New avirulence genes in the phytopathogenic fungus Leptosphaeria maculans

ABSTRACT Leptosphaeria maculans, the causal agent of stem canker of oilseed rape (Brassica napus), develops gene-for-gene interactions with oilseed rape, and four L. maculans avirulence (AVR) genes (AvrLm1, AvrLm2, AvrLm4, and alm1) were previously genetically characterized. Based on the analysis of...

Full description

Saved in:
Bibliographic Details
Published in:Phytopathology 2002-10, Vol.92 (10), p.1122-1133
Main Authors: BALESDENT, M. H, ATTARD, A, KÜHN, M. L, ROUXEL, T
Format: Article
Language:English
Subjects:
Agronomy. Soil science and plant productions
Biological and medical sciences
Fundamental and applied biological sciences. Psychology
Fungal plant pathogens
Genetics and breeding of economic plants
Life Sciences
Pest resistance
Phytopathology and phytopharmacy
Phytopathology. Animal pests. Plant and forest protection
Plant pathogens
Variation, races, biotypes, parasitic specialization, genetics
Varietal selection. Specialized plant breeding, plant breeding aims
Vegetal Biology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:ABSTRACT Leptosphaeria maculans, the causal agent of stem canker of oilseed rape (Brassica napus), develops gene-for-gene interactions with oilseed rape, and four L. maculans avirulence (AVR) genes (AvrLm1, AvrLm2, AvrLm4, and alm1) were previously genetically characterized. Based on the analysis of progeny of numerous in vitro crosses between L. maculans isolates showing either already characterized or new differential interactions, this work aims to provide an overview of the AVR genes that may specify incompatibility toward B. napus and the related species B. juncea and B. rapa. Two novel differential interactions were thus identified between L. maculans and B. napus genotypes, one of them corresponding to a complete resistance to European races of L. maculans. In both cases, a single gene control of avirulence was established (genes AvrLm3 and AvrLm7). Similarly, a single gene control of avirulence toward a B. rapa genotype, also resistant to European L. maculans isolates, was demonstrated (gene AvrLm8). Finally, a digenic control of avirulence toward B. juncea was established (genes AvrLm5 and AvrLm6). Linkage analyses demonstrated that at least four unlinked L. maculans genomic regions, including at least one AVR gene cluster (AvrLm1-AvrLm2-AvrLm6), are involved in host specificity. The AvrLm3-AvrLm4-AvrLm7 region may correspond either to a second AVR gene cluster or to a multiallelic AVR gene.
ISSN:0031-949X
1943-7684
0031-949X
DOI:10.1094/PHYTO.2002.92.10.1122