Symptoms resembling giant calyx, a graft-transmissible disease, were observed on 1-5 % of eggplant (aubergine; Solanum melongena L.) plants in production fields in Sao Paulo state, Brazil. Phytoplasmas were detected in 12 of 12 samples from symptomatic plants that were analysed by a nested PCR assay employing 16S rRNA gene primers R16mF2/R16mR1 followed by R16F2n/ R16R2. RFLP analysis of the resulting rRNA gene products (1.2 kb) indicated that all plants contained similar phytoplasmas, each closely resembling strains previously classified as members of RFLP group 16SrIII (X-disease group). Virtual RFLP and phylogenetic analyses of sequences derived from PCR products identified phytoplasmas infecting eggplant crops grown in Piracicaba as a lineage of the subgroup 16SrIII-J, whereas phytoplasmas detected in plants grown in Braganç a Paulista were tentatively classified as members of a novel subgroup 16SrIII-U. These findings confirm eggplant as a new host of group 16SrIII-J phytoplasmas and extend the known diversity of strains belonging to this group in Brazil. INTRODUCTIONEggplant (aubergine; Solanum melongena L.) is among the most important edible crop species grown in Brazil. Sao Paulo state is a leader in the production of this crop, where it is currently cultivated over 1037 ha, with a total annual yield of 47 549 tonnes (figures for 2009). A disease of low incidence affecting approximately 1-5 % of plants was recently observed in fields of eggplant grown in Bragança Paulista and Piracicaba. Symptoms of affected plants included foliar chlorosis, shoot proliferation, shortened internodes, stunting, enlarged calyces, small flowers and fruit of reduced size. Collectively, these symptoms closely resembled those described previously for giant calyx, a disease of eggplant first reported to occur in Brazil during the 1990s (Boiteaux et al., 1994). The latter disease was suspected to have a phytoplasma aetiology based on consistent observation by electron microscopy of phytoplasma cells in the phloem sieve elements of diseased plants. A subsequent investigation of DNA extracts derived from diseased eggplants in Sao Paulo state and Brasília-DF by PCR-RFLP analysis concluded that phytoplasmas associated with eggplant giant calyx were most similar to strains previously classified as members of 16Sr RFLP group 16SrIII, subgroup B (16SrIII-B; Barros et al., 1998).Eggplant diseases associated with phytoplasmas have been reported in other countries. In Japan, a phytoplasma affiliated to group 16SrI was characterized molecularly from eggplant with dwarfing symptoms (Okuda et al., 1997;Lee et al., 1998). A disease called little leaf was reported in Bangladesh and molecular identification indicated that the phytoplasma belonged to group 16SrVI (Siddique et al., 2001). The study also demonstrated the phytoplasma to be indistinguishable from brinjal little leaf (BLL) phytoplasma characterized previously in India (Lee et al., 1998; Seemüller et al., 1998). Recently, the BLL strain was classified as a member of group 16SrVI, subg...

Erigeron sp. plants showing symptoms of witches' broom and stunting were found near orchards of passion fruit in Sã o Paulo state, Brazil. These symptoms were indicative of infection by phytoplasmas. Thus, the aim of this study was to detect and identify possible phytoplasmas associated with diseased plants. Total DNA was extracted from symptomatic and asymptomatic plants and used in nested PCR conducted with the primer pairs P1/Tint and R16F2n/16R2. Amplification of genomic fragments of 1.2 kb from the 16S rRNA gene confirmed the presence of phytoplasma in all symptomatic samples. The sequence identity scores between the 16S rRNA gene of the phytoplasma strain identified in the current study and those of previously reported 'Candidatus Phytoplasma fraxini'-related strains ranged from 98 % to 99 % indicating the phytoplasma to be a strain affiliated with 'Candidatus Phytoplasma fraxini'. The results from a phylogenetic analysis and virtual RFLP analysis of the 16S rRNA gene sequence with 17 restriction enzymes revealed that the phytoplasma strain belongs to the ash yellows phytoplasma group (16SrVII); the similarity coefficient of RFLP patterns further suggested that the phytoplasma represents a novel subgroup, designated 16SrVII-D. The representative of this new subgroup was named EboWB phytoplasma (Erigeron bonariensis Witches' Broom).

Begonia is a very appreciated genus of ornamental plants, of economic relevancy, having species of flowers and foliage. In commercial croppings, plants exhibiting characteristic symptoms of phytoplasma infection have been observed, such as shoot proliferation, reduced plant, size small leaves and flowers, and phyllody. Leaves were sampled and total DNA was extracted to be used in nested Polymerase Chain Reaction (PCR), in order to detect and identify an expected phytoplasma. The results confirmed consistently the presence of a phytoplasma associated with symptomatic plants through the amplification of a typical genomic fragment of 1.2 kb by using the universal primers R16mF2/mR1 and R16F2n/R2. The use of specific primers R16(III)F2/R1 allowed to identify the phytoplasma detected as a representative of the group 16SrIII. This information is very expressive, because different diseases caused by fungus, bacteria, virus and nematodes have been reported for begonia, however, reports have not been found for begonia diseases associated with phytoplasmas. Key words: Mollicutes, yellows, phytopathogenic prokaryotes ASSOCIAÇÃO DE FITOPLASMA AO SUPERBROTAMENTO DE BEGÔNIARESUMO: Begônia é um gênero muito apreciado de plantas ornamentais, de relevância econômica, compreendendo espécies de flores e de folhagem. Em cultivo comercial foram observadas plantas apresentando sintomas característicos de infecção por fitoplasma, entre eles superbrotamento de ramos, redução no porte da planta, folhas e flores pequenas e filodia. A partir de amostras foliares foi feita extração de DNA para ser usado em duplo Polymerase Chain Reaction (PCR), visando 'a detecção de fitoplasma em tecido doente e a sua identificação ao nível de grupo de classificação. Os testes revelaram consistemente a associação de fitoplasma com os sintomas da doença, através da amplificação de um fragmento genômico típico de 1,2kb para os iniciadores universais R16mF2/mR1 e R16F2n/R2, usados na reação de PCR. O emprego de iniciadores específicos R16(III)F2/R1 permitiu identificar o fitoplasma detectado como um representante do grupo 16SrIII. Este é um resultado expressivo, pois diversas doenças causadas por fungos, bactérias, vírus e nematóides têm sido relatadas para begônia, no entanto, não têm sido encontrados relatos para doenças de begônia associadas a fitoplasmas.

No abstract

A Agroecologia vem se constituindo como uma das bases de um novo paradigma de Desenvolvimento Rural e, nessa abordagem, a Extensão Rural é um instrumento fundamental no processo de construção de saberes: agentes da extensão rural são agentes de transformação. Este trabalho evidencia ações em Extensão Universitária, pautadas no conceito de Extensão Rural Agroecológica, que vêm acontecendo, por iniciativa de educandos, no Centro de Ciências Agrárias da Universidade Federal de São Carlos (Campus Araras), desde 2009.