生物多样性 ›› 2013, Vol. 21 ›› Issue (5): 582-589.DOI: 10.3724/SP.J.1003.2013.08077

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地下结实植物白番红花地下果实的生产与种子扩散特性

付子燕, 谭敦炎*()   

  1. 新疆农业大学草业与环境科学学院, 新疆草地资源与生态重点实验室及西部干旱荒漠区草地资源与生态教育部重点实验室, 乌鲁木齐 830052
  • 收稿日期:2013-04-01 接受日期:2013-06-14 出版日期:2013-09-20 发布日期:2013-10-08
  • 通讯作者: 谭敦炎
  • 基金资助:
    国家自然科学基金(31060047和U1130301);国家科技基础性研究专项(2011FY110200-8);国家国际科技合作重点项目(2011DFA31070)

Characteristics of the production of underground fruits and seed dispersal of Crocus alatavicus, a geophytic-geocarpic species

Ziyan Fu, Dunyan Tan*()   

  1. Xinjiang Key Laboratory of Grassland Resources and Ecology & Ministry of Education Key Laboratory for Western Arid Region Grassland Resource and Ecology, College of Grassland and Environment Sciences, Xinjiang Agricultural University, Urumqi 830052
  • Received:2013-04-01 Accepted:2013-06-14 Online:2013-09-20 Published:2013-10-08
  • Contact: Tan Dunyan

摘要:

地下芽地下结实是指由植株地下芽分化形成的具长管状花被的花伸出地表开放、而子房在地下发育成果实的一种特殊结实现象。白番红花(Crocus alatavicus)是生长于天山西部亚高山带、具地下芽地下结实特性的多年生早春短命植物。本文采用野外观测和控制实验方法, 对该物种地下子房和幼果的发育特点与种子扩散特性及其适应意义进行了研究。结果表明: 白番红花从开花到地下果实露出地表的发育时间约需35 d, 地下果实在花梗的伸长生长作用下露出地面开裂并扩散种子, 且种子具有油质体等典型蚁传植物种子的特征。蚁类是白番红花种子的主要传播者。在搬运种子的Formica pressilabris、栗色林蚁和黑褐蚁中, F. pressilabris出现的频率最高, 但栗色林蚁搬运的速度最快、距离最远。3种蚂蚁搬运白番红花种子的平均距离为62.4±1.7 cm。Formica pressilabris将白番红花种子搬运至蚁穴中后取食油质体, 且有超过50%的种子被储藏在蚁穴中。啮齿类和鸟类不传播白番红花种子, 但水媒和风媒对种子的短距离散布具有一定作用。这些结果说明: 白番红花的地下结实及蚁传特性不仅可保护发育中的子房及果实躲避地表草食动物的取食, 避免自然火灾对地上果实的伤害, 以及延长果实和种子的发育时间以保障其安全成熟, 还可避免真菌和其他病原体的侵扰、减少同胞之间以及母株与子代间的竞争, 使种子在适宜环境中萌发并建立新的种群。

关键词: Crocus alatavicus, 地下芽型地下结实, 果实发育, 扩散, 蚁运植物, 种子油质体

Abstract:

Geophytic-geocarpy is a special type of fruit production in angiosperms, whereby flowers with a long tubular perianth arise from underground buds and bloom above ground with the ovary and subsequent fruit remaining below ground. Crocus alatavicus, a geophytic-geocarpic species, is a perennial early-spring ephemeral that grows in subalpine areas of the western Tianshan Mountains. Based on field observations and controlled experiments, development of the underground ovaries and young fruits and seed dispersal were investigated for C. alatavicus and their adaptive significance analyzed. The results showed that developmental time from flowering to emergence of the underground capsules above the soil was about 35 days, and emergence of the underground capsules results from elongation of the peduncles, and then capsules dehisce and seeds are dispersed. Seeds of C. alatavicus have an elaiosome, which is typical of myrmecochores. Ants make a significant contribution to seed dispersal, and three ant species, Formica pressilabris, F. gagates and F. fusca, were recorded near newly-dispersed seeds of C. alatavicus. The visiting frequency of F. pressilabris was the highest, but F. fusca removed seeds faster and to a greater distance than the other two species. The average dispersal distance of the three ant species was 62.4±1.7 cm. Formica pressilabris, the major ant species taking seeds, ate the elaiosome after it moved the seeds into its nest and then stored more than 50% of the transported seeds in the nest. Rodents and birds had no effect on seed dispersal of C. alatavicus, but hydrophily and anemophily played a minor role in short-distance dispersal. Formation of seeds underground and their dispersal by ants help ensure that seeds escape damage from herbivores and fire and that they are dispersed in a manner that reduces sib-competition and competition between mother plant and offspring, thereby ensuring seed germination and seedling establishment in suitable environments.

Key words: Crocus alatavicus, dispersal, fruit development, geophytic-geocarpy, myrmecochore, seed elaiosome