盐胁迫对4个桑树品种生理生化特性的影响

Effects of Salt Stress on Physiological and Biochemical Characteristics of 4 Mulberry Varieties

以冀桑1号、冀桑2号、物45、铁把4个桑树品种的2年生嫁接苗为试验材料,分别利用0.0%(CK)、0.2%、0.3%和0.4%的NaCl溶液进行胁迫处理,研究不同桑树品种叶片膜质过氧化程度、抗氧化酶活性、渗透调节物质含量的变化,以明确其耐盐能力。结果表明,随着土壤中NaCl含量的递增,4个品种的叶片细胞膜透性迅速增加,其中铁把在各处理下的值最低且增加最慢;各品种叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性变化均呈先上升后下降趋势,并在NaCl含量为0.2%或0.3%时达到峰值;各品种的叶片脯氨酸含量不断增加,可溶性糖含量先升高后下降,可溶性蛋白含量则呈下降趋势。可知4个桑树品种均能在一定盐胁迫范围内通过自身保护酶系统和渗透调节物质积累有效降低活性氧的伤害,各项指标呈现规律性变化,且品种间差异显著。综合比较得出,4个桑树品种抗盐能力强弱为铁把>冀桑2号>物45>冀桑1号。

Two-year-old seedlings of 4 mulberry varieties,Jisang No. 1 ,Jisang No. 2 ,Wu 45 and Tieba were treated with 0.0 % （control）, 0.2 %, 0.3 % and 0.4 % NaCI solutions, respectively, to test the changes of antioxidant enzyme activity, membrane lipid peroxidation and osmotic adjustment substance to clear their salt tolerance. The results showed that：with the increase of NaCl content in soil,the membrane permeability of the leaves increased rapidly,and among the 4 varieties,Tieba had the lowest value of membrane per- meability and the slowest increament. Activities of super oxide dismutase （SOD）,peroxidase （POD） and catalase （CAT） in the leaves increased first and then decreased with the increase of NaCl stress, and reached the peak value at NaC1 concentration of 0.2% or 0.3%. With the increase of NaC1 stress,the content of proline in the leaves of all varieties increased,and soluble sugar increased first and then decreased, but soluble protein decreased. The results demonstrated that theadverse effects of reactive oxygen species to the 4 mulberry varieties were effectively reduced by their protective enzyme system and by osmotic ad- justment substance accumulation within a certain range of salt stress （〈0.3%） ,the indicators showed regular changes, and the difference was significant. Comprehensive comparison resulted the order of salt-resist- ant ability of the four mulberry varieties was Tieba〉 Jisang No. 2〉Wu 45〉 Jisang No. 1.