Genetic variability and structure of Canadian populations of Chondrostereum purpureum, a potential biophytocide

Abstract

Genetic diversity was studied in four Canadian ecological populations, each corresponding to a Canadian ecozone, of Chondrostereum purpureum, including 93 isolates of various host origin. Pseudo‐allelic frequencies were estimated at each of 22 putative RAPD loci by scoring for presence or absence of amplicons in haploid mycelial cultures. The analysis of the hierarchical population structure did not reveal any trend with regard to ecological or host origin. Total gene diversity (HT† = 0.288) was mostly attributable to diversity within populations (HS† = 0.269). In addition, the AMOVA analysis detected most of the molecular variability within subpopulations (89.3%; P < 0.001), whereas a significant (7.3%; P = 0.001) proportion of the gene diversity was found among subpopulations, within ecozones. The results indicate that C. purpureum is a highly heterogeneous pathogen with a continuously distributed population across Canada (GST† = 0.048), and underscore the importance of considering the population structure in the process of its registration as a microbial control agent. A genotype isolated in either central or eastern Canada (ecozones 2, 4 and 5 populations) and selected for its potential as a biophytocide should be considered indigenous in any of these regions of intended use.

Genetic diversity of ochratoxigenic <i>Aspergillus</i> section <i>Nigri</i>, using RAPD and VCG techniques

“…This is because, garri from which the isolates was obtained are displays in open bowls in markets and various packaging materials use to haul this food from rural to urban areas might exacerbate fungal contamination [22], thereby causing multiple contamination which could be an important prerequisites to evolution of a new fungus as a result of sexual or parasexual recombination. In addition, the values obtained for total gene diversity (HT), diversity among and within isolates (GS and GL) are similar to those observed in fungi with known sexual life cycles [23,24]. According to Grypta et al [25], regional population structure of this nature is usually the result of more frequent interbreeding events among isolates within a site than between sites and is more common in diploid or dikaryotic organisim.…”

Population structure of the endangered wood decay fungus Phellinus nigrolimitatus (Basidiomycota)

“…ex Fr.) Pouzar (Gosselin et al 1999). In contrast, in Fomitopsis rosea and Heterobasidion annosum , population subdivisions were found, indicating a more limited ability to disperse.…”

Concordant evolution of mitochondrial and nuclear genomes in the wheat pathogen Phaeosphaeria nodorum

“…Earlier works on fungi (Fry et al, 1992;Griffith and Shaw, 1998;Ramsfield et al, 1999;Gosselin et al, 1999;Zhan et al, 2003 and other eukaryotes (Gerber et al, 2001;Nachman et al, 1994) have shown contrasting patterns of genetic variation between the two genomes and evidence for non-neutral evolution in the mitochondrial genome. In the most comprehensive analysis of mtDNA diversity in fungi to date, a global sample of nearly 1700 isolates of Mycosphaerella graminicola, a fungal pathogen sharing the same ecological niche as P. nodorum and having a nearly identical life cycle, were assayed for DNA fingerprints and RFLP markers in the nuclear and mitochondrial genomes.…”