High GAM Research Articles

Genetic Variability and Character Association in F3 Generation of Chickpea (Cicer arietinum L.) under Rainfed and Irrigated Conditions

The goal of the current study was to analyze the genetic variability and character association in F3 generations of chickpea under rainfed and irrigated conditions to finalize appropriate selection criteria for improvement of seed yield in chickpea under irrigated and rainfed conditions. Five F3 generations of chickpea crosses were evaluated in compact family block design with three replications at Research Farm, ARSS, Hanumangarh, Rajasthan, India. In analysis of variance, mean sum of squares indicated significant differences among the generations for all the characters under both conditions. The highest range of variation was observed for seed yield per plant followed by fruiting branches per plant, pods per plant, 100 seed weight and seeds per pod in irrigated condition, whereas in rainfed condition the highest range of variation was registered by seed yield per plant followed by biological yield per plant, 100 seed weight and pods per plant. The RSG-895 x RSG-888 showed high GCV and PCV for fruiting branches per plant, pods per plant, biological yield per plant, and seed yield per plant in both conditions, as well as for seeds per pod under irrigated condition. Under irrigated condition high value of GCV and PCV were noted in IPC-94-94 x RSG-888 for harvest and in CSJD-901 x RSG-931 for pods per plant, seeds per pod and seed yield per plant. Under rainfed high GCV and PCV were observed in cross RSG-888 x ICC-4958 for seeds per pod. This indicates the existence of wide variability for these traits in the progenies of particular crosses and scope of improvement through simple selection. High heritability coupled with high genetic advance as percentage of mean (GAM) was noted in RSG-888 x ICC-4958 for pod per plant under both conditions. Under irrigated condition, the cross CSJD-901 x RSG-931 for pods per plant, RSG-895 x RSG-888 for seed yield per plant, RSG-888 x ICC-4958 for harvest index, RSG-888 x ICC-4958 and CSJD-901 x RSG-931 for 100-seed weight showed high heritability along with high GAM. Whereas under rainfed, the crosses RSG-895 x RSG-888 and IPC-94-94 x RSG-888 for pods per plant, BG-362 x RSG-931 for seed yield per plant, and IPC-94-94 x RSG-888 for harvest index, demonstrated high heritability along with high GAM. This result indicates the importance of additive gene action in inheritance of these characters, hence simple selection can be used to improve seed yield. Seed yield per plant exhibited positive and significant correlation with fruiting branches per plant, pods per plant, biological yield per plant, harvest index and 100-seed weight under both irrigated and rainfed conditions. In irrigated condition seed yield per plant had significant and positive correlation with days to 50% flowering, days to maturity and plant height, whereas in rainfed condition it had significant and positive association with protein content. Further, inter se these characters were also significantly positively correlated. So, selection based on these characters is expected to bring improvement in the seed yield.

Genetic Variability and Cluster Analysis of Faba Bean (<i>Vicia faba</i> L.) Genotypes in Debre Tabor, Northwestern Ethiopia

Faba bean, a globally important pulse, offers genetic variation for plant breeders, although information on this variability is scarce in Ethiopia. Therefore, the study was conducted to assess the genetic variability of genotypes using 49 genotypes with 7 × 7 simple lattice designs. The experiment was conducted at in Fogera National Rice Research and Training Center at Debre Tabor research site in north western Ethiopia. Analysis of variance revealed that there were highly significant differences among forty-nine genotypes for all studied traits (days to flowering, days to maturity, grain filling period, number of branch, plant height, pod per plant, biomass yield, harvest index, hundred seed weight, chocolate spot and seed yield). High GCV and PCV was observed in pod per plant and chocolate spot both at genotypic and phenotypic level including number of branch at phenotypic level. Moderate to high heritability estimates were observed in all studied traits. A high genetic advance in percent of mean was observed in the number of branches per plant, the number of pods per plant, grain yield, seed weight, and chocolate spot. In conclusion, the study found that the ET 07013-1 and ET 07005-1 genotypes are potential for future breeding programs, but further experimentation across locations and seasons is needed. It is recommended to give much attention to traits with high heritability and GAM, which include the number of branches per plant, the number of pods per plant, grain yield, hundred seed weight, and chocolate spot. The best genotypes should be included in future breeding programs to maximize yield even further. It is recommended to closely monitor traits with high heritability and high GAM.

