Relationship between pathogenicity, race and vegetative compatibility grouping among Algerian populations of Fusarium oxysporum f. sp. pisi causing pea wilt

Abstract

Fusarium oxysporum f. sp. pisi (FOP) is a significant and destructive pathogen of field pea in Algeria. In the present study, 50 isolates of F. oxysporum f. sp. pisi, the causal agent of pea (Pisum sativum) wilt, collected from different parts of western Algeria and representing four races of the pathogen, were analyzed for virulence. The wilt incidence ranged from 6.66 to 88.33% on a highly susceptible cultivar (Little Marvel). Twenty-one isolates belonging to four races of FOP and one nonpathogenic F. oxysporum (FO) isolate were analyzed for vegetative compatibility in order to reveal the genetic structure of the population and to check the reliability of the method for the identification of physiological races of FOP. Obtained results showed that the FOP isolates could be classified into four main vegetative compatibility groups (VCGs) that corresponded to races l, 2A, 2B and 5. The race 6 isolate fell into the race 1 VCG. To our knowledge, this is the first such study in Algeria of its kind.

Keywords

• Fusarium oxysporum f. sp. pisi
• nit mutants
• pathogenicity
• pea wilt
• physiologic races