Gene identification is the process of identifying genomic DNA regions that encode proteins. It has a wide range of applications in structural genomics, functional genomics, metabolomics, transcriptomics, proteomics, and other genetic-related studies such as genetic disorder detection, treatment and prevention. There are several methods for finding genes, including the ab-initio method (intrinsic) and the sequence similarity search. Crops are typically improved by crossing plants with desired traits, such as high yield or drought tolerance, and selecting the best offspring after multiple generations of testing. It could take 8 to 10 years to develop a new variety. Breeders are very interested in new technologies that can speed up or improve the efficiency of this process. The term "marker-assisted selection" has been used in plant breeding and genetics science since the mid-1990s. The term MAS broadly refers to all forms of selection based on genetic data. MAS is becoming increasingly important in today's world because it aids and improves plant breeding efficiency by monitoring the presence or absence of desirable genes in breeding populations. This is achieved by precisely transferring genomic regions of interest (Foreground Selection) and hastening the recovery of the recurrent parent genome (Background Selection).

Drought stress is currently one of the major threats to the global food security as it primarily is the main cause behind yield loss and hence overall productivity. While conventional breeding, molecular breeding and genetic engineering approaches were widely used in developing drought tolerant varieties, but these techniques are laborious, time consuming and also transgenics developed have some ethical issues hence are not widely accepted. Plant breeders and biotechnologists are now keenly approaching towards genome editing and using various genome editing principles for improving various agronomically important traits in plants. Among all available genome editing principles, the clustered regularly interspaced short palindromic repeat-Cas (CRISPR/Cas) system is widely accepted due to its robust nature, simplicity, adaptability, flexibility and wide applicability. CRISPR Cas’s highly advanced technique of multiple sequence-specific nucleases has facilitated precise gene modification leading to development of novel climate resilient crops. In this review, we will try to understand the molecular mechanism of drought response in plants and the application of CRISPR/Cas genome-editing system for improving drought tolerance in plants for mitigating drought stress.

Barley (Hordeum vulgare L.) is one of the principal cereal crops grown in Western-Himalayas of India. A set of 105 barley genotypes including 38 two-rowed and 67 six-rowed genotypes were phenotyped for 10 important quantitative traits. The analysis of trait data of pre-harvest sprouting tolerance (PHST), growth, yield and yield contributing traits revealed significant variation in the germplasm and led to the identification of promising candidate genotypes for all the traits. In addition, a set of 96 barley genotypes were subjected to molecular characterization using 14 unlinked SSR markers (7 random and 7 genic SSR markers). The analysis of SSR marker data revealed a total of 67 alleles (range 2 to 8) with an average of 4.78 alleles/locus. While analyzing the data separately for random and genic SSR markers, it was observed that genic SSR markers are slightly less diverse (4.71 alleles/locus) than random genomic SSR markers (4.85 alleles/locus). A set of three markers including two random (XBmac156 and XBmag378) and one genic (XGbm1221) SSR marker detecting 7–8 alleles were found most polymorphic/informative markers for the study of allelic diversity in barley. The clustering of 96 genotypes based on genotypic data categorized all the genotypes into three broad clusters, sub- clusters and sub-sub clusters. The genotypes clustered in three sub-clusters did not show any trait-specific relationship with each other. The overall result of genotypic data analysis indicated moderate-level of genetic diversity in the 96 barley genotypes. The diverse and most promising genotypes identified for different traits during the present study could prove useful in future barley breeding programs worldwide.