根际接种木霉对干旱胁迫下华北落叶松幼苗生长的影响

Inoculation Effect of Ectomycorrhizal Fungi on Larix principis-rupprechtii under Drought Stress

为了提高华北落叶松( Larix principis-rupprechtii )苗木成活率,采用盆栽控水模拟干旱胁迫,设置对照(CK)、轻度干旱(LD)、中度干旱(MD)与重度干旱(SD)4个水分处理,并接种木霉,测定了根际接种木霉与幼苗生长相关指标。结果表明:随干旱加剧,木霉对幼苗根部侵染率下降。接种木霉可减缓MD与SD下华北落叶松幼苗株高、针叶长、地下生物量与地上生物量降低幅度,加大LD下这些指标的增幅。与正常水分相比,干旱下接菌苗的根冠比增幅、接菌贡献率更大。故,木霉对干旱下华北落叶松幼苗的接种效应最显著,可增强其耐旱性。接种木霉可增大幼苗株高与针叶长、地下生物量与地上生物量的相关性,使针叶长与地下生物量、地上生物量与根冠比紧密相关。

For increasing the survival rate of Larix principis-rupprechtii seedlings, promoting the regeneration of tree species and improving the quality of forest resources, the potted water was used to simulate drought stress, and four water treatments including CK, LD, MD and SD were designed, and Trichoderma spp. was inoculated around the rhizosphere of seedlings to measure seedlings growth index and index about inoculating Trichoderma spp.. The results showed that as drought stress increased, the infection rate to seedlings roots decreased. Trichoderma spp. inoculation slowed down the downward trend of plant height, needle length, underground biomass and above-ground biomass of L. principis-rupprechtii seedlings under MD and SD, and increased the upward trend of these indicators under LD. Inoculation with Trichoderma spp. increased the root-shoot ratio and the inoculating contribution rate under drought stress to greater than normal water. Therefore, Trichoderma spp. had the most significant inoculation effect on L. principis-rupprechtii seedlings under drought, and enhanced its drought tolerance. Inoculation with Trichoderma spp. increased the correlation between plant height and needle length, underground biomass and aboveground biomass, and correlated the length of the needle with the underground biomass, aboveground biomass and root to shoot ratio.