Characterization of Botrytis cinerea from table grapes in Chile using RAPD-PCR

Random amplified polymorphic DNA (RAPD) analysis was performed on 29 isolat es of Botrytis cinerea Pers. ex Fr. isolated from table grapes (Vitis vinif era L.) and other crops in Chile with 29 decaprimers. No single primer was found to differentiate either the host or the geographical origin of each o f the B. cinerea isolates tested. The DNA profiles obtained, particularly w ith primers OPA4 and OPA11, distinguished isolates of B. cinerea from other epiphyte fungi found on table grapes, including Alternaria alternata, Aspe rgillus niger; Cladosporium herbarum, Epiccocum nigrum; Rhizopus stolonifer , a Penicillium sp., and yeasts (Cryptococcus laurentii, Rhodotorula glutin is, and Saccharomyces cerevisiae). Regardless of host origin, primers OPA4 and OPA11 amplified a strong fragment of 1.2 kilobases (kb) and two fragmen ts of 1.10 and 0.7 kb, respectively. These DNA fragments were obtained even when only one conidium of B. cinerea was in the test sample. Three main gr oups were clearly defined based on the genetic similarities found in additi onal RAPD analysis with 19 arbitrary decaprimers and 15 selected isolates o f B. cinerea. The overall similarity coefficients (SC) between the groups o btained ranged from 0.326 to 0.891. Interestingly, all isolates from table grapes were included in group I(SC: 0.761 to 0.826), isolates from apple an d tomato were in group II (SC: 0.739 to 0.848), while isolates from blueber ry were either in group I (SC: 0.804) or III (SC: 0.673). Consequently, the genetic variability determined by RAPD analysis among these B. cinerea iso lates suggested a possible host:pathogen relationship. However, further res earch is needed to clarify its pathological significance.