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Biology and Biotechnology of Environmental Stress Tolerance in Plants, Volume 3

of breeding strategies. This chapter covers the importance of GWAS and

NGS in crop improvement against various biotic and abiotic stresses.

10.1 INTRODUCTION

The pace of conversion of arable land to wasteland is increasing due to the

rising global population, urbanization, and industrialization. One of the main

issues that agriculturalists and the plant scientists are currently facing is the

supplying food to an ever-increasing population. This predicament is made

considerably worse by environmental pressures. Despite the development of

a number of tolerance mechanisms, plants that are sensitive to environmental

extremes have a hard time surviving. It is critical to develop new techno­

logical approaches. Plant genomes have little ability to improve resistance to

environmental stress using traditional breeding strategies. Plants are in direct

contact with a vast range of environmental stresses as it lowers and control

the growth and productivity of many plants. The plants are consistently in

direct contact with different kinds and various forms of stress. The identifica­

tion of critical genes and signaling pathways underpinning plant responses to

environmental stress will aid in the development of strategies for agricultural

genetic improvement to address this problem. Abiotic stress-related genes

have been identified in large part thanks to crop functional genomics. Recent

advancements in genomic technologies now enable cost-effective solutions.

Especially with the availability of the entire genomic sequence of several

model and agricultural plant species, and high-throughput technologies

for discovering stress-related genes at a genome-wide level. Bioinformatic

approaches have been able to uncover stress-tolerant gene families across

species based on homology and synteny. Thanks to the availability of

genetic database resources. Furthermore, genome-wide association analyzes

(GWAS) for complex trait loci in crops have aided in the finding of important

stress-related genes and their beneficial alleles.

Due to the development of next-generation sequencing (NGS) technolo­

gies, GWAS has become a generally acknowledged technique for deciphering

genotype-phenotype relationships in many species. The overall purpose of

GWAS is to use the most appropriate statistical model in a given population

to link genotypic variants to phenotypic differences. Genome-Wide Associa­

tion studies (GWAS), or we can define as the studies which are associated

with the genome. They investigate genetic variants across un-identical

varieties, at the genomic level. To know that these variants are associated