Screening and molecular analysis for phyllody disease resistance in sesame genetic stock

The study was conducted to screen 542 sesame genotypes for phyllody disease resistance in the growing years of 2012, 2013 and 2014 in Antalya. The augmented experimental design was used for the field trials. Sesame plants in the field were scored for the disease according to 1-5 scale. The genotypes identified resistance the disease under field conditions were further confirmed under greenhouse condition. Phytoplasma infected and healthy sesame plant leaf samples were collected in the field and the greenhouse. DNAs were isolated from selected samples which were analysed by direct, nested and real-time PCR methods. P1-P7 primers used in direct PCR produced 1800 bp amplicons. Primers of R16F2n- R16R2 and Fu5-Ru3 were also used in nested PCR and they produced 1240 bp and 880 bp products, respectively. Sequencing of PCR amplicons and RFLP analyses of those products were realized, too. The phytoplasmas were classified into pigeon pea witches'-broom (16SrIX-C) and peanut witches'-broom (16SrII-D) groups based on the data. New primers and probes were designed for real-time PCR from sequencing of the PCR amplicons so that the detection of the disease and the relative quantification of resistance level in sesame genotypes were determined, simultaneously. Orosius orientalis was identified as the vector insect of phyllody in sesame. Using with grafting and the insect vector were successfully transferred to healthy plants. As a result, genotypes ACS38 and ACS102 were found resistant to phyllody disease.