外源IAA对小麦‘西旱2号’幼苗水分胁迫和NaCl胁迫的缓解响应

Regulation of exogenous auxin IAA on drought and salt stress during seedling stage of spring wheat(cv.Xihan No.2)

以小麦新品种‘西旱2号’为材料,研究了等渗水分胁迫、盐胁迫及水分胁迫和盐胁迫下喷施外源生长素等4种处理对小麦幼苗的生长率、组织相对含水量、根冠比、保护酶和丙二醛含量的影响.结果表明:外源生长素可以明显提高逆境中小麦幼苗的生长速率及小麦幼苗叶片的相对含水量,降低小麦幼苗的根冠比以及降低超氧化物歧化酶、过氧化物酶的活性和丙二醛的含量,说明喷施外源生长素,在一定程度上能减轻水分胁迫和盐胁迫对小麦幼苗造成的伤害,提高小麦幼苗的抗旱和抗盐能力.

In order to understand the regulation of exogenous IAA on drought and salt stress of the seedlings,spring wheat（cv.Xihan NO.2） was treated with iso-osmotic drought stress（20 % PEG6000）,salt stress（200 mmol/L NaCl） and sprayed with auxin（10-5 mol·L-1） under drought and salt stress,respectively.And then the growth rate,relative water content of organization,root-shoot ratio,protective enzymes and malondialdehyde（MDA） content of wheat seedlings were investigated.The results showed that exogenous auxin significantly enhanced the growth rate of the seedlings and the relative moisture content of leaves under drought and salt stress,the chemical also reduced the root-shoot ratio of the seedlings,activity of superoxide dismutase（SOD） and peroxidase（POD） and the content of MDA.It is suggested that exogenous IAA can alleviate drought and salt stress and effectively enhance the ability of salt-tolerance and drought resistance of the seedlings of spring wheat.