Abstract
Drought is one of the major abiotic stresses that frequently causes severe loss in crop yield worldwide. Laboratory predictors of field drought tolerance could significantly increase the effectiveness of existing plant breeding programs. In earlier field experiments, drought tolerance of 22 cultivated barley varieties has already been quantified. In order to develop laboratory markers of drought sensitivity, field drought tolerance data were correlated with parameters obtained in laboratory tests. Root and shoot length and weight were measured on control and PEG-treated (a simple laboratory drought model) seedlings. Significant correlations were found among root growth, shoot weight in laboratory stress conditions and field drought tolerance. Interestingly, a negative correlation was found between root length of the untreated seedlings and drought tolerance. Laboratory Drought Tolerance Index (DTI) was introduced as the linear combination of those laboratory parameters which were correlated with field drought tolerance. DTI showed good predictive value (r = 0.57, p < 0.05) for drought tolerance in field experiments and we suggest it for preselection of drought tolerant barley breeding lines and for the characterization of drought tolerance in general.