characters. The estimated PCV and GCV indicated existence of fairly high degree of variability for dry pod yield/plant, kernel yield/plant, number of branches/plant, number of mature pods /plant and seed protein content. In corollary to high heritability, estimates of genetic advance as per cent of mean was also observed for dry pod yield/plant, kernel yield/plant, number of mature pods/plant and seed protein content indicating predominance of additive gene effects for these traits. The association study among characters revealed that dry pod yield was positively and significantly correlated with number of pegs/plant, number of mature pods/plant and kernel yield/plant. Path coefficient analysis revealed that kernel yield/plant, biological yield/plant and harvest index had maximum positive direct effect on dry pod yield/plant. The study shows that greater emphasis should be given on these characters while selecting for higheryield and related traits in groundnut.

Correlation and path analysis in black and brown seeded soybean [Glycine max (L.) Merr.] genotypes at Melko and Modio, South-Western Ethiopia

Sixty-four soybean genotypes were evaluated to study the association among yield and related traits and determine the directions of association. The field experiment was conducted during the main cropping season in 2019 at Jimma and Bonga Southwestern Ethiopia. The experiment was laid with a simple lattice design with two replications. Data were collected on quantitative traits. Analysis of variance showed significant to highly significant differences among genotypes for all of the studied traits. Correlation analysis exhibited that grain yield was positively and significantly associated with harvest index and the number of pods per plant. Harvest index exerted the maximum positive direct effect on grain yield, followed by pod per plant, seed yield per plant at a genotypic level, and these traits could be used for selection to improve grain yield in soybean. Int. J. Agril. Res. Innov. Tech. 13(1): 67-71, June 2023

Genotypic Variability and Character Associations of Kabuli Chickpea (Cicer artietinum L.) Genotypes for Yield and Yield Related Traits at Arsi-Robe, Southeastern Ethiopia

The study was conducted at Arsi-robe, Southeast Ethiopia during August–December, 2020 to understand the extent of genetic variability and association for yield and yield related traits among Kabuli chickpea genotypes. Forty-nine Kabuli chickpea genotypes were evaluated for 11 traits at Arsi-robe using 7×7 simple lattice designs. The analysis of variance showed significant differences among genotypes. The phenotypic variances of the traits were higher than the genotypic variances, implying the influence of environment on the expression of the traits. Genotypic coefficient of variation (GCV) ranged from 1.28 for days to maturity to 41.74% for grain yield and phenotypic coefficient of variation (PCV) ranged from 1.47 to 44.06% for days to maturity and grain yield, respectively. High heritability was recorded from grain yield. High broad-sense heritability coupled with high genetic advance was observed for grain yield, number of secondary branches and hundred seed weight. Grain yield showed highly significant and positive genotypic correlations with grain filling period, number of seed plant-1 and plant height. Genotypic path coefficient analysis showed that days to maturity, number of pods plant-1, number of seed plant-1, plant height and hundred seed weight had positive direct effects on grain yield. Number of pods plant-1 exhibited a maximum positive direct effect on grain yield. The observed variations indicate the possibility for further improvement of grain yield and associated traits by utilizing selected parental genotypes and targeted crossing schemes in breeding programs.

