GENETIC-CHARACTERIZATION OF COLLETOTRICHUM-GLOEOSPORIOIDES ISOLATES OBTAINED FROM MANGO

Most isolates of Colletotrichum gloeosporioides (> 80%) obtained from anthracnose lesions on mango leaves, inflorescences and fruits from different regions in Sri Lanka showed the same ribosomal DNA (rDNA) and very similar mitochondrial DNA (mtDNA) restriction fragment banding patterns when genomic DNA was digested with endonuclease EcoR l. This rDNA restriction fragment banding pattern was the same as that revealed by C. gloeosporiodies isolates from mango in other tropical countries. Isolates obtained from inflorescences all showed the same rDNA and mtDNA restriction patterns but a few isolates from fruits and leaves from mango grown in mixed orchards in areas of Sri Lanka with two monsoons and year-round rainfall had rDNA restriction patterns associated with isolates from other fruit crops. This suggested that some cross-infection onto mango occurs. However, it is suggested that there is a strain of C. gloeosporioides specific to mango and the clonal nature of this strain implies that it has disseminated worldwide from a single source.