Electronic Journal of Plant Breeding

Molecular validation of Tomato Yellow Leaf curl Virus (TYLCV) (Ty-1/3, Ty-2 and Ty-3), Fusarium wilt (I-2) and Root- Knot Nematode (Mi-1) resistance in the breeding lines of tomato (Solanum lycopersicum L.)

Arumugam Nithyanandam — 2024-04-02

Gene based molecular screening for disease resistance has become a prominent and widely adopted approach in contemporary tomato breeding programs, both in the public and private sectors. The effectiveness of disease-resistant molecular screening relies on the selection of suitable markers that span the entire genomic region for accurate identification of resistant alleles. In this study, various co-dominant and dominant Sequence Characterized Amplified Region (SCAR) markers were employed to screen for resistance genes associated with Tomato yellow leaf curl virus (TyLCV) Ty-1, Ty-2, Ty-3, Fusarium wilt (race-2) I-2, and Root-knot Nematode ((Meloidogyne incognita) Mi-1. The selected markers exhibited high robustness in distinguishing between resistant and susceptible lines. Co-dominant SCAR markers M2 (Ty-1 gene) and TG0302 (Ty-2 gene) efficiently identify homozygous or heterozygous alleles in Tomato yellow leaf curl virus (TyLCV) screening. The P6-25 marker for Ty-3 gene discerns Ty-3, Ty-3a, and Ty-3b alleles, enhancing allele specificity. In Fusarium wilt I-2 gene screening, I-2/5 ensures accurate identification, while in Root-knot Nematode Mi-1 gene screening, co-dominant marker Mi-23 reliably identify and distinguishes homozygous or heterozygous resistant lines without false positives for I-2 and Mi-1 genes. This streamlined marker assisted approach optimizes disease resistance screening in tomato breeding, providing valuable insights for disease resistant cultivar development.

Keywords: Tomato, Molecular screening, Markers, Genes, Allele distinguishes, Disease resistant.

**Nature of gene action and combining ability effects for grain yield and quality traits in rice (Oryza sativa L.)**

S. Santhiya, R. Pushpam — 2024-04-02

Combining ability, along with heterosis was elucidated for nine yield attributing and 10 grain quality traits in a set of 40 rice hybrid combinations derived from 13 parents using Line × Tester mating approach. The analysis of combining ability unveiled significant GCA and SCA variances, highlighting the importance of both additive and non-additive genetic components. The ratio of dominant genetic variance to additive genetic variance exceeded unity, indicating the prevalence of non-additive gene action in governing the inheritance of all examined traits. The parental line CO 55 and the testers IC 457996 and IC 208262 were recognized as good combiners for the majority of yield-related and grain-quality traits. Regarding per se performance, heterosis, and sca effects, the crosses CO 55 × IC 457996 and ADT 54 × IC 115439 were found promising. Consequently, these combinations could be exploited for recombination breeding aimed at developing early maturing, high-yielding fine-grain rice varieties with market acceptance.

Keywords: Combing ability, Line x Tester, Gene action, Heterosis, Rice

Genetic analysis for estimating combining ability in Gossypium hirsutum L. x Gossypium barbadense L. hybrids

K. Baghyalakshmi — 2024-04-02

Two sets of 28 interspecific HxB hybrids generated in LxT fashion, along with their parents were evaluated for 11 yield and fibre quality parameters. GCA variances were lower than SCA variances for all the characters in both sets, as indicated by their lower ratios suggesting predominance of non-additive gene action. Based on both per se and gca effects, GJHV 374 BT, RAJAT BT, ICB 39 and CCB 141 in Set I and GJHV 374 BT, SURAJ BT, ICB 176 and SUVIN in Set II were found to be the best parents which could be utilized for the hybridization programme to obtain superior segregants with yield and fibre qualities. The hybrids viz., RAJAT BTxICB 99, RAJAT BTxICB 34,SURAJ BTxICB 39, GJHV 374 BTxICB 264, SURAJ BTxICB 264 and SURAJ BTxICB 284 showed significant sca effects. Hence, it may be concluded that the above hybrids are the best specific combiners for different yield-contributing and fibre-quality traits. The sca effect was found to be positive in17 crosses and 11 crosses for single plant yield in set I and II, respectively. Similarly, six crosses each in sets I and II were found with a positive sca effect for fibre length.

Keywords: Cotton, combining ability, GCA, SCA, interspecific Bt hybrids

**Comprehensive assessment of combining ability and heterosis for the development of superior three-line hybrids in rice (Oryza sativa L.)**

R. Nivedha — 2024-04-02

The present study involved assessment of 70 three-line hybrids obtained by crossing five CMS lines and 14 testers using line x tester mating design for combining ability and heterosis for 13 yield and grain quality traits. The Analysis of Variance identified significant difference among crosses and the ratio of GCA and SCA variances were less than unity indicating non-additive gene action for all the traits. The line COMS 24A and testers RNR 15048, WGL 32100, CBSN 504, CBSN 509, CBSN 511 and IR64 DRT were identified as best general combiners through gca effects. Among the hybrids, COMS 24A X WGL 32100, COMS 24A X CBSN 504, COMS 25A X CBSN 511, COMS 25A X CBSN 517, COMS 23A X IR64 DRT and COMS 23A X CBSN 509 demonstrated outstanding sca effects, mean and standard heterosis over CORH 3 and CORH 4. Two hybrids viz., COMS 25A X CBSN 511 and COMS 25A X RNR 15048 had medium slender grain type and hold promise for commercial exploitation in south India especially Tamil Nadu.

