格爾木賴草檢視原始碼討論檢視歷史

格爾木賴草

來自 孔夫子舊書網 的圖片

百合超目 Lilianae 禾本目 Poales 禾本科 Poaceae 賴草屬 Leymus 格爾木賴草Leymus golmudensis Y. H. Wu

格爾木賴草(gé ěr mù lài cǎo)，學名 Leymus golmudensis Y. H. Wu ，多年生草本，高25—35厘米。產於海拔約2400米，分布於新疆(Burqin，Yecheng，Yiwu)。

基於形態和葉表皮微形態特徵試論國產賴草屬屬下類群間的系統關係

李兆孟；周勇輝；劉玉萍；蘇旭*

Biosystematic Relationships among Taxa below Leymus(Poaceae) from China Based on the External Morphology and Micromorphological Characteristics of Leaf Epidermis LI Zhao-Meng；ZHOU Yong-Hui；LIU Yu-Ping；SU Xu*

摘要/Abstract 摘要： 通過對先前學者報道的國產賴草屬24個物種、72個代表居群形態和葉表皮微形態性狀特徵的觀測和研究，結果發現：

(1)原國產賴草屬物種在旗葉長寬、葉片被毛狀況、花序直曲和長寬、穗軸每節小穗數、每小穗小花數、外稃和內稃長度等15個外部形態學性狀上均存在不同程度的差異，可將參試物種區分為3個不同的組；大賴草、粗穗賴草、碩花賴草和柴達木賴草多穗組植物的穗狀花序粗壯呈圓錐狀、直立、密集，穗軸同節着生3多枚小穗，每小穗常含3~10小花，穎線狀披針形等，致使其處於該屬最原始的地位；皮山賴草、若羌賴草和格爾木賴草單穗組物種的穗狀花序細弱呈線狀、直立、疏鬆，穗軸每節僅着生1枚小穗，每小穗往往含2~5小花，穎線狀披針形或錐形，這些較高級的外部形態特徵使得該組植物隸屬於賴草屬中較高級的類群；而少穗組植物的外部形態性狀通常介於前兩組植物的中間過渡狀態，因而它的系統地位自然也應處於多穗組和單穗組植物之間。同時，依據外部形態性狀的遞變趨勢分析顯示，3組植物具有直接的派生淵源。

(2)國產賴草屬植物的葉表皮皆由長細胞、短細胞、氣孔器細胞和刺毛所組成，表現為典型的狐茅型；它們除在長細胞類型和壁的厚薄、氣孔器保衛細胞的體積和類型等性狀上具有明顯重疊而顯示相似外，其它多數性狀如長細胞的長度和壁的波曲程度、短細胞的分布式樣、副衛細胞的形狀及刺毛的類型等性狀上具有明顯差異，其可將賴草屬植物鑒分為與形態學界定結果完全相同的3個組。同時，根據3組植物及組內物種葉表皮性狀的演化趨勢，對各組和組內物種的演化關係和系統位置分析表明，多穗組植物最原始，少穗組植物較進化，單穗組植物最高級；多穗組可能直接派生了較進化的少穗組，並在少穗組的基礎上進而產生了最高級的單穗組。賴草屬屬下類群的這一系統關係與利用外部形態特徵所獲得的系統與進化關係基本一致。

關鍵詞: 禾本科, 賴草屬, 形態性狀, 葉表皮微形態, 系統關係

Abstract: We analyzed the main character differences of seventy-two reprehensive populations from twenty four Leymus species previously reported by scholars by morphological observation and anatomical analysis of leaf epidermises.

There are different degrees of difference in fifteen morphological characters including length and width of flag leaves, hairs of leaf blades, straight/curve and length/width of inflorescence, spikelet No. of each inflorescence, floret No. of each spikelet, length of lemma and palea. The tested species can be divided into three sections according to them. The sect. Racemosus species of L.racemosus, L.crassiusculus, L.pluriflorus and L.pseudoracemosus, with sturdy, erect and thick spike, 3-number of spikelets per rachis node, 3-10 florets each spikelet, linear lanceolate glume, etc., is the most primitive one in genus Leymus.

Due to the sect. Anisopyrum species including L.pishanica, L.golmudensis and L.ruoqiangensis, having thin, erect and loose spike, only one spikelet per rachis node, usually 2-5 florets each spikelet, linear lanceolate or cone glume, etc., so it is the most advanced of them. Meanwhile, because the external morphological characters of the sect. Leymus species usually lie in the intermediate transition state between the first two groups, naturally its systematics position should also be between the sect. Racemosus and sect. Anisopyrum species.

At the same time, based on the evolutionary trends of the external morphological characters of three above sections, we deduced that the sect. Racemosus might produce immediately the sect. Leymus, whereas the sect. Anisopyrum might derive immediately form the sect. Leymus. The leaf epidermis of Leymus from China consists of long cell, stomatal cell, short cell and prickle hair.

It belongs to the typical festucoid type. Except that some characters, such as the type of long-cells and thick/thin of cell walls, the volume and type of guard cells from stomatal apparatus, have obvious overlap and show similar, other characters, including the length of long-cells and curve extent of cell walls, distribution pattern of short-cells, shape of subsidiary cells, and type of prickle-hairs, have obvious differences.

They can delimitate Leymus species into three sections identical with the morphology. According to the evolutionary trends of leaf epidermal characteristics of three sections and species within each section, their evolutionary positions and relationships were inferred. The results show that the sect. Racemosus is the most primitive one among three sections, the sect.

Leymus is slightly more advanced than the former, and the sect. Anisopyrum is the most advanced of them. The sect. Racemosus might produce immediately the sect. Leymus, whereas the sect. Anisopyrum might derive immediately form the sect. Leymus. The biosystematic relationships of taxa below the genus are corroborated by the evolutionary trend of external morphology.

Key words: Poaceae, Leymus, morphological character, morphological of leaf epidermis, biosystematic relationship

引用本文 李兆孟；周勇輝；劉玉萍；蘇旭*. 基於形態和葉表皮微形態特徵試論國產賴草屬屬下類群間的系統關係[J]. 植物研究, 2016, 36(1): 10-25.

LI Zhao-Meng；ZHOU Yong-Hui；LIU Yu-Ping；SU Xu*. Biosystematic Relationships among Taxa below Leymus(Poaceae) from China Based on the External Morphology and Micromorphological Characteristics of Leaf Epidermis[J]. Bulletin of Botanical Research, 2016, 36(1): 10-25.