丝瓜的光周期反应

本文研究了普通丝瓜(Luffa cylindrica Roem.)和有棱丝瓜(L. acutan-gula Roxb.)的光周期反应。试验表明,丝瓜两个种都是在长日照下延迟发育,短日照则提早发育。短日照处理以子叶展开后开始为适宜。有棱丝瓜在10-20h光照范围内,第1雌、雄花的节位呈随着日照时数的延长而提高的趋势。不同品种对短日照的反应有所不同。‘乌耳’、‘登峰’和‘双青’三个品种对短日条件要求比较严格,而‘青皮’和‘棠东’两个品种对短日条件的要求不很严格。短日处理可加速植株的雌性发育,提早发生雌花,增加雌花数和提高雌/雄花比率等。这些效应随着短日处理天数的增加而加强。

PHOTOPERiODIC RESPONSES IN LUFFA

Development of both Luff a cylindrica ( cv.Shui-gua ) and L. acutan-gula(cvs. Wu-er, Deng-feng and Qing-pi ) was inhibited in longdays, but was promoted in shortdays. These results are similar to that reported by Bose et al. ( 1975 ) and Hideyuki Takahashi et al. ( 1986 ). The critical daylength for induction of pistillate flower in L. cylindrica was around 12-16h.in the report of Hideyuki Takahashi et al. ( 1986 ) , but our experiment show that L.acutangula can also produce female flower in 10-20h. of daylength or even less shortdays. Different cultivars of L.acutangula are not the same in shortday reactions. They fall into two groups: one group, with Wu-er, Deng-feng and Shuang-qing has strict demands to shortdays, the other group, with Qing-pi and Tang-dong has no strict demands comparatively. Shortday treatments can greatly stimulat femaleness development of plants,make them produce female and male flower earlier and increase the number of female flowers and the ratio of female to male flower, with more days of shortday increase those effects. Shortday response is slow before the cotyledon expanding, thereafter, response is sensitive,therefore,shortday treatments should begin after the cotyledon expanding.