Keywords: GCA, SCA, three-line hybrid, heterosis, combining ability

Insights into yield stability: A comparative analysis of regression, AMMI indices and Biplot Methods in pearl millet

R. Sujitha — 2024-04-02

Pearl millet is a vital crop in India cultivated across diverse agro-ecological zones. One of the primary challenges in millet farming is the absence of superior genotypes well-suited to local conditions. Hence, there is a need to develop pearl millet genotypes that exhibit high yield and stability to enhance production. With this regard, the study aimed to identify genotypes with high and stable yields across diverse seasons. Twenty-three genotypes were evaluated in four seasons in a randomized block design. Statistical analysis, including the Eberhart and Russell model, AMMI, and GGE biplot, were employed to assess genotype-environment interactions. The genotype ICMB 07999 was observed to have be stable with consistent mean yield, while PT 6679 , PT 7058 and PT 7054 were observed to have above-average stability. These findings were supported by AMMI biplots and various stability indices. GGE biplots revealed two mega-environments, from which Kharif seasons (mega environment 2) provided more informative assessments of genotype stability compared to summer seasons. Across all models and various parameters analysed, PT 6679 and PT 7058 emerged as stable inbreds with high mean seed yield. These inbreds could be tested further in larger environments for potential use in breeding program.

Keywords : Pearl millet, grain yield, stability analysis, AMMI Model

**Unveiling the genetic potential of eggplant (Solanum melongena L.) genotypes, hybrids for yield and fruit borer resistance**

Harshita Srinivas Thota and — 2024-04-02

A half-diallel cross involving nine diverse brinjal genotypes, excluding reciprocals, yielded thirty-six combinations for the investigation of combining ability and gene action related to yield components. Varied genetic differences were observed among the genotypes for analyzed features, indicating that both additive and non-additive gene actions are influencing most traits. Examination of the overall combining ability effects highlighted JBR-5, JBR-3, and JBR-4 as effective general combiners for both fruit yield per plant and fruit and shoot borer infestation. Crosses demonstrating substantial specific combining ability effects in fruit yield also displayed noteworthy impacts on one or more components of yield. Promising combinations like JBR-3 X JBR-5, JBL-1 X JBR-5, and JBL-2 X JBL-3 showed potential for varietal improvement, pending multi-location yield trials to confirm their effectiveness. The most favourable cross, JBR-3 X JBR-5 (0.60), demonstrated significantly positive SCA effects for yield per plant, coupled with high and positive effects for fruit length and number of fruits per plant. Further, it also demonstrated enhanced fruit and shoot borer resistance. Most traits exhibited high narrow-sense heritability, suggesting a predominant role of additivity in phenotypic variability. Understanding the genetic mechanisms influencing economically important quantitative traits is crucial for devising successful breeding strategies. Future research should delve into advanced genomic techniques to unravel the genetic architecture of these traits and expedite the development of improved brinjal varieties with enhanced yield and resistance characteristics.

Keywords: Half-diallel analysis, combining ability, Gene action, Yield components.

**Deciphering gene action for traits contributing to submergence tolerance and yield in rice (Oryza sativa L.)**

K. Pravin Kumar — 2024-04-02

Rice (Oryza sativa L.), a semi-aquatic crop cultivated in diverse environments from sea coasts to high altitudes, faces submergence issues impacting one-third of global cultivation. Effectively choosing superior offspring with a range of genetic traits is vital for improving yield stability, particularly in the development of submergence-tolerant varieties. This is accomplished by comprehending gene action through the generation mean analysis. This experimental material comprised six generations (P₁, P₂, F₁, F₂, B₁, and B₂) obtained from two rice crosses viz., ADT 45 x APD 19002 and CO 54 x APD 19002 involving three parents, examining twelve traits. In the cross ADT 45 x APD 19002, traits like days to fifty per cent flowering, plant height, number of productive tillers per plant, flag leaf width, total number of grains per panicle, number of filled grains per panicle, and single plant yield exhibited opposite signs of dominance (h) and dominance × dominance (l), indicating a prevalence of duplicate epistasis. Simultaneously, additive(d) and additive × additive(i) gene effects were displayed by days to fifty per cent flowering, total number of tillers per plant, panicle length, flag leaf width, total number of grains per panicle, and single plant yield. In cross CO 54 x APD 19002, traits such as days to fifty per cent flowering, plant height, flag leaf width, number of filled grains per panicle, spikelet fertility, and single plant yield suggested predominance of duplicate epistasis. Meanwhile, additive and additive × additive gene effects predominantly influenced the days to fifty per cent flowering, spikelet fertility, and single plant yield. These findings propose the potential for improvement through later-generation selection, emphasizing the integration of selection with screening for submergence tolerance to develop high-yielding submergence-tolerant varieties.

Keywords: generation mean analysis, scaling test, genetic effects, submergence tolerance

Assessment of genetic variability and character association in mid-late/late cauliflower genotypes

Neha Rana — 2024-04-02

The present investigation comprising 36 diverse cauliflower genotypes along with three checks were raised during winter season of 2021-22 to study genetic variability, association between different characters, and direct and indirect effects of component traits to formulate selection criteria for utilization in crop improvement programme. The analysis of variance indicated exitance of sufficient genetic variability for all morphological and yield traits taken for the study. High PCV and GCV were reported for marketable curd weight, net curd weight and stalk length. Similarly, high heritability coupled with high genetic advance was observed for gross plant weight, marketable curd weight and curd solidity which indicates that these traits can be easily improved through simple selection. Correlation and path coefficient analysis revealed that gross plant weight, net curd weight, curd size index, curd solidity, plant frame and stalk length could be considered as the best selection parameters for evolving high yielding cauliflower genotypes.

