INFLUENCE OF GENOTYPE, AGE OF FRUIT AT HARVEST AND AFTER-RIPENING ON SEED QUALITY IN GARDEN EGGS (Solanum aethiopicum)
The objective of this study was to determine the influence of genotype, age of fruit at harvest and after-ripening on seed quality of Solanum aethiopicum (Solanum gilo). Two genotypes of garden egg, Legon One (L1) and Kpando Nice (KN), were used in the study. Seeds from three fruit maturity stages, mature white (MW), yellow ripe (YR) and red ripe (RR), were investigated together with treatments of mature white (MWA), yellow ripe (YRA) and red ripe (RRA) fruits that had gone through after-ripening to soft-red stage. Genotype L1 had better vegetative and fruit characteristics in terms of number of days to flowering, number of days to fruiting, fruit size and weight than genotype KN which was also better in number of seeds per fruit, 100 seed weight, germination percentage, number of leaves per plant, seedling height and seedling vigour except seedling weight which the two were not different from each other. Fruits harvested at the red-ripe and stage produced the highest number of seeds per fruit, germination percentage and early seedling growth characteristics whilst fruits harvested at the mature white stage had the lowest of the characteristics stated above. Postharvest ripening to the soft-red stage improved seed characteristics of fruits harvested at the mature-white and yellow-ripe stages and enhanced the number of seed per fruit, germination percentage and early seedling growth characteristics. Flavonoid content in seeds increased with increasing maturity. Also the after-ripened treatments of flavonoid were better than the ones that did not go through after ripening. Fat percentage in genotype L1 was highest in YR followed by RR and the least MW but in genotype KN, fat percentage increased from MW to RR and the least YR. Total phenolic and protein contents were basically the same in both genotypes L1 and K. However, KN was better in flavonoid and carbohydrate content but not in fat content than L1. There were both negative and positive correlations between germination, early seedling growth characteristics and phytochemical levels in the seeds.