Abstract
Common Japanese eggplant varieties are non-parthenocarpic and need 4-CPA treatment to bear fruit in forcing culture. Performing this treatment is quite time consuming, and culturing parthenocarpic eggplant require fewer working hours. Therefore, we examined the effects of seasons and air temperatures on fruit setting and the growth of parthenocarpic eggplant lines in forcing culture. We classified parthenocarpic eggplant lines by three stable parthenocarpic eggplant lines and two unstable lines in the preliminary test. The fruit setting percentages of all parthenocarpic eggplant lines in autumn and spring were lower than those in winter. The fruit growth percentages of all parthenocarpic eggplant lines in autumn, winter and spring were very high in greenhouse test. Although the fruit setting percentages of all parthenocarpic eggplant lines were equal in winter, the fruit setting percentages of the three stable parthenocarpic eggplant lines were higher than those of the two unstable lines in autumn and spring. These results suggest that it is important for breeding of parthenocarpic eggplant varieties to select stable parthenocarpic eggplant lines in autumn or spring.