Genetic Variability Studies for Morpho-Physiological and Yield-attributing Traits in Foxtail Millet (Setaria italica L. Beauv.)

Foxtail millet is an underutilized crop which has high nutritional values and wide genetic resources, possessing the ability to tolerate several abiotic stresses efficiently. Those resources must be used in order to improve desired traits, primarily yield attributes. This investigation was carried out to assess the genetic parameters, such as variability, per se performance, heritability and genetic advance as percent of mean (GAM) for sixteen morpho-physiological, yield-attributing traits in fifty foxtail millet germplasm accessions at the Regional Agricultural Research Station, Nandyal during Rabi, 2023-2024. The study revealed the wide range of variation for all studied traits and that the accessions SiA 3290, SiA 4345, and SiA 4391 had potential for most traits and a high grain yield per plant. Thus, after multilocation testing, these accessions might be exploited for commercial cultivation. The assessment revealed that the phenotypic coefficient of variation (PCV) was slightly greater than the corresponding genotypic coefficient of variation (GCV), indicating the influence of the environment on the manifestation of these traits. It was also observed that the traits viz.., photosynthetic rate, transpiration rate, stomatal conductance, abortive grain rate, and grain yield per plant had high PCV and GCV and these traits significantly contributed to the overall variability and scope for selection. High heritability in combination with high GAM was observed for photosynthetic rate, transpiration rate, stomatal conductance, 1000-grain weight, fodder yield per plant and grain yield per plant. This indicates that, these traits are mostly governed by additive genes and thus making them suitable for simple direct selection to improve these traits and further breeding efforts focused on increasing yields.

Inheritance pattern of Qualitative traits, Genetic analysis and association of yield attributes in F2 populations of Rice (Oryza sativa)

Understanding the extent of genetic variability within the segregating generations is crucial for identifying superior segregants with high yield and better market acceptability. Thus, the present study was carried out to quantify the extent of genetic variation available in the segregating population of rice. Three crosses, viz., CO 55 × IC 457996, CO 55 × IC 464685, and CO 55 × IC 115439 were evaluated using a non-randomized experimental design for six yield attributing and two physical grain quality traits in F2 generation. The inheritance pattern of basal leaf sheath colour and grain colour in CO 55 × IC 115439 indicate digenic complementary gene interaction (9:7), whereas grain colour in CO 55 × IC 464685 exhibits inhibitory gene action (13:3). The positively skewed nature of productive tillers per plant and single-plant yield in the F2 segregants emphasizes the need for intensive selection to facilitate rapid improvement due to the influence of complementary gene action. Moderate to high GCV with high heritability and GAM for traits such as plant height, productive tillers per plant, hundred seed weight, grain width, and single-plant yield in the F2 segregants underscore the prevalence of additive gene action and thus provide the most effective condition for simple phenotypic selection. Moreover, productive tillers per plant and single-plant yield showed a strong positive association in all the crosses. Therefore, productive tillers per plant can be considered an indicator trait when selecting high-yielding segregants for grain yield improvement.

Genetic Variability and Heritability of Morpho-Agronomic Traits, Oil Yield and Fatty Acid Components in Linseed (<i>Linumusitatissimum</i> L.) Germplasm in Ethiopia

