Abstract:

In order to explore the physiological mechanism of oat salt tolerance and screen excellent germplasm, aiming to provide a theoretical basis for saline land management and variety breeding, a total of 300 core oat germplasms were used as test materials. Six physiological indexes of seedlings were measured by K-means classification combined with salt stress treatment, and the comprehensive salt tolerance was evaluated by membership function method. The 300 varieties were divided into 4 categories, and 20 extreme materials were selected for verification. The MDA content in the aboveground part of the salt-sensitive variety (‘Qingyongjiu 786’) increased by 77.88%, while the MDA content in the underground part of the extremely salt-tolerant variety (‘Hummer’) decreased by 74.22%. The proline content of the salt-tolerant variety (‘Qingyan No.1’) increased by 2329.36%, and the activities of SOD and POD were significantly enhanced, showing excellent physiological regulation ability. The salt tolerance of oats was positively correlated with the maintenance of antioxidant enzyme activity and the accumulation of proline. Finally, three extremely salt-tolerant core germplasms, including ‘Hummer’, ‘Qingyongjiu 461’ and ‘Qingyongjiu 491’, and three salt-sensitive core germplasms, including ‘Taiyangshen’, ‘Qingyin No.2’ and ‘Beile No.2’, were identified. These identified germplasms provide valuable genetic resources for further analysis of oat salt tolerance mechanism, molecular breeding and efficient utilization of saline-alkali land.

Key words: oats, salt stress, physiological indicators, salt tolerance evaluation, core germplasm, screen