Diversity and spatial distribution of vegetative compatibility types and mating types of Cryphonectria parasitica in the Aydın Mountains, Turkey

Abstract

In this study, the population structure of the chestnut blight fungus Cryphonectria parasitica in the Aydın Mountains was investigated to make inferences about fungal reproduction and population diversity. A total of 213 C. parasitica isolates from eight subpopulations were used to determine vegetative compatibility (vc) and mating types of the population. Furthermore geostatistical analysis was performed to define the spatial structure of the population. The results showed that the isolates were vegetatively compatible with the European vc types of either EU-1 or EU-12. Both vc types were found in almost all subpopulations, but their frequencies varied depending on location. The results of a PCR assay showed that both mating types of C. parasitica (MAT-1 and MAT-2) exist in the population. MAT-1 comprised 65% of the total isolates, and the ratio of mating types was significantly skewed from 1:1. Genotyping based on combined vc and mating type data revealed four genotypes: EU-1/MAT-1 (28.6%), EU-1/MAT-2 (34.7%), EU-12/MAT-1 (36.2%) and EU-12/MAT-2 (0.5%). Geostatistatical analysis indicated that vc types, mating types and vc/mating genotypes were spatially autocorrelated and clustered in their distributions. Results suggested that C. parasitica could have a clonal population structure that is generated by asexual reproduction. Low vc-type diversity suggests that the C. parasitica population in the Aydın Mountains may be highly suitable to hypovirus invasion, thereby providing a high potential for successful biological control. However, co-occurrence of sexually compatible strains of EU-1 and EU-12 at the same locations in close proximity creates a high risk of increase in vc-type diversity.

Socioeconomic Perspectives on Household Chestnut Fruit Utilization and Chestnut Blight Prevention Efforts in Turkey

“…Aydın andİzmir represent almost 40% of chestnut production in Turkey [9]. While the mean production amount per household in Aydın was found to be similar tȯ Izmir in our research, Aydın is reported as the largest producer in Turkey according to total production amount [23,29,34,35].…”

“…The chestnut blight fungus, which has been present in Turkey since the late 1960s, is considered by experts to be the most impactful of these. Most research into chestnut blight mitigation focuses on a biological control known as applied hypovirulence [8,9]. Though shown to be effective, biological control cannot be performed by smallholders.…”

Geographical distribution of vegetative compatibility and mating types of Cryphonectria parasitica in İzmir, Manisa and Denizli provinces in western Turkey

“…For the last two decades, chestnut plantations in the region have been under attack by the fungus Cryphonectria parasitica , the cause of a destructive disease known as chestnut blight. Since its first report in the Aegean region in 2001 (Çeliker & Onoğur, ), chestnut blight has caused the death of many chesnut trees especially in areas where the disease has been present the longest (Erincik, Döken, Açıkgöz, & Ertan, ; Erincik, Özdemir, Durdu, Döken, & Açıkgöz, ).…”

“…In Turkey, the vc‐type diversity of C. parasitica is low (Akıllı, Katırcıoğlu, & Maden, ; Çeliker & Onoğur, ; Erincik et al., , ). EU‐1 is the dominant vc type and is distributed in all regions of Turkey (Gürer, Ottaviani, & Cortesi, ).…”

Scientific Opinion on the pest categorisation ofCryphonectria parasitica(Murrill) Barr

“…In Portugal, northern Spain and southwestern France, the populations are quite different from those in other countries in Europe, and are dominated by vc types EU-11, EU-33, EU-66 and EU-72, which gives evidence for recurring introductions of the pathogen of an origin different from those introduced in Italy ( Robin et al, 2000;Montenegro et al, 2008;Robin et al, 2009) and substantial absence of long-distance spread of the disease. In Greece, southern Italy, Slovakia, the former Yugoslav Republic of Macedonia, Romania and Bulgaria, populations are dominated by the vc type EU-12 (Sotirovski et al, 2004;Perlerou and Diamandis, 2006;Milgroom et al, 2008;Erincik et al, 2011), whereas, in Turkey, vc types EU-12 and EU-1 coexist (Gurer et al, 2001;Akilli et al, 2009). In Georgia, the C. parasitica population has a higher diversity of vc types than those of neighbouring countries, with many new vc types unknown in Europe which have emerged locally through sexual recombination .…”