Comprehensive information on genetic variability and selection parameters is very crucial to design breeding strategies. However, very limited information is available in Ethiopian linseed germplasm. Therefore, the present study was conducted to estimate genetic variability, broad sense heritability and genetic advance; and determine selection for 19 quantitative traits using 126 genotypes (120 Ethiopian linseed accessions and six released varieties). The analysis of variance showed highly significant (P < 0.01) differences for all of the traits demonstrating the presence of high genetic diversity among the studied linseed genotypes. Higher differences between PCV and GCV estimates were observed for seed yield per plant and biological yield per plant, signifying the importance of environmental factors influence. High heritability coupled with high genetic advance was observed for seed yield per plant and biological yield per plant, indicating that this high heritability is due to additive gene effects and therefore, selection can be effective for the improvement of linseed for these traits. In addition, moderate heritability coupled with moderate genetic advance was recorded for oil yield per hectare, number of capsules, number of secondary branches, days to maturity, seed yield per hectare and plant height. These results indicated the existence of intermediate expression in these traits for both additive and dominance gene effect. In the present study, high heritability coupled with high GAM was observed for seed yield per plant and biological yield per plant, indicating greater contribution of additive gene action for the expression of these traits; and therefore, improvement can be achieved through selection in these traits.

Morphological Characterization and Genetic Diversity Analyses of Yield and Yield Attributing Traits in Sweet Corn (Zea mays var. saccharata)

The genetic diversity among the genotypes were useful resources that enabled breeders to comprehend the performance of attributes or genotypes. This understanding is crucial in selecting appropriate genotypes or traits for hybridization programmes. A total of 15 sweet corn genotypes were utilized to assess the characteristics of genetic diversity, correlation, path coefficient and genetic divergence study. The phenotypic coefficient of variation (PCV) exceeded the genotypic coefficient of variation (GCV) for all the traits examined, suggesting certain degree of interaction with the environment. The heritability estimates for all variables examined in this study were found to be high. The genetic advance as per cent of mean (GAM) identified a significant difference between high and low values. The traits ear weight with husk, ear weight without husk, husk ratio, chlorophyll content, ear length, ear girth, number of rows per ear, number of kernels per row, 100 kernel weight, shelling percentage, cob yield per plot and fodder yield per plot exhibited high heritability and high GAM. Furthermore, the correlation analysis revealed a significant and positive association for the aforementioned attributes. Additionally, the path coefficient analysis for these traits indicated a favourable direct influence. A total of 15 genotypes were categorized into seven clusters based on their genetic distance. The features that made the biggest contribution to divergence were fodder yield per plot (21%) and shelling percentage (21%), followed by ear weight (14%) and cob yield per plot (10%). The results of this study would be valuable for identifying the desirable characteristics and genetic makeup that can be used in future breeding programmes aimed at enhancing the production of corn cobs in sweet corn.

Estimates of Genetic Variability, Association Studies and Per se Performance of Tomato Genotypes for Growth and Yield Parameters Under Drought Stress Conditions

Aims: Drought tolerance is a complex phenomenon, influenced by the coordinated activity of many genes. Breeding for drought tolerance is the need for contemporary research under the present climate change scenario. Further, the estimates of variability and degree of association among the traits would facilitate the selection for yield under drought conditions as it is highly influenced by environmental factors. This study aimed for the enhancement of selection capacity for drought stress tolerance in tomato based on the measures of genetic variability parameters and extent of association among traits which in turn used to identify drought tolerant genotypes. Methodology: The experiment was conducted with 39 tomato genotypes with 2 replications under normal and drought stress condition (15 days irrigation interval) following a Randomized Block Design during summer, 2020 at Department of Biotechnology and Crop Improvement, Kittur Rani Channamma College of Horticulture, Arabhavi. Results: High heritability along with moderate to high GAM was recorded for all the characters under study in both control and drought stress condition, indicating predominance of additive gene action for these traits. Yield per plant had positive and strong association with plant height, stem girth, number of primary branches, number of fruits per plant and average fruit weight. Further, path analysis revealed high desirable direct effect of average fruit weight and number of fruits per plant on yield per plant. Thus, there is ample of scope for improving these traits through selection. The genotypes viz., EC-634394, EC-638519 and Kashi Anupama shown superior performance for yield along with other yield attributing traits and also exhibited less percent reduction in these traits under drought condition.

