Screening of microorganisms promoting rhizosphere growth in dragon fruit
A strain of Trichoderma and a strain of Bacillus were screened from the rhizosphere soil of dragon fruit(Hylocereus undulates Britt.&Rose)using nitrogen fixation,phosphorus solubilization,potassium solubilization,and IAA production media.The growth promoting effect of their fermentation broth on dragon fruit was determined through pot experiments.The results showed that strains F6(Trichoderma ghanense)and B3(Bacillus velezensis)were screened from the rhizosphere soil of dragon fruit,which had the ability to dissolve phosphorus and potassium,fix nitrogen,and produce IAA.Among them,F6 had the highest ability to fix nitrogen and produce IAA,while B3 had the highest ability to dissolve phosphorus and potassium.Inoculation with microbial agents significantly improved the agronomic traits of dragon fruit.The combined microbial agents(B3+F6)had the most significant effect,increasing the fresh weight by 33.09%and the dry weight by 23.11%.Inoculation with microbial agents can improve soil fertility,significantly increase the contents of available phosphorus,available potassium,and organic matter in the soil.Compared with CK treatment,inoculation with a single strain B3 or F6 increased the available phosphorus content by 14.49%and 9.9%,the available potassium content by 10.4%and 16.47%,and the alkaline nitrogen content by 25.85%and 14.35%,respectively,whereas the inoculation of the mixed strains B3+F6 increased the contents of available phosphorus,available potassium,and organic matter by 37.02%,12.64%,and 16.77%,respectively.Correlation analysis between soil physicochemical properties and growth promoting indicators of dragon fruit shows that under the inoculation with the combined microbial agents the content of soil available potassium is significantly positively correlated with the fresh weight and dry weight of dragon fruit above ground,as well as the accumulation of nitrogen,phosphorus,and potassium in dragon fruit.It can hence be concluded that inoculation with the combined microbial agents(B3+F6)has a significant improvement effect on the fresh and dry weight of the above ground parts of dragon fruit,as well as the root system of dragon fruit.The combined microbial agents have a synergistic effect on the accumulation of nutritional elements,nitrogen,phosphorus and potassium,in dragon fruit,and also has the effect of improving soil fertility.
NETL
NSTL
万方数据
