摘要: |
花的发生和发育过程研究可以发现早期进化的轨迹,为系统发育的研究提供重要线索。蓝堇草属(Leptopyrum)为毛茛科唐松草亚科一单种属,仅包含蓝堇草一种,其花的发生和发育过程仍为空白。为了深入理解唐松草亚科乃至毛茛科花发育多样性和演化规律,该文运用扫描电子显微镜(SEM)观察了蓝堇草各轮花器官的形态发生和发育过程。结果表明:该属植物所有的萼片、花瓣、雄蕊和雌蕊均为螺旋状发生,花器官排列式样也为螺旋状; 5枚萼片原基宽阔,5枚花瓣原基圆球形、位于萼片原基的间隔,且在后期表现为延迟发育现象,雄蕊原基较小、为圆球形; 花瓣原基和雄蕊原基连续发生,无明显的时空间隔,但与萼片原基有时空间隔; 心皮原基为马蹄形对折,柱头组织由单细胞乳突组成; 胚珠倒生、具单珠被。该属花器官螺旋状排列、胚珠具单珠被在唐松草亚科中是独有的性状,花发育形态学证据支持了该属的特殊性。 |
关键词: 蓝堇草属, 毛茛科, 花, 形态发生 |
DOI:10.11931/guihaia.gxzw201903007 |
分类号:Q944 |
文章编号:1000-3142(2020)11-1645-08 |
Fund project:国家自然科学基金目(31300158)[Supported by the National Natural Science Foundation of China(31300158)]。 |
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Floral morphogenesis in Leptopyrum(Ranunculaceae)with scanning electron microscopy |
LUO Minrong1, 2*
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1. College of Horticulture, Northwest A &2.F University, Yangling 712100, Shaanxi, China;3.2. Research Center of
Horticultural Sciences, Northwest A &
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Abstract: |
Floral initiation and development can provide important clues for phylogeny for the track of early evolution found in the study process. Leptopyrum is a monotypic genus in the subfamily Thalictroideae of family Ranunculaceae. Data on floral initiation and development of this genus are still completely lacking. In order to better understand the floral diversity and evolution of Thalictroideae and Ranunculaceae, the morphological initiation and development of the flowers of Leptopyrum fumarioides were studiedby using scanning electron microscopy. The results were as follows: Sepals, petals, stamens and carpels of this genus were initiated spirally and the phyllotaxis was spiral. The five young sepals were broad, crescent-shaped and truncate, but the five young petals were and rounded and between young sepals. After sepal initiation, there was a delay in development, and the plastochron between the last sepal and the first petal was relatively long, but the initiation of petals and stamens was continuous. The petal development was delayed with regard to other floral organs. The carpel primordia were plicate. The stigma was covered with unicellular papillae, and the mature ovule was anatropous and unitegmic. Leptopyrum showed similar development features of the sepals, petals and stamens as other members of Thalictroideae, which were also found in other Ranunculaceae. However, spiral floral phyllotaxis and unitegmic ovule were unique characters in Thalictroideae, which support Leptopyrum as a distinct genus. |
Key words: Leptopyrum, Ranunculaceae, flower, morphogenesis |