In recent years the number of phytoplasma diseases that negatively affect yield and quality of many plants has been increasing around the world. As is known grafting, plant propagation materials (seed, bulb, tuber), parasitic plants and insect vectors play active role in the spread of phytoplasmas causing these diseases. These organasim which get through plate in the sieve tube element and systemically colonize the plant, it invade and multiply salivary glands, midgut, heomocel, brain and fat tissue after sucking up insect body with stylet. Subsequently they continue the cycle by moving to a new plant with a diseased insect feeding on a healthy plant. Although the existence of functional genomics in this cycle is known, there is little information about transmission of phytoplasma from vector to host plant or from host plant to vector, the mechanism of disease caused by phytoplasma in the plant and genomics involved in different reactions in the host plant against phytoplasmal infection.

Para establecer si la aplicación de ácido incrementa el efecto benéfico del desmane sobre las características del racimo de plátano Dominico Hartón, se llevó a cabo un experimento en la granja Montelindo (Palestina, Caldas). Quince días después de floración los racimos se dejaron con seis manos. El ácido giberélico, 1.000 mg L-1, se aplicó a los 15, 45 y 75 después de floración. Se empleó un diseño en bloques completos al azar con cuatro repeticiones, en un arreglo factorial de 2 x 2 x 3 (desmane, aplicación de la hormona, época de aplicación). El desmane mejoró significativamente el peso del racimo; la aplicación de ácido giberélico, incluso en racimos sin desmane, también mejoró significativamente la calidad de los frutos; la época de aplicación de la hormona causó aumentos altamente significativos en el peso del racimo de la primera mano y en el peso promedio del dedo; el mejor efecto sobre las características del racimo se logró con el desmane y la aplicación de la hormona a los 15 días después de la floración. | To establish whether the application of gibberellic acid increases the dehandling beneficial effect on bunch characteristics of the Dominico Harton plantain, an experiment was carried out at the 'Montelindo' farm (Palestina, Caldas). Fifteen days after flowering bunches were left with six hands. Gibberellic acid applications, 1000 mg L-1, were made at 15, 45 and 75 days after flowering. A complete randomized design with four replications was used in a factorial arrangement of the treatments of 2 x 2 x 3 (dehandling, hormone application, time of application). Dehandling significantly improves bunch weight; hormone application, even in bunches without dehandling, also significantly improves fruit quality; the time of hormone application caused highly significant differences in bunch weight, first hand weight and average finger weight; the best effect on bunch characteristics is obtained with the dehandling and hormone application 15 days after flowering.

A resposta das plantas à salinidade depende de fatores fisiológicos, bioquímicos e genéticos. Com este trabalho, objetivou-se estudar o impacto do tempo de aclimatação à solução nutritiva sobre a resposta do cajueiro à salinidade. Plantas de Anarcadium occidentale L., CCP06, cultivadas em vermiculita durante 28 dias, foram transferidas para solução nutritiva de Hoagland com 1/10 de sua força iônica, onde permaneceram por 1 e 7 dias. Ao final dos dois tempos, a solução nutritiva foi suplementada com 200 mM de NaCl, condições em que as plantas foram cultivadas por 0, 12, 24, 48 e 72 h. As plantas aclimatadas por 7 dias á solução de Hoagland apresentaram sinais fisiológicos mais compatíveis com a tolerância ao NaCl, como menor acumulação de Na+ e, também, menores danos nas membranas, peroxidação dos lipídeos, degradação de proteínas, acumulação de aminoácidos livres e acumulação de prolina. A amônia livre foi o melhor indicador da intensidade do estresse salino. Os danos de membranas aumentaram com a acumulação de Na+ nas folhas. Os resultados evidenciam que o tempo de aclimatação das raízes à solução nutritiva influencia a expressão de fatores capazes de atenuar os efeitos do estresse salino.<br>The plant response to salinity depends on physiological, biochemical and genetic factors and on their interaction with external environment. This work aimed to study the impact of adaptation time in nutrient solution on the cashew response to salinity. Seedlings of Anacardium occidentale L (CCP06) grown in vermiculite, for 28 days, were placed to grow in 1/10 ionic strength Hoagland solution for 1 and 7 days. At the end of each time the solution was supplemented with 200 mM NaCl, and under this condition the plants were monitored for 0, 12, 24, 48 and 72 h. The 7 days Hoagland solution acclimated plants had physiological index more compatible to tolerance to NaCl such as low Na+ accumulation and also low membrane damage, lipid peroxidation, protein degradation and free amino acids and proline accumulation. The free ammonia was the best index to predict the salt stress intensity. Membrane damage increased with Na+ accumulation in the leaves. The results evidence that the root adaptation time in Hoagland solution has influence on the expression of factors capable to alleviate the salt stress effects.