露地•ハウス栽培の桃色および赤色系トマト品種の果実の肥大•着色特性と高温期における色素の形成

Abstract

Fruit growth, coloring and pigment formation of 13 cultivars of pink and red tomatoes were investigated. Fruit growth and development of each cultivar grown in an open field or in a plastic greenhouse showed a similar tendency. The weight of individual fruits at 30 days after flowering was more than 30% of the final weight of ripe fruits of that cultivar and the weight of fruit at 40 days after flowering was more than 70% of the final weight of ripe fruit. At 45 days after flowering fruit weight was more than 80% of the final weight of ripe fruit, chlorophyll degradation had begun in the fruits, followed by carotenoid biosynthesis (turning stage) and the fruits were fully ripe within 710 days after reaching the turning stage.Color values, a/b ratio, of full-ripe fruits of pink and red tomato cultivars were 2.61.4 and 1.91.1, respectively. Color value of pink tomatoes was higher than that of red tomatoes. Pink and red cultivars contained 7080 μg colored carotenes per g fresh weight of full-ripe fruits grown in an open field or in a plastic greenhouse.Cultivars having a greater carotene content had better pigmentation after exposure to high temperature. The cultivars with a high carotene content included 'Fukuju No. 2' and 'Saturn' of pink tomatoes, and 'Moneymaker' and 'Red Cherry' of red tomatoes.