【摘要】 在温室砂培条件下,研究了钾营养对NaCl胁迫下不同基因型小麦幼苗生长、植株可溶性糖、丙二醛(MDA)含量及几种抗氧化酶活性的影响。结果表明,100 mmol/L NaCl胁迫下,施入51~0 mmol/L K+可提高小麦幼苗茎叶及根的生长及含水量;耐盐品种DK961可溶性糖含量随外界K+浓度的提高出现先升高后降低的趋势,而盐敏感品种JN17则随溶液K+浓度的提高一直降低;两品种电解质外渗量及MDA含量都比对照增加,但随外界K+浓度的升高呈现先降低后升高的趋势,以10 mmol/L K+时最接近对照;两品种超氧物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性随外界K+浓度升高都是先升高后降低,以Na+/K+比值为10∶1最好,并且对POD活性的影响更显著。表明根据NaCl胁迫程度不同,按Na+/K+比值为10∶1的比例施用钾肥可最大限度地降低NaCl胁迫对小麦幼苗造成的伤害,促进小麦生长。更多还原

【Abstract】 The effects of potassium nutrition on the growth,soluble carbohydrate content,electrolyte leakage and MDA content,and the activities of antioxidant enzymes of different genotypes wheat seedling were investigated under NaCl(100 mmol/L) stress using sand cultivation under laboratory conditions.The results indicated that application 510 mmol/L K+,could increase the growth of shoots and roots and water content,and consequently alleviated the intimidation of salt.The soluble carbohydrate content in salt tolerant variety(DK961) was increased with the increasing of the K+ concentration at the earlier stages,but decreasing at the later stages.However,it was decreased in the whole stages for the salt sensitive variety(JN17).The electrolyte leakage and MDA content was similar with CK of two varieties under 10 mmol/L K+ treatment.The antioxidant enzymes activities in both varieties were firstly increased to a peak value and then declined afterwards.The activity of POD was more significantly affected by K+ concentration than that of CAT.In conclusion,proper ratio of Na+/K+ in the exoteric solution could alleviate the negative impact of salt stress on wheat seedling.Base on the result,the ratio of Na+/K+ 10∶1 was recommended.更多还原