Characterization of Colletotrichum acutatum causing anthracnose of anemone(Anemone coronaria L.)

Anthracnose, or leaf-curl disease of anemone, caused by Colletotrichum sp., has been reported to occur in Australia, western Europe, and Japan. Sympto ms include tissue necrosis, corm rot, leaf crinkles, and characteristic spi ral twisting of floral peduncles, Three epidemics of the disease have been recorded in Israel: in 1978, in 1990 to 1993, and in 1996 to 1998, We chara cterized 92 Colletotrichum isolates associated with anthracnose of anemone (Anemone coronaria L.) for vegetative compatibility (72 isolates) and for m olecular genotype (92 isolates) and virulence (4 isolates), Eighty-six of t he isolates represented the three epidemics in Israel, one isolate was from Australia, and five isolates originated from western Europe. We divided th ese isolates into three vegetative-compatibility groups (VCGs), One VCG (AN E-A) included all 10 isolates from the first and second epidemics, and 13 o f 62 examined isolates from the third epidemic in Israel, along with the is olate from Australia and 4 of 5 isolates from Europe. Another VCG (ANE-F) i ncluded most of the examined isolates (49 of the 62) from the third epidemi c, as well as Colletotrichum acutatum from strawberry, in Israel. Based on PCR amplification with species-specific primers, all of the anemone isolate s were identified as C, acutatum, Anemone and strawberry isolates of the tw o VCGs were genotypically similar and indistinguishable when compared by ar bitrarily primed PCR of genomic DNA. Only isolate NL-12 from The Netherland s, confirmed as C. acutatum but not compatible with either VCG, had a disti nct genotype; this isolate represents a third VCG of C. acutatum. Isolates from anemone and strawberry could infect both plant species in artificial i noculations, VCG ANE-F was recovered from natural infections of both anemon e and strawberry, but VCG ANE-A was recovered only from anemone, This study of C. acutatum from anemone illustrates the potential of VCG analysis to r eveal distinct subspecific groups within a pathogen population which appear s to be genotypically homogeneous by molecular assays.