Desenvolvimento de um protocolo para crioconservação de sementes de jatobá: controle de patógenos e cinética de congelamento.

Abstract

This work has the objective to determine the study of micoflora seed and the husk of jatoba, to study the fungus control for the fungus identified in the seeds, to determine some constitution characteristics of the seeds (dimension, volume, circular form, spherical form and density), to obtain the freezing curves of seeds for the temperatures - 30°C, -150°C, -170°C and -196 °C and to conserve the seeds in the temperatures studied, for the test of the micoflora went applied the pulp, the almond of the seed and the husk of jatoba, for the test of fitosanidade went applied the fungicides benomyl, captan, thiovit, benomyl e thiovit e o hipoclorito of sodium, for the to obtain the freezing curves at -30°C to make use of a conventional refrigerator, for -150°C went created a system that to obtain the temperature, at -170°C went realizied with the seeds exposes to liquid nitrogen vapour and the -196°C the seeds went submergeds in the liquid nitrogen, the conservation of the seeds realizied itself on the temperatures -30, -150, -170 an -190°C. with base in the results obtained can conclud that:,a) all the parts of the seeds and o f husk of jatoba present fungus incident, was indentified the fungus aspergillus sp,, aspergillus flavus, fusarium sp. e rhyzopus; b) to fungus control, the best treatment was with benomyl and captan; c) to seeds of the extremities of the husk, the necessary time to reach the geometric center of the seeds on temperature -196°C was 2 minutes, to -170°C was 18 minutes, to -150°C was 13 minutes and 60 minutes for the temperatura -30°C, to middle seeds of the husk, the necessary time was 2 minutes for -190°C, 12 minutes for -170°C, 10 minutes for -150°C and 50 minutes for the temperature -30°C; d) the thermical diffusivity wiht the fick's equation, to the seeds of the extremities husk varied 3,56201 x 10 "7 to 181, 7532 x 10"7 m2/s and to the seeds of the midle husk 1,21862 x 10 "6 to 32,9786 x 10"6 m2/s, to the Page's equation the thermical diffusivitty for the the seeds of the extremities varied 2,08404 x 10"7 to 183, 866 x 10"7 m2/s and to the seeds of the middle husk 3,54546 x 10"6 to 32, 4027 x 10"5 m2/s; e) the conservation in -196°C reported fissures so that remained impossible the process, the temperatures at 30, -150 and -170°C, didn't reported fissures, therefore recommed for the conservation for indeterminate time the temperature at - 170°C, that showed also tests of the germination and strength, high percentage.