外源硒对白术种子萌发及幼苗生理特性的影响

The Effects of Exogenous Selenium on Seed Germination and Seedling Physiological Characteristics of Atractylodes macrocephala

硒(Se)是植物非必需营养元素,但适量的硒有利于促进植物的生长发育,因而研究硒对植物生长发育的影响具有重要意义。本研究通过不同浓度的亚硒酸钠溶液(0,2.5 mg/L,5.0 mg/L,10.0 mg/L和20.0 mg/L)对白术种子和幼苗进行处理,测定白术种子萌发及幼苗生长生理指标,并用主成分分析法综合评价硒对白术幼苗生理特性的影响。结果表明:所有Se处理对白术种子萌发没有显著影响;2.5 mg/L的Se显著提高了白术幼苗的叶绿素(Chl)含量,有效提高了白术幼苗超氧化物酶(SOD)活性、过氧化物酶(POD)活性和可溶性蛋白含量(SP)含量;5 mg/L以上的Se则会破坏白术幼苗抗氧化系统,导致SOD和CAT酶活性降低,SP含量下降,MDA含量显著上升。采用主成分分析法对Se的作用效果进行评价,结果表明,适量的Se(2.5 mg/L)可以通过提高白术幼苗的光合作用和抗氧化系统来促进白术幼苗的生长,过量的Se(≥5 mg/L)则会产生抑制作用。本试验通过设置不同浓度的硒处理,评价外源硒对白术幼苗生长发育的作用效果,初步阐明外源硒促进白术生长发育的生理机制,为白术优质高效栽培提供理论基础。

Selenium(Se)is a non-essential nutrient element in plants,but a proper amount of Se is beneficial to the growth and development of plants.Therefore,it is significant to study the effects of Se on plant growth and development.In this experiment,the physiological indexes of seed germination and seedling growth of A.macrocephala at different Se levels(0,2.5 mg/L,5.0 mg/L,10.0 mg/L and 20.0 mg/L)were determined,and which also were quantitatively evaluated by principal component analysis(PCA).The results showed that Se had no significant effect on the seed germination of A.macrocephala.2.5 mg/L Se level significantly increased the content of Chl and the activities of SOD and POD,as well as the content of SP in the seedlings of A.macrocephala.However,high Se level(5 mg/L)depressed the activities of SOD,and CAT significantly,as well as the content of SP,but the content of MDA significantly was increased.The effects of exogenous Se were quantitatively evaluated by principal component analysis.Appropriate dose of Se(2.5 mg/L)promoted the growth of A.macrocephala seedlings by improving photosynthesis and antioxidant system,while excessive Se level(≥5 mg/L)inhibited the growth of A.macrocephala seedlings.This experiment evaluated the effects of exogenous Se on the growth and development of A.macrocephala seedlings by setting different concentrations of Se.The physiological mechanism of promotion of the A.macrocephala seedlings growth by exogenous Se was preliminarily clarified,which provides a theoretical basis for high efficient cultivation of A.macrocephala.