PGPR复合菌剂对辣椒生长及根际土壤微生物结构的影响

Effect of PGPR compound bacterial agents on growth of chilli and changes of soil microbial structure

为研究植物根际促生菌(PGPR)菌剂在田间条件下对辣椒的促生效果及其对根际土壤微生物结构的影响,以前期筛选到的4株PGPR菌株制备的复合菌剂为研究对象、辣椒为试验材料进行田间试验,分别设置了100%化肥组(CK)、100%化肥+PGPR复合菌剂组和80%化肥+PGPR复合菌剂组共3个处理,在幼苗期、始花期和坐果期对辣椒进行灌根,测定了不同处理组辣椒的株高及茎粗、产量和根际微生物的结构变化。结果表明:PGPR复合菌剂能有效促进辣椒植株增高和茎粗增加,单株产量及挂果数较100%化肥组分别增加34.14%、38.62%和47.44%、52.89%,每公顷鲜椒增产约9 000~10 000 kg。微生物菌群的结构变化表现为,PGPR菌剂灌根的处理组中,微生物总量和细菌数量显著性增加、真菌数量减少,放线菌数量则表现为盛果期显著增加;溶磷、解钾及固氮菌等功能菌群的数量总体上升,增幅不一致。表明施用PGPR复合菌剂对辣椒的促生效果显著,且影响了辣椒根际的土壤微生物结构。

In order to understand the growth promoting effects of plant growth promoting rhizobacteria(PGPR)agents on chilli under the field condition and its effect on the microbial structure of rhizosphere soil,the compound bacterial agents were prepared with four PGPR strains screened in the early studying stage,three treatments were set up,including 100% chemical fertilizer(CK),100% chemical fertilizer plus PGPR compound bacteria agents,and 80% chemical fertilizer plus PGPR compound bacteria agents.Root irrigation treated with PGPR compound bacteria agents was carried out in seedling stage,fruiting stage and full productive stage,respectively.The plant height,stem diameter,yield and the change of rhizosphere microbial structure of chilli under different treatments were measured.The results showed that:PGPR compound bacterial agents effectively promoted the increase of plant height and stem diameter of chilli.Compared with the 100% chemical fertilizer treatment,the yield per plant and the number of fruit increased by 34.14%,38.62%,47.44% and 52.89%,respectively,and the fresh chilli yield increased by about 9 000 ~ 10 000 kg/hm^2.After treated with PGPR compound bacterial agents,the total numbers of soil microorganisms and bacteria increased significantly,whereas the number of fungi decreased,the number of actinomycetes increased significantly at full productive period.The number of functional bacteria such as phosphorus-dissolving,potassium-dissolving and nitrogen-fixing bacteria increased in general,and the increase was not consistent.To sum up,the application of PGPR compound bacteria agents have a significant effect on the growth promotion of chilli and affect the soil microbial structure in the rhizosphere of chilli.