Germination Characteristic Under Drought Stress And Evaluation Of Drought Tolerance Of Soybean Varieties

To investigate effects of drought stress on germination index of different drought resistance soybean cultivars,85 soybean cultivars were used from Liaoning province and from Shanxi province.And polyethylene glycol(PEG-6000)as a penetrant to simulate the drought stress to carry out the seed germination test.To explore the effect of drought stress on soybean germination index of different drought tolerance,and identify soybean varieties with different drought tolerance.According to the identification and screening results,three soybean varieties with strong drought tolerance and drought tolerance were selected to compare the seed coat structure.The relationship between soybean grain traits and drought tolerance was analyzed.Trying to provide a theoretical reference for soybean drought-resistant breeding and production,Results are listed as the following1.Germination indexThe rate of water absorption,under drought stress,the declines of Fendou 62,Jindou 21,Liaodou 13 and Jindou 19 were relatively small;Tifeng 34,Liaodou 31,Shennong 19 and Liaodou The water absorption rate of No.15 decreased greatly.Germination potential and germination rate,under drought stress,Tidou54?Liaodou38?Tiedou50?Liaodou32?Liaodou55?Liaodou29?Liaodou28?Liaodou3.The decrease rate of Tiefeng38,Qidou62,Jindou19 and Jindou21 is small;Liaodou16,Shennong19,Shennong16,Liaodou34,Liaodou12,Liao Bean15,Tiefeng27,Tiefeng42,Tiefeng34,and Liaodou42 had a large reduction.Root length,drought stress and control ratios,Liaodou32,Liaodou29,Liaodou19,Tiefeng38,and Tidou52 were all reduced.Liaodou16,Shennong10,Shennong17,Shennong 6,Shennong19,and Shennong16 had significant reductions.2.Comprehensive Evaluation of Drought Tolerance during Soybean GerminationAccording to the comprehensive evaluation results of the membership function values,13 drought resistant varieties were identified and screened in order of: Tiedou54,Jindou21,Liaodou32,Fendou62,Tiedou50,Liaodou29,Liaodou55,Tiedou53,Liaodou3,Jindou19,Liaodou28,Tiefeng38,and Shennong20;12 non-drought-tolerant varieties,namely Shennong19,Liaodou16,Liaodou34,Liaodou39,Tiefeng42,Liaodou15,Liaodou12,Shennong16,Liaodou25,Tiefeng29,Liaodou11 and Liaodou42.3.Seed coat structureThe thickness of the barrier layer of the drought-tolerant soybeans Tidou54,Jindou21,and Liaodou32 is greater than that of Shennong19,Liaodou16 and Liaodou15 that are not tolerant to drought,and drought-tolerant soybeans.The contents of the barrier layer are more dense,and the columnar cell layer is more compact.The ratio of the thickness of the barrier layer to the thickness of the columnar cell layer is large.The drought-resistant varieties are the opposite.4.Relationship between soybean grain traits and drought toleranceThere was a significant negative correlation between 100-grain weight and drought tolerance;the ratios of barrier layer thickness,barrier layer thickness,and columnar cell layer thickness were significantly positively correlated with drought tolerance;protein content was significantly negatively correlated with drought tolerance.Bulk density and fat content were not related to drought tolerance;varieties with small 100-grain weight and the ratio of seed coat barrier layer thickness,seed coat barrier layer thickness,and columnar cell layer thickness were more resistant to drought at the seed germination stage.