The role of selected Auchenorrhyncha species (Hemiptera: Cicadomorpha Fulgoromorpha) in a transmission of'Candidatus Phytoplasma asteris' phytoplasma - a causal factor of oilseed rape phyllody

摘要

Phytoplasma that belongs to the aster yellows (AY), 16Srl-B subgroup and causes characteristic deformations of winter oilseed rape plants (Brassica napus) has been observed in Poland more then a decade. The diseased plants exhibit phyllody of flowers, which lead to siliques malformations and losses in seed production. The aim of this study was to find a natural insect vector of AY involved in epidemiology of oilseed rape phyllody disease in Poland. Two species: Macrosteles laevis and Psammotettix alienus were selected as potential vectors and adult leafhoppers of these species were placed in cages with phytoplasma infected oilseed rape. After acquisition period, individuals of each species were transferred to cages containing healthy seedlings of testplants: summer and winter oilseed rape (B. napus), barley (Hordeum vulgare), Madagascar periwinkle (Catharantus roseus) and broad bean (Vicia faba). After inoculation, the insects were examined for phytoplasma presence in their tissue by sequencing PCR (polymerase chain reaction) products. Only M. laevis leafhoppers tested positive. The test plants were analyzed in the same manner. The disease agent was transmitted by the M. laevis, to barley, periwinkle and broad bean, but not to oilseed rape.