Universally primed polymerase chain reaction alleles and internal transcribed spacer restriction fragment length polymorphisms distinguish two subgroups in Botrytis aclada distinct from B-byssoidea

Fifty-one isolates representing the four Botrytis spp. associated with onio n neck rot were clustered by unweighted pair group method with arithmetic m ean based on universal-primed polymerase chain reaction (UP-PCR) fingerprin ts. Bootstrap analysis of the consensus phenogram clearly demonstrated five strong clusters among the four Botrytis spp.: B. cinerea (C), B. squamosa (S), B. byssoidea (B), and B. aclada (AI and AII). Subdivision of the 30 B. aclada isolates, AI (14) and AII (16), from Europe, Egypt, North America, and Japan was further supported by restriction analysis of the internal tra nscribed spacer of the ribosomal genes and spore size measurements. Gene di versities (H) among AI and All isolates were very low (0.007 and 0.043, res pectively). A likelihood ratio chi-square test (G(2)) Of Nei's coefficient of genetic differentiation (GST) showed that both B. aclada subgroups, AI a nd All, were significantly different from B. byssoidea (P < 0.001), and tha t B. aclada subgroups Al and All were significantly different from each oth er (P < 0.001). No UP-PCR alleles were shared by AI and B. byssoidea isolat es, whereas 10 and 12 alleles were shared by AI:AII and AII:B. byssoidea, r espectively. The hypothesis that All may be a hybrid between Al and B. byss oidea is discussed.