Additive Gene Action Research Articles

Genetic Variability, Heritability and Genetic Advance Studies in Chickpea (Cicer arientinum L.)

Chickpea (Cicer arietinum L.), an essential legume for sustainable agriculture and human nutrition, exhibits considerable genetic variability that holds promise for varietal improvement. This study evaluated 40 diverse chickpea genotypes during the Rabi season of 2021–22 at the Oil Seed Research Farm, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur. Significant genetic variability was observed across key agronomic traits, including days to 50% flowering (73.67–95.67), plant height (25.55–42.47 cm), days to maturity (125.33–150.00), and grain yield per plant (8.38–18.63 g). Traits such as 100-seed weight (37.71–65.48 g), biological yield (11.14–31.84 g), and harvest index (21.83%–36.13%) demonstrated high genotypic and phenotypic coefficients of variation, heritability, and genetic advance, indicating the predominance of additive gene action. High heritability and genetic advance were observed for traits like pods per plant, biological yield, and 100-seed weight, suggesting these are promising targets for selection in breeding programs. Early flowering genotypes and those with superior seed weight and grain yield emerged as candidates for improving productivity and adaptability under diverse agroecological conditions. Additionally, traits with strong positive correlations with seed yield, such as the number of pods per plant and biological yield, offer valuable insights for breeding strategies.

Assessment of Genetic Divergence and Character Association Studies on Germplasm Accessions of Rice (Oryza sativa L.)

In this study, fifty-five rice germplasm accessions were used along with five checks, namely IR64, Swarna, Jaya, DRR Dhan 42 and MTU1010, for evaluating genetic variability, heritability and genetic advance during kharif 2023. The analysis of variance revealed extremely large genotype differences for each of the 16 traits under investigation. The highest heritability measures were found in number of filled grains per panicle followed by paddy breadth, paddy length:breadth ratio, brown rice length:breadth ratio, 100 seed weight, paddy length, plant height, brown rice breadth, number of effective tillers per plant, brown rice length, number of unfilled grains per panicle, grain yield per plant, panicle length, and harvest index. High heritability with high genetic advance shown by characters such as plant height, number of filled grains per panicle, paddy length and brown rice length this indicates that the heritability is due to additive gene action and is found least influenced by environment. Hence, the desirable characters with high heritability coupled with genetic advance can be used for selection. Grain yield per plant exhibits a positive and highly significant correlation with the days to 50% flowering (0.383), number of effective tillers per plant (0.315), number of filled grain per panicle (0.219) and paddy length (0.219). In terms of direct effect, paddy length (4.735) shows the highest impact, followed by brown rice length (1.183), number of filled grain per panicle (0.578), days to 50% flowering (0.347), panicle length (0.135), harvest index (0.082).

Assessment of genetic diversity in Nelumbo nucifera genotypes

Aim: The present investigation assessed the level of genetic diversity in the lotus (Nelumbo nucifera Gaertn.) genotypes grown naturally in Bihar (India). Methodology: In situ observations on 21 quantitative traits were recorded with five replications from each sampling site and data was analysed in a Completely Randomized Block Design. Results: Among all the genotypes BRL-01, BRL-08, BRL-21, and BRL-22 showed significant variation in the number of petals per flower, weight of flower, and flower colour. High values of genetic parameters were calculated for number of petals per flower, rhizome weight, rhizome length and weight of the flower. Number of petals per flower, number of leaf venation and diameter of the flower bud showed a significant positive correlation with the weight of flower. Path analysis revealed a highest positive direct effect of leaf length on flower weight at genotypic level. Interpretation: High GCV for all traits indicates the existence of genetic variation. The traits coupled with high heritability and genetic advance indicate the positive response for selection, primarily driven by additive gene action. Therefore, selection for traits such as number of petals per flower, length of flower stalk and weight of flower may be useful for the development of improved variety for flower attributes. Key words: Correlation coefficient, Diversity, Genotypes, Lotus, Path analysis

Genotype by year interaction and additive and epistasis gene effects for Fusarium stalk rot resistance in doubled haploid lines of maize (Zea mays L.).

