Qualidade de mudas e aspectos fisiológicos, bioquímicos e biofísicos de sementes de café armazenadas

Abstract

The poor longevity of coffee seeds is a limiting factor in the production system and which has direct reflexes on the farmers´ competitiveness, which become subject to production of seedlings in times unfavorable to the establishment of the crop in the field. Therefore, this work was conducted with the purpose of broadening the knowledge about the physiological, biochemical and molecular in the seeds of Coffea arábica L. of varying ages by utilizing different drying methods and chemical treatment over the storage. The fruits of cultivars Rubi, Acaiá and Catuaí at the berry stage were collected, pulped, without mucilage by fermentation at 30oC for 24 hours. The seeds were submitted to conventional drying (in the shade) and drying in stationary dryer at the temperature of 35ºC. Further, seeds with no drying were analyzed. The evaluations were done immediately after the drying treatments and after three, six and twelve months of storage. The seeds wee stored at 10ºC in plastic and air-tight packages. The tests of germination, emergency, electrophoresis analyses, health analysis and thermal analyses were done. It follows that there is a reduction of the quality of the moist seeds during the storage. Less activity of the free-radical removing enzymes is found in moist seeds, independent of the storage season. The chemical treatment of coffee seeds before storage impairs the seedlings´ development. Seedlings done from moist seedlings have better development when they are utilized fresh-collected. The results of the thermal analyses point that the sensitivity of coffee seeds to dissection and short longevity are not related to the thermal properties of water to the formation of intracellular glasses.