Resumo

Physalis is an herbaceous species native to the Andes region. Currently, it is cultivated in various Brazilian states due to the economic interest of growers for this new fruit. Physalis plants grown in the field showed symptoms of shoot proliferation, leaf malformation, and chlorosis. Since these symptoms are commonly induced by phytoplasmas, this study investigated to confirm the presence of these prokaryotes in symptomatic plants. After DNA extraction from symptomatic and asymptomatic plants, phytoplasmas were found in all affected plants through the nested PCR. Examination by transmission electron microscopy (TEM) using appropriately prepared segments of leaf veins allowed the visualization of typical pleomorphic cells of phytoplasmas in the phloem of symptomatic plants. The computer-simulated RFLP patterns and the phylogenetic analysis allowed identifying the detected phytoplasmas as a 'Candidatus Phytoplasma fraxini'-related strain belonging to the 16SrVII-B subgroup. Moreover, physalis was identified as an additional host species for phytoplasmas in the 16SrVII group, expanding the current knowledge on the host range of phytoplasmas in this group.

Resumo

O açúcar de coco vem se tornando popular no Brasil e no mundo devido às alegações nutricionais de ser um adoçante natural e mais saudável em relação a outros açúcares. Sua produção ocorre de forma artesanal a partir da extração da seiva do floema da inflorescência da palmeira. Este trabalho teve por objetivo analisar microscopicamente a identidade e a presença de matérias estranhas em amostras de açúcar de coco, bem como verificar sua conformidade em relação às legislações sanitárias brasileiras. Foram analisadas 13 amostras comerciais de açúcar de coco da cidade de São Paulo quanto aos ensaios de pesquisa e identificação de elementos histológicos e pesquisa de matérias estranhas. A identificação de elementos histológicos vegetais revelou a presença de amidos morfologicamente semelhantes ao padrão de Triticum sp. (trigo), Manihot sp. (mandioca) e Oryza sativa (arroz), além de amidos alterados. Também foram encontrados elementos histológicos vegetais compatíveis com padrão de Saccharum officinarum (cana-de-açúcar) e de Cocos nucifera (coco). Todas as amostras analisadas continham matérias estranhas com predomínio de fragmentos de insetos em 100% delas. Os resultados do estudo indicam falhas nas Boas Práticas de produção do açúcar de coco e a necessidade da adequação deste produto em relação às normas vigentes.

Coconut sugar has become popular in Brazil and worldwide due to the nutritional claims of being a natural and healthier sweetener compared to other sugars. Its production takes places in an artisanal way from the extraction of phloem sap from the inflorescence of the palm. The aim of this work was to microscopically analyze the identity and the presence of foreign matter in samples of coconut sugar, as well as to verify its compliance with Brazilian health legislation. Thirteen commercial samples of coconut sugar from the city of São Paulo were analyzed for the research and identification of histological elements and foreign matter. The identification of vegetable histological elements revealed the presence of starches morphologically similar to the Triticum sp. (wheat), Manihot sp. (cassava) and Oryza sativa (rice) pattern, besides altered starches. Vegetable histological elements compatible with the Saccharum officinarum (sugar cane) and Cocos nucifera (coconut) pattern were also found. All samples analyzed contained foreign matter with predominance of insect fragments in 100% of the samples. The results of the study indicate flaws in the Good Practices for the production of coconut sugar and the need to adapt this product to current standards.

Resumo

Sesame (Sesamum indicum L.) plants exhibiting symptoms of phyllody disease were observed in commercial fields in Paraguay. The symptoms were indicative of infection by phytoplasmas. Thus, the present study investigated the association between affected plants and phytoplasma, which was later analyzed using molecular and phylogenetic methods. Total DNA was extracted from symptomatic and asymptomatic plants and used in nested PCR assays using primers R16SN910601/R16SN011119 and R16F2n/16R2. Amplified products of 1.2 Kb revealed the presence of phytoplasma in all diseased plants, and electron microscopy confirmed the presence of phytoplasmas within phloem vessels. Nucleotide sequences from sesame phytoplasma shared 99 % similarity with phytoplasmas belonging to group 16SrI. Computer-simulated RFLP indicated that the detected phytoplasma is representative of the 16SrI-B, therefore, a Candidatus Phytoplasma asteris-related strain. Phylogenetic analysis was in agreement with virtual RFLP. Our findings expand the current knowledge regarding distribution of representatives of the aster yellows group in a new agroecosystem and implicate sesame as a new host of 16SrI-B phytoplasma in Latin America.

Resumo

Trigona spinipes Fabricius (Apidae: Meliponini), is a common stingless bee widely seen in urban and rural areas in Brazil, popularly known as irapuá, arapuá or bee-dog. Although these bees are considered pollinators of some cultivated plants, they are better known for the damage they cause in different crops. During experimental agroecological cultivation of Artemisia (Artemisia annuaLinn, Asteraceae), in Jaguariúna (SP, Brazil), stingless bees Trigona spinipes (Fabricius) were observed sucking phloem sap directly from the plant, a phenomenon not yet described in scientific literature. This study aimed to register and describe the phloem sap-sucking behavior performed by T. spinipesfor the first time, as well as to assess the potential impact of this behavior on A. annuacultivation. The behavior and the material collected by bees and the severity of attack were also analyzed. The aging and premature death of observed A. annuaspecimens occurred because of extensive lesions caused by T. spinipes, confirming the negative consequence of sap-sucking attacks of T. spinipesbees on the plants. Factors that could induce this unusual behavior were presented, pointing out the need for future studies on the development of strategies to protect plants, without causing damage to the T. spinipesbee populations, which are elements of Brazilian bee fauna and, therefore, protected by law.