Alterações fisiológicas e bioquímicas durante a germinação de sementes de café (coffea arabica L.) cv. Rubi

Abstract

Coffee propagation is performed through seedlings from seeds. However, germination in coffee seed is slow and uneven. Therefore, this work had the objective of studding the physiological aspects of seed germination in Coffea arabica cv. Rubi. There were evaluated effect of light, gibberellins and paclobutrazol (inhibitor of gibberellins biosynthesis) during seed germination. Seeds after treatment with light, gibberellins and paclobutrazol were subjected to electrophoresis analysis of proteins resistant to heat( LEA proteins) and the enzymes (catalase, superoxide dismutase and peroxidase), determination of sugar content (sucrose, mannose, glucose, fructose, galactose, raffinose and staquiose), the activity of endo-b-mannanase, the enzyme polyphenoloxidase and percentage of polyphenols in each time of imbibition. The speed of seed germination was inhibited in seeds treated with gibberellins. The paclobutrazol decreased speed of seed germination did not decrease the effect of light. Higher speed of germination was observed under absence of light. Regarding the patterns of isoenzymes and proteins there were changes during seed germination. Sucrose and mannose act during seed germination. The enzyme end-b-mannanase increased its activity in seeds imbibed under the presence of light and gibberellins. The enzyme polyphenoloxidase decreased its activity whereas polyphenols increased during germination.