生防菌B1619在番茄根部的定殖及对根际微生态的影响

Root colonization by Bacillus amyloliquefaciens B1619 and its impact on the microbial community of tomato rhizosphere

采用植物MS平板定殖研究法、盆栽试验和土壤酶活性检测技术研究了生防菌B1619在番茄根部的定殖规律,并评估了B1619对番茄根围土壤微生物和酶活性的影响。结果显示,生防菌株B1619在番茄根部定殖能力较强,在MS平板中,定殖量可达108CFU/g根以上。在盆栽试验中,常规土壤中或在接种青枯菌后,番茄根部生防菌的数量都呈现先下降后上升趋势,最后趋于稳定;在第15天时,定殖量达到106CFU/g根。番茄定植后,B1619对根围土壤中真菌和放线菌具有促进作用,而对细菌则表现为先促进后抑制作用。此外,B1619能够提高土壤蔗糖酶活性而抑制土壤脲酶的活性,B1619施用后第15天,蔗糖酶活性达226.3 mg/g土,比对照高88 mg/g土;土壤脲酶活性则与对照组截然相反,呈下降趋势。

The experiments of MS plate colonization, pot experiment and soil enzyme activity detection were used to clarify the root colonization ability of Bacillus amyloliquefaciens B1619 and its impact on the microbial community and soil enzyme activity. The results showed that B1619 had excellent colonization ability on tomato roots. The amount of B1619 on roots was up to 108 CFU/g root or more in MS plate at the 15th day after seeding. In the pot experiment, the trend of colonization on root surface decreased first, then increased and finally stabilized regardless of whether there was Ralstonia solanacearum or not; the colonization quantity of B1619 was up to or near to 106 CFU/g root after 15 days of inoculation. After the application of B1619 in fields, the amount of rhizosphere soil fungi and actinomycetes was stimulated, and the bacteria were promoted firstly, and then suppressed. On the other hand, B1619 was able to increase the soil sucrase activity and decrease the soil urease activity. The soil sucrase activity after treatment of B1619 was 88 mg/g higher than that of the control, reaching 226.3 mg/g soil. The trend of urease activity after treatment of B1619 was declined compared with the control.