Studies on drought tolerance in durum and genotype-environment interaction

摘要

Hydric status, energetic status (chlorophyll fluorescence), and osmoregulation (proline and soluble sugars) were studied. The analysis of yield stability showed three major varietal groups: wide adaptation, intermediate adaptation, and narrow adaptation. Varieties Bidi 17, GG Rkhem, Gloire de Montgolfier, Montpellier, and Oued Zenati had low yield and low response to favorable conditions. Mexicali, Vitron, Waha, and ZB/Flg showed high yield and linear response to favorable conditions. Capeiti, INRAT 69, Polonicum, and Sahel showed stable yield. Yield was found to be negatively correlated with the sensitivity index to environment constraints (ISCE). Vitron was identified for favorable areas. Bidi 17 for unfavorable areas, and Polonicum, INRAT 69, and Capeiti for moderate water-stress areas. Stress physiological traits, water status, energetic status, and osmoregulation contribute to varietal adaptation. The use of contrasting models was proposed: (1) Hedba 3 (low values for proline and fluorescence) and Stork (high values for proline and fluorescence); (2) Hedba 3 (low value for proline) and Waha (high value for proline); (3) Bidi 17 (high values for proline and psi, low yield) and Waha (high value for proline, low value for psi, high yield); (4) Polonicum (low values for proline and psi, low yield) and Stork (high values for proline and psi, high yield). Results showed a consistent relationship between groups in terms of physiological traits and expressed yield stability. Chlorophyll fluorescence was found to have transgressive ingeritance. The other physiological parameters have intermediate heritability. Analytical and synthetic approaches were proposed to identify drought-resistant varieties.