Fusarium stalk rot is the main factor reducing the quality of maize grain and leads to significant yield losses, which that ranges from 20 to 100%, depending on the degree of infection and weather conditions. Understanding its genetic mechanism is key to improving grain quality and ultimate yield. An experiment with 26 doubled haploid (DH) lines of maize was conducted in the northern part of the Lower Silesia Province in Poland over a ten-year period (2013-2022). The study assessed resistance to Fusarium stalk rot. The objectives were to evaluate genotype-year interactions for resistance to Fusarium stalk rot in maize DH lines using the additive main effects and multiplicative interaction (AMMI) model, to select DH lines that are stable across all years of testing and specific to particular environmental conditions, and to estimate additive and epistatic effects. AMMI results demonstrated a significant effect of genotype, year, and their interaction on Fusarium stalk rot resistance. The KN16 line is recommended for inclusion in further research within the breeding program due to its excellent stability and high average resistance to Fusarium stalk rot. Estimates of additive gene action effects were statistically significant in each year of the study. Estimates of epistasis (total additive by additive interaction) effects for Fusarium stalk rot resistance were also statistically significant in all ten years of the study. Only in 2013 was the epistasis effect positive (0.168). These results indicate that achieving biological advances in resistance to Fusarium stalk rot should be an important focus of ongoing maize breeding programs.

Impact of Heterotic Potential in Rice (Oryza sativa L.) for Certain Yield and its Contributing Traits in Salt-Affected Soil

The present investigation was undertaken with the objectives to estimate genetic variability for yield and yield contributing components. The experimental materials of rice for this investigation comprised of 22 genotypes as lines (female) and three testers (male) viz., Narendra Usar 3, NDR 359 and CSR 36. Each of the three testers was crossed with 22 lines during Kharif, 2013. The experiment was based on the evaluation of a line × tester set of 66 hybrids (F1s) along with their 22 parents and check varieties viz., Narendra Usar 3 and Arize 6444, for twelve quantitative trait in salt affected soil in randomized block design with three replications. The analysis of variance revealed that all the treatments, parents, parent vs crosses, crosses, lines and lines x testers were highly significant for majority of the yield and its contributing traits indicated sufficient variation among the treatment/materials under study.In the present investigation, a wide range of variation in estimates of heterobeltiosis and standard heterosis in positive and negative directions was observed for grain yield per plant and its contributing components. In case of grain yield per plant heterobeltiosis ranged from -1.76 per cent (IR 47427-2B-2-2B-1-1× Narendra Usar 3)to 100.14 per cent (Kashturi Chandauli× NDR 359), standard heterosis over SV1varied from -30.85 per cent (AGAMI MI× CSR 36) to 50.84 per cent (Kashturi Chandauli× NDR 359) while over it ranged from -3677 per cent (AGAMI MI× CSR 36) to 37.92 per cent (Kashturi Chandauli× NDR 359). Kashturi Chandauli× NDR 359, IR 74095 AC 5 × NDR 359, Narendra 6096 × NDR 359, Sarjoo 52 × Narendra Usar 3 and Kashturi Chandauli× Narendra Usar 3 were found highly significant over BP, while Kashturi Chandauli× NDR 359, IR 74095 AC 5 × NDR 359, Narendra 6096 × NDR 359, Sarjoo 52 × Narendra Usar 3 and Jaya × Narendra Usar 3 had highly significant over standard variety SV1. Further Kashturi Chandauli × NDR 359, IR 74095 AC 5 × NDR 359, Narendra 6096 × NDR 359, Sarjoo 52 × Narendra Usar 3 and Jaya × Narendra Usar 3 were found to be highly significant over SV2 for grain yield per plant. The estimates of heterosis were attributed to genetic interaction arising from both additive as well as high degree of non additive gene action for major physiological traits. Two physiological traits viz., biological yield per plant and harvest index followed by spikelets per panicle, 1000- grain weight, L: B ratio and flag leaf area remained as major contributors to heterobiltiosis and standard heterosis. It reflects that emphasis should be given to select these traits to enhance the production and productivity in salt affected soil.