Impact of seasons on genetic variability parameters in soybean (Glycine max (L.) Merrill)

Soybean being a photoperiod sensitive crop usually grown during kharif season. Due to higher returns from soybean, the farmers are growing even in rabi and summer seasons. Hence, understanding genetic variability during different seasons is essential for undertaking selection during particular season. In this regard, fifteen soybean genotypes were studied at Main Agriculture Research Station, UAS, Dharwad during kharif, rabi and summer. Significant differences were observed among the genotypes for physiological, phenological, yield components, yield and quality traits in all the seasons. Higher mean was noted across soybean genotypes for chlorophyll ‘a’, days to maturity, plant height, protein content, number of branches per plant, number of pods per plant, hundred seed weight and seed yield during kharif while for oil content during rabi. Higher range was observed for SCMR, chlorophyll ‘a’, ‘b’ and total, days to initiation of flowering, days to 50 per cent flowering, plant height, number of branches per plant during summer. PCV and GCV was high for chlorophyll ‘b’, number of pods per plant, seed yield during rabi and summer. Chlorophyll ‘b’, plant height, number of pods per plant and seed yield have high heritability and GAM in all the seasons indicating the scope for phenotypic selection.

Genetic variability and association study of SSR markers for yield and powdery mildew disease in pea (Pisum sativum)

Makhyatmubi, one of the most popular local varieties of field pea (Pisum sativum L.) in Manipur has morpho- physiological bottlenecks such as tall nature and high susceptibility to fungus Erysiphe pisi causing powdery mildew disease. Therefore, an experiment was conducted during winter (rabi) seasons of 2018–19 and 2020–21 at College of Post-Graduate Studies in Agricultural Sciences (Central Agricultural University, Imphal, Manipur), Umiam, Meghalaya to generate genetic variability by hybridization of Makhyatmubi with Prakash variety which is a well-known powdery mildew resistant variety in India and possesses several contrasting characters. Fruitful heterosis was estimated with highest record in number of pods per plant (114.75%) and seed yield per plant (108.04%). These two characters also showed high PCV, GCV, heritability and GAM. Number of pods per plant (0.95) was found to have highest positive significant correlation with seed yield per plant. MP-5 and MP-119 recorded superior performance in several characters under study. For the association study of simple sequence repeats (SSR) markers, easily scorable polymorphic markers were selected for surveying association with the traits. Results revealed that SSR marker AA122 may be associated with seed yield and number of pods per plant while marker AA136 with number of seeds per pod. A5 marker was found to be associated with the powdery mildew disease. Hence, it can be employed for marker assisted selection (MAS) to identify and select pea genotypes exhibit resistance to powdery mildew disease.

Genetic variation and trait association of fine rice genotypes

To explore high yielding genotype and significant yield contributing trait, field experiment was conducted using alpha lattice design replicated three times at the National Wheat Research Program (NWRP), Bhairahawa, Nepal in 2022. Eighteen fine rice genotypes were evaluated based on nine quantitative traits (Heading days, maturity days, plant height, panicle length, effective tillers, filled grains per panicle, unfilled grains per panicle, thousand grain weight and grain yield per hectare). Variance analysis, correlation and estimation of genetic parameters were conducted to comprehend genetic variations and interrelationships among traits within genotypes. The results showed most of traits except unfilled grains had statistical significance differences. Tarahara-107 (3940 kg/ha) had the highest grain yield followed by Tarahara-2 (3700 kg/ha) and NR 2381-RGA1-RGA2 (3665 kg/ha). Similarly, grain yield showed positive and significant association with filled grains at both phenotypic and genotypic level (rp = 0.7074 ** and rg= 0.9482 **). Elevated values of PCV and GCV were recorded for filled grains (22.05 and 17.57). The high value GAM coupled with high heritability was recorded for filled grains (28.83%), plant height (23.10%), number of effective tillers (21.57%) and thousand grain weight (19.37%). Thus, identified genotypes NR 2380-RGA1-RGA2 and NR 2381-RGA1-RGA2 exhibited early and potential high yielding genotypes while Tarhara-107 and Tarhara-2 identified as high yield, medium maturity and good filled grain number per panicle. In addition, filled grains trait displayed tightly linked with grain yield and possess high GCV, PCV, GAM with moderate heritability indicated direct selection could be employed for trait enhancement in breeding program.

