全 文 ：文章编号: 1007-0435( 2005) 03-0260-02 ·博士论文摘要·
披碱草属( Elymus L. )植物遗传多样性研究
博士生:严学兵1, 2　导师:周　禾1,王　 1
( 1.中国农业大学草地研究所, 北京　100094; 2.郑州牧业工程高等专科学校, 河南郑州　450008)
　　以我国 9种披碱草属( Elymus L. )的40个居
群为材料,采用形态学、等位酶和微卫星3种标记对
28个形态特征、7个等位酶位点和 11对 SSR 引物
进行遗传多样性分析。结果表明:不同居群的披碱草
间形态差异显著;不同种、居群和形态特征变异规律
也有所不同。旗叶与穗基部长度、生长速度(幼苗-分
蘖)、小穗柄、植株绒毛分级在种内变异较大,而穗的
形状、穗节数、株高和内稃的变化较为稳定。聚类分
析结果表明:披碱草( E. dahuricus T urcz. )、圆柱披
碱草( E. cy lindri-cus( Fr anch. ) Honda)、紫芒披碱
草( E . purp uraristatus C. P . Wang et H. L . Yang )
变异很大, 垂穗披碱草( E . nutans Gr iseb L . )和老
芒麦( E . sibiricus Linn. )的居群按种归类比较清晰
明显。
等位酶分析结果表明, 在 40个居群材料中 7
个位点发现了 22个等位基因。在属的水平上多态
性位点百分数为 87. 5%, 居群内平均多样性指数
( H s)为 0. 0830, 居群间平均多样性指数( Dst )为
0. 2149, 所有多态性位点的遗传分化系数( Gst)为
0. 7213。在该属中,遗传多样性( H e )和Shannons
信息指数( H e= 0. 2974; I= 0. 4565)最大水平上
反应了披碱草居群之间的变异。在种的水平上遗
传多样性和 Shannons 信息指数分别为 0. 0800
～0. 2528和 0. 1173～0. 3769,而居群内二者分别
在 0. 0160～0. 1680和 0. 0250～0. 2433 范围内。
在属内, 遗传分化的分配量依次为种间( 38. 9% )、
种内居群间( 33. 2%) 和居群内个体之间( 29.
8% )。居群之间基因流( Nm)很低,为 0. 1932。属
于同一种的居群基本能聚类在一起, 同时和地域
之间亦有明显的关系。9种披碱草属植物虽然不
是按照穗的形状(披碱草组( Sect. T urcz aninov ia
( Nev ski) Tzvel. )和老芒麦组( Sect . Elymus ) )分
为两组,但属于披碱草组和老芒麦组内的披碱草
关系亲近。以垂穗披碱草为例,海拔是影响遗传差
异最重要的因素, 其次是地理位置(纬度和经度)。
11个多态性微卫星位点发现有 1～8个等位
基因, 共检测出 38个等位变异,平均 3. 5个等位
变异。来自于披碱草的微卫星引物平均 4. 5个, 而
来自于小麦的2. 2个 ,披碱草的特异 SSR 引物在
反应遗传多样性方面具有更好的作用和效果。位
点 ECGA22、ECGA114、EAGA51 和 WMS43 遗
传变异信息含量比较高, 对于构建披碱草高密度
的微卫星种(品种)指纹是很好的选择。种内和种
间的遗传多样性变异结构, 多个引物具有很好的
一致性,大多数基因多样性存在于种内,占总变异
的 75. 74%。无论等位酶还是微卫星标记, 在青藏
高原地区都拥有遗传丰富的披碱草资源。在披碱
草种的多样性指数变化也很大, 基因多样性和
Shannons 信息指数变化范围分别在 0. 1622～
0. 3619和0. 2248～0. 5318。相似性和聚类分析结
果显示,对居群水平大致可按种来进行划分。SSR
标记对不同披碱草居群的聚类和材料间的亲缘关
系和地域分布有较好的一致性。披碱草的 9个种
并没有分成几个明显的组, 而以老芒麦和青海披
碱草( E . gem inatus L. )最近, 其次是披碱草和紫
芒披碱草亲缘关系, 垂穗披碱草和短芒披碱草
( E. br eviar istatus( Keng ) Keng F. )也相对较近。
地理位置(纬度和经度)是影响垂穗披碱草居群微
卫星遗传差异最重要的因素,其次是海拔。
关键词: 披碱草;形态特征; 等位酶;微卫星;遗传多样性
中图分类号: S812; Q943　文献标识码: A
完成时间: 2005年 5月
收稿日期: 2005-06-24;修回日期: 2005-07-26
基金项目:青海省重大科技攻关项目“青南适用牧草品种选育( 21031423)”资助
作者简介:严学兵( 1974-) ,男,博士,讲师,研究方向为草业科学, Email: yxbbjzz@ 163. com
导师简介:周　禾( 1955-) ,王 ( 1962-) ,男,中国农业大学草地研究所教授,研究方向为草业科学, E-mail: wangk un6060@ sina. com . cn
第 13卷　第 3期
　Vo l. 13　　No. 3
草　地　学　报
ACT A AGRESTIA SIN ICA
　　2005年　 9 月
　Sept. 　　2005
Study of Genetic Diversity of Elymus Species
Candidate: YAN Xue-bing　Advisor s: ZHOU He, WANG Kun
( 1.Grass land Ins t itute of China Agricul ture University, Beijin g 100094, Ch ina;
2. Zheng zhou College of Animal Husbandry, Zhengzh ou , Henan Province 450008, China)
　　T he genetic diversit ies of 40 populat ions of 9 Elymus species from China were determined, using morpho lo-
gy , allozyme and m icrosatellite marker s for 28 mor pholog ical t rait s, seven allo zyme lo ci and elev en pairs of mi-
cro satell ite primers. M orpholog ical t rait s dif fered greatly among populat ions and variation t rends also deviated
w ithin species and populat ions. The distance betw een the f lag leaf and the spike of a plant , the g row th r ate
during the seedling to the t illering stag e, the rachilla and the plant villus g rade var ied species f rom species,
though the spike shape, the spike pitch number, the plant height , and the palea changed unvar ying ly. Dendro-
gram of relat ionships show ed that , though E. dahuricus T urcz. , E . cy l indricus ( Franch. ) Honda, and E. pur-
