Analysis of the mechanism of flower color mutation in carnation MINAMI series (Hayato Morimoto)
Carnations that have various petal colors have been generated not only by conventional cross breeding, but also by bud sport. Flower color mutation by bud sport is thought to occur as a result of periclinal chimaeras or transposons, however, the mechanism is still unknown. To elucidate the mechanism of flower color mutation by bud sport, I used a mutant cultivar group (MINAMI series) showing various petal colors, which had occurred by bud sport. The MINAMI series includes 10 commercial cultivars showing cyanic or acyanic flowers that originated from a pale yellow-flowered genotype. Firstly, the composition of flower pigments was analyzed using HPLC. Cyanic cultivars of the MINAMI series had the highest content of pelargonidin 3,5-malyldiglucoside, which is an anthocyanin. However, acyanic cultivars of the MINAMI series had the highest content of chalcone 2'-glucoside, which contributes to yellow floral coloration. Secondly, to reveal the cause of the flavonoid component change in the MINAMI series, I investigated the extent of expression of several genes associated with flavonoid biosynthesis, i.e. dihydroflavonol reductase (DFR), chalcone glucosyltransferase (CHGT) and glutathione S-transferase (GSTF). The results showed that expression levels of some genes were different among these cultivars, suggesting that the amount of expression of these genes may determine the petal coloration in the MINAMI series.
Hayato Morimoto won an ISHS student award for the best oral presentation at the II Asian Horticultural Congress (AHC2016) in China in September 2016.
Hayato Morimoto, Laboratory of Floriculture, Faculty of Agriculture, Kagawa University, Miki-cho Kagawa 761-0701, Japan, e-mail: email@example.com