Browsing by Author "Munnesh Kumar"

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Assessment of genetic diversity of maize (Zea mays L.) hybrids under water logging condition
(Indian Society of Plant Breeders, 2020) Gayatri Kumawat; Jai Prakash Shahi; Munnesh Kumar
The screening of fifty five CIMMYT maize hybrids was carried out to estimate the genetic diversity which was evaluated undermanaged waterlogged or excess soil moisture condition, indicated presence of considerable diversity. The experiment was conducted in an alpha lattice design with two replication and phenotypic data were analyzed using fifteen agro-morphological traits. The fifty five maize single cross hybrids grouped into eight clusters based on Mahalanobis D2 statistic. Among them cluster I accommodated maximum number of inbred lines (41) followed by cluster V (8). Presence of six solitary clusters indicated larger genetic diversity. The character plant height showed highest contribution towards genetic divergence followed by number of kernel per row, ear height, number of rows per ear, grain weight per plot and 100 seed weight. Based upon the divergence studies suggesting crossing may be made between genotypes of cluster II (P3502) and V (ZH17505, ZH17507, ZH17497, ZH15567, ZH15557, ZH15564, ZH15563 and ZH15562), and the hybrid in these cluster could be used as donor parents for new double cross maize hybrid development for improving yield under water logging condition. © 2020, Indian Society of Plant Breeders.
Genetic gains in tropical maize hybrids across moisture regimes with multi-trait-based index selection
(Frontiers Media S.A., 2023) Ashok Singamsetti; Pervez H. Zaidi; Kaliyamoorthy Seetharam; Madhumal Thayil Vinayan; Tiago Olivoto; Anima Mahato; Kartik Madankar; Munnesh Kumar; Kumari Shikha
Unpredictable weather vagaries in the Asian tropics often increase the risk of a series of abiotic stresses in maize-growing areas, hindering the efforts to reach the projected demands. Breeding climate-resilient maize hybrids with a cross-tolerance to drought and waterlogging is necessary yet challenging because of the presence of genotype-by-environment interaction (GEI) and the lack of an efficient multi-trait-based selection technique. The present study aimed at estimating the variance components, genetic parameters, inter-trait relations, and expected selection gains (SGs) across the soil moisture regimes through genotype selection obtained based on the novel multi-trait genotype–ideotype distance index (MGIDI) for a set of 75 tropical pre-released maize hybrids. Twelve traits including grain yield and other secondary characteristics for experimental maize hybrids were studied at two locations. Positive and negative SGs were estimated across moisture regimes, including drought, waterlogging, and optimal moisture conditions. Hybrid, moisture condition, and hybrid-by-moisture condition interaction effects were significant (p ≤ 0.001) for most of the traits studied. Eleven genotypes were selected in each moisture condition through MGIDI by assuming 15% selection intensity where two hybrids, viz., ZH161289 and ZH161303, were found to be common across all the moisture regimes, indicating their moisture stress resilience, a unique potential for broader adaptation in rainfed stress-vulnerable ecologies. The selected hybrids showed desired genetic gains such as positive gains for grain yield (almost 11% in optimal and drought; 22% in waterlogging) and negative gains in flowering traits. The view on strengths and weaknesses as depicted by the MGIDI assists the breeders to develop maize hybrids with desired traits, such as grain yield and other yield contributors under specific stress conditions. The MGIDI would be a robust and easy-to-handle multi-trait selection process under various test environments with minimal multicollinearity issues. It was found to be a powerful tool in developing better selection strategies and optimizing the breeding scheme, thus contributing to the development of climate-resilient maize hybrids. Copyright © 2023 Singamsetti, Zaidi, Seetharam, Vinayan, Olivoto, Mahato, Madankar, Kumar and Shikha.