Interspecific Hybridization between Gossypium hirsutum (American Cotton) and Gossypium barbadense (Egyptian Cotton) for Quality Improvement

Cotton (Gossypium spp.) is a globally important cash crop, valued for its fiber and economic contributions to the textile industry. This study investigated the variability, heritability, and genetic advance of yield-related traits in interspecific hybrids of American (G. hirsutum) and Egyptian (G. barbadense) cotton. Using a randomized complete block design, 28 hybrids were evaluated for traits such as seed cotton yield, plant height, bolls per plant, and boll weight. Significant genetic variability was observed among hybrids, with high heritability estimates for seed cotton yield (96.84%), plant height (93.51%), and bolls per plant (76.44%), coupled with moderate genetic advance, suggesting additive gene action. Regression analysis revealed that the number of bolls emasculated and pollinated significantly influenced total seed production, with coefficients of determination (R²) of 0.5924 and 0.5102, respectively. The hybrid JA-08/A × JA-12/203 demonstrated superior crossability (100%) and seed production, making it a promising candidate for breeding programs. These findings emphasize the potential for exploiting genetic variability and hybrid vigor to develop high-yielding and high-quality cotton varieties.

Study on genetics of yield component traits under salt stress in two rice crosses raised using honeycomb selection design

Abstract Yield components related to grain yield were severely affected by salinity. For the agronomically important traits, precise phenotyping of crop plants is essential under stress where soil heterogeneity is aggravated for genetic analysis and developing improved crop varieties. A set of two F2 populations obtained from ADT(R)45 × FL478 (A × F) and ADT(R)45 × Nona Bokra (A × N) crosses along with check variety CSR10 were raised in Honeycomb Selection Design (HSD) to study the genetics of yield component traits under salt stress. The study found that the trait, panicle weight in A × F exhibited normal distribution while the other traits exhibited non-normal distribution in both the crosses. Negative skewness was observed for panicle length in both the crosses and days to flowering in the A × N indicating duplicate (additive × additive) gene interactions. Whereas positive skewness was observed for plant height, number of tillers, productive tillers and single plant yield in both the crosses, days to flowering and spikelet sterility in A × F and panicle weight in A × N indicating complementary gene interactions. Leptokurtosis was observed for days to flowering in the A × F. While the remaining characters in both the crosses exhibited platykurtosis. Transgressive segregants in both directions (towards both the parents) were obtained for all the eight characters studied in both the crosses suggesting that all traits were governed by additive gene action. Honeycomb selection design (HSD) provides an excellent phenotyping framework for studying the genetics of any quantitative traits, particularly yield and its component traits, as well as for breeding varieties that will provide more consistent results in yield in a shorter time frame. Keywords: Skewness, kurtosis, transgressive segregation, gene action

Genetic variability studies of diverse cashew (Anacardium occidentale L.) cultivars for growth and yield parameters in coastal zone of Karnataka

Abstract The present study aimed to evaluate the performance of cashew cultivars developed/collected from different cashew growing regions of the country. The experiment was conducted at Agricultural and Horticultural Research Station, Ullal, belonging to coastal zone of Karnataka during 2023-24. Fifteen year old standing cashew orchard planted with 42 diverse cashew cultivars were evaluated for 15 fruit, nut, growth and yield parameters following randomized complete block design with two replications. Highly significant variations of GCV and PCV coupled with high heritability and GAM was observed for most of the traits indicating the predominance of additive gene action and possibilities of achieving high genetic gain from selection. Character association studies revealed the importance of yield component traits like nuts per panicle, canopy surface area and canopy spread (E-W and E-W) that forms the basis for selection of promising cultivars for yield improvement in cashew. Potential high yielding varieties like Ullal 1, Bapatla 8, Gubbi 3/111, NRCC Selection 2, Ullal 3 and VRI-3 were found to be suitable in coastal zone of Karnataka. Bapatla 8, Priyanka and Vengurla 7 cultivars exhibited superiority for both nut weight and nut yield per tree. This study provides useful information on genetic control of important yield traits and choice of potential cultivars in hybridization program to explore the variability and hybrid vigor for improvement of productivity and quality in cashew. Keywords: Cashew, coastal zone, nut yield, variability, correlation

Genetic Parameters in Germplasm Lines for Yield and Its Contributing Traits in Grain Amaranth (Amaranthus hypochondriacus L.)

The present investigation was conducted to estimate the genetic variability, heritability and genetic advance of genotypes of grain amaranth during kharif, 2022 at Agricultural Research Station, Tornala. Fifty nine genotypes of grain amaranth along with 4 checks (Suvarna, BGA-2, GA-5 and RMA 7) were evaluated in an augmented block design for access their performances. High phenotypic and genotypic coefficient of variation were observed for grain yield/plant (82.73/82.70), no. of spikelets/ plant (62.41/62.36), inflorescence length (49.72/49.66), plant height (41.54/41.47) and days to 50% flowering (21.78/21.66) indicating the presence of high variability in germplasm for selection. The characters viz., days to 50% flowering, plant height, inflorescence length, no. of spikelets/ plant and yield/plant expressed high heritability coupled with high genetic advance as percent of mean, which indicates preponderance of additive gene action in controlling the traits. Hence, the characters having high GCA & PCA can be relied upon and simple selection can be practiced for further improvement. Based on the performance, genotypes SKGPA183, EC322998, IC 551493, IC 551496 and IC 551499 have been found superior among the genotypes which can be used in breeding programmes for crop improvement.

