Fitness Characters in Parasexual Recombinants of the Rice Blast Fungus, Pyricularia oryzae

JARQ : Japan Agricultural Research Quarterly
ISSN 00213551
書誌レコードID(総合目録DB) AA0068709X
41-02-03.pdf397.77 KB

We examined the fitness characters in parasexual recombinants derived from cocultures of two isolates, NAO-02 (race 133.1) and TH77-1 (race 047.0), of the rice blast fungus, Pyricularia oryzae, in liquid yeast extract medium. The cocultured isolates were transferred to oatmeal agar to produce a conidial inoculum. Then, the conidial suspension was sprayed on the japonica rice cultivar Akiyutaka, which has two resistance genes to rice blast: Pik and Piz. Three pathogenic variants were isolated from the typical leaf blast lesions that were subsequently produced. We used randomly amplified polymorphic DNA (RAPD) to examine whether the variants were derived from parasexual recombination between the parents. Eleven RAPDs indicated that the variants possessed genomic DNA from both parents. After inoculating Akiyutaka 7 times in succession, the variants maintained their original pathogenicity. The parasexual recombinants produced more conidia and larger lesions on the host than did parent TH77-1, but fewer conidia and smaller lesions than parent NAO-02. Disease development on plants inoculated with either variant or a parental isolate was also midway between the disease caused by each of the parents in a field containing a single cultivar, but the variant caused the most severe disease in a plot with a mixture of cultivars. These results suggest that parasexual recombination produces variation in fitness.

作成者 NOGUCHI Masako Tsujimoto YASUDA Nobuko FUJITA Yoshikatsu


Magnaporthe oryzae

公開者 Japan International Research Center for Agricultural Sciences
国立情報学研究所メタデータ主題語彙集(資源タイプ) Journal Article
開始ページ 123
終了ページ 131
DOI 10.6090/jarq.41.123
権利 Japan International Research Center for Agricultural Sciences
言語 eng