Evaluation of drought tolerance for Atlas fescue, perennial ryegrass, and their progeny

Perennial ryegrass (Lolium perenne L.) has good turf quality but low drought tolerance. Atlas fescue (Festuca mairei) has exceptional drought tolerance but poor turf quality. Intergeneric hybridization between the two grasses would have the potential to develop a plant combining the important turf traits of perennial ryegrass and the improved drought tolerance of Atlas fescue. The objectives of this study were to (1) investigate drought tolerance of progeny from the crossing of perennial ryegrass with Atlas fescue and (2) identify characteristics for screening under drought stress. A total of 19 genotypes were exposed to a 14-week drought treatment. Soil water content, leaf elongation, leaf water content, and leaf water potential were measured weekly, and root length and biomass were recorded after the treatment. Based on the weekly measurements of leaf elongation, leaf water content, and leaf water potential to drought stress, the plants were classified into four groups. Leaf elongation was a sensitive and helpful parameter for screening drought tolerant plants. Three groups were identified with high, moderate, and low drought tolerance based on a decrease in leaf elongation in response to declining soil water content. Some progeny in a high drought tolerant group rated better than the Atlas fescue parent. The results suggested that an improved drought tolerant perennial ryegrass could be developed through intergeneric hybridization by inheriting drought tolerance of Atlas fescue.