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20232
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Subject: Biotechnology and molecular Biology ×

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    ThesisItemOpen Access
    Studies on Physiological, Biochemical and Molecular responses of Lentil (Lens culinaris) Genotypes under Abiotic Stresses
    (SARDAR VALLABHBHAI PATEL UNIVERSITY OF AGRICULTURE AND TECHNOLOGY, MEERUT- 250110 (U.P.),, 2023-08) SHRUTI; Dr. Anil Sirohi
    Lentil (Lens Culinaris) is a significant global pulse crop cultivated in countries like India and Canada. However, the production of lentil faces significant challenges due to abiotic stresses. While it exhibits moderate tolerance to drought and salinity, its productivity is substantially diminished by intermittent and terminal drought as well as salinity. These stress conditions instigate a cascade of morphological, physiological, biochemical, and molecular transformations that detrimentally impact the plant's growth and yield. To enhance stress tolerance in lentil plants, a thorough understanding of how various abiotic stress factors, such as drought and salinity, affect the plant at a molecular and physiological level is essential. In this study, the drought and salinity tolerance of ten lentil genotypes (DPL-15, DPL-62, IPL- 81, IPL-316, IPL-406, K-75, JL-3, L-4076, PDL-1, PDL-2) were examined. Drought stress was induced by subjecting the plants to PEG 6000 (18% w/v) for 15 days, while salt stress was imposed using 200mM NaCl for the same duration. The objective was to analyse various morphological, physiological (Chlorophyll content, relative water content, and Membrane stability index) and biochemical parameters (Catalase test, total soluble sugar, anthocyanin, and proline contents) under drought and salt stress conditions. The current research focuses on the molecular characterization and functional significance of abiotic stress-tolerant genes (DREB2a, F-Box, LEA4, SOS1, ASR) from lentil (Lens culinaris). Through a series of analyses, including conserved domain search, protein structure prediction and validation using Swiss Model, Swiss-PDB viewer, and Expasy, the study establishes the involvement of these hypothetical proteins in regulating responses to drought and salt stress. Furthermore, an expression analysis was conducted for abiotic stress-tolerant genes (DREB1A, DREB2A, F-Box, LEA4, SOS1, SPS, ASR, Wrky41) to gain a better understanding of how these genes respond to the drought and salt stress. The results will contribute to better understanding the mechanisms of drought and salinity tolerance in lentil genotypes, potentially aiding in the selection of suitable parents for breeding drought-resistant and salt-resistant varieties. This investigation has the potential to identify novel abiotic stress-tolerant genes that play pivotal roles in drought and salt tolerance. Additionally, it aims to develop functional markers that could be utilized to enhance lentil crops. Moreover, the study offers fundamental insights into the drought and salt tolerance capacity of the studied genotypes, which could be further validated at the field level.
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    ThesisItemOpen Access
    Molecular characterization and gene expression analysis of wheat (triticum aestivum l.) under heat stress conditions
    (SARDAR VALLABHBHAI PATEL UNIVERSITY OF AGRICULTURE AND TECHNOLOGY, MEERUT- 250110 (U.P.),, 2023-08) PRAFULLA KUMAR; Dr. Ravindra Kumar
    Wheat (Triticum aestivum L.) is an important cereal crop grown globally, covering 217.3 million hectares and producing 653.36 million tons annually. India accounts for 14 percent of the global wheat area. Uttar Pradesh is a leading wheat-producing state, contributing significantly to national food security. However, global warming and late sowing of wheat in western Uttar Pradesh have resulted in terminal heat stress which ultimately reduce yield. In response to these challenges, current study aimed to examine the morphological, physiological and biochemical traits associated with terminal heat tolerance. Studies were also conducted to estimate molecular diversity and gene expression analysis. The results revealed significant phenotypic and genotypic variations for 14 measured traits under normal and late sown conditions. Twelve genotypes were identified as terminal heat tolerant and eighteen genotypes as heat susceptible based on different selection indices. Genetic variability was also observed for all traits, and several traits exhibited high heritability with moderate genetic advance thus suggesting the potential for selection in breeding programs. The genetic diversity analysis shows that genotypes are clustered into five groups in control and terminal heat stress. The distribution of genotypes into various clusters suggested that change of environment was effective in affecting the performance of genotypes and providing insights into potential hybrid combinations. SSR marker analysis showed a total of 90 alleles and all were polymorphic. The number of alleles ranged from 1 to 8 with an average of 4.5 alleles per primer. Based on SSR polymorphism, the genotypes were grouped into two divergent multi-genotypic clusters. Twelve terminal heat-tolerant genotypes that are clustered into 3 groups which indicates that their parents are genetically divergent. The genetic structure illustrated by the Structure Software (at K = 7) using the SSR molecular data showed that 30 wheat genotypes are composed of seven major ancestral components present in different combinations in different genotypes. Various physiological traits were also associated with improved tolerance under heat stress conditions. Relative gene expression analysis of HSP101a, HSP101b, and HSP101c emphasized their vital role in heat tolerance. HSP101c showed the highest expression among all genotypes and heat shock treatments. HSP101 gene has shown potential for improvement of heat tolerance-related traits which ultimately reflected in stable grain yield. By incorporating these findings into breeding programs, breeders can create wheat genotypes having terminal heat tolerance.