溶磷真菌固体发酵菌肥对玉米生长及根际细菌群落结构的影响

溶磷微生物可将土壤中难溶性磷转化为有效态磷,施用溶磷菌肥是提高土壤磷素利用率的有效措施。选取溶磷效果较好的草酸青霉(Penicillium oxalicum)NJDL-03和黑曲霉(Aspergillus niger)NJDL~(-1)2两株真菌进行土培实验,探究了溶磷真菌在石灰性土壤中的溶磷效果,揭示了经固体发酵获得的溶磷菌肥对玉米生长及根际细菌群落结构的影响。结果表明:真菌NJDL-03和NJDL~(-1)2比细菌San8溶磷效果更强,盆栽试验中NJDL-03、NJDL~(-1)2及San8菌肥处理的土壤速效磷含量分别较CK提高了4.36、5.03、0.71倍,且NJDL-03、NJDL~(-1)2、San8及Substrate等处理的玉米植株干重分别较对照增加了67.14%、67.70%、33.96%、24.04%。各处理土壤中细菌厚壁菌门(Firmicutes)的丰度较CK显著降低,真菌菌肥处理后在细菌属水平上鞘氨醇单胞菌属(Sphingomonas)、分枝杆菌属(Mycobacterium)、小囊菌属(Plesiocystis)及嗜盐杆菌属(Halotalea)等的丰度相对于CK均有显著增加,而赖氨酸芽孢杆菌属(Lysinibacillus)及溶杆菌属(Lysobacter)丰度则较CK显著降低。生物菌肥处理提高土壤速效磷含量,影响了根际土壤细菌群落结构,并促进玉米植株生长。

Effects of solid biofertilizers of phosphate-solubilizing fungi on maize growth and the bacterial community structure in rhizospheres

Phosphate-solubilizing microorganisms (PSMs) play important roles in phosphorus cycling, and can convert insoluble P into available P. The application of phosphate-solubilizing biofertilizers is an effective way to improve the P utilization of soils. In this study, two strains of Penicillium oxalicum NJDL-03 and Aspergillus niger NJDL-12, with distinct abilities of phosphate solubilization, were applied to an incubated soil sample. The P release was evaluated in the soil using abundant carbonates. In addition, the growth of maize and the bacterial community structure in the rhizosphere was studied. The results showed that NJDL-03 and NJDL-12 were more effective in solubilizing phosphorus than Enterobacter sp. San8. The results of the maize pot experiment showed that the soil availability of P for NJDL-03, NJDL-12 and San8 increased by 4.36, 5.03, and 0.71 folds, compared to CK. The dry weight of plants treated with biofertilizers NJDL-03, NJDL-12, San8, and Substrate, increased by 67.14%, 67.70%, 33.96%, and 24.04% respectively, compared with CK. The abundance of Firmicute bacteria in the soil was significantly lower than that in CK. Moreover, the populations of Sphingomonas, Mycobacterium, Plesiocystis, and Halotalea were significantly increased after the application of the biofertilizers, while for Lysinibacillus and Lysobacter, the effect was opposite. Phosphate-solubilizing biofertilizers could obviously increase the soil availability of P and promoted the growth of maize.