Keywords: Cauliflower, genetic variability, heritability, correlation, path analysis

Disruption of miR156 binding site of the GW8 gene affects rice grain morphology in the variety ASD16

A. Shanthinie — 2024-04-02

Rice grain width is intricately governed by multiple aspects of grain development, such as cell division and expansion, thereby affecting overall grain morphology. Several key genes were identified and studied for their role in regulating grain width. OsSPL16/GW8 is a positive regulator of grain width by boosting grain weight, a major determinant of grain yield. The GW8 mRNA transcripts are cleaved by miR156, leading to reduced gene expression. In this study, we employed the CRISPR/Cas9 system to generate gw8 mutants with a disrupted GW8-miR156 binding site to enhance both grain morphology and yield in the ASD16 rice genetic background. Agrobacterium-mediated rice genetic transformation resulted in the generation of 25 putative gw8 mutants. Sanger sequencing revealed the presence of mutations within and outside the GW8-miR156 module. Notably, plants harboring mutations disrupting the GW8-miR156 module exhibited an altered grain morphology with awn and poor grain set. Further research is needed to unravel the pleiotropic effects associated with the GW8-miR156 module in rice.

Keywords: Rice, Grain width, SPL16 gene, GW8, miR156, CRISPR/Cas9

Stability analysis **for yield attributing traits and total alkaloid content in ashwagandha (Withania somnifera L.)**

Iqbal Ahmed and — 2024-04-02

An experiment to study stability of Ashwagandha genotypes was conducted during Kharif 2018-19 at three different environments. High influence of environment was observed as G x E was significant for all the studied traits. Based upon stability parameters, the genotypes JA-20, UWS-305, UWS-309 and UWS-314 were identified as stable for above average environment, whereas JA-134 was found stable under below average environment for root yield at harvest. UWS-305 showed below average stability for total alkaloid content. Out of the 45 crosses, above average stability was depicted by UWS-305 x UWS-10 and UWS-304 x RVA-100 while below average stability was showed by UWS-309 x RVA-100 for root yield at harvest along with total alkaloid content. Hence, above identified stable genotypes may be beneficial in breeding programme for improvement of root yield and alkaloid content in ashwagandha.

Keywords: Ashwagandha, G x E interaction, Root yields at harvest, Total alkaloid content.

Integrating principal component and regression analyses for genetic diversity and trait evaluation in oat genotypes

Rukoo Chawla — 2024-04-02

Oat holds significant importance in global agriculture and nutrition due to their adaptability and versatility. In the present study, Principal Component Analysis (PCA) and Regression analysis were carried out to identify the cause and effect relationship among various traits. PCA on 13 yield attributes revealed five main components contributing to 80.75% cumulative variance. PC1, associated with green fodder yield, dry matter yield, tillers per plant and seed yield was a prominent contributor. PC2 was influenced largely by days to 50% flowering and days to maturity. Biplot analysis identified two distinct trait groups. Multiple regression analysis revealed tillers per plant, test weight and number of spikelets as significant predictors of seed yield. The findings offer insights into genetic association among traits in oat by uncovering the quantitative relationships among them and to identify patterns of genetic variation among different oat genotypes. The analysis of individual trait regression graphs enhances understanding of trait contributions to seed yield. This study advances oat improvement strategies for enhanced crop productivity and resilience.

Keywords: Oat, Principal component, Regression analysis, Yield

**Multivariate analysis of grain yield attributes and spot blotch incidence in wheat (Triticum aestivum L.) under sub-Himalayan agroclimatic condition**

Ponaganti Shiva Kishore — 2024-04-02

An Elite Spring Wheat Yield Trial (EWYT) was conducted with 50 diverse genotypes of Wheat (Triticum aestivum L.) and analyzed by multivariate analysis during 2018-19 rabi season. Correlation analysis revealed positive association of plant height, grains per spike, spike length, test weight and biomass with grain yield. Path analysis revealed the highest direct effect on grain yield/metre by biomass/metre (1.508) which was also positively associated with grain yield/metre (0.833). PCA analysis showed 11 principal components out of which five principal components (PC1 to PC5) exhibited eigen value greater than one. The correlation between AUDPC and physiological characters indicated that chlorophyll loss was associated with high spot blotch disease incidence at later stages of crop growth.

Keywords: Wheat, correlation, path analysis, PCA, spot blotch

**Genetic diversity and decoding the genetics of phytic acid by investigating the inheritance of lpa 2 allele in maize (Zea mays L.)**

S. M. Indhu — 2024-04-02

Developing biofortified maize varieties with increased bioavailability of nutrients is crucial for addressing global food challenges and meeting the diverse needs of growing population. Hence, to formulate need based breeding programme, a comprehensive multidimensional approach was employed to assess the variability among 49 inbreds. PCA analysis revealed that single plant yield along with hundred kernel weight, number of kernels per row, number of kernel rows, cob length, ear height, cob diameter and leaf length contributed maximum towards variability. However, phytic acid displayed a relatively lower contribution to the overall variability. Based on cluster analysis , inbreds in the cluster III were found to have maximum mean performance for yield and its associated traits. Cluster V showed maximum mean performance for Pi. Based on the results, the genotype lpa 2 - UMI 395 from cluster V was selected as donor for hybridisation. From UMI 1201 x lpa 2-UMI 395 and UMI 1230 x lpa 2-UMI 395 crosses, a total of 11 and 10 F_2:3plants were identified respectively as homozygous for lpa 2 using molecular markers. The selected plants with lpa 2 allele were found to have Pi in the range of 1.1 and 1.4 mg/g. Inheritance pattern of phytic acid based on these observations confirmed the recessive nature of the trait. Hence, these selected plants with lpa 2 allele can be selected for yield and its associated traits in further generations.

