Chickpea (Cicer arietinum L.) is an important
food legume crop mainly grown under rainfed conditions. Drought is the most
important abiotic stress in most of the chickpea growing areas and occasionally
severe drought leads to complete crop failure. Studies on drought management in
different crops reveal that host tolerance is the best strategy to overcome the
stress. The present study was designed
to differentiate a set of drought tolerant and drought susceptible genotypes
with respect to root and shoot traits, and to study which relationships, if
any, could be used to select drought tolerant cultivars in a breeding program.
Eight diverse chickpea genotypes were grown in polyvinyl chloride (PVC) pipes
(1.2 x 0.15m) in the greenhouse at the Department of Plant Sciences, University
of Saskatchewan, Canada during 2005. Three moisture treatments included well
watered, drought starting at the 6-leaf stage, and drought starting at
flowering. Roots were collected from 0.2m depth increments at two growth
stages, two weeks after flowering and at maturity. Genotypes were characterized
for 15 morpho-physiological traits and data were analyzed for their
associations. Significant differences were observed among genotypes and
genotypes x stress interactions for most of the morpho-physiological traits
under varying stress levels. The two sampling dates exhibited non-significant
differences and all the genotypes attained their full root growth potential by
the first sampling date i.e. two weeks after the initiation of flowering. Root
lengths among genotypes varied with the stress levels. Cluster analyses
performed on genotypic similarities of the root systems showed two distinct
groups of genotypes, drought tolerant (high yielding under stress conditions)
and drought susceptible (low yielding under stress conditions). The
discriminatory analyses giving details of traits contributing towards high
yield under drought conditions will be discussed.