†Both authors contributed equally to the work.
Clonal populations of Leptosphaeria maculans contaminating cabbage in Mexico
Article first published online: 3 AUG 2012
© 2012 The Authors. Plant Pathology © 2012 BSPP
Volume 62, Issue 3, pages 520–532, June 2013
How to Cite
Dilmaghani, A., Gout, L., Moreno-Rico, O., Dias, J. S., Coudard, L., Castillo-Torres, N., Balesdent, M.-H. and Rouxel, T. (2013), Clonal populations of Leptosphaeria maculans contaminating cabbage in Mexico. Plant Pathology, 62: 520–532. doi: 10.1111/j.1365-3059.2012.02668.x
- Issue published online: 22 APR 2013
- Article first published online: 3 AUG 2012
- Brassica oleracea ;
- cropping practices;
- Phoma ;
- population structure;
- reproduction regime;
- stem canker
The race structure and genotypic diversity of four Leptosphaeria maculans populations isolated from Brassica oleracea (broccoli, cauliflower, cabbage, etc.) in central Mexico (Aguascalientes, Guanajuato and Zacatecas states) were analysed. Race structure was characterized by an unusually low diversity at three locations out of four. Fourteen minisatellite markers revealed a high proportion of repeated multilocus genotypes in these populations, combined with a significant linkage disequilibrium and strong clonal fraction (65–87%). The occurrence of the mating-type idiomorphs always significantly departed from the 1:1 proportion expected in the case of random mating. Each population thus consists of a few (four to nine) multilocus genotypes which are specific to each location. These data strongly support the hypothesis of exclusive, or a high rate of, clonal multiplication. Comparison of cropping practices between B. oleracea and B. napus indicate that the shift in reproductive behaviour of the fungus is chiefly man-mediated.