Study of root traits of chickpea (Cicer arietinum L.) under drought stress

Roots are among the first defence towards drought with other morpho-physiological and biochemical mechanisms employed by plants. To understand precisely the root traits contribution towards yield, parental chickpea genotypes with well known drought response were field evaluated under drought and optimal irrigation in rain-out shelter. A total of ten genotypes planted in 1.2 m PVC lysimeters were subjected to three water stress levels: high moisture stress, medium water stress, and low water stresses. Root traits, such as root length density, total root dry weight, root dry weight and root: shoot ratio, were measured at 40 days after sowing. The roots were washed and scanned using WinRHIZO software. The ANOVA showed that there was significant difference (P < 0.05) in traits measured amongst test genotypes which included shoot biomass, root biomass, total root length (RL) and root length density (RLD). The results also showed that there were significant variations (P < 0.05) in water regimes and traits decreased with increasing moisture stress from low to high moisture regime. Furthermore, there were variations in root anatomy between the two major chickpea types where majority of the best performing genotypes under low moisture regimes were of the Desi type (e.g. ICC 4958, ICCV 00108, ICCV 92944 and ICCV 92318) as compared to Kabulis which had better and higher response under high moisture regime in this study. These traits could be used for indirect selection for drought tolerance especially in early stages of breeding for drought tolerance which would consequently reduce the cost of multi-location field evaluation in the breeding programs.   Key words: Genotypes, Chickpea Cicer arietinum L., drought stress, root traits.