矩镰荚苜蓿地下茎次生结构异常发育的解剖学研究  

Anatomic Study on Abnormal Development of Secondary Structure in Medicago archiducis-nicolai Rhizome

作　　者：李永强 杨艳丽 刘济泽 张京萍 方强恩[1] LI Yongqiang;YANG Yanli;LIU Jize;ZHANG Jingping;FANG Qiang’en(College of Pratacultural Science,Gansu Agricultural University,Key Laboratory of Grassland Ecosystem,Ministry of Education,Pratacultural Engineering Laboratory of Gansu Province,Sino-U.S.Center for Grazingland Ecosystem Sustainability,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学草业学院,草业生态系统教育部重点实验室,甘肃省草业工程实验室,中-美草地畜牧业可持续发展研究中心,兰州730070

出　　处：《西北植物学报》2022年第10期1663-1670,共8页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金项目(31760703);草原生态系统教育部重点实验室开放课题(KLGE202212)。

摘　　要：矩镰荚苜蓿是中国特有植物,分布于青藏高原东缘,具有发达的地下扩展茎。为探明矩镰荚苜蓿地下茎异常发育与高原气候适应的关系,该研究采用常规石蜡切片法对地下茎初生结构与次生结构进行解剖观察。结果表明:(1)与初生结构相比,矩镰荚苜蓿地下茎次生结构发育不均衡,仅有少量维管束正常发育,木质部发达。(2)地下茎次生生长会产生内、外两种周皮,外周皮由靠近韧皮部的内皮层细胞形成,内周皮由靠近木质部的髓细胞形成,内、外周皮形成后取代了表皮和初生结构中的主要薄壁组织,形成了较复杂的新防护系统。(3)外周皮向内隘缩或内周皮向外延伸都会引起地下茎的分裂,但暂未观察到两种分裂方式同时发生。研究认为,矩镰荚苜蓿地下茎形成内、外周皮与异常分裂,可以增强对干旱和寒冷胁迫的抵御能力,是矩镰荚苜蓿对青藏高原寒旱环境的适应策略。Medicago archiducis-nicolai was endemic to China,distributed in the eastern margin of the Qinghai-Tibet Plateau,and has developed spreading rhizome.In order to explore the relationship between the abnormal development of M.archiducis-nicolai rhizome and plateau climate adaptation,we anatomized the primary and secondary structure of the plant rhizomes by paraffin section.The results showed that:(1)compared with the primary structure,the secondary structure of M.archiducis-nicolai rhizome was unbalanced,only a few vascular bundles developed normally,with developed xylem.(2)The secondary growth of rhizome produced two kinds of periderm:inner periderm and outer periderm.The outer periderm was formed by endodermis cells near phloem,and the inner periderm was formed by medulla cells near xylem.After the formation of inner and outer periderm,they replaced the epidermis and the main parenchyma in primary structure,formed a complex new protective system.(3)The inward constriction of the outer periderm or outward extension of the inner periderm could cause the split of the rhizome,but the two types of splits had not been observed at the same time.It was concluded that the formation of inner and outer periderm and abnormal split of the rhizome of M.archiducis-nicolai could enhance the resistance to drought and cold stress,which was the adaptive strategy of M.archiducis-nicolai to the cold and drought environment of Qinghai-Tibet Plateau.

关 键 词：矩镰荚苜蓿 地下茎 解剖结构 分裂 

分 类 号：Q944.55[生物学—植物学] S551.7[农业科学—作物学]