Drought Resistance under PEG-6000 Stress during Germination of Onobrychis viciifolia (Sainfoin) from Different Regions of China

Background: Sainfoin (Onobrychis viciifolia) is a nutritious perennial leguminous herb with strong resistance to stress and is a valuable livestock forage and ecologically beneficial crop. It grows in many Chinese provinces, where its stress resistance varies due to different ecological environments. This study aimed to evaluate drought resistance during germination of sainfoin from different regions. Methods: The registered sainfoin variety Onobrychis viciifolia cv. Mengnong was used as a control andaqueous solutions of PEG-6000 (0-20%) were used to simulate drought stress in wild varieties collected from seven regions of China. Seed germination characteristics were determined andthe drought resistance of each variety was comprehensively evaluated using membership function analysis. Result: As PEG-6000 concentration increased, germination indices initially increased then decreased, showing that mild drought stress was conducive to the germination of sainfoin. Calculation of comprehensive drought resistance coefficients revealed that sainfoin from Shizuishan City exhibited strong drought resistance, those from Hami City and Jiuquan City showed medium resistance, the registered cultivar Mengnong and varieties from Ejin Banner and Yulin City were weakly resistant, while samples from Kunming City were non-resistant.