12-植物的成花生理.ppt

Chapter nine floral physiology of plants 植物的成花生理 Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. ?植物由营养生长转入生殖生长需要一些特殊的环境条件。无论一年生还是多年生植物,都必须达到生理成熟状态才能感受所要求的环境条件而开花。这种具有感受环境条件而诱导开花的生理状态称为花熟状态(ripeness to floral state) ,是植物由营养生长转入生殖生长的标志。?植物开花的顺序:成花诱导(floral induction); 成花启动(floral evocation) 和花发育(floral development) 。在自然状态下,温度和昼夜长度随季节有规律地变化, 植物在长期的环境适应和系统进化过程中,形成了对温度和昼夜长度的感应,以顺利完成生活周期。 Evaluation only. Evaluation only. Created with Client Profile . Created with Client Profile . Copyright 2004-2011 Aspose Pty Ltd. Copyright 2004-2011 Aspose Pty Ltd. 春化作用(vernalization) ? 发现和概念: Cold may affect the flowering response. For example, if winter rye (Secale cereale) is planted in the autumn, it germinates during the winter and flowers the following summer, 7 weeks after growth resumes. If it is planted in the spring, it does not flower for 14 weeks. In 1915, the plant physiologist Gustav Gassner discovered that he could influence the flowering of winter rye and other cereal plants by controlling the temperature of the germinating seeds. He found that if the seeds of the winter strain are kept at near-freezing (1 ℃) temperatures during germination, the winter rye, even when planted in late spring, will flower the same summer it is planted. This procedure, which came to be known as vernalization (from the Latin vernus, meaning "spring"), is now mon practice in agriculture. ?低温诱导促使植物开花的作用,称为春化作用。成花受低温影响的植物,主要是一些二年生植物(如芹菜、胡萝卜、萝卜、葱、蒜、白菜、荠莱、百合、鸢尾、甜菜和天仙子等)和一些冬性一年生植物(如冬小麦、冬黑麦等)。在自然条件下,冬小麦等是在头一年秋季萌发,以营养体过冬,第二年夏初开花和结实。对这类植物来说,秋末冬初的低温就成为花诱导所必需的条件。冬小麦经低温处理后,即使在春季播种也能在夏初抽穗开花。 Evaluation only. Evaluation only. Created with Client Profile . Created with Client