Mini Core Collection as a Resource to Identify New Sources of Variation

Abstract

In chickpea, bottlenecks associated with its domestication and low use of germplasm in improvement programs have resulted in a narrow genetic base and its vulnerability to abiotic and biotic stresses. The core and mini core collections, representing diversity in the entire collection, have been advocated for enhanced utilization of germplasm in crop improvement. A chickpea mini core (211 accessions) was evaluated for agronomic traits from 2000 and 2001 to 2003 and 2004 in post‐rainy seasons under irrigated and non‐irrigated conditions. The published information on the response of chickpea mini core accessions to stress revealed that 40 accessions had resistance to abiotic stress, 31 to biotic stress, and 24 had no resistance to either of the stresses. The abiotic and biotic stress resistant groups had six accessions in common. The mini core collection accessions were also a part of composite collection accessions in chickpea, which was genotyped using 48 simple sequence repeats (SSRs; BMC Plant Biol. 8:106, 2008). The agronomic evaluation, stress response, and molecular profiling data on 93 accessions, including four controls, were used to identify genetically diverse germplasm with agronomically beneficial traits. A number of genetically diverse accessions possessing agronomically beneficial traits, such as ICC 440, 637, 1098, 3325, 3362, 4872, 7441, 8621, 9586, 10399, 12307, 14402, 15680, and 15686, which meet breeders’ needs, have been identified for use in breeding and genetics to map genomic regions associated with beneficial traits and as source materials for developing high yielding and widely adapted chickpea cultivars with multiple resistance to abiotic and biotic stress.

Assessing Genetic Variability for Root Traits and Identification of Trait‐Specific Germplasm in Chickpea Reference Set

“…ICC 8261, which is found to be superior for root-length density, was earlier reported as the best drought and salinity resistant accession with a higher 100-seed weight (30-38 g) than L 550 (20 g) and resistant to Botrytis gray mold (BGM). ICC 1422 and ICC 14446 were found to be resistant to drought (Upadhyaya et al, 2013). ICC 15406 is also confirmed to be resistant to BGM and legume pod borer, also with a greater 100-seed weight (29-43 g) than L 550 (20 g).…”

“…A subsequent marker-assisted breeding for these traits by incorporating the quantitative trait loci (QTL), well associated with root and other drought avoidance related traits, has facilitated identification of progenies with a 30% yield advantage in multilocation drought environments (Varshney et al, 2014). The molecular-marker-based reference set of chickpea germplasm has been considered as an ideal set for this exploration, as research to date suggests that mini core collection (Upadhyaya and Ortiz, 2001) and genotype-based reference sets (Glaszmann et al, 2010) were highly useful in extracting germplasm with beneficial agronomic, physiological, and nutritional traits for use in crop improvement programs involving resistance to abiotic and biotic stresses (Krishnamurthy et al, 2013a,b;Upadhyaya et al, 2013). The molecular-marker-based reference set of chickpea germplasm has been considered as an ideal set for this exploration, as research to date suggests that mini core collection (Upadhyaya and Ortiz, 2001) and genotype-based reference sets (Glaszmann et al, 2010) were highly useful in extracting germplasm with beneficial agronomic, physiological, and nutritional traits for use in crop improvement programs involving resistance to abiotic and biotic stresses (Krishnamurthy et al, 2013a,b;Upadhyaya et al, 2013).…”

“…This success encourages further diversification of parental base for use in subsequent breeding efforts catering the needs of vast chickpea growing agroecological environments. The molecular-marker-based reference set of chickpea germplasm has been considered as an ideal set for this exploration, as research to date suggests that mini core collection (Upadhyaya and Ortiz, 2001) and genotype-based reference sets (Glaszmann et al, 2010) were highly useful in extracting germplasm with beneficial agronomic, physiological, and nutritional traits for use in crop improvement programs involving resistance to abiotic and biotic stresses (Krishnamurthy et al, 2013a,b;Upadhyaya et al, 2013). With an objective to understand the genetic variation for root traits (w/w) of Vertisol and sand mixed with di-ammonium phosphate at a rate of 0.07 g kg −1 .…”

Forming Core Collections in Barnyard, Kodo, and Little Millets using Morphoagronomic Descriptors

“…The availability of core collections in these neglected crops provides researchers opportunity to discover new sources of variation for use in genetic improvement of these crops. To date, research at ICRISAT and elsewhere has proven beyond doubt the utility of these representative subsets in identifying agronomically beneficial germplasm for use in crop breeding (Bowman et al, 2001;Brick et al, 2006;Grunwald et al, 2003;Mahuku et al, 2003;Micklas et al, 1999;Tullu et al, 2001;Upadhyaya et al, 2013Upadhyaya et al, , 2014. Molecular characterization of these subsets should further provide information on population structure and diversity and allelic richness, which may be used to identify genetically diverse germplasm for use in genomics and applied breeding of these crops.…”

Association of mid-reproductive stage canopy temperature depression with the molecular markers and grain yields of chickpea (Cicer arietinum L.) germplasm under terminal drought

“…To test any given assumption, it is important to select a population that is elaborately characterized and well known to be diverse not only for drought but also for cross stress reactions. The mini-core collection of chickpea germplasm is assembled based on morphological and agronomic diversity (Upadhyaya and Ortiz, 2001) and also been characterized for most biotic and abiotic stress reactions (Upadhyaya et al, 2013). A subset of extremely contrasting accessions (n = 84) were chosen for checking the reaction in canopy temperature.…”