| Drought at germination is a main factor limiting wheat emergence. The objectives of this study were to screen strong drought resistance wheat varieties for mechanical sowing in the southwest hilly areas and provide some identification index for drought resistance breeding. A hydroponic experiment was conducted to measure the germination potential,germination rate,germination index,seeding height,coleoptile length,radicle length,radicle number of 41 wheat varieties under simulated drought stress with 20% PEG-6000,and the comprehensive evaluation for drought resistance of each variety was conducted by weighting the membership functions and cluster analysis. The results suggested that: compared with normal condition,the radicle number were decreased except for Xikemai 5,Chuanmai 104 and the germination potential,germination rate,germination index,seedling height,coleoptile length,radicle length were all decreased to different extent for the diverse varieties under 20% PEG-6000 simulation stress. Weighted membership function analysis showed that Shuwan 8,Mianmai 228,Mianmai 37,Chuanmai 104 and Neimai 316 had higher D values; clustering analysis indicated that the 41 varieties could be classified as: five with highly resistant (Level 1,e.g. Shuwan 8 and Mianmai 37,etc.),thirteen with drought resistant (Level 2,e.g. Chuanmai 60,Changmai 30,etc.),ten with moderate resistant (Level 3,e.g. Neimai 9,Chuanmai 43,etc.),eight with sensitive (Level 4,e.g. Mianyang 26,Shumai 482) and five with highly sensitive (Level 5,e.g. Chuanmai 55,Chuanmai 42,etc.). Besides,except for radicle length,the other indexes showed significant and positive correlation with the weighted membership function value (D value),among which germination rate and germination index had the highest correlation coefficients with D value(0.87),which could be served as the rapid identification index for wheat drought tolerance during germination stage in Southwest area. The three highly drought tolerant varieties (Suwan 8,Mianmai 37 and Mianmai 228) can be used to further research for drought tolerance mechanism and be served as germplasm resource for drought tolerance breeding. |
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