植物生态学报 ›› 2008, Vol. 32 ›› Issue (4): 883-890.DOI: 10.3773/j.issn.1005-264x.2008.04.017

• 论文 • 上一篇    下一篇

太白山红桦种子的萌发特性

任坚毅, 林玥, 岳明()   

  1. 西北大学西部资源生物与现代生物技术省部共建教育部重点实验室, 西安 710069
  • 收稿日期:2007-09-27 接受日期:2008-01-08 出版日期:2008-09-27 发布日期:2008-07-30
  • 通讯作者: 岳明
  • 作者简介:*E-mail:yueming@nwu.edu.cn
  • 基金资助:
    国家自然科学基金(30370269);国家自然科学基金(30670366);教育部留学回国人员启动基金

SEED GERMINATION CHARACTERISTICS OF BETULA ALBO-SINENSIS AT MOUNTAIN TAIBAI, CHINA

REN Jian-Yi, LIN Yue, YUE Ming()   

  1. Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi’an 710069, China
  • Received:2007-09-27 Accepted:2008-01-08 Online:2008-09-27 Published:2008-07-30
  • Contact: YUE Ming

摘要:

红桦(Betula albo-sinensis)广布于我国太白山中高海拔地区, 普遍存在着更新障碍。为了给红桦林的自然更新提供新的解释与证据, 我们对2 400粒红桦种子进行了去果皮观察并计数发芽率, 观察了红桦种子在不同光合有效辐射(Photosynthetically active radiation, PAR)和不同光照时间(强光照: PAR为 464.7 µmol photons ·m-2·s-1, 12 h·d-1; 中光照: PAR为233.8 µmol photons ·m-2·s-1, 12 h·d-1; 弱光照: PAR为233.8 µmol photons ·m-2·s-1, 0.5 h·d-1)、不同昼夜温差(25/20 ℃、20/15 ℃、15/10 ℃)和去果皮处理下的发芽率, 以及无光照处理下的发芽率。此外, 还观察了种子在不同覆盖物(阔叶、针叶、针阔混合)和不同基质(土、沙)中以及在落叶(阔叶、针阔混合)中的发芽率。红桦种子成熟时, 大约54.29%为饱满具活力的种子。种子在25/20 ℃的昼夜温差下发芽率最高, 而在15/10 ℃的昼夜温差下极少萌发。中光照下, 种子发芽率略高于其它两种光照, 无光照则完全抑制了种子萌发。去果皮处理可促进其萌发, 各种覆盖物会导致种子发芽率下降。不同的萌发基质对萌发无影响。以上结果暗示, 自然条件下太白山红桦种子的萌发将依赖于自然的扰动。

关键词: 红桦, 种子, 光照, 温度, 自然更新

Abstract:

Aims Betula albo-sinensis occurs in the middle to high elevations of Taibai Mountain, China where its forests have regeneration barriers. We studied the germination and physiological characteristics of B. albo-sinensis seeds to investigate natural regeneration.

Methods We observed 2 400 seeds of B. albo-sinensis without pericarp and recorded germination rates. We studied germination rates under different photosynthetically active radiation (PAR) and photoperiod (high light: PAR = 464.7 µmol photons ·m-2·s-1, 12 h·d-1; middle light: PAR = 233.8 µmol photons ·m-2·s-1, 12 h·d-1; low light: PAR = 233.8 µmol photons ·m-2·s-1, 0.5 h·d-1), different day/night temperatures (25/20 ℃, 20/15 ℃ and 15/10 ℃) and with and without pericarp. We also recorded germination rates without light, under different culture media (soil and sand) and mulch (broad leaf, needle leaf and mixed leaf) or covered with leaf (broad leaf and mixed leaf).

Important findings We found that 54.29% of the seed is full in the fully maturated ones. The optimum germination temperature is 25/20 ℃, and few seeds germinated under 15/10 ℃. Germination rates under middle light were highest, and there was no seed germination under no light. Shelling the pericarp could improve germination rates. Germination rates declined in the groups covered with mulch, but there was no significant difference among culture media. We conclude that B. albo-sinensis seed germination depends on natural disturbances in its natural environment.

Key words: Betula albo-sinensis, seed, light, temperature, natural regeneration