Screening for Winter-Hardiness in a Cultivated Chickpea/Wild Relative Ril Population.

As a legume, chickpea (Cicer arietinum L) is an integral part of cereal-based cropping systems worldwide as they significantly contribute to agricultural sustainability by fixing atmospheric N, breaking disease cycles, improving the cereals grain and protein yields, and providing diet diversification. As a spring-planted crop, the short growing season of chickpea limits its grain yield and leaves very little crop residues to combat soil erosion and contribute to soil organic matter. The development of a fall-planted, winter chickpea could improve yields by increasing the length of the growing season, help escape late season drought, and provide additional protection from cool temperatures during seed set in the early spring. Chickpea lack winter hardiness due to genetic bottlenecks and subsequent loss of critical alleles during its development in evolutionary history. However, alleles for winter hardiness and a vernalization requirement still exist and are prevalent in chickpea’s wild progenitor, C. reticulatum. A recombinant inbred line population was made between cultivated chickpea (ICC 4958) and C. reticulatum (PI 489777) that differ in their winter hardiness response. The population, consisting of 131 individuals, is being screened for differential winter hardiness responses over multiple environments. Here we reported data from the first year (planted fall 2011 in Central Ferry, Washington). A mild winter limited winter kill, so the plots were scored by cold-induced leaf damage. The data were analyzed with logistic regression and the log of odds ratio for similarity to each parent was estimated. The data showed a trimodal distribution with two extreme peaks roughly centered on each parent and a peak in the middle of the histogram. This study will be repeated next year across five environments and sequence data derived from digital gene expression profiling will be used to detect QTL consistently associated with winter hardiness.