Onion is one of the most widely consumed vegetables. There are many cultivars, which are grouped according to skin color as yellow, white or red. Onions can also be classified as sweet or non-sweet. Their importance in cooking comes from their typical taste and flavour. The sugars, pyruvic acid accumulation and transcript level of some transcription factors involved in the biosynthesis of high sugars and pyruvic acid was analyzed at different stages of bulb onion (Allium cepa) growing under light and dark condition using High Performance Liquid Chromatography (HPLC) and Quantitative real time PCR. A genetic map and cultivar lines 36101and 36122 were used to identify transcription factors controlling pungency and sugar. We compared 2 different lines for low pungency and high sugars during water and photoperiod stress, which showed significant positive phenotypic and genetic correlations. These results could be presumably used as useful information to obtain onion varieties rich in sugars.
To effects of sex maturation in olive flounder by regulating long photoperiod, gonadal development and GTH mRNA expression in the pituitary were investigated. Photoperiod was treated natural photoperiod and long photoperiod (15L:9D) conditions from September 2011 to March 2012. The results showed that natural photoperiodic group showed a higher gonadosomatic index (GSI) than long photoperiodic group during the spawning season (March 2012). The histological analysis of ovarian tissue showed that natural photoperiod group of ovaries contained vitellogenic oocytes, but long photoperiod group of ovaries mainly contained perinucleolus staged oocyte and oil-drop staged oocytes. The FSH mRNA of olive flounder, under natural photoperiod group, showed a significantly higher expression but no significant difference under long photoperiod group. The LHβ mRNA showed a significantly higher expression only under natural photoperiod group. These results may suggest that long photoperiodic information regulates secretion of pituitary FSH and LH and maintain early growing stage of gonadal development in this species.