Horticultural Science and Technology ISSN:1226-8763(Print) 2465-8588(Online) 원예과학기술지

This study was conducted to evaluate parthenocarpy in two butternut squash lines held at an institute and to determine differences in the fruit development and other characteristics among pollinated, hormone-treated, and unpollinated fruits The material seeds were seeded in 50-hole plug tray which were raised on seedling stage in Kangwon National University greenhouse on April 20th. Once the material reached the stage, they’d been planted in a plastic greenhouse of Kangwon National University on May 20th. The plants were then separated into pollinated, hormone-treated, and unpollinated groups, and the fruit length, width, and degree of development were measured using a non-destructive method. The fruit and seed characteristics of harvested fruits were examined one month after ripening. The unpollinated fruits of both cultivars of set fruit and showed a weight, total soluble solid content, and fruit section area similar to those of the pollinated fruits. There were differences in the morphology; the placental region of the unpollinated fruit of the 17R-1s sample set was inferior in terms of developed to the pollinated fruit, and the placental region of 19-7s was shorter than that of the pollinated fruit. Additionally, the seeds of unpollinated fruits, i.e., traces, were undeveloped. Fruit treated with 2,4-dichlorophenoxyacetic acid (2,4-D), which induces parthenocarpy, developed with a morphology identical to that of pollinated fruit, and the corresponding seeds developed despite being unfertilized, but without embryos. This study reports the genetic resources of two cultivars (17R-1s and 19-7s) with parthenocarpic traits. Furthermore, the cultivars used as plant materials in this study are valuable as breeding materials for developing parthenocarpic squash cultivars.