干旱区生态环境知识资源中心(Arid): Diaspore characteristics and ecological adaptation of Bromus tectorum L.from different distribution regions

Arid

	Diaspore characteristics and ecological adaptation of Bromus tectorum L.from different distribution regions
	Liu Yaobin; Zhang Yuanming; Nowak Robert S; Dimeyeva Liliya
来源期刊	Journal of Arid Land
ISSN	1674-6767
出版年	2013
卷号	5 期号:3 页码:310-323
英文摘要	The invasion of nonnative plants is considered one of the main threats to the structure and function of North American ecosystems.Moreover,they can alter ecosystem processes and reduce biodiversity.In arid and semi-arid region of North America,the species of European annual grass Bromus tectorum L.is an outstanding example of these problems,which not only increase the fire density and change the fire regime,but replace native communities.Therefore,there are amount of researches on B.tectorum,including resource acquisition,water use efficiency and growth.Whereas the relevant research on the morphology of diaspore is scare.Diaspores have a fundamental role in seed germination and seedling establishment.Besides,as an important link between different generations,diaspores have a vital significance on individual reproduction and population extension.Hence,diaspores under selection for studying have an important implication.This study compares differences in seed morphology for Bromus tectorum collected from the United States,Kazakhstan,and Xinjiang of China.The following indices of B.tectorum diaspores were analyzed:size,thickness of covering layers,and micromorphological characteristics of the base,middle and transition area of diaspores as well as of the awn.Micromorphology of the lemma and the cross-section of the diaspore were observed by scanning electron microscopy.Results showed that thickness of the lemma and the palea of diaspores from B.tectorum-infested grasslands in the United States were reduced(P<0.05),likely because of environmental influences.This reduction facilitated the germination of diaspores and lowered the resistance of B.tectorum to adverse environmental conditions.The length of the awn also increased significantly(P<0.05),which helped in dispersal and anchoring of diaspores.Therefore,B.tectorum adapted ecologically to its new environment in the United States by strengthening its establishment ability.However,the defense capability of B.tectorum decreased.These results fit the evolution of increased competitive ability hypothesis(EICA)of invasive species.Analysis of various cells on the lemma revealed that prickle densities and collapsed,long epidermal cells were easily influenced by environmental factors such as temperature and moisture because of the physiologic function of these structures on silicon accumulation.However,the form and the position of silica cells,which were not greatly influenced by environmental factors,might be genetically controlled.Studying these structures at the microscopic level helps define the relationship between the diaspore and its environment.This study has a reference value for future studies on B.tectorum.
英文关键词	Bromus tectorum diaspore micromorphology lemma Kazakhstan United States Xinjiang of China
类型	Article
语种	英语
开放获取类型	Bronze
收录类别	CSCD
WOS研究方向	Plant Sciences
CSCD记录号	CSCD:4899895
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/335213
作者单位	Liu Yaobin, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Key Laboratory of Biogeography and Bioresource in Arid Land, Chinese Academy of Sciences, Urumqi, Xinjiang 830011, China.; Zhang Yuanming, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Key Laboratory of Biogeography and Bioresource in Arid Land, Chinese Academy of Sciences, Urumqi, Xinjiang 830011, China.; Nowak Robert S, Department of Natural Resources and Environmental Science, University of Nevada-Reno, Reno, 89557, USA.; Dimeyeva Liliya, Institute of Botany and Phytointroduction, Almaty, 050040, Kazakhstan.
推荐引用方式 GB/T 7714	Liu Yaobin,Zhang Yuanming,Nowak Robert S,et al. Diaspore characteristics and ecological adaptation of Bromus tectorum L.from different distribution regions[J],2013,5(3):310-323.
APA	Liu Yaobin,Zhang Yuanming,Nowak Robert S,&Dimeyeva Liliya.(2013).Diaspore characteristics and ecological adaptation of Bromus tectorum L.from different distribution regions.Journal of Arid Land,5(3),310-323.
MLA	Liu Yaobin,et al."Diaspore characteristics and ecological adaptation of Bromus tectorum L.from different distribution regions".Journal of Arid Land 5.3(2013):310-323.