Phytochrome Regulation of Seed Germination in a Dwarf Strain of Watermelon1
in Journal of the American Society for Horticultural ScienceAbstract
Continuous, low intensity, far red (FR) irradiation prevented germination, and continuous, low intensity, red (R) irradiation decreased the rate of germination of seed of dw-2 dwarf watermelon [Citrullus lanatus (Thunb.) Matsumara and Nakai]. Intermittent, 15 minute light treatments with R or FR at 6 hour intervals affected germination similarly to continuous irradiations. Seeds germinated best in darkness and would germinate in darkness following prolonged incubation in FR light. A short exposure to R light following a prolonged FR treatment enhanced subsequent germination in darkness (D), and the effect of R light was reversed by a short exposure to FR light, indicating phytochrome control of germination. Responses to single, short exposures to FR light after different periods of incubation, and to different intervals of D and prolonged FR light, indicated that germination of dwarf watermelon seeds is regulated by phytochrome between about 6 to 24 hours of incubation at 29 to 30°C.
Contributor Notes
Received for publication September 22, 1978. Published with approval of the New Hampshire Agriculture Experiment Station as Scientific Contribution No. 926.
Present address: Department of Agronomy, University of Missouri, Columbia 65211.
