植物激素调节和预先冷处理对破除红景天种子休眠和发芽的影响

近数百年以来,红景天已广泛用于中国的传统中草药.但其种子发芽缓慢,参差不齐和发芽率低,这是由种子休眠所引起的.采用预先冷冻处理、外源植物激素刺激,进行破除种子休眠、激发种子发芽、促进幼苗平衡生长,以及外源刺激、内源植物激素变化、种子发芽和幼苗生长等生理作用研究.结果表明,4℃预先冷冻3周处理,在25～10℃可获得最高发芽率(48±2)%,用外源激素GA3、2,4-D和GA3+2,4-D处理可降低红景天种子胚的内源ABA水平并使其保持在低水平.此外还发现,中等水平内源IAA能促进其根和苗平衡生长,使幼苗的存活力达到最高水平.

Study on the effect of plant hormones and pre-chilled treatment to break dormancy and germination of Rhodiola rosea seeds

Rhodiola rosea has been widely used as traditional herb medicine in China for centuries. Its seeds germinate unevenly and at a low rate; this is due to dormancy of the seed. We use pre-chill treatment and exogenous plant hormones stimulation to break dormancy of Rhodiola rosea seeds, to trigger seed germination and to gain high quality seedlings; as well as to research the physiologicalinteractions between exogenous stimulation, endogenous plant hormone change, the germination of seedsand growth of seedling. It is observed that seeds pre-chilled at 4 ℃ for three weeks should the highestgermination rate at 25-10 ℃, the rates of germination get to (48± 2)%. From our research, we foundthat in the embryos of seeds of Rhodiola rosea the endogenous level of ABA decreased and thenmaintained at low level after being treated with exogenous GA3, 2,4-D and GA3 +2,4-D. Medium levelof endogenous IAA (from 611.8 ng/gFW to 494.6 ng/gFW) can balance the growth of root and shoot,endogenous IAA content change at this range, the survival rate of seedling is the highest.