purar istatus C. P . Wang et H. L . Yang varied to a g reat ex tent , populat ions of E . nutans Gr iseb. L . , and E.
sibir icus Linn. clearly clustered tog ether w ithin the species.
Allozyme data indicated that , 7 allozyme lo ci w ere encoded by 22 alleles acr oss 40 populat ions. T he po ly-
morphic loci percentag e w as 87. 5 at g enus level. Mean of diversity index w er e 0. 0830 w ithin populat ions ( Hs)
and 0. 2149 among populat ions ( Dst ) . Coeff icient o f genet ic v ariat ion across all po lymo rphic loci w as 0. 7213.
Genetic diver sity( H e) and Shannons information index ( I ) had the bigg est variation values ( H e= 0. 2974; I=
0. 4565) among populat ions o f Elymus genus, ranging f rom 0. 0800 to 0. 2528 and 0. 1173 to 0. 3769 at species
level, f rom 0. 0160 to 0. 1680 and 0. 0250 to 0. 2433 within populat ions, respect ively. Of the total genet ic varia-
tion of Elymus genus, 38. 9% existed among species, 33. 2% am idst populat ions w ithin the species, and 29. 8%
amid individuals within a populat ion. Gene f low among the populat ions w as sluggish, a mere 0. 1932. Popula-
tions belonging to the same species normally cluster ed tog ether, and the dendr ogram was obviously related to
the geographical orig ins. T hough 9 Elymus species w er e not divided by spike mo rpholo gy into tw o g roups:
Sect . T urczaninovia ( Nev ski) T zvel. , and Sect . Elymus, all the Elymus species in the tw o Sects. show ed close
relationship. Take E . nutans Gr iseb. L . for an instance, elevat ion w as the most impo rtant facto r inf luencing
the plant s g enetic dif ference, while the geog raphical site ( lat itude and long itude) played only a secondary role.
M icrosatellite data indicated that there w ere 1～8 alleles in the 11 polymor phic SSR loci, and 38 mult iple
alleles, w ere detected, averaging 3. 5 mult iple alleles. Microsat telite primers developed fr om E lymus species
averaged 4. 5 alleles, higher than that of w heat o f an aver age of 2. 2, indicat ing that micro satel lite primers de-
veloped from Elymus species funct ioned bet ter in determining its genet ic diversity . Loci ECGA 22、ECGA114、
EAGA51 and WMS43 transferr ed mo re informat ion on the genetic variat ion, helping to the const ruct ion of f in-
gerprint o f Elymus species. Primers consistent ly indicated that 75. 74% of the variation ex isted among popula-
tions w ithin the species. T ibetan plateau w as genet ically resourceful o f Elymus species based on both allozyme
and SSR markers. Gene diversity and Shannons info rmat ion index at species level v ar ied g reat ly f rom 0. 1622
to 0. 3619 and 0. 2248 to 0. 5318, respectiv ely . Sim ilarity and dendrog ram of clustering among populat ions
show ed consistence w ith their species and geographical origins. Nine E lymus species w ere no t clear ly divided in-
to dif ferent gr oups, though E . sibi ricus and E . geminatus related most clo sely, E . dahur icus and E . purp ur aris-
tatus came next . So w ere E. nutans and E . brev iaristatus. Geog raphical site ( lat itude and longitude) w as the
most important factor inf luencing the genet ic dif ference. Elevat ion came nex t .
Key words : Elymus; M orpho logical t rait ; Allo zyme; M icrosat telite; Genetic diver sity
261第 3期 严学兵等:披碱草属( Elymus L . )植物遗传多样性研究