Genetic Variability in Root Development in Relation to Drought Tolerance in Spring Wheats

Abstract
Fifteen Australian and exotic wheat varieties revealed genotypic differences in their patterns of root development and drought tolerance. Earliness in plant maturity, which accounted for 40 to go per cent of the observed variation in drought tolerance, appeared to be by far the most important characteristic of tolerant genotypes, but there nevertheless appeared to be a measurable relationship between some parameters of root development, water use efficiency and drought tolerance. The impact of study of this kind on the problem of breeding for drought tolerance is briefly discussed.