植物的成花生理ppt課件(存儲(chǔ)版)
【正文】 日狀態(tài)時(shí)．以紅光延長(zhǎng)光照 8h，成花不顯著；如在紅光中加入幾小時(shí)遠(yuǎn)紅光，明顯促進(jìn)成花。這個(gè)反應(yīng)可以反復(fù)逆轉(zhuǎn)多次，而開(kāi)花與否決定于最后照射的是紅光還是遠(yuǎn)紅光。又如長(zhǎng)日植物天仙子，在12h日長(zhǎng)和 12h暗期環(huán)境下不開(kāi)花，但以 6h日長(zhǎng)和6h暗期處理則開(kāi)花。蒼耳將因 14h短于它的臨界日照長(zhǎng)度 ( h)而開(kāi)花，天仙子也將因 14 h長(zhǎng)于它的臨界日照長(zhǎng)度 (11 h)而開(kāi)花。如黃瓜、月季、茄子、番茄、辣椒、菜豆、君子蘭、向日葵、蒲公英等。植物對(duì)白天和黑夜的相對(duì)長(zhǎng)度的反應(yīng)，稱為光周期現(xiàn)象 (photoperiodism)。反過(guò)來(lái)，如把芹菜放在冰冷的室內(nèi)，而使莖生長(zhǎng)點(diǎn)處于高溫下，也不能開(kāi)花結(jié)實(shí)。根據(jù)原產(chǎn)地的不同，小麥可分為冬性、半冬性和春性類型。 (vernalization) ? ： 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 nearfreezing (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 a mon practice in agriculture. ? 低溫誘導(dǎo)促使植物開(kāi)花的作用，稱為春化作用。無(wú)論一年生還是多年生植物，都必須達(dá)到生理成熟狀態(tài)才能感受所要求的環(huán)境條件而開(kāi)花。對(duì)這類植物來(lái)說(shuō)，秋末冬初的低溫就成為花誘導(dǎo)所必需的條件。 ? 較高溫度 或短日處理可使春化作用減弱或消失，這種現(xiàn)象只在低溫處理初期才有，稱為去春化作用 (devernalization)或解除春化。 ? GA含量增加：一些需春化的植物（如天仙子、白菜、胡蘿卜等）未經(jīng)低溫處理，若施用 GA也能開(kāi)花。如大麥、小麥、黑麥、油菜、菠蘿、蘿卜、白菜、甘藍(lán)、芹菜、甜菜、胡蘿卜、 金光菊 、山茶、杜鵑、桂花、天仙子等。 ? 兩極光周期植物 (amphophotoperiodism)：與中日照植物相反，在中等日照條件下保持營(yíng)養(yǎng)狀態(tài)，而在較長(zhǎng)或較短日照下才能開(kāi)花。對(duì)長(zhǎng)日植物來(lái)說(shuō)，日長(zhǎng)大于臨界日長(zhǎng)，即使是 24h日長(zhǎng)都能開(kāi)花；而對(duì)短日植物來(lái)說(shuō)，日長(zhǎng)必須小于臨界日長(zhǎng)才能開(kāi)花，然而日長(zhǎng)太短也不能開(kāi)花，可能因光照不足，植物幾乎成為黃化植物之故。 The soybean was cultivated under cycles of 10 h light and 8 62 h of darkness. Ordinate: Number of Flowers. The maxima are at 10 h light and 14 h darkness and at 10 h light and 30 h darkness (Periods of light are symbolized by light blue, periods of darkness by redv
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