Sexual reproduction contributes to vegetative compatibility type diversity in the population of Cryphonectria parasitica in the East Black Sea region of Turkey

Abstract

Vegetative compatibility (vc) -type diversity in Cryphonectria parasitica comes from several factors such as mutations, migration and sexual recombination of the multiallelic vegetative incompatibility (vic) genes. This study aimed at determining the diversity of vc types of C. parasitica in the East Black Sea Region and its relation to sexual reproduction. A total of 344 C. parasitica isolates were subjected to a vc-type assay based on the barrage/merging response. Mating types were detected by using PCR with specific MAT primers. Single ascospore isolates obtained from field perithecia were also subjected to the vc-type assay. In the results, 10 vc types were identified. This is the greatest vc-type diversity ever detected in Turkey. Among 344 isolates, 235 were identified as EU-1, 23 as EU-17, 21 as EU-12, and 14 as EU-3 whereas 51 isolates were not compatible with any of the European testers. The unidentified isolates were divided into six new vc groups. MAT-1 and MAT-2 comprised of 37.4% and 55.3% of the isolates, respectively. Thirteen isolates were heteroallelic carrying both MAT alleles. Perithecia were found in 130 samples. Among the single ascospore isolates, up to 13 vc groups were found per perithecia. This study revealed that vc-type diversity of C. parasitica increases in the Eastern Black Sea Region and this increase can be partially related to the sexual reproduction.