Dissecting the Genetic Relationship between Root Morphological Traits with Grain Yield of Introgression Lines (ILs) Derived from Wild Rice (Oryza rufipogon Griff) under Low Soil Phosphorous Condition

Soil phosphorous (P) deficiency is one of the limiting factors in rice production in both upland and rainfed lowland ecosystems. Since P is diffusion limited in depleted root zones, understanding the link between root morphological traits and yields is crucial for improving rice productivity. To understand this link, phenotypic screening experiment was conducted for the 38 ILs (BC1F6) derived from the wild rice (Oryza rufipogon Griff) along with the six checks in specialized low P plots and normal soil P (RDF) plot at ICAR-IIRR, Hyderabad during rice growing season Kharif-2020 by adapting augmented block design. The genotypes were screened for grain yield along with root traits such as tiller number per plant (TN), shoot length (SL), root length (RL), root volume (RV), shoot fresh weight (SFW), shoot dry weight (SDW), root fresh weight (RFW), root dry weight (RDW), root to shoot ration on wet weight basis (RSRWW), root to shoot on dry weight basis (RSRDW), SPAD chlorophyll meter reading (SCMR). The results from ANOVA revealed that, MSS due to genotypes, (checks + genotypes) were significant ((p<0.01 and p<0.05)) for most of the root architectural traits and for two different regime of P under investigation. Wide range of genetic variation was recorded for the traits such as RL, RV, SFW, SDW, RFW, RDW, RSRWW, RSRDW and GYP with high GCV and PCV and high h2 coupled with high GAM under both P gradient conditions. Strong inter-correlation among the component traits was observed for the root traits such as RV (0.43**: 0.50**), SFW(0.81**:0.60**), SDW (0.65**: 0.81**), RFW (0.87**:0.64**), RDW (0.83**: 0.87**) and RL (0.36**: 0.43**) along with GYP (0.52**) under low soil P and normal soil P. Principal component analysis with first four PCs revealed existence of 69.40 and 70.30% of total variance and clustering analysis identified the promising genotypes as IL-9-10, IL-11-2, IL-21-8, IL-19-3, IL-22-1, IL-23-2, IL-23-7, IL-31-3, IL-42-3, IL-67-2, IL-69-1, IL-75-2, Swarna and Rasi with root traits RV, RDW, RFW, RL, and GYP are effective traits for rice cultivation.

The Genetic Dissection of Economically Important Traits in Chilli Genotypes (Capsicum annuum L.) through Multivariate Analysis

Chilli (Capsicum annuum L.) cultivar share a variety of different and intriguing growth and yield characteristics, for a plant breeder studies on genotypic and phenotypic relationship for horticulture cum vegetable spicy crop and its traits are useful to design, evaluate and to develop selection criteria for desired traits. With this background information the present study focused on identification of crucial characteristics required for boosting yield and to determine the parameters for the selection of superior genotypes. A total of 30 chilli genotypes were subjected to variability, divergence and mutual correlation studies for yield and yield component traits by using multivariate analysis.
 Results from the analysis of variance and variability revealed highly significant differences at (p≤0.01) and (p≤0.05) for all the studied traits. The highest genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were observed for FL fallowed by FYP, NFP, IFW, WPDM, FD, PH and NSF respectively, except for MC has revealed low GCV and PCV. All the traits were shown the presence of high heritability ( ) in broad sense (>60%) coupled with high GAM (>20%), except for MC, indicating the presence of positive additive gene action and effective transmission of characters to the next generation with selection. Highly significant and positive strong correlation was observed for IFW (r = 0.68**), WPDM (r = 0.54**), TW (r = 0.40*) and FD (r = 0.37*) with FYP, while the path analysis revealed highest direct effect for the traits such as FPT, FL and NFP. Principle component analysis revealed a 70.60% total variation accounted with first four PCAs with Eigen vector values more than one.
 Further cluster analysis grouped the 30 chilli genotypes into four major cluster (Cluster I, II, III and IV) and combined cluster analysis identified genotypes contributing to the maximum variability, viz., cultivars such as LIPSTICK, B.KADDI, B.DABBI, BHOOT JALOKIA, SUM- 17, BCH- 42, PBC- 80, LCA- 310, M- 262, KA2- L, S. SELECTION 1, JCH- 42 and 9608- U, so these genotypes serves as a donor for further breeding programme to develop superior cultivars.