Keywords: Maize, PCA, Cluster, lpa 2, low phytic acid, Inheritance

**Multi trait genotype- ideotype distance index (MGIDI) for early seedling vigour and yield related traits to identify elite lines in rice (Oryza sativa L.)**

M. Pallavi, B. P. Maruthi Prasad — 2024-04-02

Rice (Oryza sativa L.) stands as a important cereal sustaining over half of the world's population. This study delves into the challenges confronting breeders in the realm of crop improvement, specifically focusing on the intricate task of designing an ideotype—a genotype amalgamating diverse attributes for optimal performance. Traditional methodologies, exemplified by the Smith–Hazel (SH) index, grapple with issues such as multicollinearity and the complexities of economic weighting decisions. In response to these challenges, the Multi-Trait Genotype–Ideotype Distance Index (MGIDI), conceptualized by Olivoto and Nardino (2021), emerges as a ground breaking approach. Principal Component Analysis (PCA) aids in the reduction of trait dimensionality, revealing four key factors that collectively contribute to 79.444% of total variability. The Scree plot guides factor selection, ensuring a targeted analysis. The MGIDI index computation yields a total genetic gain of 273.025%, with specific traits like spikelet fertility and seedling dry weight exhibiting significant gains. Six high-performing rice accessions—SM227, NLR33892, MTU3626, 239(3), SMB3, and 405C3 were identified through MGIDI. These identified genotypes serve as valuable resources for developing recombinant populations, aligning with sustainable and effective crop improvement strategies. Additionally, these promising varieties exhibit strengths across various traits, offering potential for simultaneous trait improvement in future breeding programmes. The efficiency of MGIDI is highlighted through its innovative application in simultaneous trait selection, underscoring its significance across a wide range of crops.

Keywords: MGIDI, multi-trait selection, Scree plot, Ideotype, Rice

**Stability analysis for yield and yield related traits in advance breeding lines of chickpea (Cicer arietinum L.)**

V. Jayalakshmi — 2024-04-02

An experiment was carried out during Rabi 2018-19 at three locations (Nandyal, Gulbarga and Vijayapura) in Southern India to identify high yielding and stable chickpea genotypes for cultivation in South Zone. At each of the locations, the stability and adaptability of 35 advance breeding lines and two checks viz., JG 11 and JAKI 9218 were tested in a Randomized Block Design with three replications. Highly significant genotype × environment interaction was evident for days to 50 percent flowering, days to maturity, 100 seed weight and seed yield. Among three locations, Gulbarga was the most favourable environment for expression of the traits. The study identified BDNG 2017-1, RKG 13-22, RVSSG 67, DBGC-2 and DC 17-1111 as stable genotypes which can be recommended for all the three locations where as NBeG 798, BG 4001, PG 215, CSJ 1065, H15-27, RG 2016-134, DC17-115 and ICCV 171117 are appropriate for favourable environments.

Keywords: Chickpea, genotype × environment interaction, regression coefficient and stability

**Generation mean analysis for yield and quality traits in basmati rice (Oryza sativa L.)**

Aarti Sharma, Shubham Kumawat — 2024-04-02

The present study explicates the genetics of 15 (eight yield traits and seven quality traits) basmati traits by employing generation mean analysis in six crosses of basmati rice crosses. Generation mean analysis is a biometrical tool which not only can identify presence of epistasis but also explain its types and role in inheritance of traits. Simple and Joint scaling test indicated role of epistasis in inheritance all the six crosses except for alkali spread value in the cross HUBR10-9 x PuB-1509, which showed dominance gene action. 90 individual tests each of simple and joint scaling tests divulged role of one or the other type of epistasis in inheritance of different traits in all the six crosses except for alkali spread value in cross HUBR10-9 x PuB-1509, which showed dominance gene action. Complementary digenic interaction were observed for yield per plant trait; however, other traits showed equal importance of complementary and duplicate digenic interaction in inheritance of different traits examined in the present study. Most of the traits were governed by epistatic gene action which suggested that traits of such population can be improved when the selection process is delayed. However, selection can be practiced at early stage of breeding program in such traits which were governed by additive gene action.

Keywords: Basmati, complementary and duplicate interaction, epistasis, generation mean analysis

**Study on blackgram (Vigna mungo (L.) Hepper) genotypes for yield stability and Mungbean Yellow Mosaic Virus (MYMV) resistance**

K. Rajalakshmi — 2024-04-02

A total of 50 genotypes were evaluated during Kharif 2022 in three different locations in Tamilnadu, India. The data on seed yield per plant was subjected to AMMI and GGE biplot analysis for stability study. The IPCA values explained 100% and 98.8% variation in AMMI and GGE biplot respectively. Results from both analyses inferred that the genotypes viz., Mash 114, Mash 1008, VBN (Bg) 4 and VBN 10 were stable across the environments with high mean seed yield per plant. Hence these varieties can be utilized for cultivation in varied environments of Tamilnadu. Besides, the genotypes; MASH 1008, MASH 114, VBN (Bg) 4, VBN 8, VBN 10 and VBN 11 were found to be resistant to MYMV based on the field screening at National Pulses Research Centre, Vamban, Pudukkottai.