Genotype × environment interaction and selection of maize (Zea mays L.) hybrids across moisture regimes
(Elsevier B.V., 2021) Ashok Singamsetti; J.P. Shahi; P.H. Zaidi; K. Seetharam; M.T. Vinayan; Munnesh Kumar; Saurav Singla; Kumari Shikha; Kartik Madankar
Genotype × environment (GE) interaction effect is one of the major challenges in identifying cultivars with stable performance across environments and years. Objective of the present study was to identify maize hybrids with high and stable yields under different soil moisture regimes such as drought, waterlogged and well-watered conditions. The trials were carried out in subsequent winter (Rabi) and summer-rainy (Kharif) seasons of 2017 and 2018 totaling seven test environments at the two different locations of India viz, Banaras Hindu University, Varanasi and CIMMYT, Hyderabad. After observing substantial and statistically significant GE interaction for studied traits, the phenotypic stability of maize hybrids was analyzed by AMMI, GGE biplot and multi-trait stability index (MTSI) methods. The study emphasized on the significance of AMMI and GGE biplots in deciphering the GE interactions based on grain yield data. Estimation of stability indices, WAASB (Weighted Average of Absolute Scores from the singular value decomposition of the matrix of BLUPs) for the GE interaction effects and WAASBY (a combination of WAASB and yield) scores for identification of the best suitable genotypes with high stability and maximum yield potential was highlighted. The investigation delineated the applicability of MTSI that computed based on the genotype-ideotype distance considering the multiple variables. The methods studied were concordant in the identification of the promising maize hybrids with high mean performance and greater phenotypic stability across the different soil moisture conditions. © 2021 Elsevier B.V.
IDENTIFICATION OF WATERLOGGING STRESS TOLERANT MAIZE (ZEA MAYS L.) HYBRIDS USING DIFFERENT SELECTION INDICES
(Punjab Agricultural University, 2023) Ashok Singamsetti; J.P. Shahi; P.H. Zaidi; K. Seetharam; Munnesh Kumar
[No abstract available]
Investigation on genotype-by-environment interaction and stable maize (Zea mays L.) hybrids across soil moisture conditions
(Springer, 2021) Ashok Singamsetti; J.P. Shahi; P.H. Zaidi; K. Seetharam; Kartik Madankar; Munnesh Kumar
Maize production and productivity are challenged by multiple and co-occurring stresses that impact crop growth, development and consequently the yields. Maize crop is often exposed to a combination of drought and waterlogging stresses during the same or alternative growing seasons, therefore it became a major challenge to select promising cultivars that fit across varied soil moisture conditions. In this context, the present experiment was carried out to evaluate 75 maize hybrids under six environments with a combination of cropping season, location and soil moisture condition. The objective of the present investigation is to carry out simultaneous selection of ideal maize hybrids with better yield potential and stable across soil moisture regimes through additive main effects and multiplicative interaction (AMMI) analysis. The analysis of variance for mean grain yield across test environments showed significant variation for genotype-by-environment interaction (GEI), along with genotypes and environments that ensured stability analysis. Five maize hybrids viz., ZH161303, ZH161478, ZH161330, ZH161047 and ZH161068 were found promising hybrids with high stability and productivity across the soil moisture regimes including low, excess and optimal soil moisture environments. © 2021, Society for Plant Research.
Standard heterosis analysis in maize hybrids under water logging condition
(Editorial board of Journal of Experimental Biology and Agricultural Sciences, 2020) Gayatri Kumawat; Jai Prakash Shahi; Munnesh Kumar; Ashok Singamsetti; Manish Kumar Choudhary; Kumari Shikha
Maize is one of the important food and forage crops with abundant natural diversity. Determination of heterosis in CIMMYT maize hybrids under water logging condition is necessary for their commercial exploitation. The synthetics and composites have contributed to maize production in India in the initial stages of maize improvement programme, of late, hybrids are playing a vital role due to their high yielding potential. Breeding of water logging tolerant maize varieties will likely boosts maize production beyond the present level. Data derived from current study were complied to determine standard heterosis and identify high yielding hybrids. Among the tested 55 maize hybrids, the maize hybrids, namely, ZH17506, ZH17496 and VH11128 produced high heterosis which indicating that these hybrids are available for commercial cultivation. Maize hybrids that perform better than the checks could be used for release as hybrid variety after re-evaluation in multi-location trials. © 2020, Editorial board of Journal of Experimental Biology and Agricultural Sciences. All rights reserved.