Genetic variability, heritability and genetic advance in chrysanthemum (Dendranthema grandiflora) genotypes evaluated for loose flower production

Abstract Twenty-five genotypes of chrysanthemum were evaluated for loose flower yield under open field conditions in a Completely Randomized Block Design during the year 2023-24 to ascertain their genetic variability, heritability and genetic advance for various quantitative and qualitative qualities that can be used to choose parents. Analysis of variance exhibited noteworthy variation in the genetic potential of the genotypes for every trait under study. The magnitude of phenotypic coefficient of variation (PCV) for each trait was discovered to be higher than the genotypic coefficient of variation (GCV), which demonstrated an interaction between the genotype and environment. High (>20%) PCV and GCV were noticed for all the traits evaluated in the present study. Heritability estimates ranged from a low 29.78% (stem diameter) to as high as 99.968% (flower diameter). High heritability (>60%) was noted for each of the characteristics except stem diameter. All of the growth, flowering and yield examined, estimates of high heritability combined with high genetic advance as a percentage of mean (GAM) was found, suggesting that potential significance of additive gene action among the genotypes. Keywords: Chrysanthemum, Genetic variability (GCV, PCV), Heritability, Genetic advance (GAM)

Genetic analysis for forage yield and quality characters in cowpea (Vigna unguiculata L. Walp)

This study was carried out to determine the combining ability of forage yield, its components and quality traits among crosses derived from nine selected cowpea parents. About 36 crosses were generated from diallel crosses, excluding reciprocals. These crosses and nine parents were evaluated for combining ability for forage yield, its components and quality traits. The results indicated that parent 85-5E was the best combiner for green fodder yield, dry matter yield, leaf length, leaf breadth, number of leaves per plant, number of branches per plant, crude protein content and in-vitro dry matter digestibility. Similarly, parent FOS 1 proved to be the best combiner for vine length, number of leaves per plant, number of branches per plant, crude protein content and in-vitro dry matter digestibility. The crosses involving FOS 1 x CL 398, CL 391 x C 88, FOS 1 x C 74, CL 396 x CL 391 and FOS 1 x C 88 were the best specific combiner for green fodder yield and most of its components traits. The ratio of gca/sca values was greater than unity for most of the forage and quality traits, inferring that additive gene action played an important role in their inheritance. In contrast, for traits like vine length, dry matter yield, crude protein content, and in-vitro dry matter digestibility, the above-said ratio was less than unity, indicating non-additive gene action played an important role. So, to utilize both additive and non-additive gene effects, modification of conventional breeding methods such as bi-parental breeding or reciprocal recurrent selection will be the better choice for initiating any cowpea breeding program.

Genetic Variability and Association Analysis for Various Quantitative Traits in Lentil (Lens culinaris Medik. ssp. culinaris)

Background: Lentil (microsperma) is the earliest domesticated grain legume grown for its lens shaped seeds. The current study was carried out to assess genetic variability, trait association between seed yield and its attributing components and to assess the direct and indirect effects of various attributing components on seed yield. Methods: The current experiment evaluated hundred lentil germplasm lines with three checks in augmented design across two environments viz., timely sown (E1) and late sown (E2) during rabi 2022-23. The data was recorded on 11 quantitative traits and all the statistical analyses were done using R studio. Result: High PCV and GCV coupled with high heritability and genetic advance as percent of mean was observed for seed yield per plant, biological yield per plant, 100 seed weight and number of pods per plant suggesting that these traits are genetically controlled by additive gene action and their direct selection is effective. Path analysis revealed that biological yield per plant, harvest index, number of primary branches, seeds per pod and days to flowering were the highest positive direct contributors to the seed yield. Based on the observations of the present study, genotypes PL 105, LH 18-03, IPL 406, LH 18-38, LH 18-42, LH 18-45 and LH 18-46 were found to be better performing under timely sown conditions. Similarly, genotypes LH 09-18, LH 09-19, LH 09-20, LH 09-26, LH 09-27, WBL 77 and Kota Masoor 2 were found superior under late sown conditions.