GENETIC DIVERSITY OF DIFFERENT RADISH (RAPHANUS SATIVUS L.) CULTIVARS UNDER THE BASTAR PLATEAU OF CHHATTISGARH, INDIA

The presented study, held at the Research cum Instructional Farm of the College of Horticulture and Research Station, Jagdalpur, Chhattisgarh, India, ran during the Rabi season of 2021, to investigate superior radish cultivars for selection having high yield potential and better quality root for Bastar plateau. The experiment, laid out in randomized block design (RBD), had 15 treatments and three replications. Observing high genotypic and phenotypic coefficient of variation was for the following traits: dry and fresh weights of roots, plants, and leaves; root and leaf yields; days to 50% germination; the diameter and length of the root, North-South and East-West spread of the plant; plant height, and the number of leaf plant-1, having recorded significant heritability and high genetic advance. Similarly, high heritability showed for root yield and fresh and dry weights of roots. Moderate heritability levels appeared for the traits, viz., the plant’s dry weight and the root diameter. The genetic gain resulted high for characters, viz., root yield and fresh and dry weights of roots. High heritability followed by high genetic advance indicates that selection may be effective for improving such characteristics. Root yield (t ha-1) exhibited a highly significant positive correlation with the fresh weight of the plant at the phenotypic and genotypic levels, followed by dry weight of roots, dry weight of the plant, East-West spread of the plant, the diameter of the root, and leaf yield plot-1 . The fresh weight of roots had the maximum positive direct effect on root yield in the genotypic path, followed by the dry weight of roots and the plant, the East-West spread of the plant, the diameter of the root, and leaf yield in radish. The selection of these characters can benefit in improving the yield of radishes.

Correlation and Path Analysis for Yield and Yield Attributes in Maintainer Lines of Rice (Oryza sativa L.)

The study was conducted during kharif season (June–October) of 2016 at the Regional Agricultural Research Station, Agriculture College, Professor Jayashankar Telangana State Agricultural University (PJTSAU), Jagtial, Telangana, India. Forty (40) maintainer lines of rice (Oryza sativa L.) were grown in randomized block design replicated twice to find the relationships between the yield and its components, as well as their direct and indirect effects on the rice grain yield. Observations were recorded for yield, yield attributing characters and quality traits on five randomly selected competitive plants for each entry in each replication for 15 characters. The results revealed that the analysis of variance was significant for all the characters investigated. Grain yield was significantly correlated with its component characters like number of tillers plant-1 (0.9191**), panicle length (0.3339**), milling percentage (0.3214**) and hulling percentage (0.2873**) whereas it showed a negligible positive correlation with days to 50% flowering, days to maturity, plant height, panicle length, number of grains per panicle, kernel length, kernel breadth, L/B ratio, test weight, hulling percentage, and head rice recovery percentage. Path coefficient analysis revealed that number of tillers plant-1 (0.9439) exerted maximum positive direct effect on plant yield followed by kernel breadth, L/B ratio, panicle length, milling percentage, days to flowering and head rice recovery percentage indicated their importance in determining the complex character and therefore should be kept in mind while practicing selection aimed at improving the grain yield.

Unraveling the Genetic Architecture of Rice (Oryza sativa L.) Using Variability, Correlation, Path analysis and Diversity Analysis: Insights for Crop Improvement Strategies

The present study aimed to assess the genetic architecture of rice through various biometrical techniques and this was achieved through a field experiment conducted during the Kharif 2022 season utilizing 23 distinct genotypes of rice. The trial was performed at the field experimentation center, Department of genetics and plant breeding, School of agriculture, Lovely Professional University. The research concluded that the highest genotypic and phenotypic coefficients of variation were for the number of productive tillers per plant, grain L/B ratio and grain yield per plant. Additionally, high heritability was observed for all traits except for kernel breadth. The investigation also explains high genetic advance as a percent of the mean for all traits except spikelet fertility and kernel breadth. Grain yield per plant had a significant positive genotypic correlation with the number of productive tillers per plant, filled grains per panicle, and total number of grains. Path analysis revealed that kernel L/B ratio, kernel length, filled grains per panicle, total number of grains, and number of productive tillers per plant had the maximum positive direct effects. The study suggests that selection based on these traits could be more effective in improving rice yield. The germplasms falling in different clusters with high mean for grain yield and other component characters can be utilized for hybridization programme to obtain elite segregants.

