QTL and Candidate Gene Analysis for Early Flowering in Chickpea

In climates that experience short growing seasons due to drought, heat or end-of-season frost, early flowering time is a highly desirable trait for chickpeas.  In this study, we have mapped, sequenced and characterized what is likely to be Efl-1, an orthologue of the Arabidopsis gene ELF3 that confers early flowering and photoperiod insensitivity.   In a RIL population derived from a cross between CDC Frontier and ICCV 96029, this gene was mapped on Ca5 that explained approximately 60% of flowering time variation under short day photoperiod. Sequencing of the Efl-1 in chickpea cultivar ICCV 96029 revealed an 11-bp deletion in the first exon that was predicted to result in a premature stop codon.  This polymorphism does not appear to be widely-distributed within global chickpea germplasm, indicating that this mutation arose relatively recently.  Analysis of circadian clock function failed to show any clear loss of rhythm in the expression of clock genes in ICCV 96029 suggesting a possibility of an alternative mode of action for this gene in chickpea.  The effect of this polymorphism on flowering time is currently being tested through transgenic complementation of the Arabidopsis elf3-1 mutant.