Assessment of Genetic Variability and Trait Associations in Chickpea (Cicer arietinum L.) Germplasms for Targeted Breeding Strategies

Chickpea (Cicer arietinum L.) is a pivotal legume crop with substantial contributions to global food security and agricultural sustainability due to its high protein content, adaptability and nitrogen-fixing ability. The efficiency of breeding programs in enhancing chickpea productivity and resilience relies heavily on understanding and utilizing genetic variability within the germplasm. This study investigates the extent of genetic variability among forty-three chickpea genotypes, focusing on key traits such as number of pods (NPP), biological yield (BY), harvest index (HI), days to flowering (DTF), days to maturity (DTM), that influence yield and other agronomic characteristics. Analysis of variance showed significant variability among genotypes for various traits. Higher phenotypic coefficients of variation (PCV) compared to genotypic coefficients (GCV) indicated the presence of environmental influence, particularly for traits like number of pods per plant (NPP) and biological yield (BY). High heritability was observed for days to flowering (DTF) and maturity (DTM), while genetic advance as percent of mean (GAM) varied, indicating additive gene action for some traits. Correlation and path analysis revealed positive relationships between plot yield and traits such as Days to Flowering (DTF), plant height (PH), and harvest index (HI). Principal component analysis (PCA) and cluster analysis indicated significant genetic diversity, grouping genotypes into clusters and identifying top performers like GJG1801 and NBEG 924. This study emphasizes the importance of genetic variability in breeding programs, aiding in the selection of elite genotypes for targeted traits improvement.

Variability Studies in Soybean Genotypes under Different Water Regimes

Soybean (Glycine max L.) is economically one of the most important oilseed crop worldwide which have high protein and oil content. Its productivity is frequently affected due to drought occurrence in India. Variability for root shoot traits under early seedling stage under drought stress may be important selection criteria for development of drought tolerant genotypes. The present investigation was carried out at Net house of Experimental Farm, Mandsaur University, Mandsaur. Sixty genotypes, procured from ICAR-IISR, were used to know the extent of genetic variability under different water regimes [normal, 100 ml (100%), S1, 50 ml (50%), S2, 25 ml (25%) and S3,0 ml (0%)] for root-soot traits and relative leaf water content under early seedling stage. Significant genetic variability was recorded for all the traits among genotypes studied under normal and water stress conditions respectively which showed the presence of ample variability in studied material. High Phenotypic Coefficient of Variation than their corresponding Genotypic Coefficient of Variation for the entire trait under different water regimes denoted influence of environment on these traits. The large genetic variation found in these genotypes may be used to develop varieties with better drought tolerance behavior and used as drought donor lines in drought breeding programs. We measured high heritability for selected characters under non water stress condition (75.05% to 100%) and water stress conditions S1 (81.40% to 100%), S2 (85.69% to 100%) and S3 (92.60% to 99.26%) respectively. Additive gene action interacted to control characters under different water regimes because high broad sense heritability along with high genetic advance as percentage of mean were recorded for most of traits. It is indicating that simple phenotypic selection would be effective for these traits under water stress condition.

Inheritance, heterosis and combining ability analysis in line × tester crosses of cotton

Abstract. The aim of this research was to study heterosis, combining ability and genetic control of most important traits in line × tester crosses. It was found that the non-additive variance (σ2D) was larger than the additive variance (σ2A) for productivity per plant and fiber length revealing the greater importance of non-additive gene action in the inheritance of both traits and the selection of desirable forms should be conducted in the later hybrid generations. Non-additive genetic variance was also more important for boll weight, whereas additive gene action was of greater importance for lint percentage and the selection for this trait can be effective in early segregated generations. Line 266 was identified as a good general combiner for productivity per plant and fiber length, line 346 for lint percentage and fiber length. The Turkish cultivar Nazili 954 can be used in crosses to improve productivity, while the Spanish cultivar FR-H-1001 can be used to increase lint percentage and fiber length. The hybrids 191 × Nazili 954 and 266 × FR-H-1001 exhibited the highest productivity per plant with high SCA effects and the highest heterosis of 30.7-31.7%. The highest lint percentage of 42.1-42.3% was achieved in hybrids from the crosses Nazili 954 × 266 and 346 × FR-H-1001 showing significant positive heterosis of 2.4 - 9.0%. Hybrids from the crosses FR-H-1001 × 266 and 346 × FR-H-1001 had the longest fiber and exhibited heterosis of 8.4% and 5.7%, respectively. The cross combination 346 × FR-H-1001 was very promising for lint percentage and fiber length showing high mean levels for both traits with high SCA effects and positive heterosis.