Genetic Variability Studies in F2 Population of the Wheat Cross DDK-1029 x GPM DIC 66

The selection of breeding material heavily relies on genetic variation and its inherited components. A thorough understanding of genetic variation is necessary in order to develop an improved variety. Thus, genetic parameters were assessed in the F2 population of the cross between DDK-1029 and GPM DIC 66. The genetic variability results indicated a moderate to high phenotypic and genotypic coefficient of variation for characters like days to 50% flowering, plant height, productive tillers per plant, spike length, spikelets per spike, grains per spike, thousand grain weight and grain yield. In contrast, the protein, iron and zinc contents exhibited low to moderate phenotypic and genotypic coefficient of variation. All the traits had higher heritability except for grain yield which exhibited a moderate heritability. All the characters exhibited significant GAM except for days to maturity, iron content and protein content which exhibited moderate GAM. This suggests that high genetic variation, heritability, and GAM for such traits will aid in their improvement through both direct and indirect selection.

Estimation of Genetic Variability Parameters and Character Association in F2 Generation of Chickpea (Cicer arietinum L.) Crosses under Irrigated and Rainfed Conditions

The present study was carried out to estimate genetic variability parameters, heritability (in broad sense), genetic advance as percentage of mean and character association in F2 generation of five chickpea crosses under irrigated and rainfed conditions for yield and its components traits. The estimates of these parameters will help us to decide selection criteria for improvement of seed yield in chickpea. Significant differences were observed among the crosses and generations for all the characters under both the conditions. The highest range of variation was observed for 100 seed weight followed by seed yield per plant, biological yield per plant, seeds per pod and plant height in irrigated condition, while in rainfed condition the highest range of variation was registered for 100 seed weight followed by days to 50% flowering, fruiting branches per plant, seed yield per plant, days to maturity and harvest index. Hence, selection should be done on characters having wide range of variation under the respective environmental condition. Phenotypic variance was higher than the corresponding genotypic variance for all the characters studied under both the conditions, indicating more contribution of environment in the phenotypic appearance of the traits than their genetic makeup. The high estimates of GCV and PCV were obtained for fruiting branches per plant, pods per plant, seeds per pod, biological yield per plant, seed yield per plant and 100 seed weight in most of the crosses under both the conditions. High heritability coupled with high genetic advance as percentage of mean was observed for pods per plant in most of the crosses under both the conditions. RSG-895 × RSG-888 showed high heritability coupled with high GAM for seed yield per plant and harvest index, CSJD-901 × RSG-931 for seed yield per plant, RSG-888 × ICC-4958 for harvest index under irrigated condition indicated the importance of additive gene action in the inheritance of these characters; hence, selection based on phenotypic performance would be effective for improvement of these characters. Seed yield per plant had positive and significant correlation with fruiting branches per plant, pods per plant, biological yield per plant, harvest index and 100 seed weight under both the conditions and with plant height in rainfed condition only. So selection based on these characters is expected to bring improvement in the seed yield of chickpea.

Variability on Seed Yield and Related Agronomic Traits in Mesoamerican Common Bean (Phaseolus vulgaris L.) Genotypes under Contrasting Environments at South Eastern Ethiopia

