根围促生菌对黄瓜幼苗的促生效应与防病作用

从菜园土盆栽的黄瓜健壮幼苗根围分离出196 株细菌,用于黄瓜种子的细菌化处理,在光照培养箱中模拟自然状况,首先在平皿中培养初步筛选出30 株促进种子萌发、促进根和下胚轴伸长的菌株;之后用于无菌土盆栽测定,筛选出了能明显提高出苗率,提前出苗时间,增加株高、鲜重等具促生效果的5 株细菌:CN11,CN31,CN45,CN116 和CN129,即为根围促生菌(简称PGPR)。并将5 株PGPR 分别用于接种了引起黄瓜苗期立枯病和猝倒病的三种主要病原菌——立枯丝核菌AG4 (Rhizoctonia solaniAG4)、瓜果腐霉(Pythium aphaniderm atum )、终极腐霉(P. ultim um )后的盆栽测定,发现在促进黄瓜幼苗生长的同时也降低了发病率,与对照相比均达显著水平(P= 0.05),实验结果证明PGPR 促生作用与防病作用具有一致性。

Effect of plant growth promoting rhizobacteria on disease control of cucumber seedlings

One hundred and ninety six isolates were obtained from rhizosphere of cucumber seedlings grown in vegetable field soil. Among them, 30 isolates of bacteria were demonstrated to improve germination and to increase the length of root and hypocotyl of cucumber after seed bacterization. Then, these bacteria were used for pot testing in sterile soil. Five strains of bacteria, CN11, CN31, CN45, CN116 and CN129, largely promoted growth of cucumber seedlings, including increasing incidence of emergence, bringing forward the time of emergence, increasing seedling's height, fresh weight, dry weight and so on. These 5 plant growth promoting bacteria (PGPR) were used to test the effect of biocontrol on the cucumber Rhizoctonia rot and damping off caused by Rhizoctonia solani AG4, Pythium aphanidermatum , and P. ultimum , respectively. Results showed that while the growth of seedlings was promoted, the diseases were suppressed too.