Unraveling the genetic diversity, population structure, and stability for yield-related traits of rice genotypes in mid-hills of northeastern India.

The cultivation of nearly 10,000 indigenous rice landraces in the North-Eastern Hill (NEH) region by various ethnic groups creates opportunities for the utilization of unique landraces through systematic evaluation of genetic variability. In the present study, a set of 102 rice landraces were assessed based on morphological and SSR markers, and five checks in augmented design vis-à-vis high-yielding rice genotypes with stable performance were identified. The presence of high estimates of heritability, genotypic coefficient of variation, and genetic advance over mean indicated the predominance of additive gene action, which necessitated the effectiveness of selection in augmenting productivity. A total of 83.73% of the total variation was accounted by the first five principal components. A total of 132 alleles were detected, with an average of 3 alleles per locus. The PIC values ranged from 0.01 to 0.70, with an average of 0.40. Based on FST value (5.1%), significant differences between the genotypes of Arunachal Pradesh and Sikkim were observed. The percentage of variation among the population, among individuals within the population, and within individuals was 5.14, 75.66, and 19.2%, respectively. Both Nei's genetic distance and model-based clustering have differentiated the genotypes into five distinct clusters. Principal coordinate analysis illustrated that the genotypes of Manipur were scattered in all quadrants, showing that they are highly diverse, while the genotypes of Nagaland, Sikkim, and Meghalaya were found together, which represent the chance of mixing of the population at a certain point in time. Markers, namely RM 474, OSR 13, RM 413, and RM 259, were found to be associated with key traits for increasing yielding ability of plant. In a stability evaluation based on AMMI analysis and multi-trait genotype-ideoptype distance matrix (MGIDI), genotypes, namely Jyotrirmayie, RCPL 1-411, Tsamum firri, Ching Phouren, Rato Bhan Joha, MN-47, and Tara bali, were selected with higher yield potential.

Genetic Variability and Association Studies on Yield and Yield Attributing Traits in Blackgram (Vigna mungo L. Hepper)

Aims: Low and static productivity (450–800 kg/ha) is one of the main obstacles in blackgram (Vigna mungo L. Hepper) crop. The low productivity is due to inadequate seed systems, a lack of access to genetic and genomic resources, and a lack of active breeding initiatives. Hence the present study was carried out to assess the variability and association among yield contributing traits for blackgram improvement programmes. Place and Duration of Study: The field study was carried out during 2019-2020 in V.O. Chidambaranar Agricultural College and Research Institute, Killikulam, Tamil Nadu Agricultural University at Department of Genetics and Plant Breeding. Study Design and Methodology: A total of 60 F4 progenies developed from the cross IC 436656 x KKB14045 in blackgram for the assessment of per se performance, genetic variability and association studies. Results: Based on the production of a single plant, seventeen offspring were determined to be promising. The traits viz., number of clusters per plant, number of pods per plant, and single plant yield showed high PCV and GCV, which indicated that there was a high level of genetic variability in the population. The variables of plant height, number of clusters / plant, number of pods/plant, and single plant yield showed significant heritability and high genetic advancement, indicating additive gene action. Single plant yield was positively and significantly correlated with the traits viz., plant height, number of clusters / plant, number of pods / plant, and number of seeds / pod. Therefore, choosing these characteristics is crucial to creating high yielding blackgram cultivars.