Keywords: Blackgram, Stability, AMMI, GGE Biplot, MYMV, Field Screening

**Genetic diversity analysis for physiological, reproductive, biochemical and yield traits of blackgram (Vigna mungo L.) genotypes under high temperature stress**

N. Pavithra, K. Jayalalitha, T. Sujatha — 2024-04-02

In the present study, 30 blackgram genotypes were evaluated for physiological, reproductive, biochemical and yield traits at flowering stage during summer, 2022 and 23. ANOVA showed highly significant genetic variability among the 30 blackgram genotypes for 20 heat tolerance traits studied indicating that significant amount of genetic variability among the genotypes. Higher PCV, GCV and heritability was recorded for seed yield per plant and number of pods per plant during both the years. Moreover, the results of cluster analysis for these heat tolerance traits revealed that the genotypes TBG-129, LBG-1015, PU-1804, TBG-104 and PU-31 were identified as promising genotypes under high temperature stress conditions during both the years. Principal component analysis showed that first three components showed 82.62 % of total variation during summer, 2022, whereas 77.06 % of the total variance was covered by the first two principal components during summer, 2023. The identification of genotypes displaying heat tolerance can be useful in future breeding programmes for the development of heat stress tolerant genotypes.

Keywords: Blackgram, Genetic diversity, High temperature stress, Principal component analysis

Identification of diverse forage sorghum genotypes based on cluster analysis

N. Y. Akshitha, Pummy Kumari, S. K. Pahuja — 2024-04-02

A field experiment comprising of 50 genotypes of forage sorghum was laid out in CRBD. Enough variability was observed among the genotypes under study as revealed by ANOVA. Genetic divergence analysis grouped the genotypes into six clusters based on quantitative and qualitative traits. Cluster I had the maximum number of genotypes, followed by clusters III and V with ten genotypes each; cluster IV had nine genotypes; cluster II had seven genotypes and cluster VI had only one genotype. The maximum intra cluster distance was observed in clusters I followed by cluster V and cluster III. Intra-cluster distance is measure of the amount of variability present within cluster. The highest inter-cluster distance was found between the clusters I and III followed by the clusters I and V which confirms that genotypes in these clusters are more diverse. Use of genetically diverse genotypes of clusters VI and III in hybridization program would help to evolve the genotypes with high fodder yield and good quality.

Keywords: Forage sorghum, diversity, green fodder, quality

Genetic variability, correlation and path analysis studies for yield traits in stable mutant lines of black aromatic rice of Manipur

M. Usha, Pramesh Khoyumthem — 2024-04-02

The study involved assessment of genetic variability and trait association of seed yield and its component traits in 20 EMS-derived stable mutant lines of black aromatic rice. The traits grain yield / plant, harvest index, effective tillers and biological yield/ plant recorded maximum GCV and PCV. Heritability estimates ranged from 67 percent for total number of tillers/ plant to 99 percent for days to 50 percent flowering. The trait grain yield per plant revealed high heritability (>80%) coupled with high advance in genetics (>50%). The traits fertile spikelets per panicle, effective tillers/ plant, biological yield, panicle length, and plant height were significantly and positively correlated with grain yield. The path analysis revealed maximum positive direct effects of fertile spikelets per panicle, harvest index, biological yield, grain length and effective tillers on grain yield indicating the selection of these traits for efficient crop improvement.

Keywords: Ethyl Methane Sulphonate, Black aromatic rice, variability, correlation, path analysis

**Multivariate analysis for assessing the genetic diversity and association patterns of yield attributing traits in little millet (Panicum sumatrense)**

R. Narasimhulu, C. Vijaya Kumar Reddy — 2024-04-02

Little millet is an important small millet grown mostly in India. The availability of genetic variability is a critical requirement for crop improvement. Principal Component Analysis (PCA) and correlation study was undertaken in a set of 28 little millet genotypes to estimate genetic diversity, association pattern among seven quantitative traits and to select suitable genotypes for crop improvement. In cluster analysis, the genotypes were classified into three distinct clusters, each with one or two subgroups. Cluster I had the major genotypes with comparable ancestry, followed by Cluster II. The total variance was split into seven major principal components, with the top two PCs with eigenvalues greater than one accounting for 82.57% of the overall variation. PC1, which explained a larger part of the variance (58.05%), was strongly influenced by days to 50% flowering, days to maturity, number of productive tillers per plant, 1000-grain weight, and grain yield. PC2 was primarily influenced by plant height and fodder yield. PCA and association analysis revealed a significant positive association between grain yield and the number of productive tillers per plant, 1000-grain weight, plant height. These traits would be useful for direct selection for little millet crop improvement. In both cluster analysis and PCA, the genotypes DHLM 14-5, IIMR LM-8004, NDL LM1, TNPSu 242, VS 33, WV 168, DPLN 1 and VS 38 displayed diversity, implying that these lines may be used in crossing programme to generate further genetic variability to select suitable transgressive segregants.

