林业科学Issue(6)：67-73,7.DOI:10.11707/j.1001-7488.20140609
干旱胁迫下植物根际促生细菌对侧柏生长及生理生态特征的影响
Effects of Plant Growth-Promoting Rhizobacteria on Physio-Ecological Characteristics of Platycladus orientalis under Drought Stress
摘要
Abstract
A plant growth-promoting rhizobacterium ( PGPR) was screened from plant rhizospheric soil by the bioassay methods of wheat leaf green retaining and radish cotyledon growth and isolated,and then,the PGPR was identified with molecular biology means. A pot experiment of Platycladus orientalis was conducted with controlled water supply ( control, light drought stress,moderate drought stress and severe drought stress) and the PGPR was inoculated. Effects of the plant growth-promoting rhizobacteria on dry weight,antioxidant enzyme,and endogenous hormone of P. orientalis was studied in the present research. According to the morphologic characteristics,physiological biochemical properties and phylogenetic analysis of 16S rRNA genes,the PGPR isolated in the present study was identified as Bacillus cereus. Under well-watered conditions,there was little effect of PGPR inoculation on antioxidant enzyme,osmotic adjustment substance,and lipid peroxidation products of P. orientalis. Under drought stress conditions,B. cereus inoculation increased the antioxidant enzyme activities. However,osmotic adjustment substance,and lipid peroxidation products were decreased as a result of PGPR inoculation. Regardless of the water status,the contents of indoleacetic acid,gibberellins,and zeatin in P. orientalis were significantly increased as a result of B. cereus inoculation. Besides,PGPR decreased abscisic acid content by 23. 81% under severe drought stress. The dry matter accumulation of P. orientalis was significantly improved due to B. cereus inoculation. Additionally,B. cereus inoculation promoted shoots dry matter accumulation of P. orientalis,however, it had a decreasing effect on roots dry mass accumulation with the increasing drought intensity. The results suggest that B. cereus inoculation could effectively alleviate the damage of drought stress to P. orientalis by regulating the antioxidant enzyme and osmotic adjustment substance,and stimulating some endogenous hormone production. In summary,PGPR inoculation could improve drought resistance of P. orientalis,and improve the shoot dry matter accumulation,and it would be a supplementary measure for afforestation in arid and semi-arid environment.关键词
侧柏/干旱/胁迫/植物根际促生细菌/生理生态特征Key words
Platycladus orientalis/drought/stress/plant growth-promoting rhizobacteria/physio-ecological characteristics分类
农业科技引用本文复制引用
刘方春,邢尚军,马海林,杜振宇,马丙尧..干旱胁迫下植物根际促生细菌对侧柏生长及生理生态特征的影响[J].林业科学,2014,(6):67-73,7.基金项目
山东省科技发展计划项目“山东省干旱瘠薄山地集雨造林关键技术研究”(2010GSF10621)。 （2010GSF10621）
