林业科学2017，Vol.53Issue(4)：65-73,9.DOI:10.11707/j.1001-7488.20170408
极度濒危树种羊角槭的种胚发育与休眠解除
Embryo Development and Dormancy Releasing of Acer yangjuechi, the Extremely Endangered Plant
摘要
Abstract
[Objective]The study was to reveal the seed dormancy mechanism of Acer yangjuechi and to obtain the effective dormancy-releasing method of improving seed germination, so as to improve the breeding efficiency, expand population size to mitigate the situation of being extremely endangered.[Method]Seed development of two different individuals growing in National Nature Reserve of Tianmu Mountain, Zhejiang province, was tested in 3 successive years.Through cabbage seeds germination test, the germination inhabitation of testa, endotesta and embryo was conducted.The techniques for seed dormancy releasing were studied by treatment of hormone-presoaking or stratification of testa-removed seeds at 5 ℃.[Result]Embryo of Acer yangjuechi was poorly developed and differs between the two individuals.The average percentage of well-developed seeds ranged from 9.73% to 33.98% and the average rate of viable seeds was 52.22%.Compared with other Acer plants, the lower percentage of well-developed seeds confirmed its high infertility rate.The methanol extractant from testa and embryo had the higher inhabitation effect on germination than that from endotesta which have a high correlation with the content of endogenous ABA.The content of endogenous ABA in embryo was the highest one, reaching 1 818.58 ng·g-1, followed by those in testa with a value of 1 053.34 ng·g-1 and endotesta with a value of 859.05 ng·g-1.The complete seeds moist-stored at 5 ℃ and testa-removed seeds at room temperature can not germinate while the testa-removed seeds germinated and the germination rate increased significantly to 30%.And the treatment of presoaking seeds with 100 mg·L-1 GA3 or 200 mg·L-1 6-BA for 12 hours promoted seed germination rate reaching to 46.67% and 43.33% respectively.The duration of seeds-presoaking with hormone had a significant influence on germination rate of seeds(P<0.01)while hormone type and concentration didn't present significant influence(P>0.05).[Conclusion]Seeds of Acer yangjuechi often has a high rate of infertility and become empty seeds, this is associated with limitation pollen supply.Outcrossing as a supplement to self-pollination favors pollination success and embryo development.Stands of the species should be planted in small tree-tree distance to promote outcrossing which leads to successful reproduction.Both forced dormancy by testa and embryo dormancy are existing in the seeds of A.yangjuechi.The main inhibitor of seed-germination is the endogenous ABA.Low temperature sand stratification of testa-removed seeds combined with hormone-presoaking could improve germination rate.It is recommended as the method for seed dormancy-releasing.The study is of significant implication to population enlargement and sustainable conservation of Acer yangjuechi.关键词
羊角槭/种胚发育/种子休眠/种子萌发/休眠解除Key words
Acer yangjuechi/embryo development/seed dormancy/seed germination/dormancy releasing分类
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陈香波,刘杨,赵明水,涂淑萍..极度濒危树种羊角槭的种胚发育与休眠解除[J].林业科学,2017,53(4):65-73,9.基金项目
上海市绿化与市容管理局辰山植物园专项"几种濒危植物致濒机制与种质资源保护研究"(G102406). （G102406）
