HIGHLY VARIABLE MOLECULAR KARYOTYPES IN THE PLANT PATHOGEN COLLETOTRICHUM-GLOEOSPORIOIDES

Isolates representing two types (A and B) of Colletotrichum gloeosporioides, which cause different anthracnose disease on the tropical pasture legumes Stylosanthes spp. in Australia, were found to have distinct electrophoretic karyotypes. Type A isolates had five large maxi-chromosomes (2-6 Mb) and eight to ten smaller mini-chromosomes (270-600 kb), while Type B isolates had three maxi chromosomes (4.7->6 Mb) and three to five mini-chromosomes (330-1200 kb). Extensive chromosomal polymorphisms for both length and number were observed in the mini-chromosomes amongst isolates within both types. Results indicate that chromosomal rearrangements may have a role in generating variation in this pathogen. © 1990 Springer-Verlag.