12_植物的成花生理.pptVIP

Chapter nine floral physiology of plants;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。;9.1春化作用(vernalization);9.1.2 植物对低温反应的类型;9.1.3春化的感受部位和传递;经过低温处理开花结果;9.1.4 作用机理和应用;9.1.5.2春化过程中的生理生化变化;9.2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 short-day 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.;9.2.2 光周期反应类型 ;长短日植物(long-short day plant)：要求先长日后短日的双重日照条件，如芦荟、夜香树等 短长日植物(short-long day plant)：要求先短日后长日的双重日照条件，如风铃草、鸭茅、瓦松、白三叶草等。 中日照植物(intermediate-day plant )：只能在一定的日照长度下才开花，延长或缩短日照都抑制开花，如甘蔗只有在日长12.5 h下才开花。 两极光周期植物(amphophotoperiodism)：与中日照植物相反，在中等日照条件下保持营养状态，而在较长或较短日照下才能开花。如狗尾草。 ;Representative short-day (a) and long-day (b) plants, each grown under short-day (on left) and long-day (on right) conditions. (a) Chrysanthemum(菊花). (b) Spinach(菠菜) (Spinada oleracea). Note that the plants exposed to long days have longer stems than those exposed to short days, regardless of whether or not they flower.;(a) and (b) Natural 24-hour light/dark cycles must have short nights any time the days are long (summer) and long nights when days are short (winter), so plants could detect season by measuring either day or night. When photoperiodism was first discovered, it was assumed that day length wag important, so all our terminology was based on that. ;临界日长和临界暗期;在自然条件下，