Effects of Drought Stress on Growth and Development of Wheat Seedlings

In this study, two wheat cultivars XM13 and AK58 under different drought tolerance were compared by evaluating seed germination, seedling growth and microstructures in order to identify the drought resistance of two wheat cultivars.Results showed that the germination of wheat seeds could be inhibited by drought stress, the germination energy significantly decreased with the increase of drought degree, and the germination energy of AK58 was significantly stronger compared with XM13.Although the root length of wheat XM13 were little influenced by drought stress, AK58 can be promoted and appeared significant differences with the control except the stress of 25% PEG6000.Along with the increase of drought degree, the volume of cortex cell in root had a trend of decline, even shrank at the stress of 15-25% PEG6000, but effect of drought stress on root growth of wheat XM13 was especially significant compared with wheat AK58.In addition, leaf area of wheat seedling decreased under drought stress, but the decreasing amplitude of wheat AK58 leaf area was greater than XM13.Further study identified that palisade tissue cell in leaf gradually became shorter and disorder, and the thickness of spongy tissue decreased, which was especially significant under the stress of 20-25% PEG6000.Compared with wheat XM13, the atrophy of endodermis cell in leaf of wheat AK58 should be later.Therefore, the drought-resistant ability of two cultivars wheat was different, and wheat AK58 might be stronger and could better adapt to drought stress compared with wheat XM13.