烯效唑(S3307)对干旱胁迫下薏苡幼苗生长及生理特性的影响

摘要

薏苡(Coix lachryma-jobi)是一种药食兼用的作物,干旱是限制薏苡种植和生长最为主要的因素.为探讨烯效唑(uniconazole,S3307)在薏苡苗期抗旱方面的应用效果,本研究采用营养液水培法,以薏辽5号为材料,研究在温室条件下,外源S3307对干旱胁迫下薏苡生长指标、抗氧化酶活性、叶绿体含量及超微结构的影响.结果表明,9 mg/L S3307显著提高了干旱胁迫下薏苡幼苗的茎粗和生物量(P＜0.05).茎粗比干旱组(S0)提高了16.19％,地上、地下生物量比S0分别提高了19.56％和22.75％.另外,9mg/L S3307组中,过氧化物酶(peroxidase,POD),过氧化氢酶(catalase,CAT)和超氧化物歧化酶(superoxide dismutase,SOD)活性显著增加(P＜0.05),其中根系的抗氧化酶活性要显著高于叶片(P＜0.05).在所有处理组中,9 mg/L S3307组中叶绿体含量最高,比干旱组增加7.35％ (P＜0.05).同时,S3307能够减轻干旱胁迫下对叶片和根系细胞超微结构的影响;9 mg/L S3307能够有效减轻干旱胁迫对薏苡幼苗的伤害.研究结果为明确S3307缓解薏苡抗旱能力的生理机制提供了基础资料,同时为S3307在薏苡抗性生产中的应用提供理论依据.%Coix (Coix lachryma-jobi) is a kind of medicine and food crop,while drought is the most main factor limiting its growth.To explore the applicative effects of uniconazole (S3307) on coix seedlings under drought stress,the growth parameters,anti-oxidant enzyme activities,chlorophyll content and chloroplast ultrastructure in Yiliao No.5 under drought stress were investigated through nutrient solution cultivation in greenhouse.The results showed that the stem diameter and ground biomass were significantly improved with 9 mg/L S3307 under drought stress (P＜0.05).Compared with the S0 (drought group),stem diameter were increased for 16.19％,and the above-ground and under-ground biomass increased for 19.56％ and 22.75％,respectively.The activities of peroxidase (POD),catalase (CAT) and superoxide dismutase (SOD) were significantly enhanced (P＜0.05),while POD and CAT activities of roots were higher than those of leafs.Total chlorophyll content in the S3 (9 mg/L S3307 group) was the highest in all the treatments,which was increased by 7.35％ compared to S0 (drought treatment group) (P＜0.05).Meanwhile,S3307 addition could improve chloroplast and root cell ultrastructure and lighten the damage to grana ultrastructure under drought stress,which was consistent with increasing chlorophyll content.All the analysis showed that 9 mg/L S3307 concentration was effective on alleviating the injury of coix seedlings under drought stress.This study can clarify physiological mechanism of coix drought resistance and provide a theoretical basis for S3307 in coix production and practice of drought resistance.