Developmental of protocol for micrograffiting to tomato Lycopersicon esculentum Mill/Desenvolvimento de protocolo para microenxertia do tomateiro Lycopersicon esculentum mill

The bacterial wilt, caused by Ralstonia solanacearum, is the most important vascular disease among plants in the world. The causal agent is a strain of bacteria found in all regions of Brazil, mainly in places with high humidity and temperature. This bacterium is difficult to control with chemical products, being able to survive in diverse hosts, especially in species of Solanaceae as well as other families of great food, condimental, or medicinal importance. The use of species of the genus Solanum has been attempted, but the practice of grafting and micrografting of tomato Lycopersicon esculentum is limited by incompatibility. In this work, the micrografting method was used to obtain resistant plants using the species Solanum palinacanthum Dun., which features a series of interesting characteristics from a commercial point of view, mainly the resistance to diseases that are difficult to control, as in the case of bacterial wilt. For this, two methods of micrografting were used-the conventional inverted T method; and the Bisel cut method. The experiment was submitted to five evaluations in weekly intervals. It was determined that MS salt medium in the 1/8 concentration, added to sucrose (30 g [L.sup.-1]), showed to be suitable for the practice of micrografting using the inverted T method. Key words: Solanaceae, bacterial wilt, Ralstonia solanacearum, micropropagation, in vitro culture. A murcha bacteriana, causada por Ralstonia solanacearum, e a principal doenca vascular de plantas em todo o mundo. O agente causal e uma bacteria que ocorre em todas as regioes do Brasil, predominando em condicoes de umidade e temperatura elevadas, fatores propicios ao desenvolvimento do patogeno. Este agente causal e de dificil controle, pois sobrevive nos mais diversos hospedeiros, especialmente Solanaceas, alem de outras familias de importancia alimentar, condimentar e medicinal. O uso de especies do genero Solanum na enxertia convencional e minienxertia em tomateiro Lycopersicon esculentum e limitada em funcao da incompatibilidade. Neste trabalho, utilizou-se o metodo da microenxertia para obtencao de plantas resistentes a doencas como a murcha bacteriana, tendo como cavalo a especie Solanum palinacanthum Dun. Utilizaram-se dois metodos de microenxertia: convencional em T-invertido e corte em bisel. Foram testados meios de culturas para execucao das duas praticas de micropropagacao; para isso, realizou-se experimento em diferentes condicoes ambientais, com presenca e aus