Browsing by Author "Anima Mahato"

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Genetic diversity of sweet corn inbreds using agro-morphological traits and microsatellite markers
(Springer Verlag, 2018) Anima Mahato; Jai Prakash Shahi; Pawan Kumar Singh; Monu Kumar
Assessment of genetic diversity is a pre-requisite to broaden the genetic background of cultivated base of sweet corn, an endosperm mutant of field corn that alters starch biosynthesis pathway in endosperm. In the current investigation, genetic divergence among 39 inbred lines was assessed on the basis of 14 agro-morphological traits, two quality parameters and 63 microsatellite markers, selected on the basis of their association with QTLs affecting kernel quality. The cluster analysis based on unweighted pair-group method using arithmetic averages for agro-morphological and quality traits grouped the 39 inbreds into three clusters with 5, 14 and 20 genotypes, respectively. The unweighted neighbor-joining method for microsatellite markers also categorized the inbred lines into three major clusters grouping 10, 9 and 20 genotypes in cluster I, II and III, respectively. The two cluster distribution patterns showed approximately 36 percent similarity. The assay of 30 microsatellite repeats identified 82 alleles with allele size ranging from 80 to 400 bp. The major allele frequency and PIC value of the markers ranged from 0.42 to 0.79 and 0.27 to 0.63, respectively, which suggested the presence of high amount of polymorphism among the inbreds. The average heterozygosity was recorded to be 0.19 which signifies proper maintenance of inbred population. Principle co-ordinate analysis also depicted diverse nature of inbred lines and agreed well with the previously determined clustering pattern. This study has identified several inbreds, having good yield and high sugar content which will not only enhance the genetic background of sweet corn germplasm but will also lead to development of high-yielding hybrids with improved quality. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
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.
NDVI and grain fill duration are important to be considered in breeding for terminal heat stress tolerance in wheat
(John Wiley and Sons Inc, 2023) Monu Kumar; Vinod Kumar Mishra; Ramesh Chand; Sandeep Sharma; Uttam Kumar; Jai Prakash Jaiswal; Mukesh Choudhary; Anima Mahato; Ashutosh; Prashant Singh; Arun Kumar Joshi
Terminal heat stress is a major constraint for taking a profitable crop of wheat by small and marginal farmers in the Indo-Gangetic Plains of south Asia. Hence, breeders remain in constant search for heat-tolerant genotypes. This study was done with the purpose to find out high-yielding wheat genotypes that perform stably under terminal heat stress as well as to conclude an easy phenotyping trait for this objective. A cross (HUW 234 × HUW 468) was made using two popular cultivars of the eastern Gangetic Plains of India. HUW 234 carries terminal heat tolerance whereas, HUW 468 is high yielding but suffers from terminal heat stress when planted late. So obtained 167 recombinant inbred lines (RILs) were exposed to both timely sown (TS) and late sown (LS) conditions at three locations for two consecutive years 2016–17 and 2017–18 at Varanasi (Uttar Pradesh), Jabalpur (Madhya Pradesh) and Pusa, Samastipur (Bihar). Combined ANOVA revealed that normalized difference vegetation index (NDVI) at anthesis stage (NDVI_AH) and grain filling duration (GFD) was significant for genotype (G), environment (E) and genotype × environment interaction (GEI). Likewise, differences were significant for grain yield (GY) and 1000-grain weight (TGW). AMMI analysis revealed similar results. However, NDVI_AH showed low variation under heat stressed late sown conditions. Furthermore, the which-won-where model and mean versus stability identified the best performing, above-average yielding and stable lines across the environments. Correlation among measured traits revealed that NDVI_AH had a significant association with GY in most of the environments. Several lines that performed superior to better parent for GY also showed higher values for NDVI_AH and GFD. The study demonstrates that NDVI_AH and GFD appear to be important traits to be considered while breeding for terminal heat stress tolerance in wheat. © 2023 Wiley-VCH GmbH. Published by John Wiley & Sons Ltd.
Phenomics-assisted breeding: An emerging way for stress management
(Springer Singapore, 2020) Monu Kumar; Anima Mahato; Santosh Kumar; Vinod Kumar Mishra
The challenges posed by several known and unknown biotic and abiotic stresses arising due to increasing population, global warming, and other potential climatic factors have severely affected the growth and yield of many agriculturally important crops. Abiotic stresses such as drought, flood, salinity, high temperature, etc. not only influence the physiology of plants but also accompany occurrence and spread of various pathogens, insects and weeds, which may sometimes lead to a famine-like situation. In this context, understanding the crops' response towards different stress conditions and the underlying stress resistance mechanisms has become a challenging task for plant breeder in breeding stress-resistant or climate resilient varieties. With the advent of molecular technologies and functional genomics over past decade, whole genome sequence of many crops is now available and has simplified the process of cloning and characterization of key genes governing important agronomic traits along with the physiological pathways underlying them. But to appraise the full potential of a genotype under stress condition, it is important to evaluate the response in terms of phenotypic behavior and the elements coordinating such responses. So, this post-genomic era has given rise to the need of advanced phenotyping tools for efficient utilization of the vast amount of genomic data in climate resilient breeding. The advanced phenotyping approaches use different imaging techniques that record interaction between plant and light which are transmitted, reflected or absorbed and provide measurements related to quantitative phenotypic traits with desired accuracy and precision. The various imaging techniques record the interaction between plants and light like photons, which are transmitted, reflected or absorbed and provide the desired level of accuracy and precision in measurements related to quantitative phenotypic traits. Visible light imaging, infraredand thermal-based imaging, fluorescence imaging, spectroscopy imaging, and other integrated imaging techniques are currently in use for precise phenotyping of crops under varied environments. The advanced phenomics tools measure plants' response to different abiotic stresses in terms of root architecture, chlorophyll content, canopy temperature deficit and other morphological traits along with disease and insect infestation with a great precision without taking much time and simplifying the germplasm screening process to a great extent. Hence, phenomics is an indispensable tool needed to bridge the gap between phenotyping and genotyping that is highly recommended to cope up the climate resilient varieties. © Springer Nature Singapore Pte Ltd. 2020. All rights reserved.