Physiological and biochemical characterization of jiló seeds (Solanum gilo) in different harvest times

Abstract

The evaluation of seed quality during the development process is important for the definition of the moment of harvest. In this context, the objective in this study was to evaluate the quality of Jiló seeds during development through physiological, biochemical and electrophoretic tests of enzymes. Six genetic materials, JIL white, JIL 001, JIL 005, JIL 006, H1 and H2 were used. Fruits were harvested at 35, 40, 45 days after anthesis (DAA). A total of 50% of all fruits harvested at 45 DAA remained at rest for seven days which were labeled as 45 DAAr. The seeds at each maturation stage were extracted from the fruits and evaluated by water content, weight of one thousand seeds, electric conductivity, germination, germination speed index, seedling emergence, and seedling emergence rate index. The chemical composition of the seeds was also evaluated, as well as the expression of the enzymes esterase, isocitrate lyase, malate dehydrogenase, alcohol dehydrogenase, superoxide dismutase, catalase, peroxidase and endo-β-mannanase. The highest values of germination and vigor were found in seeds harvested at 45 DAA and 45 DAAr, mainly for hybrids H1 and H2. The highest values of lipids and proteins and lower carbohydrates were found in the most immature seeds of Jiló. The enzymes analyzed showed higher expression in the initial stages of development, however reduced with the advancement of the maturation stage. Endo-β-mannanase expression increased with seed development. Jiló seeds harvested at 45 DAAr presented the highest of germination and vigor values. This “being” considered as the ideal harvest point.