Survey and Molecular Characterization of Phytoplasma Incidence in The Pepper Crop Grown in The Fields of Aleppo Governorate, Syria.

Abstract

The pepper crop is an important dietary vegetable grown in Aleppo Governorate. A field survey for phytoplasma infection was conducted during the 2022 growing season in 9 fields distributed in Deir Hafer, Al-Safira, and Kuweres, and the observed symptoms caused by phytoplasma were described, and 22 samples with disease symptoms were collected. The genomic DNA was extracted and characterized for its concentration, purity, and integrity. Nested PCR was performed in two stages using two primers pairs P1/P7 and R16F2n/R16R2 to detect the phytoplasma infection. For PCR-RFLP technique, the PCR products of stage II were digested with six restriction enzymes: AluI, HinfI, BamHI, EcoRI, HhaI and Rsal. The digestion products were separated on 2% agarose gel, and the results were compared with reference studies to identify the molecular groups based on the 16S rRNA gene in phytoplasma. The average phytoplasma incidence was around 2, 3 and 1% in Deir Hafer Al -Safira, and Kuweres, respectively. Based on PCR results, all pepper samples tested were 100% infected with phytoplasma. The results of enzymatic digestion with four restriction enzymes AluI, HinfI, HhaI, and Rsal showed incomplete profile match between the isolates and the revised classification scheme of phytoplasma. Therefore, DNA sequencing for 16S RNA gene is required for the classification of molecular groups of phytoplasma based on the available restriction sites.

Keywords:

Pepper, phytoplasma, molecular characterization, PCR-RFLP.