Gravi malformazioni in melanzana in Sicilia associate alla presenza di fitoplasmi

Stunting and leaf malformation were repeatedly observed during vegetative growth in eggplant cultivations located in Sicily (Ragusa). Symptoms appear during first weeks after transplantation, and modify normal shape of plants as well as decrease their production, in several cases stunting was present but only in half of the plant. The disease was scattered distributed in the fields and with percentages below 10%. Samples were collected from symptomatic and asymptomatic plants, and shoots and midribs were used for nucleic acid exstraction to verify possible phytoplasma presence and identity. Nested PCR assays with primers P1/P7 followed by R16mF1/R16mR1 (Gundersen and Lee, 1996) allow to obtain bands of the expected lenght, about 1,500 bp, only from symptomatic samples. Sequencing of one of the amplicons after purification with NucleoSpin kit (Macherey-Nagel) was obtained with primers R16mF1, R16mR1 and M1 (Gibb et al, 1995); a 1,379 bp sequence fully homologous to phytoplasma related to ‘Candidatus Phytoplasma aurantifolia’ was obtained, in particular the 16Sr sequence obtained was identical to the one described in cactus pear with malformation symptoms in Sicily (AY995133; Granata et al., 2006). Reamplification of positive samples with primers R16F2/R2 followed by RFLP analyses with TruI, Hpy8I and TaqI allow to classify the eggplant phytoplasma in the 16SrII-C subgroup. This is the fist identification of phytoplasmas of this subgroup in eggplant, the species is however quite susceptible to phytoplasma infection worldwide since these prokaryotes were identified in Bangladesh (16SrI), Turkey (16SrVI) and Brazil (16SrIII). In Southern Italy phytoplasma symptoms were described in eggplant and attributed to stolbur, however molecular identification was not carried out (Polizzi et al., 1990).