EFFECTS OF CPPU ON THE GROWTH, SUGAR ACCUMULATION AND ACTIVITY OF RELATED ENZYMES IN MELON FRUIT

The growth, sugar accumulation and carbohydrate metabolic enzyme activity in the seeded melon (Cucumis melo L.) and the parthenocarpic fruit induced by CPPU[1-(2-chloro-4-pyridyl)-3-phenylurea] were investigated.

CPPU promoted the growth of the fruit during the early growth stage (from anthesis through to the 15th day), but the growth rate was just slower than that of seeded fruit during the later growth stage.
The acid invertase activity in both the seeded and CPPU-treated fruits was highest on the 5th day after anthesis, but after that it declined as the fruit matured.
The activity in the CPPU-treated fruits was higher than that of seeded fruit during the early stage, but between the 25th and 40th day after anthesis it was lower.
The alkaline invertase activity was very much lower than the acid invertase activity in both control and treated fruits.
However, the changes in neutral invertase activity throughout fruit development were similar to the changes in acid invertase activity.
A close reverse relation between the growth curve and the invertase activity in melon fruit was recognized.

The sucrose content in the placenta of seeded fruit rapidly increased during the maturing stage, whereas in the placenta of CPPU-treated fruit (non-seeded) sucrose content increased only slightly, indicating that the seed is one of factors regulating sugar accumulation.
However, no relationship was found between the role of seed and Sucrose synthase or Sucrose phosphate synthase in the sucrose accumulation of melon fruit.

XXV International Horticultural Congress, Part 4: Culture Techniques with Special Emphasis on Environmental Implications

Y. Hayata, C. Yoshioka, Y. Niimi, L. XinXian

CPPU, enzyme, growth, melon, sugar

https://doi.org/10.17660/ActaHortic.2000.514.25