Evaluation Of Wheat Cultivars For Drought Resistance During Germination And Screening Of Plant Growth Regulator In Southwest Area

A hydroponic experiment was conducted to measured the germination characteristics and seeding morphologyical indexes of 41 wheat varieties in southwest bred and 21 kinds of plant growth regulator under PEG stress, Analysis the effcct of drought resistance of different wheat varieties and plantgrowth regulator in germination of wheat,On this basis,the big drought resistance of different as material,physiologi-cal response of wheat to drought stress during seed germination period and effect of plant growth regulator seed soaking on germination physiological characteristics in wheat seed, the main research results are as follows:1. Compered with normal condition,the radicle number were decreased except for Xikemai 5,Chuanmai 104 and the germination potential, germination rate, germination index, seeding heighr,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,Mianmai228, Mianmai 37, Chuanmai 104 and Neimai 316 had the higher D values;Chuanmai 55,Shumai 969, Chuanmai 42,Yunmai 53,Mianmai 1403 had the lower D values. Clustering analysis indicate that the 41 varieties could be classified as:five of highly resistant(Level 1, e.g. Shuwan8 and Mianmai37,etc.), thirteen of drought resistant varieties (Level 2, e.g. Chuanmai 60, Changmai 30, etc.), ten moderate resistant varieties(Level 3,e.g. Neimai 9,Chuanmai 43,etc.), eight sensitive varieties (Level 4, e.g. Mianyang26, Shumai482), five highly sensitive varieties (Level 5, e.g. Chuanmai 55, Chuanmai 42,etc.). Besides, except for radicle length, the other indexes showed significant positive correlation with the weighted membership function value(.Dvalue), among which germination rate and germination index had the highest correlation coefficients with D-value(0.87).2. The contents of soluble sugar, soluble protein, malondialdehyde increased significantly with the increase of drought stress in germination priod of different wheat varieties.Seed relative water absorbing rate decreased, chlorophyll content firstly increased, then decreased.Different types of varieties had different seed relative bibulous rate, chlorophyll content, soluble sugar content, free proline content is highly strong drought resistance wheat varieties compared with variety is highly sensitive to water stress.Malondialdehyde content show is highly sensitive to water stress of wheat varieties is higher than the height of drought resistance varieties.3. Most of the plant growth regulator could increase in wheat germination drought resistance under PEG stress.The performance for germination potential, germination rate, germination index, seeding height, coleoptile length, radicle length, radicle number, root-shoot ratio,storage transport rate were increase, different plant growth regulator on wheat germination drought resistance ability of adjusting the degree there are some differences.Different degree regulation and control of plant growth regulator is different in wheat germination drought resistance. By the weighted method of subordinate function analysis, comprehensive evaluation value (D value) in the top five plant growth regulator is:ethrel, fulvic acid, choline chloride, gibberellin, indole butyric acid, naphthalene·acetic acid. The correlation analysis results show that each index and the D value were significantly or extremely significantly positive correlation except of radicle length, root-shoot rate. seeding height has largest correlation coefficient (0.80), the germination potential, the germination rate, germination index, seeding height, coleoptile length, radicle number, storage transport rate is more reliable than radicle length, root-shoot rate. We propose that every index except of radicle length, root-shoot rate can serve as the rapid identification index for soaking seeds with plant growth regulator during germination stage.4. Under PEG stress, ethephon seed treatments significantly improved the wheat seedlings chlorophyll, soluble sugar and free proline content, malondialdehyde content to remain in a lower level, so as to improve the drought-resistant ability of wheat germination period; Seed soaking concentration to 200 mg/L is preferred.