Fungi isolated from cankered tissues of declining apricot trees in Malatya and Elazığ provinces of Turkey

Abstract

Surveys were carried out in apricot (Prunus armeniaca L.) production areas of Malatya and Elazığ provinces from April to November in 2015 and 2016. Fungal and oomycetous diseases causing dieback and decline symptoms were investigated and locations where the diseases were prevalent were determined according to the districts in these provinces. Nine and 40 orchards were visited in Elazığ and Malatya during the course of the surveys. A total of 665 out of 5750 apricot trees were checked and the disease incidence was found to be 44% in the surveyed orchards. Out of isolates obtained from root and crown tissues of symptomatic trees, isolates obtained from cankered tissues were characterized according to their morphological characteristics. Genomic DNA was extracted from representative isolates. The internal transcribed spacer (ITS) region of rDNA was amplified using the ITS6/ITS4 primer pair and sequenced and submitted to GenBank. NCBI BLAST results showed 98 to 100% similarity with the ITS sequences of many Clonostachys rosea f. rosea (Link : Fr.) Schroers et. al. 1999 (Ascomycetes, Hypocreales), Sarocladium kiliense (Grütz) Summerb. 2011 (Ascomycetes, Incertae sedis) (Syn: Acremonium kiliense), Phoma sp. (Ascomycetes, Pleosporales), Entoleuca spp. (Ascomycetes, Xylariales) strains deposited in NCBI GenBank. The sequences were submitted to GenBank and given accession numbers were MF536537 and MF536538 for C. rosea, MF536539 for S. kiliense, MF536540 and MF536541 for Phoma spp., and MF536542, MF536543, MF536544 and MF536545 for Entoleuca spp. isolates. Moreover, Verticillium dahliae and Macrophomina phaseolina were also isolated from inner tissues of necrotic branches and morphologically identified. However, pathogenicity of these isolates needs further investigations. If some isolates were not pathogenic, their endophytic or hperparasitic characteristics against pathogenic ones should be tested in order to fully exploit their potential for use as biological control agents.