Browsing by Author "Sameer Upadhyay"

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Discerning Genes to Deliver Varieties: Enhancing Vegetative- and Reproductive-Stage Flooding Tolerance in Rice
(Elsevier B.V., 2025) Sanchika Snehi; K. T. Ravi Kiran; Sanket R. Rathi; Sameer Upadhyay; Suneetha Kota; Satish Kumar Sanwal; B. M. Lokeshkumar; Arun Balasubramaniam; Nitish Ranjan Prakash; Pawan Kumar Singh
Flooding in rice fields, especially in coastal regions and low-lying river basins, causes significant devastation to crops. Rice is highly susceptible to prolonged flooding, with a drastic decline in yields if inundation persists for more than 7 d, especially during the reproductive stage. Although the SUB1 QTL, which confers tolerance to complete submergence during the vegetative stage, has been incorporated into breeding programs, the development of alternative sources is crucial. These alternatives would broaden the genetic base, mitigate the influence of the genomic background, and extend the efficacy of SUB1 QTL to withstand longer submergence periods (up to approximately 21 d). Contemporary breeding strategies predominantly target submergence stress at the vegetative stage. However, stagnant flooding (partial submergence of vegetative parts) during the reproductive phase inflicts severe damage on the rice crop, leading to reduced yields, heightened susceptibility to pests and diseases, lodging, and inferior grain quality. The ability to tolerate stagnant flooding can be ascribed to several adaptive traits: accelerated aerenchyma formation, efficient underwater photosynthesis, reduced radial oxygen loss in submerged tissues, reinforced culms, enhanced reactive oxygen species scavenging within cells, dehydration tolerance post-flooding, and resistance to pests and diseases. A thorough investigation of the genetics underlying these traits, coupled with the integration of key alleles into elite genetic backgrounds, can significantly enhance food and income security in flood-prone rice-growing regions, particularly in coastal high-rainfall areas and low-lying river basins. This review aims to delineate an innovative breeding strategy that employs genomic, phenomic, and traditional breeding methodologies to develop rice varieties resilient to various dimensions of flooding stress at both the vegetative and reproductive stages. © 2025 China National Rice Research Institute
Genetic analysis and trait association for yield related traits in F2:3 biparental population of rice under slightly sodic condition
(Indian Society of Plant Breeders, 2019) Prashant Bisen; P.K. Singh; Bapsila Loitongbam; Namrata Rathi; Sanket R. Rathi; Sameer Upadhyay; B. Sinha
Genetic variability and correlation studies provide basic information concerning the genetic properties of the population based on which, breeding methods could be formulated for further improvement of the crop. The estimates of heritability, coefficients of variability, genetic advance and trait association were computed for eleven yield related traits in F2:3 segregating populations of biparental crosses under slightly sodic condition. Analysis of variance revealed significant differences for the traits studied except, effective tillers per plant, panicle length and test weight, indicating the existence of high genetic variability among the lines. Estimates of phenotypic coefficients of variation (PCV) were higher than genotypic coefficient of variation (GCV) for all the characters studied, indicating considerable effect of environment. Moderate heritability accompanied with high genetic advance was recorded for filled grains and unfilled grains per panicle which, indicates heritability is most likely due to additive gene effect and selection for the traits will be effective. Traits like: effective tillers per plant, panicle length, filled grains per panicle and total grains per panicle that showed, positive and significant association with grain yield per plant, could be useful for breeders in any breeding program for further improvement of the traits under sodic condition. © 2019 Indian Society of Plant Breeders.
Identification of QTLs for zinc deficiency tolerance in a recombinant inbred population of rice (Oryza sativa L.)
(John Wiley and Sons Ltd, 2022) Bapsila Loitongbam; Pawan Kumar Singh; Rameswar Prasad Sah; Om Prakash Verma; Balwant Singh; Prashant Bisen; Sandhya Kulhari; Sanket R Rathi; Sameer Upadhyay; Nagendra Kumar Singh; Rabin Sahu; Rakesh Kumar Singh
BACKGROUND: Deficiency of Zn is a major soil constraint in rice plant growth and yield. Edaphic factors such as Zn deficiency in soil in relation to plant performance are still poorly understood. Here, we report promising quantitative trait loci (QTL) conferring tolerance to Zn deficiency, which were identified through biparental mapping. The experiment was conducted using the 236 F7 recombinant inbred line mapping population derived from the cross of Kinandang Patong (Zn deficiency sensitive) and A69-1 (Zn deficiency tolerant). RESULTS: A total of six QTLs (qLB-2B, qLB-4B, qPM-4B, qPM-6B, qRZC-4B, qSZC-4B) on chromosomes 2, 4 and 6 were identified for environment 1, whereas five QTLs (qLB-2 N, qLB-4 N, qPM-4 N, qRZC-4 N, qSZC-4 N) on chromosomes 2 and 4 were detected for environment 2. Among these, five major (51.30, 48.70, 28.60, 56.00, 52.00 > 10 R2) and one minor (5.40 < 10 R2) QTLs for environment 1 and four major (51.48, 50.20, 53.00, 48.00 > 10 R2) and one minor (4.44 < 10) QTLs for environment 2 for Zn deficiency tolerance with a logarithm of odd threshold value higher than 3 were identified. The QTLs (qLB-4B, qPM-4B, qRZC-4B, qSZC-4B, qLB-4 N, qPM-4 N, qRZC-4 N, qSZC-4 N) for leaf bronzing, plant mortality root zinc concentration and shoot zinc concentration identified on chromosome 4 were found to be the most promising and highly reproducible across the locations that explained phenotypic variation from 48.00% to 56.00% with the same marker interval RM6748–RM303. CONCLUSION: The new QTLs and its linked markers identified in the present study can be utilized for Zn deficiency tolerance in elite cultivars using marker-assisted backcrossing. © 2022 Society of Chemical Industry. © 2022 Society of Chemical Industry.
Sustainable production of rice under sodicity stress condition
(Springer Singapore, 2020) Sameer Upadhyay; P.K. Singh; S.R. Rathi; Prashant Bisen; Bapsila Loitongbam
In today's world population, explosion is not an unknown phenomenon and so is climate change. Resources are limited, and hence, the act of sustainable production comes into play in agriculture. The word sustainable production in agriculture aims at producing food not compromising the food security of future generation. Rice is one of the major cereals which feed the entire South East Asia and its neighbouring countries contributing a major share in dietary consumption, and on the other hand, sodicity stress is engulfing areas which could otherwise contribute towards increased rice production. Therefore, to achieve the target to feed the ever-growing population, it is of paramount importance to utilise the sodicity condition such that it should contribute towards rice production in a sustainable way. Growing science of agriculture will play a prominent role for increasing production and will provide an opportunity to achieve the objective of extirpating hunger and ensuring food security. © Springer Nature Singapore Pte Ltd. 2020. All rights reserved.