The experiment was conducted during July-November, 2022 at Melkassa and Kulumsa Agricultural Research Center main station under rain fed condition to assess the extent of genetic variability and to identify potential candidate genotypes. A total of 64 small seeded common bean genotypes were evaluated for 18 quantitative traits using 8*8 triple lattice design. The analysis of variance showed that there was highly significant (p<0.01) difference among genotypes for all studied traits at both individual locations. The genotypes variation for seed yield was ranged from 1685.09 kg ha-1 to 4499 kg ha-1 at Melkassa and from 1369.76 kg ha-1 to 4848.38 kg ha-1 at Kulumsa. High PCV and GCV were recorded for total number of seeds per plant, number of fertile pods and total number of pods per plant in both locations. Moderate to high value of GCV and broad sense heritability coupled with high GAM were obtained for seed per plant, dry pod yield per plant, fertile pods per plant, seed weight per plant, hundred seed weight and seed yield per hectare in both locations; indicating the importance of those traits in yield improvement of small seeded common bean. G-39, G-27, G-58, G-35, G-29, G-18, G-8, G-61, G-37 and G-33 showed yield advantage from 49% to 88.9% at Melkassa and G-33, G-8, G-4, G-12, G-58, G-11, G-45, G-13, G-36 and G-30 from 16% to 36% at kulumsa over the best standard check G-64. The existed variations implied the possiblity for further improvement of seed yield and atributing traits through utlizing selected potential genotypes and targeted hybridization schemes in breeding programs.

Assessment of Various Variability Parameters and Correlation of Quantitative Characters in Maize (Zea mays L.) Inbred Lines

The present research problem was carried out to assess the variability parameters, heritability, genetic advance and correlations among various quantitative traits in maize inbred lines. A total of 69 inbred lines were evaluated in alpha lattice design with 2 replications at Winter Nursery Centre, Hyderabad. ANOVA results displays genotypes were significantly different from each other. From the results it was depicted that Phenotypic Coefficient of Variation (PCV) was higher than Genotypic Coefficient of Variation (GCV) indicating the influence of environment. The traits, No. of kernels per row, Cob weight, Grain yield per cob showed high GCV and PCV values likewise Days to 50% tasseling, Days to 50% silking and Days to 75% dry husk showed low GCV and PCV values. Most of the characters showed high heritability and traits such as Plant height, Tassel length, Ear length, No. of kernels per row, Cob weight and Grain yield per cob showed high GAM and its values ranged from 21.5% to 101.30%. So, the traits such as No. of kernels per row, Cob weight and Grain yield per cob can be used for further crop improvement in the breeding programme. Of all the traits under study except, Days to 50% tasseling, Days to 50% silking and Days to 75% dry husk showed positive significant correlation with grain yield per cob indicating selection for the traits will enhance the grain yield whereas the excepted traits showed negative significant association with grain yield per cob indicating selection for these traits is also essential as it reduces duration of crop.

Understanding the Genetic Variability for Growth and Leaf Yield of Coriander (Coriandrum sativum L.)

Background: Coriander (Coriandrum sativum L.) is a popular herbaceous annual seed spice crop. It is mainly grown for seed as well as green leaf, the leaf and seed yield is varied with the genetic background of genotypes. Therefore, the selection of genotypes with high leaf yield is highly desired, along with the magnitude of heritability and genetic advance for wider adaptation and cultivation. In this view, the accessions were collected and their genetic variables were assessed. Methods: The experimental material included 48 coriander accessions along with two check varieties CO4 and CO5. The plant materials were obtained from the coriander germplasm repository at the Department of Spices and Plantation Crops, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, India. The experiment was laid out in Randomised Block Design with two replications. Results: The results of the analysis of variance revealed significant differences among the accessions. High heritability coupled with high GAM was observed for the economical trait (87% and 48.93% for leaf yield) indicating that, the traits were highly heritable in nature, hence selection breeding is most effective. The PCV and GCV were moderate to high for all traits except the number of days for harvest and moisture content among all the accessions of coriander. The leaf yield was highly significant, and positively correlated with all the traits except the number of days for harvest and leaf protein. The genotypic correlation was greater than the phenotypic correlation among the genotypes. Therefore, to increase the seed yield of coriander accessions, either simple selection or mass selection of desirable traits and their associated traits would be effective.

