摘要
短花针茅(Stipa breviflora)属亚洲中部荒漠草原种,分布范围极其广泛,为荒漠草原地带重要的牧草资源。在内蒙古地区,短花针茅群落类型复杂多样,与本氏针茅(S.bungeana)、小针茅(S.klemenzii)和克氏针茅(S.krylovii)均能共同建群,具有很广的生态幅和很强的适应能力。研究以8个不同的短花针茅地理种群为对象,随机采集健康、无锈短花针茅叶片样本,通过RAPD(Random Amplified Polymorphism DNA,RAPD)分析,研究短花针茅种群的遗传多样性,丰富人们对短花针茅生物多样性的认识,也为合理利用短花针茅草原提供依据。结果表明,(1)从102条10碱基随机引物中筛选出28条有效引物,共扩增出308条DNA带,多态性DNA带151条,占49.03%,特异性DNA带45条,占14.61%。(2)遗传多样性较为丰富,多态性位点百分率为49.03%,但低于同种方法获得的大针茅(54.75%)和克氏针茅(74.67%)的遗传多样性。(3)等级聚类、PCA分析和UPGMA聚类3种不同方法都将8个不同地理种群分为同样的两类:暖温性种群和中温性种群,热量差异是主导因素,而且,与种群的空间分布相吻合。(4)经Mantel检验发现,遗传距离与地理距离存在显著相关性(r=0.534,P<0.05)。(5)Pearson相关分析表明,特异性位点百分率与≥10℃积温、干燥度和年平均降水量之间均无显著相关性。
Stipa breviflora is a desert steppe plant species found widely in central Asia,and is a major forage plant in the desert steppe region of Inner Mongolia.The desert steppe is dominated by several Stipa species,including S.bungeana,S.klemenzii and S.krylovii.S.breviflora is adapted to a wide range of environment conditions,and tolerant to extremely tough climatic and soil conditions.The objective of the study was to estimate the genetic diversity of S.breviflora populations by studying different S.breviflora populations from 8 geographic locations in the Inner Mongolia steppe.Healthy and rustless leaves of S.breviflora individuals were sampled randomly at each site for RAPD analysis.Our results showed：（1）28 primers were screened from 102 arbitrary primers with 10-bp.A total of 308 bands were produced,including 151 polymorphic bands,accounting for 49.03% of the total.There were 45 unique loci obtained,accounting for 14.61%.（2）The genetic diversity of S.breviflora（49.03%）was lower than that of S.grandis（54.75%）and S.krylovii（74.67%）reported earlier by other authors.（3）Eight different geographical populations could be grouped into 2 categories：warm-temperate and cold-temperate populations with 3 different methods,i.e.Hierarchical cluster analysis,PCA and UPGMA clustering.These 2 groups were mainly characterized by marked differences of thermal factors,corresponding to their spatial distribution boundaries.（4）Mantel test showed a significantly positive correlation between genetic distance and geographical distance（r=0.534,P〈0.05）.（5）The percentage of unique loci of 8 populations showed no significant correlations with accumulative temperature above 10℃,aridity and annual mean precipitation,according to Pearson correlation analysis.
出处
《生态学报》
CAS
CSCD
北大核心
2008年第7期3447-3455,共9页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目(30760158)
内蒙古大学"513"人才项目和人才引进资助项目
内蒙古自然科学基金资助项目(200308020507)
内蒙古高等学校科研资助项目(NJ02008)
省部共建"内蒙古草地生态学国家重点实验室培育基地"资助项目~~
关键词
短花针茅
地理种群
RAPD
遗传多样性
Stipa breviflora,geographic population,RAPD,genetic diversity