Keywords: Little millet, genetic diversity, correlation, principal component analysis, biplot

**Genetic variability and trait relationship in green chilli (Capsicum annuum L.) under high altitude conditions**

Nancy Banyal — 2024-04-02

An experiment was carried out to determine the genetic variability parameters and character associations in thirty-two chilli genotypes. Based on mean performance, 11 genotypes were observed to be superior for marketable green fruit yield than the standard check varieties ‘Him Palam Mirch-2’ and DPCH-40-2. High to moderate estimates of PCV and GCV with high heritability coupled with high genetic advance were observed for marketable green fruits/plant, marketable green fruit yield/plant, total green fruits/plant and average green fruit weight. Marketable green fruit yield/plant had positive and significant association with average green fruit weight, marketable green fruits/plant, total green fruits/plant, percent marketable green fruits/plant, ascorbic acid and capsaicin content. In view of direct and indirect contribution of component traits, selection on the basis of total fruits/plant and average green fruit weight would be a paying preposition for evolving high yielding genotypes for marketable green fruit yield. The present findings could be useful in selecting superior genotypes to achieve genetic gain and yield advantage in chilli breeding programmes.

Keywords: Correlation, Genetic variability, Heritability, Mean, Path analysis

Discerning genetic diversity among sunflower germplasm accessions through multivariate analysis

Bana Venkata Ravi Prakash Reddy — 2024-04-02

The objective of the present investigation was to evaluate 135 sunflower germplasm accessions through Principal Component Analysis and Hierarchical cluster analysis to assess the extent of genetic diversity. The principal components with eigen values more than one i.e., PC1 and PC2 describes 38.3% and 21.24% respectively with a cumulative effect of 59.62% of the total variation. The biplot analysis revealed positive association of seed yield per plant for 100 seed weight, head diameter, days to 50% flowering and it was negatively associated with oil content. By using Wards method of clustering, 135 sunflower accessions were aggregated in 12 clusters based on different traits in which cluster VIII includes 30 accessions and is the largest one. The accessions in cluster IV, I and VI had maximum values for 100 seed weight, seed yield per plant and oil content, respectively. The germplasm accessions 213R, 121R, RHA-GPR-110, CMS-107B, IB-11-3, SCG-107, 132R, NGM-15 and OPH-123 were identified to be potential accessions and these can be used for improvement of yield and its attributing traits in sunflower.

Keywords: Sunflower, Genetic diversity, Principal component analysis, Cluster analysis

**Genetic variability, correlation, path coefficient and cluster analysis in Indian mustard (Brassica juncea L.)**

Duluri Sowmya — 2024-04-02

Twenty-eight diverse mustard (Brassica juncea L.) genotypes were assessed for genetic variability, heritability, genetic advance, trait association and genetic diversity based on 14 yield and its attributing traits during the Rabi 2023 at the Post Graduate Research Farm, School of Agriculture, LPU, Punjab. The study revelled significant differences among the mustard genotypes both in their genotypic and phenotypic level. Significant differences were observed in traits such as number of siliquae per plant, number of siliquae on the main stem, and seed yield per plant. Moreover, it is noteworthy to emphasize that a pronounced degree of heritability was founded for all traits except for days to maturity. Significant genetic advancements expressed as a percentage mean was observed for all attributes examined, except for days 50% flowering and maturity. Seed yield per individual plant manifested a substantial and positive genotypic correlation with the number of secondary branches per plant, 1000-seed weight, biological yield per individual plant, and the harvest index. Path analysis further elucidated that biological yield per individual plant and the harvest index exerted the most substantial positive direct effects on seed yield per plant. Based on these findings, the study suggests that choosing mustard genotypes based on these particular traits could lead to a more effective strategy for increasing overall yield. Additionally, genotypes grouped into distinct clusters with higher average values for seed yield and other essential characteristics present an attractive opportunity for inclusion in hybridization efforts aimed at producing superior offspring.

Keywords: Brassica, Heritability, Correlation, Path analysis, Diversity

A comprehensive approach to improve brinjal hybrid seed yield through emasculation, timing, and crossing ratio

A. V. Ginoya — 2024-04-02

Brinjal hybrid seed production primarily utilizes the seed-to-seed method. Optimal results require synchronized stigma receptivity and pollen viability, timing of emasculation and pollination along with the appropriate quantity of pollen on the female parent's stigma. With this perspective, the research was carried out, employing the parents of the GJBH 4 brinjal hybrid. The study involved 18 experiments, considering two emasculation options namely emasculation on same day as flower opening, emasculation on a day prior to flower opening, three pollination times namely 8-9 am, 9-10 am and 10-11 am and three cross-pollination ratios namely two female flowers per male flower, four female flowers per male flower, six female flowers per male flower. The results revealed that for better hybrid seed yield, emasculation on the day prior to flower opening, pollination between 9-10 am and using one male flower to pollinate four female flowers could be adopted.

Keywords: Brinjal, Crossing ratio, Day of emasculation, Pollination, Viability

**Assessment of genetic diversity in germplasm collections of browntop millet (Brachiaria ramosa (L.) Stapf.) using morphological traits**

G. K. Rahul — 2024-04-02

Browntop millet (Brachiaria ramose (L.) Stapf.), is an important small millet crop. It can thrive in variety of climates, uses limited amount of water for growth and development and has high minerals and fibre. As the genetic diversity in any crop species is crucial for crop improvement, present study was aimed at evaluating the diversity present in the germplasm accessions by measuring 13 morphological traits across 27 accessions of browntop millet. The data revealed significant variations between the accessions for each of the traits that were examined. GCV and PCV were observed to be more for the trait panicle width and it was found less in case of days to maturity. The difference in GCV and PCV was very narrow for panicle width indicating least influence of surrounding environment which was further supported by high value of broad sense heritability. While grain yield per plant recorded highest heritability with GAM. Grain yield per plant showed significant positive correlation with plant height, number of panicles per plant, panicle length, peduncle length, flag leaf width and flag leaf length. Principal component analysis revealed 88.73 per cent of total variation was from grain yield per plant, total panicle weight per plant, panicle width and flag leaf length comprising the accessions viz., namely IC617956, IC613546, VBT 002, TNBr 016 and IIMR BTL. The study identified best accessions for different traits based on correlation and multivariate analysis that could be of further use in the browntop millet breeding programmes.

