首页分享《植物的成花生理》ppt课件

《植物的成花生理》ppt课件

来源：花匠小妙招时间：2025-05-13 09:43

2024-12-30 22:48 本页面

【正文】过程中形成一种刺激物质，称为春化素(vernalin)，这种物质还没有从植物体中分离出来，但嫁接试验证明春化素的存在。经过低温处理开花结果未经低温处理没有花果作用机理和应用 • • 呼吸速率增强； • 核酸代谢加速，在春化过程中核酸（特别是 RNA）含量增加，而且 RNA性质有所变化； • 蛋白质代谢，可溶性 Pr及游离 AA含量（ Pro）增加。 • GA含量增加：一些需春化的植物（如天仙子、白菜、胡萝卜等）未经低温处理，若施用 GA也能开花。 GA以某种方式代替低温的作用。 • 应用：人工春化处理 (如小麦闷种、加速育种进程 )；引种调种；控制花期。 (photoperiodism) • ： The effect of day length on flowering was discovered some seventy years ago by two investigators from the . Department of Agriculture, . Garner and . Allard, who found that neither the Maryland Mammoth variety of tobacco (Nicotiana tabacum) nor the Biloxi variety of soybean (Glycine max) would flower unless the day length was shorter than a critical number of hours. Garner and Allard called this phenomenon photoperiodism. Plants that flower only under certain daylength conditions are said to be photoperiodic. Photoperiodism is a biological response to a change in the proportions of light and dark in a 24 hour daily cycle. • 在一天之中，白天和黑夜相对长度的交替变化，称为光周期 (photoperiod)。光周期对花诱导有着极为显著的影响。植物对白天和黑夜的相对长度的反应，称为光周期现象 (photoperiodism)。 The relative length of day and night determines when plants flower. The four curves depict the annual change of day length in four North American cities at four different latitudes. The horizontal colored lines indicate the effective photoperiod of three different shortday plants. The cocklebur(苍耳 ), for instance, requires 16 hours or less of light, in Miami, San Francisco, and Chicago, it can flower as soon as it matures, but in Winnipeg(温尼伯湖 [加拿大中南部 ]), the buds do not appear until early August, so late that the frost will probably kill the plants before the seed is set. 光周期反应类型 • 长日植物 (longday plant,LDP)：在 24h昼夜周期中，日照长度长于一定日数才能成花的植物。延长日照提早开花，延长黑夜推迟开花。如大麦、小麦、黑麦、油菜、菠萝、萝卜、白菜、甘蓝、芹菜、甜菜、胡萝卜、金光菊、山茶、杜鹃、桂花、天仙子等。 • 短日植物 (shortday plant,SDP)：在 24h昼夜周期中，日照长度短于一定