不同氮磷条件下施加促生菌对多花黑麦草生长的影响

为进一步筛选适于田间条件的根际促生菌(PGPR),从豆科和禾本科植物根际分离出活性较强的3株固氮菌(C1、C2、C3)和3株溶磷菌(P1、P2、P3),经16S rRNA基因序列分析后,接种于多花黑麦草品种邦德,并探讨在单一固氮菌替代50%氮肥、单一溶磷菌替代全磷以及固氮菌和溶磷菌的不同组合替代50%氮肥+无磷三种条件下多花黑麦草生物量、氮磷含量的变化。结果表明:分离的溶磷菌为肠杆菌属和假单胞菌,固氮菌为伯克霍尔德氏菌和芽孢杆菌,都是较好的益生菌种,固氮酶活性在131.20~135.48IU/L之间,溶磷量在239.84~287.44μg/mL之间。施入单一菌剂的多花黑麦草生物产量、氮磷含量以C2和P2表现最佳;施组合菌肥的多花黑麦草生物量、全N及全P含量比无菌肥组对照显著提高(P<0.05),比施单一菌肥效果好,综合分析表明P3+C1和P1+C1促生效应最佳,应用潜力最大。

Effects of Growth-promoting Bacteria on the Growth of Lolium multiflorum under Different Nitrogen and Phosphorus Conditions

In order to further screen the rhizosphere growth-promoting bacteria(PGPR)adapted to field conditions,three strains of nitrogen-fixing bacteria(C1,C2,C3)with strong nitrogenase activity and three strains of phosphorus-solubilizing bacteria(P1,P2,P3)with phosphorus-dissolving activity were isolated from the rhizosphere of legumes and gramineous plants.After 16S rRNA gene sequence analysis,inoculated into Italian ryegrass(Lolium multiflorum L.cv.Bond)for investigating the changes of biomass,nitrogen and phosphorus content of L.multiflorum under conditions of single nitrogen-fixing bacteria replacing 50%nitrogen fertilizer,single phosphorus-solubilizing bacteria replacing total phosphorus,and different combinations of nitrogen-fixing bacteria and phosphorus-solubilizing bacteria replacing 50%nitrogen fertilizer and no phosphorus.The results showed that the isolated phosphate-dissolving bacteria were Enterobacter,and Pseudomonas,and the nitrogen-fixing bacteria were Burkholderia and Bacillus,both of which were all good probiotics.The nitrogenase activity was 130.20~135.48IU/L,and the phosphorus solubilization was 239.84~287.44μg/mL.The biomass yield,nitrogen and phosphorus contents of Lolium multiflorum with C2 and P2 treatment were the highest(P<0.05).The biomass yield,total N and P contents of Lolium multiflorum with combined bacterial fertilizer were significantly higher than those of the control group(P<0.05),which is more effective than applying a single bacterial fertilizer.Comprehensive analysis showed P3+C1 and P1+C1 has the best growth-promoting effect and the greatest application potential.