外源微生物对木麻黄幼苗生长和土壤微生物群落的影响

将解淀粉芽孢杆菌(YB706)和伯克氏菌(BK8)外源添加至木麻黄盆栽苗中,运用Biolog生态板和磷脂脂肪酸(PLFA)技术,探究外施细菌能否改善连栽木麻黄土壤养分和微生物群落及植株生长。结果表明:与空白处理(CK)相比,YB706和BK8处理的木麻黄盆栽苗土壤碱解氮、速效磷显著增加,土壤全氮、全磷、全钾和速效钾无明显变化,幼苗株高分别增加59.1%和63.9%,BK8处理叶绿素含量提高81.9%。各处理平均颜色变化率(AWCD)呈现YB706>CK>BK8;除氨基酸类外,土壤微生物对不同碳源的利用率也表现为YB706>CK>BK8;经YB706和BK8处理的土壤微生物种类和数量均显著增加,除放线菌外,各类微生物PLFA总含量均为BK8>YB706>CK,与CK相比,土壤真菌/细菌有所提高。YB706和BK8处理的土壤微生物群落Simpson、Shannon、Brillouin和McIntosh指数均显著提高。表明外施YB706和BK8可促进木麻黄幼苗生长,且显著增加土壤速效养分含量,提高土壤微生物群落结构多样性,改善土壤微生物环境。

Effects of exogenous microorganisms on seedling growth and soil microbial community of Casuarina equisetifolia

With a pot experiment, the Biolog microplate and phospholipid fatty acid (PLFA) technology were used to explore whether the application of bacteria, Bacillus amyloliquefaciens (YB706) and Burkholderia (BK8), could improve the soil nutrient, microbial community and growth of Casuarina equisetifolia. The results showed that the concentrations of soil alkali-hydrolyzed nitrogen and available phosphorus of C. equisetifolia treated with YB706 and BK8 increased significantly compared with the control (CK), but the concentrations of total nitrogen, total phosphorus, total potassium and available potassium changed little, plant height increased by 59.1% and 63.9%, respectively, and the chlorophyll content of plant treated with BK8 increased by 81.9%. The average well color development values showed a pattern of YB706>CK>BK8. The utilization rate of different carbon sources showed the same trend except the amino acids. Both YB706 and BK8 treatments significantly increased the richness and quantity of soil microorganisms. The PLFA of all kinds of microorganisms was BK8>YB706>CK except actinomycetes. The ratio of soil fungi to bacteria was increased compared with CK. The Simpson, Shannon, Brillouin and McIntosh indices of rhizosphere soil microbial community in YB706 and BK8 treatments were significantly increased. Our results suggested that application of YB706 and BK8 could improve the growth rate of C. equisetifolia seedlings, effectively increase the contents of soil available nutrients, increase soil microbial diversity, and improve soil microbial environment.