The Correlation Of The Population Density Of The Pathogen And The Disease Severity Of Banana Fusarium Wilt In Soil

Banana fusarium wilt is a devastating disease in the world, there is no effective method to prevent and control, so, the forecastof banana fusarium wilt is very important before planting banana. We can offer scientific basis for plant banana, making monitoring and prevention and control tactics by studying extent of injury of banana fusarium wilt and the population density of the pathogen in soil.The primary results of my study from2010to2013are summarized as follows:1. Developed KP selective medium, KP medium can detect fusarium oxysporum f.sp.cubense race4(FOC4) in soil effectively, and the detection efficiency is95%.10CFU/g and103CFU/g was detected the population of FOC4in21days and106CFU/g in a day after inoculated with FOC4.2. There were significant differences between the experimental group and the control group in the five indicators in64st days; in a specific range, Banana Seedling growth slow down with the density of Foc4increasing; banana plant The inoculation of FOC4in the concentration of1OCFU/mL can cause the banana fusarium wilt;90%of banana seedlings’ leaves appear deformity when infectted by FOC4.3. In the analog inoculation of10s103106CFU/g FOC4spores in the soil, the population of FOC4was detected in21st days of10CFU/g and103CFU/g inoculation and1st day of106CFU/g inoculation. Conventional PCR can detect FOC4when its colony count is greater than1.7×105cfu/g.4. The greater the initial soil inoculum density, the more severe the disease severity. The disease severity index of all treatments was the highest in54-61days after inoculation. When the initial inoculum density is middle and low, such as10CFU and103CFU, in1-61days after inoculation, FOC soil population density and disease severity was positively correlated with a correlation coefficient of0.9676and0.8292.5. The pathogen population density of FOC4has a great influence on mycoflora in soil, it can inhibit or promote the growth of different groups of fungi strains and even promote them into advantage;The frequency of occurrence of Enzyme bands of FOC4increased along with soil inoculation concentration,some of them can be distinguished with time though they are have the same enzyme sites. Some groups of fungi in the soil inoculating of FOC4in the low concentration, can promote each other to grow, become the dominant fungi in the environment of bananas’ soil, and high concentration of vaccination of FOC4can inhibit the fungi into advantage.