Keywords: Browntop millet, Brachiaria ramosa, Genetic variability, Heritability, PCA

**Genetic variability, correlation and path-coefficient analysis for yield and yield attributing traits in aerobic rice (Oryza sativa L.)**

Harshraj Salunkhe, Ashutosh Kumar — 2024-04-02

The present research was conducted to examine different parameters of variability, correlations, and path coefficients associated with yield and yield-related traits in aerobic rice. The analysis of variance indicated noteworthy variations among the genotypes for all the traits investigated. Among them, flag leaf area and alkali spreading value showed high PCV and GCV. Except for days to fifty per cent flowering, days to maturity, and amylose content, the remaining traits demonstrated substantial heritability combined with high genetic advance as percentage of mean. The correlation analysis revealed significant positive association between grain yield per plant and several traits, namely effective tillers per plant, test weight, chlorophyll content, and length breadth ratio. Traits such as test weight, effective tillers per plant, and flag leaf area showed a positive direct effect on grain yield per plant. Therefore, it is crucial to give priority to traits that exhibit significant positive correlations and substantial direct effects during selection process. This approach will yield rewarding results in the development of high-yielding cultivars suitable for aerobic conditions.

Keywords: Aerobic rice, PCV, GCV, Heritability, Correlation coefficient, Path analysis

**Assessment of genetic diversity for yield, yield attributes and water use efficiency related traits in groundnut [Arachis hypogaea L.]**

S. Divya Sree — 2024-04-02

To establish the degree of genetic diversity for 14 quantitative parameters, 36 groundnut genotypes were investigated using the Mahalanobis D² Statistics. Tocher's method separated the entire genetic resource set into nine distinct, non-overlapping clusters demonstrating the presence of significant amount of genetic diversity. Cluster I had the maximum number of accessions (15), followed by cluster IV with 7 accessions, cluster VI with 5 genotypes, cluster V with 3 genotypes and cluster VII with 2 genotypes. The clusters II, III, VIII and IX were monogenotypic. The inter-cluster distance was maximum between the clusters VI and IX. Shelling percent contributed maximum to the genetic divergence followed by pod yield plant^-1. Hence due emphasis should be given to these traits as improvement of these characters would result in increase in pod yield plant^-1.

Keywords:Groundnut, D² Statistic, Tocher’s technique.

**Genetic variability and character associations for grain yield and other secondary traits in little millet (Panicum sumatrense L.) at Eastern Ghats Zone of Odisha**

Rupali Behera — 2024-04-02

A set of thirty genotypes of little millet were studied using thirteen morphological traits to assess genetic variability, character association and their effects on grain yield during Kharif 2022 at Centurion University, Paralakhemundi, Odisha in a randomized block design with three replications. Analysis of variation revealed significant (p≤0.01) variation in the studied genotypes for all the traits recorded. The characters viz., number of productive tillers, test weight and grain yield had high genotypic (GCV) and phenotypic coefficient of variation (PCV) whereas characters viz., number of productive tillers, number of braches per panicle, culm length, culm diameter, test weight and grain yield had high genetic advance coupled with high heritability. Most of the traits except days to 50% flowering, days to maturity and flag leaf length showed strong significant (p≤0.01) positive associations with grain yield at genotypic and phenotypic levels. The traits such as plant height, number of productive tillers, culm length, test weight, flag leaf length and breadth recorded positive direct effect on grain yield that indicates direct improvement of these traits could be beneficial for the improvement of little millet cultivars with higher grain yield.

Keywords: Genetic Variability, Heritability, Correlation, Path Analysis, Panicum sumatrense

**Heterosis and inbreeding depression for grain yield and yield contributing characters in wheat (Triticum aestivum L.)**

Nageshwar, Som Veer Singh — 2024-04-02

The present investigation on heterosis and inbreeding depression in wheat was carried out at the Crop Research Farm of CSAUA&T, Nawabganj, Kanpur, U.P., India, during the Rabi crop season 2019-20. A ten parental half-diallel cross comprising of 45 F₁s and 45 F₂s together with parents was grown in three replications. The outcome of better parent heterosis revealed that the cross combinations, namely, HD3086 x HD-2733, HD3086 x K0307, HD3086 x HD2967, HD3086 x K1601, and HD2967 x K0402 exhibited positive and high heterosis for grain yield. In the case of economic heterosis over the check (HD2967), the cross combination viz. HD3086 x K0307, HD3086 x HD2967, HD-967 x K0402, HD2967 x K1601, and HD2967 x K1314 exhibited significant and positive heterosis for grain yield. Inbreeding depression for grain yield ranged from 1.51 (DH 29767 x K 8962) to 8.95 (DBW 88 x K 8962) percent. For grain yield, out of the 45 crosses, all combinations exhibited significant and positive inbreeding depression in F₂. The cross combinations may be used to increase grain yield and to produce better transgressive segregants for future breeding programs to maintain the specific gene pool of bread wheat.

