• 研究论文 • 下一篇
1 2金飚*; 1李娜; 3贾妮; 4周武忠; 1王莉; 2向其柏
1 2JIN Biao*, 1LI Na, 3JIA Ni, 4ZHOU Wu-Zhong, 1WANG Li, 2SHANG Chih-Bei
摘要: 为了探讨影响琼花Viburnum macrocephalum f. keteleeri有性生殖的因素, 对其生殖生物学和传粉生物学进行了研究。研究内容主要包括琼花花部特征、生殖器官解剖结构、花粉活力、花粉胚珠比(P/O)、繁育系统、传粉形式、传粉昆虫和花粉管生长路径等。结果表明: (1)琼花聚伞花序由大型不孕花和小型可孕花组成, 可孕花雌雄蕊发育正常, 雄蕊5枚, 雌蕊1枚, 干型柱头, 单子房, 倒生胚珠; 不孕花的雌雄蕊在发育早期正常, To a better understanding of the evolutionary mechanism between reproductive organs and pollinators in Viburnum, this paper reports reproductive characteristics of Viburnum macrocephalum f. keteleeri, including floral characteristics, anatomical features of reproductive organs, pollen viability, pollen/ovule ratio (P/O), pollinators, pollen tube growth path, breeding system, and fertilization. This species possesses a compound umbel including fertile and infertile flowers. The fertile flower has one pistil and five stamens; each pistil has a dry stigma and an ovary that contains one anatropous ovule. The stamens and pistils of the infertile flower are normal initially but degenerate later during flowering; degenerated stamens are mainly characterized by disappearance of stamens, short filaments, absence of filaments, or different size of anthers, whereas degenerated pistils have smaller or ruptured stigmas; occasionally, pistils and stamens become petal-like. Pollen viability of individual flowers declined significantly 4–5 d after pollen dissemination. Within population, pollen viability of all flowers rapidly decreased at the end of April. Pollen/ovule ratio (P/O) was 12800–18700. Pollinators for this species include bees, flies, butterflies and beetles, but bees and butterflies are the main ones. Artificial pollination treatments demonstrated that this species was self-incompatible and seed production depended on pollinator visits. Pollen dissemination of fertile flowers mainly occurred during 9:00 am–4:00 pm, and the peak of pollinator visits was 11:00 am–3:00 pm. Pollen grains usually germinated within 1 h after pollination and pollen tubes penetrated the stig
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