二氢茉莉酮酸甲酯对高羊茅幼苗生长及抗旱性的影响

Effects of methyl dihydrojasmonate on seedling growth and drought resistance in tall fescue

采用100、200和400 mg.L-1二氢茉莉酮酸甲酯(MD J)对草坪草高羊茅幼苗进行叶面喷施处理。结果表明:MD J对高羊茅株高有抑制作用且具有浓度效应;100和200 mg.L-1MD J在处理前期抑制地上部鲜重,但处理16 d后地上部生物量与对照无显著差异。100和200 mg.L-1MD J处理12 d或400 mg.L-1MD J处理8 d后,高羊茅叶片叶绿素含量显著降低;MD J也显著抑制高羊茅的根鲜重,但不影响根的伸长;在干旱胁迫下,MD J处理可提高叶片的相对含水量及抗氧化酶(SOD、CAT和POD)活性,降低叶片电解质渗透率,增强高羊茅幼苗的抗旱性。

Tall fescue seedlings were foliary sprayed with methyl dihydrojasmonate （MDJ） at concentrations of 100, 200, 400 mg ·L-1. The results showed that MDJ inhibited the plant height of tall fescue seedlings in a dose-dependent manner. Above- ground biomass decreased in the prophase of 100 and 200 mg ·L-1 MDJ treatment, but had no obvious difference between MDJ- treated seedlings and the control after 16 days. Leaf chlorophyll content significantly decreased 12 days after the treatment of 100 and 200 mg ·L-1 MDJ, or 8 days after 400 mg ·L-1 MDJ treatment. MDJ inhibited the root weight, but had no significant effect on root elongation. Under drought stress, MDJ increased both the relative water content and the activities of antioxidant enzymes such as superoxide dismutase （SOD）, catalase （CAT） and peroxidase （POD）, and decreased the electrolyte permeability in tall fescue leaves. Therefore, MDJ treatment can enhance drought resistance of tall fescue seedlings.