对一株分离自玉米植株的内生细菌R-4进行鉴定，并测试其对玉米南方锈病（SCR）的防病增产效果。用盆栽方法测定菌株R-4对玉米植株的促生效果，根据16S rDNA序列对菌株R-4进行鉴定，并采用自然发病方式测试其对SCR的防病增产效果。促生测试结果表明，菌株R-4处理玉米的发芽率、播种18d株高、播种28d株高、植株地上部干重及根干重比对照分别增加17.19%、32.03%、41.80%、92.53%和37.03%。通过16S rDNA序列分析，将菌株R-4鉴定为蜡样芽孢杆菌（Bacillus cereus）。田间试验结果表明，菌株R-4在3个玉米品种（先玉335，银糯 1号，俊单20）上对SCR的防效达39.2~92.1%（平均65.7%），经该菌处理后玉米增产2.58~9.02%（平均6.66%）。研究结果证明，R-4是一株对SCR具有防病增产效果的生防菌，在玉米可持续生产上有良好的应用前景。
英文摘要:
A bacterial endophyte R-4 isolated from the maize plant was identified, and its efficacies in controlling southern corn rust (SCR) and enhancing corn yield tested. The growth promotion effects of strain R-4 were tested using potted maize plants. The identification of strain R-4 was performed based on 16S rDNA sequence analysis. The SCR-controlling and yield-enhancing capacities of strain R-4 were evaluated using natural field disease occurrence method. In the growth promotion tests, the R-4-treated corn germination rates, 18-day-old plant height, 28-day-old plant height, dry weight of above-ground part and dry weight of roots increased by 17.19%, 32.03%, 41.80%, 92.53% and 37.03%, respectively, compared to their respective controls. Strain R4 was identified as Bacillus cereus based on 16S rDNA sequence analysis. The field trial showed that strain R4 had a control efficacy of 39.2-92.1% (av. 65.7%) against SCR on three varieties (Xuanyu-335, Yinnuo-3 and Jundan-20). The yields of the R-4-treated plots increased by 2.58~9.02% (av. 6.66%). Based on the results presented, strain R-4 is a promising biocontrol and yield-enhancing agent against SCR, and could be utilized for sustainable corn production.
;
