Developing a Resource of Wild x Cultigen Introgression Lines for Crop Improvement of Chickpea

Abstract

Abstract Most cultivated germplasm pools have a narrow genetic basis of diversity due to domestication bottleneck and selection pressure in modern breeding. The combined genetic bottlenecks limit the potentials of improving traits of high agricultural significance. Crop wild relatives (CWRs) represent a primary source of novel genotypes from where pre-domestication genetic diversity can be restored into modern cultivars. Among the members of the wild Cicer species, C. reticulatum and C. echinospermum are the closest relatives having high cross-compatibility with the cultigen, C. arietinum. A wild x cultigen introgression cross was initiated by mating 20 wild founder parents with farmer-preferred elite cultivars aimed at mining trait-improving alleles from CWRs. Six broad sets of introgression panels were established by involving the 20 founders and three elite cultigens that generated 46 diverse families, and a total of 525 F1 hybrids. Selfing of the F1 progenies produced a total of 3,199 F2 populations. The study revealed significant variation among the founder parents and their derivative progeny for basic plant growth, vigor and architecture traits. A noticeable proportion of the introgression progeny outperformed both parents for yield-attributable traits, suggesting high breeding value of CWRs that resulted in positive allelic recombination. Of the 20 founder parents, 9 were identified as genetically superior for desirable and heritable traits. The study uncovers the genetic power of chickpea’s CWRs in preserving wide-ranging allelic variants vital for harnessing resilience traits. The introgression breeding initiatives reported here generated diverse pre-breeding populations as immortalized genetic resources ideal for future genetic studies.