矩镰荚苜蓿地下器官贮藏组织中淀粉粒变化规律  

Changes in starch granules in the storage tissues of the underground organs of Medicago archiducis-nicolai

作　　者：李永强 杨小霞 张京萍 杨艳丽 方强恩[1] LI Yongqiang;YANG Xiaoxia;ZHANG Jingping;YANG Yanli;FANG Qiang’en(College of Pratacultural Science,Gansu Agricultural University/Key Laboratory of Grassland Ecosystem,Ministry of Education/Gansu Grassland Engineering Laboratory/China-US Center for Grazing Land Ecosystem Sustainability,Lanzhou 730070,Gansu,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,甘肃兰州730070

出　　处：《草业科学》2024年第3期675-683,共9页Pratacultural Science

基　　金：国家自然科学基金项目(32360341);草业生态系统教育部重点实验室开放课题项目(KLGE202212);甘肃省高校教师创新基金项目(2023A-49)。

摘　　要：矩镰荚苜蓿(Medicago archiducis-nicolai)分布于青藏高原东缘高寒地区,具有极强的抗寒能力。为了探明矩镰荚苜蓿地下器官的越冬抗寒机理,本研究采用常规石蜡切片法,对自然越冬过程中根、根颈和地下茎贮藏组织中淀粉粒的变化进行动态观测。结果显示:矩镰荚苜蓿越冬过程中,淀粉主要贮藏在地下器官的髓和栓内层薄壁细胞中,少量存在于木质部薄壁细胞,根颈与根内淀粉粒分布较为密集;地下不同器官中淀粉数量在越冬前后变化趋势基本一致,总体呈现出先减少后增加的变化规律,越冬前期淀粉在地下器官中大量积累,越冬中期逐渐消失,后期又逐渐积累起来;各地下器官中根颈对温度变化响应最快,地下茎对低温最敏感。研究发现,矩镰荚苜蓿地下茎除具有扩展、繁殖能力外,还兼具贮藏与抗寒等能力,是该植物不同于其他苜蓿属物种的特殊地下器官;越冬期矩镰荚苜蓿地下器官抗寒力形成的不同步性,可能是其应对高寒环境的适应性策略。Medicago archiducis-nicolai is distributed in the high,cold area of the eastern edge of the Qinghai-Xizang Plateau,and has strong cold resistance.In order to explore the cold resistance mechanism of its underground organs,the conventional paraffin sectioning method was used to observe how starch granules changed in the root,crown,and rhizome storage tissues during natural wintering.We found that starch was mainly stored in the parenchyma cells of the pith and phelloderm of underground organs during the wintering process,and a small concentration existed in the xylem parenchymal cells.In contrast,the distribution of starch granules in the crown and roots was denser.The trend of changing starch quantities in different underground organs before and after wintering was basically the same:there was an overall pattern of first decreasing and then increasing.Starch accumulated in the underground organs in large quantities during the early stage of wintering,gradually disappeared in the middle stage of wintering,and accumulated in the later stage.Among the underground organs,the crown responded the fastest to temperature changes,whereas the rhizome was the most sensitive to low temperatures.This study found that the rhizome of M.archiducis-nicolai had the functions of expansion,reproduction,storage,and cold resistance.The unique underground organ of this plant differs from all other Medicago species.The asynchronicity of the formation of cold resistance in the underground organs of M.archiducis-nicolai during the wintering period is its adaptive strategy to cope with the cold alpine environment.

关 键 词：解剖结构 组织化学 越冬 薄壁组织 青藏高原 地下茎 淀粉粒 

分 类 号：S541[农业科学—作物学]