Bitki Koruma Bülteni

Phytoplasmas cause infections in numerous plants in agricultural ecosystems, causing significant yield and quality losses in products. In recent years, it has been known that diseases caused by phytoplasmas cause economic losses in eggplant (Solanum melongena L.) cultivation. In Turkey, research on infections caused by phytoplasmas in eggplant growing areas is quite limited. This study was carried out to detect phytoplasma infections symptomatologically and molecularly in eggplant production areas in Şanlıurfa province. Fourteen samples were collected from eggplants exhibiting symptoms such as witches’ broom, flower abnormalities (virescence, phyllody), elongation of the pedicle, arising of new shoots from flower parts, yellowing and proliferation. Phytoplasma infection was detected in 8 symptomatic samples using 16S rRNA-specific primers, P1/P7 and R16F2n/R16R2, by direct and nested PCR. Sequence information of fragments obtained as a result of molecular studies was extracted and BLAST analyses were performed. According to nucleotide sequence similarity in the 16S rRNA gene region, it was determined that the genetic group of phytoplasma causing infection in eggplant was related to ‘Candidatus Phytoplasma solani’ (CaPsol) belonging to 16SrXII-A subgroup with 98% sequence identity. To our best knowledge, this study suggests comprehensive symptomatic diagnosis of CaPsol infecting eggplants in Türkiye.

Apple, pear and apricot trees showing phytoplasma associated symptoms from Ankara and Isparta provinces were sampled and investigated to verify the presence of phytoplasma-associated diseases. Totally 31 samples were tested with phytoplasma universal and group specific primers and the PCR products were restricted using Tru1I, RsaI and SspI endonucleases. Different RFLP profiles were obtained and selected samples were directly sequenced. The apple samples were found infected with 16SrX-A (‘Candidatus Phytoplasma mali’), while the majority of the pear samples were infected with 16SrX-A and 16SrX-C subgroup phytoplasmas in mixed infection. The 16SrX-B (‘Candidatus Phytoplasma prunorum’), 16SrX-C (‘Candidatus Phytoplasma pyri’) and mixed infection of 16SrX-A/16SrX-C and 16SrX-C/16SrI (aster yellows) were detected in the apricot samples. In this study the 16SrI phytoplasmas in apricot and the mixed phytoplasma infections in pear and apricot trees were detected in Turkey for the first time.