| In order to identify the drought resistance of 15 Triticosecale Wittmack lines (Z1,Z3,Z5,Z6,Z9,Z12,Z19,Z21,Z23,Z36,Z41,Z48,Z49,Z50,Z55) at the seedling stage, two triticale varieties, Gannong No.1 (CK1) and New triticale No.5 (CK2), were used as the controls. Two treatments including the normal irrigation and drought stress were set in this experiment that 30% of PEG-6000 was used to simulate the drought environment. Samples were collected at day 28 after treatment, and contents of chlorophyll (CHL), proline (Pro), soluble sugar (SS), malondialdehyde (MDA) and relative water content (RWC) in leaves of triticale materials were determined. In the meantime, according to the correlation between each index and drought-resistance coefficient, the drought resistance of triticale materials was evaluated comprehensively combined with the subordinate function. Results showed that significant differences existed in physiological parameters of triticale materials, which Z9 had the highest average RWC (77.26%), Z49 had the highest average CHL content (0.55 mg·g-1), Z1 had the highest average Pro content (0.36 mg·g-1), CK2 had the highest average SS content (113.33 mg·g-1), and Z50 had the highest average MDA content (4.05 μmol·g-1). The average RWC decreased significantly, while the average contents of CHL, Pro, SS and MDA increased significantly under the drought stress. The values of the physiological index under normal irrigation and drought stress were 82.73% and 56.11% (RWC), 0.33 mg·g-1 and 0.40 mg·g-1 (CHL), 0.13 mg·g-1 and 0.47 mg·g-1(Pro), 28.23 mg·g-1 and 116.19 mg·g-1(SS), 2.50 μmol·g-1 and 4.39 μmol·g-1 (MDA), respectively. The interaction of triticale materials and drought stress indicated that RWC decreased with that Z12 had the smallest decrease, CK1 had the largest decrease, CHL content changed inconsistently, and the contents of Pro, SS and MDA increased under the drought stress, Z12, Z19 and Z9 had the smallest increase, respectively, and CK1, Z3 and Z50 had the largest increase, respectively. Based on the comprehensive evaluation results, 17 triticale materials were divided into 5 groups according to the comprehensive evaluation value of drought resistance (D value), among which Z1, Z5, and CK1 belonged to the high drought resistance type, Z3, Z6, Z36, Z41, Z48, Z49 and Z50 belonged to the medium drought resistance type, Z21 belonged to the middle type, Z19, Z23, Z55 and CK2 belonged to the more sensitive drought type, Z9 and Z12 belonged to the sensitive drought type. Therefore, triticale variety Gannong No.1 and triticale lines Z1 and Z5 had strong drought resistance, which suitable for the semi-arid rain-fed areas. |