Determination of plant pathogens, phytoplasms causing diseases in almond production areas of Adıyaman province, by molecular methods and evaluation of their phylogenetic relationships

There are many disease agents that cause significant quality and yield losses in almond cultivation in the world. Diseases caused by phytoplasmas, which are important pathogens among these disease agents, cause very serious yield losses. Phytoplasmas constitute a major problem because they restrict almond production. Within the scope of the research, it was aimed to reveal the presence of phytoplasma infections in almond production areas in Adıyaman province and its districts, which phytoplasma agent causes diseases, if any, and its phylogenetic relationship with other phytoplasmas in the world. In line with this goal, almond trees were checked symptomatically in the production areas where the research was conducted. In the garden checks, trees showing symptoms such as yellowing of leaves, shrinkage of leaves, stunting, bushyness and color change in flower petals thought to be caused by phytoplasmas were targeted and samples were collected from these plants. On the other hand, samples were also taken from healthy plants. DNA was obtained from the leaf midrib and plant shoots containing the peel tubes of the plants collected as a result of symptom-oriented or guided surveys and brought to the laboratory to be used as material in molecular analyses. The presence of phytoplasma agent in the obtained DNA mixture was checked by direct and nested PCR (polymerase chain reaction) studies performed in two stages using universal primers. Comparison and phylogenetic analysis of DNA sequences of nested PCR products revealed that there was a phytoplasma related to "Ca. Phytoplasma aurantifolia" in symptomatic almond trees found in the research areas. This study is the first to reveal the presence of phytoplasmas in almond production areas in Adıyaman province. Detection of the presence of phytoplasmas in almond cultivation areas is important in terms of understanding yield losses and taking quarantine measures.