光周期对白芥下胚轴和子叶形态发生的影响

以 15h/d的长光照和 10h/d的短光照预处理 7d的白芥幼苗下胚轴和子叶切段为材料 ,诱导愈伤组织和器官再生 .结果表明 ,外植体的切口处均有愈伤组织形成 ,但生理学下端切口处出愈率高于上端 .下胚轴生理下端有根的分化 ,芽仅出现在下胚轴的生理上端。子叶外植体中只有根的分化 ,长光照预处理与短光照相比 ,愈伤组织形成较早 ,生长较快 ,对外植体生理下端的诱导作用较明显 .长光照对器官发生的影响因外植体部位而异

Effect of Photoperiod on Morphogenesis of Hypocotyl and Cotyledon of Sinapis alba

The callus induction and organogenesis of Sinapis alba seedling which was irradiated 15 h/d (LE) or 10 h/d(SE) for seven days were studied. The results showed that callus formed at all eut ends of explant. The callus induction percentage of physiologically lower cut end was highter than that of upper cut end. Root differentiated from physiologically lower end of hypocotyl. The buds differentiated only from physiologically upper end of hypocotyl. Root differentiated only from explant of ctyledon.The callus from LE occurred earlier, grew quicker that from SE. The callus induction of physiologically lower end of explant was obvious. The effect of LE on organogenesis varies from explant.