The extension of the growth period and enlargement of fruit induced by low temperature at the late phase of fruit growth in parthenocarpic tomato cultivars.

• Project/Area Number: 24580041
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Horticulture/Landscape architecture
• Research Institution: Ehime University
• Principal Investigator: KATAOKA Keiko 愛媛大学, 農学部, 准教授 (80204816)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥5,590,000 (Direct Cost: ¥4,300,000、Indirect Cost: ¥1,290,000); Fiscal Year 2014: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2013: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2012: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
• Keywords: トマト / 果実発育 / 低温 / 糖濃度 / ペルオキシダーゼ / 果実肥大 / 単為結果 / クライオミクロトーム / インベルターゼ / 低温耐性

Outline of Final Research Achievements

It has been suggested that the extension of the growth period and enlargement of fruit induced by low temperature at the late phase of fruit growth is common in tomatoes, because it has been observed not only in parthenocarpic cultivars, as expected at the start, but also in other cultivars, such as ‘Micro Tom’ and ‘Frutica’. At low temperature condition, the influx of photoassimilate was continued, although the fruit growth became slower, and the final fruit at ripening became larger because of the extension of the growth period. Furthermore, the sucrose content was increased remarkably, and the organic acid was reduced in low temperature treatment. This could be useful to improve the fruit quality.
Invertase and peroxidase were examined as the enzymes that participate in this phenomenon, but I could not find the clear evidence of this.