Diversity of Cryphonectria parasitica populations from the Carpathian Basin

Abstract

The ascomycetous fungus Cryphonectria parasitica (Murr.) is one of the most important fungal pathogens of chestnut (Castanea sativa Mill.), causing chestnut blight. It is originated from Eastern Asia and was introduced into North America, and later into Europe. Almost 100 C. parasitica isolates were collected mainly from the Carpathian Basin to study their diversity and phylogenetic relationships. Three nuclear molecular markers were tested: (i) internal transcribed spacers (ITS), (ii) translation elongation factor 1 subunit alpha (tef1), and (iii) six microsatellite loci. The ITS region proved to be highly polymorphic but this kind of variability did not reflect the geographical regions of the isolates, while the tef1 sequences were identical in all isolates. Microsatellite haplotype diversity was relatively high (0.923-0.984) calculated for the fungal populations of the Carpathian Basin. This may have resulted from the multiple introductions from diverse origins of the populations, close to the first site of observation in Northern Italy. The BAPS analysis of the microsatellite markers occasionally grouped together samples from remote geographical origin, suggesting human assistance in the introduction of new C. parasitica haplotypes from distinct areas.

Genetic diversity of Cryphonectria parasitica causing chestnut blight in South Tyrol (northern Italy)

“…Occurrence of the three ITS haplotypes H1, H2 and H3 in different districts of South Tyrol (b) and the association of ITS haplotypes of C. parasitica with vc types in South Tyrol. Each color represents a different vc type (c) ◂ ITS sequence variation was found (Görcsös et al, 2015). In addition, Görcsös et al (2015) found that the variability of ITS sequences of C. parasitica was not related to geographical distribution and suggested that human-mediated introductions (such as infected propagation material) might be responsible for the observed patterns.…”

“…Each color represents a different vc type (c) ◂ ITS sequence variation was found (Görcsös et al, 2015). In addition, Görcsös et al (2015) found that the variability of ITS sequences of C. parasitica was not related to geographical distribution and suggested that human-mediated introductions (such as infected propagation material) might be responsible for the observed patterns. In South Tyrol, three different ITS haplotypes were identified and their phylogeographic relationship was assessed in a global context.…”

Molecular Variation of the Phytopathogenic Fungus Sporisorium reilianum in Valle del Mezquital, Hidalgo

“…In this context, one problem at the local or regional level in some states of Mexico is the lack of an agroecological culture that seeks to adequately manage certain economically important crops. This means that the dissemination of fungal structures may be fostered through physical media like transport in organic material used as fertilizer, or contaminated seeds, farm machinery, or other agricultural equipment (Jones and Belmar, 1989;Görcsös et al, 2015). The latter factor could be determinant by allowing the movement of contaminating biological material to distant, but contiguous, regions.…”