太子参连作对根际土壤微生物的影响

Effects of Pseudostellariae heterophylla continuous cropping on rhizosphere soil microorganisms

采用微生物培养法和末端限制性片断长度多态性(T-RFLP)技术分析连作对太子参根际土壤微生物多样性的影响。结果表明:连作导致太子参根际土壤细菌和好气性自生固氮菌数量极显著下降,相反,真菌、放线菌、厌气性纤维素分解菌数量极显著增加,而硝化细菌数量变化不显著。T-RFLP分析显示:与太子参-水稻-太子参轮作的土壤相比,太子参连作的土壤细菌种(属)略有减少,其中致病菌和病原菌种(属)增多,并出现一些具拮抗功能的链霉菌属(种);真菌种(属)则表现出上升的趋势,但未检索到与植物致病相关的真菌种(属)。

By adopting microbiological culture method and terminal restriction fragment length polymorphism （T-RFLP） technique, this paper analyzed the effects of Pseudostellariae heterophylla continuous cropping on the microbial community structure in the rhizosphere soil. Compared with the rotation system of P. heterophylla-rice-P. heterophylla, the P.heterophylla continuous cropping led to a significant decrease of the amounts of bacteria and aerobic nitrogen-fixing bacteria in rhizospheric soil, but increased the amounts of fungi, actinomycetes, and anaerobic cellulose-decomposing bacteria significantly. No significant change was observed in the amount of nitrifying bacteria. Under P.heterophylla continuous cropping, soil bacterial species （genus） had a slight decrease, in which, the pathogenic and nosogenetic bacteria species （genus） increased, and some Streptomyces genus （species） with antagonistic function were found. The fungi species （genus） had an increasing trend, but none of the plant pathogenic fungi species （genus） was observed.