LGG_2024v15n5

Legume Genomics and Genetics 2024, Vol.15, No.5, 221-231 http://cropscipublisher.com/index.php/lgg 222 addressing these aspects, this paper seeks to provide a comprehensive overview of the advancements and future directions in chickpea genetic improvement. 2 Key Traits for Chickpea Improvement 2.1 Yield and yield-related traits Yield potential in chickpeas is influenced by several key traits, including early maturity, photosynthetic efficiency, and resistance to both biotic and abiotic stresses. Early maturing varieties have been developed to escape terminal drought and heat stresses, which are critical in short-season environments (Gaur et al., 2012). Additionally, enhancing photosynthetic efficiency has been identified as a vital factor for increasing seed yield per plant. Genetic studies have pinpointed specific genes, such as those coding for chlorophyll A-B binding proteins, which are associated with improved photosynthetic efficiency and, consequently, higher seed yields (Basu et al., 2018). Breeding for yield stability involves developing cultivars that can maintain high yields under varying environmental conditions. This includes incorporating resistance to major diseases and pests, as well as tolerance to abiotic stresses like drought and heat. Marker-assisted selection (MAS) is being utilized to combine resistance to multiple stresses, thereby improving the overall yield stability of chickpea cultivars (Millán et al., 2006). The integration of genomic technologies has also started to enhance the precision and efficiency of breeding programs aimed at yield stability (Gaur et al., 2012). 2.2 Resistance to biotic stresses Chickpea production is significantly hampered by various biotic stresses, including fungal diseases like Fusarium wilt and Ascochyta blight, as well as pests such as the pod borer (Helicoverpa spp.) (Millán et al., 2006; Li et al., 2015; Choudhary et al., 2022). These diseases and pests can cause substantial yield losses, sometimes up to 100% under severe conditions. Incorporating genetic resistance into chickpea cultivars is a primary objective in many breeding programs. Quantitative trait loci (QTL) for resistance genes have been identified and mapped, and molecular markers associated with these loci are being used for efficient pyramiding of resistance traits (Li et al., 2015; Choudhary et al., 2022). Advances in genomics, such as the development of high-resolution phenotyping tools and next-generation sequencing, are expected to further enhance the efficiency of breeding programs focused on biotic stress resistance (Gaur et al., 2012). 2.3 Tolerance to abiotic stresses Drought and heat are major abiotic stresses that limit chickpea productivity. Mechanisms for drought tolerance include early maturity to escape terminal drought and the development of deep root systems to access water from deeper soil layers (Millán et al., 2006). Heat tolerance is often achieved through the selection of genotypes that can maintain reproductive success under high temperatures (Gaur et al., 2012). Improving water-use efficiency (WUE) is crucial for chickpea cultivation in arid and semi-arid regions. Breeding programs are focusing on traits such as reduced stomatal conductance and increased root depth to enhance WUE. Marker-assisted selection is being employed to identify and incorporate these traits into elite chickpea lines. 2.4 Nutritional quality and biofortification Chickpeas are a vital source of protein and micronutrients, especially in developing countries. Breeding efforts are aimed at enhancing the protein content and bioavailability of essential micronutrients like iron and zinc. Genomic tools are being used to identify candidate genes associated with these nutritional traits, facilitating their incorporation into high-yielding cultivars (Figure 1) (Acharjee and Sarmah, 2013; Varshney et al., 2013; Halladakeri et al., 2023). Anti-nutritional factors such as phytic acid can reduce the bioavailability of essential nutrients in chickpeas. Breeding programs are targeting the reduction of these compounds to improve the nutritional quality of chickpeas. Advances in molecular breeding and the use of functional markers are aiding in the identification and selection of genotypes with lower levels of anti-nutritional factors.

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