Drought Resistance Of Different Wheat Cultivars And Physiological Response To Drought Stress

With the global climate change,the frequency of extreme weather in the wheat growth period is increasing year by year.To explore the physiological response of different winter wheat cultivars to drought stress,six wheat cultivars widely planted in Henan were used to study their morphological indicators,physiological indexes,yield and the three factors of yield.We set two varieties PEG treat: A1(PEG concentration 100 g · L-1,10%)and A2(PEG concentration 200 g · L-1,20%)and three kinds of irrigation treatment: Full quantity of water(1050m3·hm-2);half quantity of water(450m3·hm-2)and no irrigation.The main results of this paper are as follows:In the PEG-6000 conditions,the plant height of different wheat varieties was significantly decreased,the degree of inhibition increased with the increase of the degree of stress.Among them,the plant height of ZM 26 affected by the most serious.Under the condition of mild stress,the root length of winter wheat has been obviously inhibited,and it can be seen that the root system of winter wheat is more sensitive to water stress.With the increase of stress,the root length of each cultivar was inhibited.With the increase of the degree of stress,the number of root changes did not appear this law.The effects of water stress on fresh weight and dry weight of winter wheat cultivars were higher than those of winter wheat cultivars.The contents of chlorophyll in wheat cultivars increased with the increase of water stress,and the chlorophyll content of leaves of HG35,KM21 and AK58 seedlings increased under mild water stress,and the contents of XN979,ZM366 and ZM26 seedlings The content of chlorophyll in leaves was lower than that in(CK),and the content of chlorophyll in leaves of other cultivars was lower than that of(CK)under severe stress.leaf relative water content(RWC),plant height and leaf area decreased significantly under drought stress.The activity of peroxidase(POD),catalase(CAT)decreased less of HG 35 and KM21 than ZM366 and ZM26 under drought stress.The increasing of(MDA)content also showed the same trend.At the same time,effective spike number,grain number,and yield of wheat decreased under drought stress.Besides,the impact of drought stress on effective panicle number and grain number more serious compared to other investigated indexes.The decreasing level of Wheat leaf relative water content,plant height,leaf area,dry matter accumulation,POD activity and increasing level of MDA caused by drought stress were both significantly and negatively correlated with drought-resistant index or drought-resistant coefficient.In six wheat varieties,HG 35 and KM21 belong to strong drought-resistant wheat cultivars,XN 979 and AK58 belong to moderate drought-resistant of wheat cultivars,ZM366 and ZM26 belong to drought-sensitive wheat cultivars.