COMPARATIVE CHARACTERIZATION OF WHEAT VARIETIES FOR YIELD AND RELATED TRAITS UNDER DROUGHT STRESS

This study aims to evaluate the performance of selected wheat varieties under the world's most prevalent and increasing drought conditions and to recommend suitable drought-resistant varieties to the farming community to increase yields even under stressful conditions to meet growing food needs. For this purpose, seven wheat genotypes were grown in sandy loam soil at the experimental field area of the College of Agriculture, Bahauddin Zakariya University, Bahadur sub-campus Layyah, during 2020-21. Data were collected for the number of tillers, spikelets, flag leaf length, plant height, thousand-grain weight, spike length, and grain yield per plant. The results showed variation in the production level of wheat genotypes under control and different drought stress levels. Analysis of variance exhibited highly significant differences for all the seven characters studied. Based on mean performance Fakhar-e-Bhakkar, Gold, and Faisalabad may be top contributors to grain yield. The highest positive correlation indicates a highly significant and positive correlation between all measured morphological parameters of wheat genotypes. Path coefficient analysis recommended maximum positive direct and indirect effects on yield except for spike length. All of the genotypes performed well, even in drought conditions. However, all genotypes have some excellent features producing genetic diversity in germplasm. Therefore, these traits may be helpful for wheat breeding programs in the future.

Trait Association and path coefficient analysis for yield and yield attributing traits in Sesame (Sesamum indicum L.)

Correlation and path analysis were carried out in 36 diverse genotypes of sesame collected from different parts of the country along with North-East region of India for local landraces. Analysis of variance indicated the presence of good amount of genetic variability among the genotypes under study. Correlation studies indicated that seed yield per plant was significantly and positively associated with traits, i.e. plant height, internodal length, number of capsules per plant, number of branches per plant, stover yield per plant and harvest index both at genotypic and phenotypic levels which indicate the importance of these traits in selection for enhancing the seed yield. Path analysis revealed that maximum positive direct effect on seed yield per plant was imposed by days to 80% physiological maturity, internodal length, capsule length, stem height from base to first branch, stover yield per plant, harvest index, relative water content, oil content and protein content both at genotypic and phenotypic levels. This indicate that these are the real independent characters and they have maximum contribution towards increase in the seed yield per plant.

Studies of genetic variability, correlation and path coefficient for various characters in French Bean

The research was conducted during the Rabi season of 2019-2020 on 32 genotypes of French bean (Phaseolus vulgaris L.) to evaluate genetic variability, correlation coefficient and path coefficient. The genotypes were studied for 13 different characters of growth and yield attributing characters in Randomized Block Design with three replications for each genotype. All characters recorded higher PCV value over GCV thereby indicating the influence of environmental factors in their expression. High heritability observed in all the characters studied and high heritability coupled with high genetic advance found in the parameters viz. number of pods per plant, average pod weight, 100 seed weight and pod yield per plant. Correlation coefficient analysis showed pod yield had significant and positive correlation with number of pods per plant, pod length, average pod weight and 100 seed weight. Path analysis revealed that maximum positive direct effect w.r.t pod yield per plant was brought about by the parameters viz. 100 seed weight, days taken to marketable maturity, number of seeds per pod, number of pods per plant, average pod weight, pod width and pod length hence, should be given more importance for genetic improvement to bring about an increase in overall production of french bean through enhanced pod yield per plant. SAARC J. Agric., 20(2): 83-91 (2022)

Character Association and Path Coefficient Studies in Cucumber (Cucumis sativus L.): Experimental Investigation

Thirty two cucumber genotypes were collected from different states of India and were evaluated for yield and quality characters at Bhubaneswar, Odisha during Rabi season of 2019. The relationships between fruit yield and yield components in cucumber genotypes were investigated and correlation studies revealed that yield per plant had positive and significant association with vine length, number of fruits per plant, fruit length, fruit diameter and average fruit weight, while significant negative correlations were observed with node at which first female flower appears, number of days to first female flower production, days to first harvest and severity of downy mildew percentage both at phenotypic and genotypic levels. Path coefficient analysis revealed that fruit diameter had maximum positive direct effect on yield per plant followed by fruit length, number of fruits per plant, days to first harvest, average fruit weight while, negative direct effect of number of days to first female flower production and severity of downy mildew percentage was observed on yield per plant. Future breeding should focus on selecting the characters having direct effects to improve yield per plant.

