Abstract:

Twenty rice varieties with different drought resistance (DR) in the field were selected to be revaluated on the DR degree using the identification method with soil moisture gradient. After 24 days drought stress treatment, the soil water contents in normal irrigation and drought stress treatments were 42.0% and 7.9%, respectively. The results showed that both normal irrigation and drought stress treatments in the same field were achieved at the same time. These varieties were classified into five groups based on drought index. According to drought index and major agronomic performance, five “marker variety” were selected: IR55459-05 (high resistance), MARAVILHA (resistance), MONOLAYA (medium resistance), IR30358-084-1-1 (medium susceptible) and IR7790-18-1-2 (susceptible). The marker varieties and the standard DR screening process can be used as a reference rice drought resistance studies and breeding in the future.

Key words: Cultivated rice, Drought resistance identification, Moisture gradient, Marker varieties