钩状木霉与枯草芽孢杆菌在核桃根际土壤中的定殖研究

[目的]植物病害生防菌在植物根际土壤中的定殖情况是影响其发挥生防作用的重要因素之一.近年来,由核桃炭疽病菌引起的核桃炭疽病对云南省核桃产业的发展产生了较为严重的危害,已成为该省核桃产业发展的重要制约因素.前期,通过对大理州漾濞县光明村核桃根际土壤生防菌的筛选工作,获得了具有重要生防潜力的钩状木霉YB-4-15和枯草芽孢...

Colonization of Trichoderma hamatum and Bacillus subtilis in rhizosphere soil of walnut

  Objective  The colonization of plant disease biocontrol agents in plant rhizosphere soil is one of the important factors affecting its biocontrol effect. In recent years, walnut anthracnose has caused serious harm to the development of walnut industry in Yunnan Province of southwestern China, and it has posed a serious threat to the development of walnut industry in the growing areas. In the early stage, Trichoderma hamatum YB-4-15 and Bacillus subtilis yb33, which are important biocontrol agents, were obtained indoors by screening biocontrol of anthracnose on walnut in rhizosphere soil of Guangming Village, Yangbi County, Dali City. To better promote the above biocontrol agents, the colonization of the above strains in the rhizosphere of walnuts should be firstly considered.   Method  Trichoderma spore suspensions of different concentrations were applied to sterilized rhizosphere of walnuts.   Result  The colonization amount of the two biocontrol agents in rhizosphere soil was regularly measured, and it was found that after one month of mixing the biocontrol agents to the rhizosphere soil, the colonization amount of T. hamatum was 2 × 104 cfu/g at lowest level to 5 × 104 cfu/g at maximum level. At the same time, the rifampicin-resistant B. subtilis yb33-Rif was used to determine the colonization ability in sterilized soil and field soil, the colonization amount of tested bacteria ranged from 7.07 × 106 to 1.08 × 108 cfu/g, significantly lower in field soil than in sterilized soil, ranging from 1.03 × 106 cfu/g at lowest level to 7.53 × 106 cfu/g at maximum level. In addition, the two tested biocontrol agents were mixed in the rhizosphere soils of walnut, osmanthus, camphor and heather, and it was found that the two biocontrol agents were found to grow well in walnut rhizosphere soil.  Conclusion  The current study lays a solid base for future application of the two biocontrol agents in walnut fields.