Screen Sugarcane Germplasm With Resistance To Fusarium Sacchari And EMS Mutagenesis In Fusarium Sacchari

Sugarcane pokkah boeng is a serious fungal disease that has occurred on sugarcane in recent years.The known pathogens of sugarcane pokkah boeng in China mainly include Fusarium sacchari,F.verticillioides,F.proliferarum,F.andiyazi and F.oxysporum.In order to understand the growth,pathogenicity and toxicity of F.sacchari,inoculation in vitro method was used to evaluate the resistance of 70 sugarcane varieties to pokkah boeng.The original strain of F.sacchari was chemically induced with EMS.Utilization of different nitrogen sources by the mutagenized strains and the original strains were characterized,and explored the variation mechanism from molecular biology,metabolomics and transcriptome for an in-depth understanding of the pathogenicity and genetic variation of sugarcane pokkah boeng pathogens.The result shows:1 、 Inoculation in vitro was used for assessment the resistance of 70 sugarcane varieties to pokkah boeng.The results showed that tillering stage of sugarcane more susceptible to F.sacchari than elongation stage.Among the 70 varieties tested,6 varieties with a resistance level of HR accounted for 8.57%;15 varieties with a resistance level of R accounted for 21.43%;13 varieties with a resistance level of MR accounted for 18.57%;12 varieties with MS resistance level accounted for 17.14%;13 varieties with S resistance level accounted for18.57%;11 varieties with HS resistance level accounted for 15.71%.Variety Ho CP02-263 did not infected during twice inoculation test experiments in growth period,which was probably immune to Fusarium sacchari.2、The results of EMS mutagenesis showed: original strain was treated with set 6 EMS concentrations(0.0%,1.0%,2.5%,5.0%,7.5%,10.0%)for 30,60,90,120 min.The lethal dose of 10.0% EMS was reached after 60 minutes of treatment.Twelve mutant strains with colony growth variation were found in morphology,and three muatant strains were found in the pathogenicity identification.The pathogenicity of 2 mutant strains increased and 4 strains were reduced.3、Nitrogen source utilization and nitrogen metabolic enzyme activity of pokkah boeng germs: Potassium nitrate is the most suitable nitrogen source for the growth of the original strain and the mutagenized strain.The promoting effect of ammonium,yeast powder,glycine and urea on the growth of the mutagenized strains was significantly higher than that of the original strains.The activity of nitrate reductase and glutamine synthetase in nitrogen is higher than that of the original strain.4 、 Key genes of nitrogen metabolism and mycotoxin expression: The expression of FUM1,Aer A and Mea B genes were detected in F.sacchari,and the expression of FUM19 and FUM21 genes were not detected,further verifying the synthesis of fumonisin synthetic genes regulated.The expression of FUM1 in F.sacchari was not significantly affected by the nitrogen source.Ammonium nitrogen can inhibit the expression of FUM1 gene in F.sacchari,Ammonium chloride could promote the expression of Aer A and Mea B genes.In the mutant strain,calcium nitrate could promote the expression of FUM1,and organic nitrogen could promote the expression of Aer A and Mea B genes.5 、 Metabolomics analysis: Fumonisin,Gibberellin,Beauvericin,and Fusarium moniliforme were all detected in F.sacchari.The content of fumonisin,beauvericin and moniliformin were 0.25 times that of original strain.F.sacchari’s ability to produce gibberellins was not significantly affected bynitrogen sources.Yeast powder was good for F.sacchari to produce FB1,ammonium chloride was good for mutant strains to produce FB1 and FB3.F.sacchari and mutant strains produce beauvericin,calcium nitrate and ammonium chloride were beneficial to F.sacchari and mutant strains to produce gibberellin.6、Transcriptome analysis: The original strain PB6-3 and the mutagenic strain MPB6-3 produced a total of 12,943 differentially expressed genes,of which 287 were significantly different,149 were up-regulated and 138 were down-regulated.13 genes related to sporulation,2 genes related to pathogenicity,13 genes related to enzyme activity,17 genes related to gibberellin synthesis,and voma There are 13 differences in the genes related to toxin synthesis.