Phenotypic Variability among Parental Lines and Progenies of Bread Wheat

Wheat is the second most important cereal staple food crop consumed nearly 35% of world population and provides 20% food calories. It’s a self-pollinating annual plant in the true grass family Gramineae (Poaceae) and genus Triticum, is the world’s most famous energy rich cereal crop. The wheat is a hexaploid (allohexaploid) species (2n =6x= 42) having AABBDD with A, B and D genome. The present research investigates fifty-six genotypes of bread wheat consisting of 33 F1s obtained by crossing eleven lines with three varieties in a line x tester mating design along with their parents and two well-known checks. The experiment was laid out in a randomized block design with three replications. Results revealed considerable genetic variability among the genotypes. Traits like grain yield per plant and number of tillers per plant exhibited higher values of PCV with moderate GCV. High heritability with moderate values of genetic advance were recorded for grain weight per spike (17.688%) followed by number of grains per spike (17.4 %), biological yield per plant (14.7 %), 1000 grain weight (11.9 %) indicating involvement of additive gene action in the inheritance of these traits and hence selection along with progeny testing can be employed for improvement of these characters. According to correlation studies, there is a substantial positive link between the trait grain yield per plant and the number of tillers per plant, harvest index, and biological yield per plant. Selection for these qualities will therefore eventually contribute to the genotypes' increased total output. Early maturing cultivars should be chosen when breeding for a better yield because it was also shown that the number of days to maturity had a negative correlation with the yield.

Breeding potential of red- and white-skinned onion (Allium cepa L.) genotypes for economic traits using multivariate analysis

ABSTRACT The improvement of onion (Allium cepa L.) depends on the characterization and evaluation of the germplasm to find superior genotypes with desired horticultural qualities and utilization of diversity in future breeding. The study aimed to evaluate advanced breeding lines (consisting of both red- and white-skinned types) through genetic component analyses and genetic divergence using multivariate analysis to identify genotypes that can be utilized in breeding for table and dehydration purposes, respectively. Genotypes ‘(EM-AVT-2) REC-21-48,’ ‘(RIET) RVA-21-01,’ and ‘(EM-AVT-2) REC-21-46’ were found to be high yielders. Higher estimates of the genotypic coefficient of variation, heritability and genetic advance for the percentage of the double bulb, total soluble solid, and reducing sugar contents indicate additive gene action, and selection based on these parameters would be more reliable. The plant height, polar diameter, equatorial diameter, and neck thickness emerged as important selection indices. Principal components such as the plant height, number of leaves per plant, percentage of bolting and double bulb had values of >1, accounting for 81.73% of the total variation. Based on mean values and multivariate analysis, onion genotypes ‘(EM-AVT-2) REC-21-46’ (red-skinned), ‘(EM-AVT-2) REC-21-52’ (red-skinned), ‘(WIET) WVA-21-47’ (white-skinned), ‘(WAVT-2) WVC-21-74’ (white-skinned), ‘(WIET) WVA-21-39’ (white-skinned) and ‘(WHTSS-AVT-2) WTC-21-84’ (white-skinned) could be utilized as potential genitors in future breeding for table and dehydration purpose.

Breeding Brassica juncea hybrids with higher seed weight and oil content: Defining criteria for selection of parents

Most of the released high-yielding hybrids of Brassica juncea have a low 1000-seed weight (TSW) with no increment in the percent oil content (OC), and, therefore, these hybrids have poor acceptance among the farmers in India. It is, thus, imperative to understand the genetic basis of these traits and deploy them in commercial hybrid breeding programs. The present study utilized a set of 15 diverse B. juncea genotypes with TSW and OC ranging from 1.32 to 8.26 g and 31.93–43.39 %, respectively, to generate 210 hybrids following a full diallel mating scheme. These hybrids along with their parents, were evaluated in three different environments. Inheritance of TSW suggests the predominance of additive gene action, whereas non-additive gene action was observed to regulate OC. Further, TSW and OC were reported to be influenced by maternal and non-maternal effects, respectively. Parents with bold seeds viz., NPJ 253, RH 761 and EC 223389 were identified as good general combiners for both the traits. Hybrid generated from the cross NPJ 253 x NPJ 161, with both parents having high seed weights, exhibited the highest mean values (8.43 g) and heterobeltiosis (17.2 %) for TSW. Whereas, hybrid between parents NPJ 253 and IC 426372, possessing high and low seed weights, respectively, observed the highest mean value (44.95 %) and heterobeltiosis (14.89 %) for OC. Keeping both TSW and OC together, hybrids viz., NPJ 253 x EC 223389 (H1), NPJ 253 x NPJ 161 (H2) and NPJ 253 x Pusa Tarak (H4) were identified as promising using the Multi-trait Genotype-Ideotype Distance Index. Lines with higher TSW and better combining ability for OC shall be converted to male and/or female lines for generating commercial hybrids. The scheme for deploying higher seed weight and improved oil content in B. juncea hybrids is discussed.