Keywords: Wheat, Inbreeding depression, Heterosis

**Genetic diversity assessment in Indian finger millet (Eleusine coracana L.) germplasm via qualitative traits**

Anoop Singh — 2024-04-02

The present research investigates the genetic diversity of finger millet (Eleusine coracana L.), a nutrient-rich crop vital for sustainable agriculture and food security. Sixteen qualitative traits, including growth habits, pigmentation, and grain attributes, were examined among 150 accessions, shedding light on the diversity within the germplasm. The study quantified and interpreted trait relationships using the Shannon-Weaver Diversity Index and Spearman's Rank Correlation. Principal Component Analysis (PCA) revealed the pivotal traits shaping genetic diversity. Most genotypes exhibited decumbent growth habit and diverse leaf sheath pubescence intensities. Round-shaped grains predominated with copper brown as a common color among grain traits. Pericarp persistence remained consistent among all genotypes. The Shannon-Weaver Diversity Index highlighted varying levels of diversity among traits, with ‘ear head shape’ exhibiting the highest diversity. Spearman's Rank Correlation exposed relationship between leaf sheath pubescence and seed shattering, emphasizing the importance of trait management in crop breeding. These results provide insights into genetic diversity within finger millet germplasm and its potential application in developing resilient and productive cultivars, addressing food security and sustainability challenges in agriculture.

Keywords: Finger millet, Genetic diversity, Qualitative traits, Spearman’s rank correlation, PCA

**Correlation and path coefficient analysis for some yield-related traits in apple (Malus domestica Borkh) under mid-hill conditions of Himachal Pradesh, India**

Praveen Verma — 2024-04-02

To understand the utility of genotypes in the breeding program in mid-hill environments of the north-western Himalayas of India, apple cultivars were studied during 2019 and 2020 to discover inter-relationships of variables as well as to study genetic variation across yield attribution traits. For fruit set, fruit drop and fruit volume, high heritability and moderate genetic gain was observed. Substantial correlation between fruit yield per plant and pruning weight, tree volume, tree spread and TSS was observed. However, the increments in tree height and trunk girth were strongly and adversely linked with fruit yield per plant. Thus the traits tree spread, tree volume and flowering length may be used as selection indicators for increased production with high-quality apple cultivars.

Keywords: Apple, Correlation, Genetic variability, Heritability, Path analysis

Assessment of variation in rice maintainer lines using principal component analysis

B. Edukondalu — 2024-04-02

The aim of this study was to explore the characteristics essential for a maintainer line to effectively complement the A lines in hybrid rice production. The experiment was conducted at the Regional Agricultural Research Station, Jagtial and Telangana, India during kharif, 2016 (June-October). A total of 40 genotypes were raised in Randomized Block Design (RBD) with two replications. PCA identified five principal components (PCs) with Eigen values over 1, collectively accounting for approximately 75.50% of the total variance. PC1 predominantly representing yield and related features (number of tillers per plant, panicle length, length-to-breadth ratio, grain yield per plant), while the other PCs corresponded to unique aspects like grain numbers, morphological and quantitative traits. The study also utilized biplot analysis to elucidate the relationships among these traits, revealing significant correlations and interactions crucial for rice breeding. It indicated a negative correlation between 1000 grain weight, kernel breadth, and the number of grains per panicle, while showing positive correlations among traits influencing grain yield. This method also proved assistance in identifying superior genotypes for specific traits, as exemplified by genotypes JMS18B and JMS20B excelling in grain numbers per panicle and genotype B18 standing out in grain yield and other yield-related traits.

Keywords: PCA, Maintainer lines, Hybrid rice, Biplot

Electronic Journal of Plant Breeding

Molecular validation of Tomato Yellow Leaf curl Virus (TYLCV) (Ty-1/3, Ty-2 and Ty-3), Fusarium wilt (I-2) and Root- Knot Nematode (Mi-1) resistance in the breeding lines of tomato (Solanum lycopersicum L.)

Nature of gene action and combining ability effects for grain yield and quality traits in rice (Oryza sativa L.)

Genetic analysis for estimating combining ability in Gossypium hirsutum L. x Gossypium barbadense L. hybrids

Comprehensive assessment of combining ability and heterosis for the development of superior three-line hybrids in rice (Oryza sativa L.)

Insights into yield stability: A comparative analysis of regression, AMMI indices and Biplot Methods in pearl millet

Unveiling the genetic potential of eggplant (Solanum melongena L.) genotypes, hybrids for yield and fruit borer resistance

Deciphering gene action for traits contributing to submergence tolerance and yield in rice (Oryza sativa L.)

Assessment of genetic variability and character association in mid-late/late cauliflower genotypes

Disruption of miR156 binding site of the GW8 gene affects rice grain morphology in the variety ASD16

Stability analysis for yield attributing traits and total alkaloid content in ashwagandha (Withania somnifera L.)

Integrating principal component and regression analyses for genetic diversity and trait evaluation in oat genotypes

Multivariate analysis of grain yield attributes and spot blotch incidence in wheat (Triticum aestivum L.) under sub-Himalayan agroclimatic condition

Genetic diversity and decoding the genetics of phytic acid by investigating the inheritance of lpa 2 allele in maize (Zea mays L.)

Multi trait genotype- ideotype distance index (MGIDI) for early seedling vigour and yield related traits to identify elite lines in rice (Oryza sativa L.)

Stability analysis for yield and yield related traits in advance breeding lines of chickpea (Cicer arietinum L.)

Generation mean analysis for yield and quality traits in basmati rice (Oryza sativa L.)

Study on blackgram (Vigna mungo (L.) Hepper) genotypes for yield stability and Mungbean Yellow Mosaic Virus (MYMV) resistance

Genetic diversity analysis for physiological, reproductive, biochemical and yield traits of blackgram (Vigna mungo L.) genotypes under high temperature stress