Research Of One Mutant Of Colony Growth Slowness Of Magnaporthe Grisea

A slow-growth mutant, K1304, was obtained by screening from the REMI mutant library constructed with wild type strain P131 of Magnaporthe grisea. The changed phenotype was due to insertion of plasmid pUCATPH by co-segregation genetic cross analysis. The biological characteristics of mutant K1304 was compared with the wild type strain P131. The results showed that the colony growth rate of the mutant was 60%, sporulation was 1/3 of P131. Conidia germination, appressorium formation, production of penetration peg and infectious hyphal growth of K1304 on onion epidermis surface were late to the wild strain P131. While the final results was similar and there was no obvious difference in pathogenicity to rice between the two strains.In order to clone the gene related to colony growth of Magnaporthe grisea, genomic DNA of K1304 was hybridized with probe pUCATPH. The Southern blot result indicated that mutant K1304 had one insert of two copy of plasmid in series. The plasmid KH3 was obtained by HindIII. By comparing the rescued flanking sequence and rice blast genome sequence it was found that the marker plasmid insert site was at 6604 of contig2.288. The fragment was cloned into the vector K.N with Neuomycin resistance to transform the mutant for complementation, but all transformants didn't restored the wild phenotype. Now the other side sequence is being rescued.