海桐种子的休眠解除与萌发  

Study on Eliminating Physiological Dormancy and Germination of Pittosporum tobira (Pittosporaceae) Seeds.

作　　者：唐安军[1] 柳建平[1] 

机构地区：[1]重庆师范大学生命科学学院,重庆沙坪坝401331

出　　处：《种子》2011年第5期46-49,共4页Seed

基　　金：中科院生物多样性保护专项项目(KSCX2-YW-Z-0925);重庆市教委金科技项目(KJ100610)

摘　　要：观赏植物海桐(Pittosporum tobira(Thunb.)Ait.)种子的休眠和萌发特性已被进行了较充分的研究。TTC检测出新鲜海桐种子是高活力的(98%),但在5个恒温和1个变温(12 h/d的光周期)下,其萌发率仅为27%,这说明海桐种子处于休眠状态。经不同浓度(100 mM和200 mM)的GA3溶液处理后,新鲜海桐种子的萌发率有所提高;在25/15℃与200 mM的处理下,其发芽率最高是41%,但仍不理想。当经过低温(5℃)处理一段时间(15、30、45、60、90 d)后,海桐种子的萌发率显著提高,尤其是在25℃和25/15℃处理下,萌发率分别为87%和95%。此外,冷层积30 d和45 d的海桐种子经200 mM的GA3溶液处理后的萌发率分别达69%和94%,效果显著。可见,海桐种子的休眠是浅生理休眠,单一的GA3溶液处理不能有效地打破海桐种子的休眠,但冷层积90 d或200 mMGA3溶液处理冷层积45 d的种子,可有效地解除其休眠;同时,温度对种子的萌发有较大影响,在适宜的萌发温度(25℃或25/15℃)与周期性(12 h/d)光照下,种子的萌发率超过90%。由此推断,海桐种子在自然条件下难以萌发的原因与其生理休眠有关。The dormancy and germination of ornamental Pittosporum tobira seeds were adequately investigated in this study. The embryos of almost fresh seeds （98%） were dyed red,but only a small part of fresh seeds could germinate at range of constant temperatures（ 10,15,20,25 ~C and 30℃ ） and altering temperature （25/ 15℃ ）. Two GA3 solutions （e. g. , 100 mM and 200 raM） slightly promoted fresh seeds to germinate ,the highest germination rate was 41% at 25/15℃ with 200 mM. After cold stratification at 5℃ for 90 d,the germination was significantly enhanced to 84% and 95% after 60 d and 90 d at 25℃and 25/15℃,respectively. Interestingly,seeds germination percentages would increased to 69% and 94% at 25/15℃ ,which were stratified for 30 d and 40 d in light, respectively. The results indicated that seeds of this specie with non-deep physiological dormancy, which could be broken by cold stratification, but the treatments with only GA3 solutions didn break dormancy, the treatments by 200 mM of GA3 solution combined with cold stratification for some days （ e. g. ,30 d or 40 d） also significantly facilitated the germination. Also, temperature directly affected the germination of non-dormant seeds. Among a few temperatures ,the altering tepmperature treatment of 25/15℃was optimum for its germination in light, which the final germination percentage was more than 90% , followed by that of 25℃. This study indicated that the physiological dormant mechanism might block the germination in natural environments.

关 键 词：冷层积 赤霉素 生理休眠 萌发 海桐 

分 类 号：S330.33[农业科学—作物遗传育种]