INFLUENCIA DE UN POLÍMERO DE QUITOSANA EN EL CRECIMIENTO Y LA ACTIVIDAD DE ENZIMAS DEFENSIVAS EN TOMATE (Solanum lycopersicum L.) Influence of a chitosan polymer in the growth and the induction of defensive enzymes in tomato (Solanum lycopersicum L.)

Palabras clave: tomate, crecimiento, plantulas, raices, tallos ABSTRACT. The aim of this work was to evaluate the effect of chitosan in growth and induction of defence responses in tomato (Solanum lycopersicum L.). Tomato seeds from the Amalia cultivar, were imbibed 4 hours in chitosan solutions of 0,1, 1,0, 2,5 y 10 g.L -1 . Besides, plants of 21 days were sprayed with chitosan concentrations of 0,1, 1,0 y 2,5 g.L -1 . Root length, stem length, protein concentrations, and the induction of β-1,3 glucanase and phenylalanine ammonia-lyase (PAL) activities were evaluated in several moments. Results showed that the length of the root and the stem were incremented in dependence of chitosan concentration, but not the total dry weighs. The highest increment in PAL activity in relation to control was observed when the seeds were treated at concentration of 0,1 g.L -1 of chitosan, while foliar aspersion treatments did not showed significances differences in this parameter. The seeds treatments with chitosan at concentrations of 2,5 y 10 g.L -1 induced increases in the β-1,3 glucanase activity, but foliar sprays of 0,1g.L -1 showed the highest levels of this enzymatic activity. These results suggested that chitosan induce defensive and growing responses in tomato which depends of concentrations and application manner. RESUMEN. El objetivo del trabajo fue evaluar el efecto que ejerce la quitosana sobre algunos parametros asociados al crecimiento y la induccion de respuestas defensivas en tomate (Solanum lycopersicum L.). Para ello se embebieron semillas del cultivar Amalia durante 4 horas en las concentraciones de quitosana 0,1, 1,0, 2,5 y 10 g.L -1 . Ademas, plantulas de 21 dias de germinadas se asperjaron foliarmente con concentraciones de 0,1, 1,0 y 2,5 g.L -1 de quitosana. Se evaluo la longitud de las raices y el tallo, el peso seco de las plantulas, asi como la concentracion de proteinas totales