Dynamic Analysis Of Fusarium Oxysporum F.sp.cubense Race 4 In Different PH And Organic Soils

Banana(Musa spp),one of the most popular fruit in the world,is the fourth largest food crop in the world,after rice wheat and corn.However,the booming banana industry is subject to devastating disease,the Fusarium wilt of banana which is caused by Fusarium oxysporum f.sp.cubense(Foc).Understand the reasons for bananas in banana wilt dynamic changes of soil bacteria and related microorganisms in different soil pH and organic matter in the analyzed all kinds of changes,has become one of the urgent problems.In this study,real-time quantitative PCR was used to detect and analyze soils with different pH and soil with different organic matter content,and the contents of pathogens and microorganisms in different time periods changed.The main results are as follows:(1)Different pH gradient settings(4.5、5.5、6.5、7.5、8.5)in natural soils and sterilized soils,the quantity of Foc4 was significantly lower under alkaline treatment than under acidic treatment.There was no significant difference in soil entrainment between pH7.5 and pH=8.5 at 75 d,which was significantly lower than other treatment groups.The decline efficiency of Foc4 from 15 days after inoculation in natural soil and sterilized soil was 19% and 14% higher than that of alkaline treatment.It shows the basic process of the soil can be Foc4 content in soil banana play a significant inhibitory effect.(2)Different pH gradient settings(4.5、5.5、6.5、7.5、8.5)in natural soils and sterilized soils,at 75 d after inoculation,the number of cultivated actinomycetes and bacteria in the pH=7.5 and pH=8.5 soil treated was not significantly different,significantly higher than other treatments.The amount of culturable actinomycetes can be cultured was 1.76,2.87 and 4.39 times of pH 6.5,pH5.5 and pH4.5,respectively.And the number of culturable bacteria was 1.34,2.00 and 2.288 times of pH 6.5,pH5.5 and pH4.5,respectively.(3)The soil with different organic potassium addition(16 g/kg,32 g/kg,64 g/kg,96 g/kg),the amount of Foc4 was significantly lower than that without added blanks in 30 d after inoculation.And the amount of soil bacteria decreased with the increase of organic matter addition.After inoculation 30 days,falling efficiency of Foc4 in soil with different organic potassium addition(16 g/kg,32 g/kg,64 g/kg,96 g/kg)was 11%,9%,8%,13% higher than blank treated,respectively.Moreover,the greater the amount of organic matter added,the higher the efficiency of falling efficiency for Foc4.(4)Quantitative analysis of culturable bacteria and actinomycetes in soils with different organic matter additions(16 g/kg,32 g/kg,64 g/kg,96 g/kg).The results showed that the number of colonies of culturable bacteria and actinomycetes treated with different organic matter was significantly higher than that of CK treatment;and with the increase of organic matter,the number of colonies of culturable bacteria and actinomycetes increased,and with the passage of time,this difference is more and more obvious;while the amount of fungi in the soil decreases with time and the amount of organic matter added.This indicates that the increase of organic matter content in the soil has an inhibitory effect on the growth and reproduction of Fusarium oxysporum in the soil.This inhibition may be related to the number and types of culturable bacteria and actinomycetes in the soil.(5)The occurrence and damage of banana wilt were significantly different in soils with different organic matter additions(16 g/kg,32 g/kg,64 g/kg,96 g/kg).After the 7th day of inoculation,except for the addition of 64 g/kg and 96 g/kg of organic matter,the incidence of plants was observed in other treatments;at 14 days,all treatments showed disease;at the 21 st day The CK control disease index without organic matter reached 100;at 28 days after inoculation,the soil disease index increased with the addition of organic matter,but the treatment was 25.0%,25.0%,41.7% lower than the CK control without organic matter added,respectively.33.3%;at 35 days,except for the condition index of 64 g/kg and 96 g/kg organic matter treatment group,the disease index was 100.This indicates that adding a certain amount of organic matter in the soil can significantly reduce or slow down the occurrence of banana wilt.