Abstract:

【Objective】 The objective of the study was to analyze the relationship between the fatty acid and pathogenicity of Ralstonia solanacearum. 【Method】 The fatty acid types were divided into 3 groups, FAT Ⅰ, Ⅱ, Ⅲ. FAT Ⅰ was characterized with＞0.8 avirulent index, 0% infected mortality, belonging to the non-pathogenicity type, FAT Ⅱ with 0.6-0.8 avirulent index, 6.7%-100% infected mortality, belonging to Transition-virulent type in which the pathogenicity was changeable to cause high and low mortalities to the tomato plantlets, FAT Ⅲ with ＜0.6 avirulent index, 100% stable infected mortality. 【Result】 Using cluster analysis to group the fatty acid, principle component analysis was used to select key factors of fatty acid, discrimination analysis was used to build up the discrimination model, three fatty acid of 14:0(X1), 17:0(X9), 18:0(X13) were put into the model set as follow: Y1=-16.3353 + 0.0012X1 + 0.0056X9 - 0.0016X13，Y2=-3.4928 + 0.0002X1 + 0.0003X9 + 0.0025X13，Y3= -9.1550 - 0.0003X1 + 0.0039X9 + 0.0042X13. 【Conclusion】 The accurate rate for discrimination was up to 90.00%. The model of fatty acid type for R. solanacearum was built to provide experiences for computer-based standardized analysis of the pathogen evolution under species level, furthermore with the new idea for other pathogen differentiation.

Key words: Ralstonia solanacearum, fatty acid type, pathogenicy