Abstract:

Separate the Alternata strains and study the genetic diversity using ISSR and molecular markers RAPD analysis, compared with two kinds of molecular biology method in Alternata genetic analysis, the good and bad for the study of Alternata genetic diversity and tobacco resistant varieties of cultivating lay the foundation. ISSR and RAPD molecular markers were used to analysis the genetic diversity of 28 A. alternate. Through the primers tested, 10 ISSR primers and 10 RAPD primers were selected for their reproducibility and high polymorphism. 112 polymorphic bands were amplified by ISSR. The ratio of polymorphic band was 86.82%. The coefficient of similarity between strains was 0.53-0.97. While 70 polymorphic bands were amplified by RAPD and the ratio of polymorphic band was 81.39%. The coefficient of similarity between strains was 0.53-0.94. The correlation of genetic distance of two markers was used analyzed with SPSS 17.0 software. The results proved that these two markers were significantly correlated. The results revealed that lSSR and RAPD markers were suitable for assessment of genetic diversity of A. alternata. The ISSR marker was superior to the RAPD marker. The results reveal that there was little correlation between geographic origin and genetic diversity of A. alternate using NTSYS program by UPGMA cluster analysis.