Diversity of SCAR Markers of Pyricularia grisea Isolated from Digitaria ciliaris Following Cross Infection to Rice

Abstract

Cross infection of Pyricularia grisea from grass to rice and vice versa has been reported, but genetic changes are not known yet. This research aimed at estimating the possibility of the genotype alteration in P. grisea dc4 isolated from Digitaria ciliaris, following cross infection to either rice cv. Kencana bali, Cisokan, and IR64 or Panicum repens, Cynodon dactylon, Digitaria sp., and Ottochloa nodosa. The genotypes were analyzed by employing three SCAR markers, Cut1; PWL2; and Erg2. The results indicated that the dc4 was only able to infect Kencana bali, Cisokan, and P. repens. The dc4 had only two out of three SCAR markers, Cut1 and Erg2. Host shift was followed by genotype alteration in two loci of SCAR. Isolates derived from lesions on Kencana bali (dc4-kb) and Cisokan (dc4-c) of the dc4 infection, both lost their Cut1 and gained PWL2. On the contrary, there was no genotype alteration from dc4 to isolate derived from P. repens of dc4 infection (dc4-pr. Neither the isolate dc4-kb that was cross-inoculated to Cisokan nor the dc4-c that was cross-inoculated to Kencana bali showed SCAR marker change. In comparison, race 173 isolate and those derived from Kencana bali and Cisokan did not show genotype alteration. All had two out of three SCAR markers, PWL2 and Erg2. The isolate 173 was adapted to rice. This indicated that genotype diversity of the dc4 might arise following host shift from grass to rice