Characterization of Exotic Tomato Germplasm from ICAR-NBPGR Gene Bank

The present study describes the characterization of 148 exotic tomato accessions from ICAR-NBPGR, New Delhi gene bank. The degree of variance for morphological features was high. Mean plant height of 72.36 cm, number of primary branches 2.7, days to 50% flowering 74.9, number of flower clusters per plant 5.91, number of flowers per cluster 3.91, number of locules per fruit 3.08, fruit weight 62.06 g, pericarp thickness 4.32 mm, fruit length 45.98 mm, fruit width 45.9 mm, total soluble solids 4.81° Brix and yield per plant 0.28 Kg were recorded. The first eight PCA extracted accounted for 89.23% of the total variation based on 12 phenotypic characters. A significant positive association was observed among the fruit characters. High PCV, GCV, heritability and GAM were recorded for most of the characters studied. The high variability especially for economically important fruit characters among the tomato germplasm like EC716696, EC715399, EC705451, EC705439, EC699717, EC695044, EC695038, EC695037, EC759285, EC759989 and EC759255 recorded higher TSS values and, germplasm like EC753226, EC716696, EC753220 and EC759989 recorded higher fruit yield per plant, makes this germplasm a potential resource for future tomato breeding programmes.

Genetic variability, heritability, and genetic advance for quantitative traits of sorghum [Sorghum Bicolor (L.) Moench] genotypes at Fedis, Eastern Ethiopia

Sorghum is the second most important food crop after teff in Ethiopia. The objective of the study was to estimate the genetic variations, heritability, and expected genetic advances in the selected sorghum genotypes. Sixty-four sorghum genotypes were evaluated for 17 quantitative traits in 8x8 simple lattice designs at the Boko research site. The analysis of variance revealed highly significant differences among genotypes for all traits. The Phenotypic Coefficient Of Variation (PCV) ranged from 4.74% for days to flowering to 24.74% for panicle width, while Genotypic Coefficients Of Variation (GCV) ranged from 3.58% for leaf length to 20.33 % for panicle width. The highest PCV and GCV values were recorded for panicle width, head weight, and harvest index. Moderate PCV and GCV were recorded for grain filling period, grain filling rate, plant height, panicle length, and grain yield; indicating the effectiveness of selection based on the phenotypic performance of the genotypes. Broad sense heritability (H2) ranged from 24.74 % for biomass yield to 96.6% for head weight, whereas GAM ranged from 4.8% for biomass yield to 41.95% for panicle width. High H2 coupled with high GAM was observed for grain filling rate, panicle length, panicle width, head weight, grain yield, and harvest index; indicating that these characters are controlled by additive gene action and phenotypic selection for these characters will be effective. However, the information generated in the current study it can be useful for breeders who want to improve yield and yield contributing traits of sorghum.

High-density GBS-based genetic linkage map construction and QTL identification associated with leaf cuticular wax, adaxial stomatal density and leaf water retention capacity in banana

The drought tolerance quantitative trait locus (QTL) in Banana has not been studied to date. In this study, the susceptible parent Musa acuminata ssp. burmannicoides Colla –'Calcutta-4' and the resistant parent Musa balbisiana collection 'Bee hee kela' were crossed to produce an F1 mapping population of 96 individuals for the purpose of mapping drought tolerance traits in banana. Consequently, an entirely novel mapping population was developed using progenitor lines with distinct genomic compositions (A genome and B genome). We employed, the GBS (Genotype By Sequencing) technique to develop a genetic linkage map. The map contained a total of 1015 SNP markers, 11 linkage groups, and a total distance of 4828.88cM. The average distance between markers was 4.9cm. The two primary methods that a plant loses water are through stomata and cuticle transpiration, both of which is not beneficial for the plant. Thus, in the present investigation, the AB mapping population's adaxial stomatal count is measured using a microscopic technique, and leaf cuticular wax was estimated using a spectroscopic method. In addition, the leaf's water retention capacity was estimated. Genetic analysis showed that the drought tolerance traits exhibited moderate to moderately high PCV, GCV, and GAM values, as well as high heritability. Using the GBS-based genetic linkage map and phenotyping information, the QTL analysis identified five main QTLs for drought tolerance on chromosomes 2, 5, and 8. They were designated as wax13_1, wax15_1, wax15_2, lwrc_1, and asd_1. The PVE (per cent) of the identified QTLs varied between 15.9 and 19.8 percent. To our knowledge, this is the first report on the employing of SNP markers to identify QTLs associated with drought tolerance traits in banana. This study's findings will be helpful in fine-mapping and marker-assisted selection in banana for drought related traits.