Character Association and Path Analysis for Okra (Abelmoschus esculentus (L.) Moench) Yield, Fruit Quality and Resistance to Yellow Vein Mosaic

Objective: To find the best parents for desirable traits, particularly earliness, yield, and fruit quality, as well as YVMV (Yellow Vein Mosaic Virus) resistance, in order to create novel hybrids or varieties.
 Experimental Design: The experiment was carried out using a randomised block design with three replications.
 Place and Duration of Experiment: The study was conducted in the 2016 kharif seasons at the Department of Horticulture's field experimentation centre at Sam Higginbottom University of Agriculture, Technology, and Sciences, Prayagraj (U.P.). At 78 metres above mean sea level, this location is situated between 25.87° N latitude and 81.15° E longitude. The experimental area's soils have a sandy to sandy loam texture, are moderately well to well drained, and include a provision for ground water irrigation.
 Methodology: 25 genotypes were collected for this Trail during the 2016 kharif season. To grow the crop, good agricultural methods were used. Plant height (cm), number of branches/plant, number of leaves/plant, first flowering (in days), 50% flowering (in days), first flowering node, fruit length (cm), fruit diameter (cm), fresh fruit weight (g), number of fruits/plant, fruit yield/plant (g), fruit yield/plot (g), YVMV incidence (%), YVMV severity (%), and crude were the observations to be recorded for five randomly chosen plants from each genotype in each replication To calculate the genetic correlation coefficient analysis, the data were subjected to statistical analysis. The Miller et al. algorithm was used to determine the genetic and phenotypic correlation coefficients.
 Results: Based on collected and analysed data, a substantial and positive connection between Days to First Flowering and Days to 50% Flowering (0.94) and between Fruit Weight (g) and Fruit Yield/plant (g) was found (0.91). Demonstrating that okra could experience real improvement thanks to these characteristics. At both the genotypic and phenotypic levels, fruit weight demonstrated the highest beneficial direct impact on fruit yield per plant. The genotype Kashi Satdhari had the lowest YVMV incidence (%), followed by Kashi Vardan (16.38%), whereas 151-10-1-2-3 had the highest YVMV incidence (79.17%), followed by Larem-1 (75.31%).
 Conclusion: A very strong positive and significant correlation was recorded between Days to First Flowering with Days to 50% Flowering and Fruit Weight with Fruit Yield/plant. Negative and significant association of YVMV Incidence % with Fruit Yield/plant (g) indicates that fruit yield/plant decreases with increase in YVMV incidence %.Fruit weight showed maximum positive direct effect on fruit yield per plant at both genotypic and phenotypic level indicating that effective improvement through these characters could be achieved in okra.

Selection parameters for improving grain yield of bread wheat under terminal heat stress

Improving terminal heat tolerance is an issue of top priority in wheat breeding in the present era of climate change. Present study was carried out to identify the association among traits of economic importance under terminal heat stress environment. The grain yield/sq. meter under terminal heat stress environment recorded highly significant positive correlation both at genotypic and phenotypic level with grain weight/spike, number of spike/sq. meter, harvest index and 1000-grain weight in both the crop seasons. Path coefficient analysis carried out using genotypic correlation coefficients revealed that days to heading contributing maximum positive direct effect towards grain yield under terminal heat stress environment followed by grain filling duration. Other characters contributing positive direct effects towards grain yield were grain weight/spike, number of spike/sq. meter, harvest index and biological yield/sq. meter under both the crop season. Thus, for improving the wheat grain yield under terminal heat stresses conditions, breeder should aim for selecting genotypes with bold grains or high grain weight /spike, more number of tillers/sq. meter, higher harvest index and longer grain filling duration.