Assessment of ICCV 2�נJG 62 chickpea progenies shows sensitivity of reproduction to salt stress and reveals QTL for seed yield and yield components

Vincent Vadez et al., 'Assessment of ICCV 2�נJG 62 chickpea progenies shows sensitivity of reproduction to salt stress and reveals QTL for seed yield and yield components', Molecular Breeding, vol. 30(1), pp.9-21, Springer Science and Business Media LLC, 2011

Salinity is a complex abiotic stress and understanding the physiological and genetic basisof salinity tolerance is a prerequisite for improving existing crop cultivars. Experimentswere undertaken using 126 recombinant inbred lines from a cross between JG 62(tolerant) and ICCV 2 (sensitive) to characterize traits related to seed yield differencesunder saline conditions and to map quantitative trait loci (QTL). The populationsegregated for flowering time and entries were separated into ?early? and ?late? phenologygroups to undertake the analysis. In both groups seed yield varied under salinity, with4seed number being the most closely related trait to yield. In contrast, seed yield was notrelated to 100-seed weight or flowering time. Shoot dry weight was positively correlatedwith seed yield in the early entries only, but had no significant relationship with seednumber. The higher sensitivity to salinity of the early entries was related both to a smallerbiomass and lesser seed number under saline conditions. A QTL for seed yield undersaline conditions was found in linkage group 3 in the late group, and a cluster of QTLsfor seed yield components in linkage group 6, including a QTL for seed number whichexplained 37% of the variation. In contrast, no QTL for seed yield was found in the earlygroup, but a QTL for seed number under saline conditions was found. These data indicatethat salinity tolerance traits are linked to the degree of earliness in chickpea. Tolerance isdetermined by the success of reproductive sites in both early and late entries, whichrelates in part to constitutive traits, and by the capacity of maintaining growth in earlyfloweringlines only. This is the first report of QTLs for seed yield and seed number inchickpea exposed to salinity