Genetic Diversity and Pathogenic Variability Among Isolates of Colletotrichum Species from Strawberry

Abstract

Ninety-five isolates of Colletotrichum including 81 isolates of C. acutatum (62 from strawberry) and 14 isolates of C. gloeosporioides (13 from strawberry) were characterized by various molecular methods and pathogenicity tests. Results based on random amplified polymorphic DNA (RAPD) polymorphism and internal transcribed spacer (ITS) 2 sequence data provided clear genetic evidence of two subgroups in C. acutatum. The first subgroup, characterized as CA-clonal, included only isolates from strawberry and exhibited identical RAPD patterns and nearly identical ITS2 sequence analysis. A larger genetic group, CA-variable, included isolates from various hosts and exhibited variable RAPD patterns and divergent ITS2 sequence analysis. Within the C. acutatum population isolated from strawberry, the CA-clonal group is prevalent in Europe (54 isolates of 62). A subset of European C. acutatum isolates isolated from strawberry and representing the CA-clonal and CA-variable groups was assigned to two pathogenicity groups. No correlation could be drawn between genetic and pathogenicity groups. On the basis of molecular data, it is proposed that the CA-clonal subgroup contains closely related, highly virulent C. acutatum isolates that may have developed host specialization to strawberry. C. gloeosporioides isolates from Europe, which were rarely observed were either slightly or nonpathogenic on strawberry. The absence of correlation between genetic polymorphism and geographical origin in Colletotrichum spp. suggests a worldwide dissemination of isolates, probably through international plant exchanges.

Identification of Colletotrichum spp. isolated from strawberry in Zhejiang Province and Shanghai City, China

“…[teleomorph Glomerella cingulata (Stoneman) Spauld. & Schrenk], and C. fragariae Brooks (Gunnell and Gubler, 1992;Denoyes-Rothan et al, 2003). C. gloeosporioides and C. acutatum are distributed worldwide on a number of hosts, while C. fragariae has a very narrow host range (MacKenzie et al, 2008).…”

Variability of seed-borne Colletotrichum strains in cotton based on ITS1 and ITS2 ribossomal genes analysis

“…This suggests that the strains from strawberry from the CA-cloned subgroup have gone through a process of specialization. In that study, no correlation between genetic groups and pathogenicity was established (Denoyes-Rothan et al, 2003).…”

“…Among the DNA regions used to compare species within the genus Colletotrichum the Internal Transcribed Spacers (ITS1 and ITS2) of the rDNA, that flank the 5.8S gene, are mostly mentioned in literature (SHERRIFF et al, 1994(SHERRIFF et al, , 1995BAILEY et al, 1996;SREENIVASAPRASAD et al, 1996;HSIANG and GOODWIN, 2001;DENOYES-ROTHAN et al, 2003;CANO et al, 2004). By using primers specific to the ITS2 region to characterize Colletotrichum spp.…”

Microsatellite isolation and characterization for Colletotrichum spp, causal agent of anthracnose in Andean blackberry

“…In strawberry, anthracnose is caused by three different fungi: C. gloeosporioides, C. fragariae, and C. acutatum (Denoyes-Rothan et al, 2003;Mackenzie et al, 2006). Studies have also demonstrated that the fungal species C. fragariae and C. gloeosporioides are highly interrelated regarding morphological and pathological aspects.…”