Effects of Potato Soil-borne Pathogen Stress on Culturable Microorganisms in Rhizosphere Soil
The effects of soil-borne pathogens on the growth and development of potato plants and the number of culturable microorganisms in rhizosphere soil were studied by artificial inoculation and dilution plate counting method.The results showed that the emergence rate,plant height,leaf SPAD value and tuber yield of potato were not affected by soil-borne pathogens.The addition of soil-borne pathogens significantly increased the incidence of potato diseases.The number of culturable microorganisms in potato rhizosphere soil increased first and then decreased during the whole growth period,and the order was bacteria>actinomycetes>fungi.The stress of scab pathogen stress can significantly increase the number of culturable bacteria and fungi in potato rhizosphere soil.Powdery scab pathogen stress can significantly increase the number of bacteria,fungi and actinomyces.The stress of bacterial wilt pathogens promoted the growth of bacteria in rhizosphere soil,but inhibited the growth of fungi and actinomyces.The incidence of potato scab and powdery scab was negatively correlated with the number of culturable actinomycetes in soil.