This work aimed to control leaf abscission of seedlings of angico using AgNO3 and CoCl2 and evaluate the effect of the paclobutrazol on the in vitro behavior of seedlings. The seeds were disinfected and inoculated in Petri plates containing germtest paper, previously sterilized and imbibed in sterile water. The plates were kept in the dark for two days, until seed germination. Seeds were transferred to test tubes containing WPM medium. In the first experiment, the culture medium was supplemented with different concentrations of (0.0; 5.0; 10.0; 20.0; 40.0 µM) and types (AgNO3 and CoCl2) of ethylene inhibitors. In the second experiment, the medium was supplemented with different concentrations (1.7; 3.4; 6.8; 13.6 µM) of paclobutrazol. There was increase in the number of leaves and reduction in foliar abscission with 10 and 20 µM respectively, independent of the used ethylene inhibitor. Both the AgNO3 and the CoCl2 helped to increase the number of buds and shoots. The increase in the concentration of paclobutrazol reduced seedling growth, with lower means for the variables - length of aerial part, number of leaves, number of senescent leaves and dry matter of the aerial part in the highest concentration (13.6 µM) of paclobutrazol. This growth inhibitor had also effects on the root system, reducing root length and number of secondary roots, however promoting root thickening.
Angico; paclobutrazol; AgNO3; CoCl2
