The fruit growth of the snake melon (Cucumis meloL. var. flexuosus Naud) and the plant hormones contained in its immature fruit were investigated. The fruit growth started 5 days after pollination and its rapid growth continued for about 10 days. During this period the growth rate (length) was 9 cm per day. The final size of the fruit was about 120 cm in length and 6 cm in width 25 days after pollination. The cell number of the fruit increased to more than twice that of the fruitlet before pollination. The increase started immediately after pollination and stopped at 10 days after pollination. On the other hand, no change in cell size was observed during the first 7 days after pollination. After this period, rapid growth started and continued to the end of the fruit growth. The cell size increased to more than 7 times that of the fruitlet before pollination.In rapidly developing immature fruit including placenta and immature seeds,trans-zeatin riboside (ZR) and ABA were identified with gas-liquid chromatography-selected ion monitoring or gas-liquid chromatography-mass spectrometry analysis. In addition, the presence oftrans-zeatin (Z) and another very polar cytokinin, and a novel gibberellin-like substance which is probably an isomer of GA3was suggested. The possible significance of these plant hormones in fruit growth is discussed.
展开▼
