Distribution Of Fusarium Oxysporum F.sp.cubense Race 1 And 4 In Infected Banana And Soil

Banana（Musa spp）,one of the most popular fruit in the world,is positioned as the fourth crop in developing country by United Nations Food and Agriculture Organization（FAO）.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）.In China,the most destructive agents are Fusarium oxysporum f.sp.cubense race 1（Foc1）and Fusarium oxysporum f.sp.cubense race 4（Foc4）.In this study,Foc1 and Foc 4 was inoculated respectively to two banana varieties,Brazilian（Musa acuminate L.AAA group）and Fenjiao（M.paradisiaca L.AAB group）.Quantitative polymerase chain reaction（qPCR）was used to detect the concentrations of pathogen in different part of plant at different time.The distribution of Foc1 and Foc4 in soil around the banana was also detected.In addition,a loop-mediated isothermal amplification（LAMP）was developed for the rapid and sensitive detection of Foc1 and Foc4 in soil and plant.The results are as follows:1、In the treatment of Brazilian infected by Foc1 and Foc4 respectively,both Foc1 and Foc4 in roots could be detected at 2 day post inoculation（dpi）,but they couldn?t be detected in rhizomes.During the 21 days?observation,the titter of Foc1 and Foc4 was accumulated in root.Besides,the titter of Foc4 was more than that of Foc1 in Brazilian?s root at every point of observation.At 21 dpi,the titter of Foc1 in rhizomes has been the maximum.However,the titter of Foc4 in rhizomes had not been the maximum until 14 dpi.In the treatment of Fenjiao infected by Foc1and Foc4 respectively,the same as the results as Brazilian,both Foc1 and Foc4 in roots and in rhizomes could be detected at 2 dpi.Moreover,there were more Foc4 in rhizomes or in root of Fenjiao than Foc1.At 10 dpi,the titter of Foc4 in Fenjiao?s root had been the maximum,and the titter of Foc1 was increasing until 21dpi.At 8dpi,the titter of Foc4 in rhizomes was the most.Nevertheless,there were two peaks of Foc1 concentration in rhizome,one was at 6 dpi,the other one was at 14 dpi.2、The Results of distribution for Foc1 or Foc4 in soil around Brazilian plant after 30days?artificial infection were showed as that:The biomass of Foc1 increased with depth at the distance of 5 cm.At the distance of 15 cm to the plant,Foc1 content was the most at the depth of 10¹5 cm.The content of Foc1 at the depth of 25³0 cm took the second place.The least content of Foc1 was at the depth of 0⁵ cm.At the distance of 30 cm,the content of Foc1 at 10¹5 cm was more than which was at 25³0 cm and 0⁵ cm depth.Moreover,the content of pathogen at 25³0 cm depth was not significantly different from which was at 0⁵ cm.In the treatment of Foc4 infested soil,same as Foc1,the biomass of Foc4increased with depth at the distance of 5 cm.At the distance of 15 cm to the plant,Foc4content was the most at the depth of 10¹5 cm.The content of Foc4 at the depth of 25³0cm was less,and the content was the least at the depth of 0⁵ cm.At the distance of 30 cm,The content of Foc4 at the depth of 25³0 cm was the most,the content at the depth of 0⁵cm was less,and the content at the depth of 25³0 cm was the least.A comparison with samples at the same depth and different distances showed that Foc1 was increasing with the accumulating distances,so was Foc1.In addition,the content of Foc4 was more than Foc1at the same distance and depth from the plant except one 30 cm distance、25³0 cm depth away.3、A loop-mediated isothermal amplification（LAMP）was developed for the rapid and sensitive detection of Foc.The primers could specifically detect Foc1 and Foc4.9.6×10^-7ng/uL and 6.3 10^-7 ng/uL of gene DNA could be detected,indicating that the method is highly sensitive.Besides,the methods could be used to detect the pathogen in soil or in plant.And as we know,it?s the first reported for LAMP detection method of Foc1.