Investigation of phylogenetic relationship of some isolates of Magnaporthe oryzae in different hosts

Rice is one of the most important agricultural products having more than ۹۰% of its world production inAsia. However, a large amount of that is wasted by pests and diseases. Blast is an influential disease of rice,responsible for a significant yield loss of about ۱۰% to ۳۰% of total rice production every year. The fungalplant pathogen, Magnaporthe oryzae, is the causal agent of the devastating rice blast disease. It can infectmillet and other grasses, but rice is the most economically significant host. In this study, the phylogeneticrelationships of isolates obtained from rice and other wheatgrass are compared based on the ITS regions. TheITS nucleotide sequences were selected from the NCBI gene bank; Then, a strain of Gaeumannomycesgraminis (GGG۳۱۷ ۱۸S) was used as an out-group array for rooting deciduous trees. The obtained sequenceswere aligned using BioEdit v, ۰,۹ software and the Clustalw algorithm. Phylogenetic analysis was performedbased on the sequence of ITS region using the maximum likelihood algorithm. Also, the validation test of۱۰۰۰ replications was carried out by MEGA.۶ software. ITS-based phylogenetic analysis of M. oryzaeisolates, which were isolated from different grasses, were classified into four groups based on their host:group A (Rice), group B (Wheat), group C (Corn, Barley, and so on), and D (Rice). The results indicated thatM. oryzae was identified for rice isolates in groups A and D, but the Blast agent of Iranian rice was notincluded in these categories. According to our studies, it can be found that the phylogenetic properties of M.oryzae in Iranian rice are similar to group C. Therefore, we conclude the Blast agent in Iran will probably bedifferent from other regions.

Keywords:

Iran , ITS region , Phylogenetics , Rice Blast