LGG_2024v15n5

Legume Genomics and Genetics 2024, Vol.15, No.5, 221-231 http://cropscipublisher.com/index.php/lgg 224 models. The integration of GS with high-throughput phenotyping and genotyping technologies can further enhance the efficiency of chickpea breeding programs, making it a valuable tool for developing climate-resilient chickpea varieties (Roorkiwal et al., 2016; Budhlakoti et al., 2022; Biswas et al., 2023). 3.3 Genetic mapping and QTL analysis Quantitative Trait Loci (QTL) mapping involves identifying regions of the genome that are associated with specific traits. In chickpeas, QTL mapping has been used to identify loci linked to important agronomic traits such as drought tolerance, disease resistance, and yield components. The development of dense genetic maps has facilitated the identification of these QTLs, providing valuable targets for MAS and GS. QTLs play a crucial role in the genetic improvement of chickpeas by enabling the targeted introgression of beneficial alleles into breeding lines. For example, QTLs associated with Ascochyta blight resistance have been successfully introgressed into chickpea cultivars, enhancing their resistance to this devastating disease. The identification and utilization of QTLs are essential for the development of chickpea varieties with improved performance under various environmental conditions (Varshney et al., 2017; Sandhu et al., 2022; Zhong, 2024). 3.4 CRISPR/Cas9 and genome editing CRISPR/Cas9 is a powerful genome-editing tool that allows for precise modifications of specific genes. In chickpeas, CRISPR/Cas9 has the potential to target and edit genes associated with key traits such as disease resistance, drought tolerance, and yield. This technology offers a rapid and efficient means of introducing desirable genetic variations, thereby accelerating the breeding process (Varshney et al., 2017; Budhlakoti et al., 2022). Recent advances in CRISPR/Cas9 technology have demonstrated its potential in crop improvement. For instance, gene editing has been used to enhance disease resistance and stress tolerance in various crops, including chickpeas. The successful application of CRISPR/Cas9 in chickpeas could lead to the development of superior cultivars with enhanced agronomic traits, contributing to increased productivity and sustainability in chickpea farming. 4 Case Study: Enhancing Drought Tolerance in Chickpeas 4.1 Importance of drought tolerance in chickpea cultivation Drought is a significant constraint in chickpea cultivation, leading to substantial yield losses. Chickpea, primarily grown in arid and semi-arid regions, is highly susceptible to terminal drought stress, which can result in up to 50% reduction in production (Varshney et al., 2013; Sachdeva et al., 2020). The increasing frequency and intensity of droughts due to climate change further exacerbate this issue, affecting various growth stages of the crop, including flowering and podding (Karalija et al., 2022). The economic and social implications of drought tolerance in chickpeas are profound. Chickpeas are a crucial source of protein for many resource-poor farmers in developing countries. Enhancing drought tolerance can stabilize yields, ensuring food security and economic stability for these communities. Moreover, drought-tolerant varieties can reduce the need for irrigation, conserving water resources and reducing production costs (Asati et al., 2022; Tiwari et al., 2023). 4.2 Genetic basis of drought tolerance Research has identified several key genes and pathways involved in drought tolerance in chickpeas. For instance, transcription factors such as WRKY, DREB2A, and CarNAC3 have been shown to play significant roles in regulating drought responses (Borhani et al., 2019). Additionally, the ASR gene has been characterized for its involvement in drought stress regulation, with increased expression under drought conditions (Sachdeva et al., 2020). Genomic studies have also identified QTL clusters, particularly on CaLG04, which are associated with multiple drought tolerance traits (Varshney et al., 2013). Advancements in genomic resources and tools have facilitated the breeding of drought-tolerant chickpea varieties. Whole genome resequencing and the development of high-density genetic maps have enabled the identification of SNPs and QTLs associated with drought tolerance (Thudi et al., 2023). Marker-assisted selection (MAS) and genome-wide association studies (GWAS) are powerful tools that have been employed to enhance the precision and efficiency of breeding programs (Asati et al., 2022).

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