STM Article Repository

This study looked at the possibility of parasexual recombination among the blast fungus obtained from several host plants. If so, the parasexual recombination theory for rice blast fungus would gain a lot of traction. In order to achieve this, crosses between the widely prevalent rice blast fungus (P. oryzae) and the crabgrass (Digitaria ciliaris) blast fungus (P. grisea) were created. Although the virulence of rice blast fungus can alter, it does not have a sexual life cycle. It is conceivable that such a flawed fungus has a different method for producing genetic variants. Recent comparative genomics investigations have shown that parasexual recombination may have had a significant impact on rice blast fungus evolution. In this experiment, the twofold inoculation and punch methods of the fungus were used to study the parasexualism of rice blast (Pyricularia oryzae) and crabgrass blast (Pyricularia grisea). A total of 520 isolates collected from the double inoculated lesions was subjected to PCR-RFLP analysis of the ITS region to identify subcultures of the inocu- lated rice blast isolates. As a result, four isolates from the three double inocu- lated lesions with SA13-1ME and TP106 were identified as subcultures of TP106. To access the recombination genotypes, a total of 17 isolates from the three lesions was subjected to MAGGY-DNA fingerprint analysis. However, recombinant DNA fingerprint patterns between TP106 and SA13-1ME were not detected among the 17 isolates. Although TP022 was not recovered from the double inoculated lesions, the fact that TP106 was recovered from the double inoculated lesion indicates that rice blast fungus can invade and colo- nized in blast lesion on crabgrass. The opportunistic infection on the double inoculated lesions observed in this study potentially provides new insight into the life cycle of rice blast pathogen. An extraordinary manner of DNA exchange within the conidial cell may be provided by opportunistic infection.