title: High genetic differentiation of Hippophae rhamnoides ssp. yunnanensis (Elaeagnaceae), a plant endemic to the Qinghai-Tibet Plateau.
abstract: RAPD markers were used to detect genetic diversity and population genetic differentiation of Hippophae rhamnoides ssp. yunnanensis, a sea buckthorn endemic to the Qinghai-Tibet plateau. The genetic parameters of percentage of polymorphic bands (92.86%), Nei's gene diversity (h, 0.255), and Shannon's index (I, 0.397) indicated high genetic diversity in this subspecies. The subpopulation differentiation suggested that 45.9% of genetic variation was among populations. High genetic differentiation among populations was also detected using AMOVA (47.02%). The main factors responsible for high genetic differentiation are probably related to natural geographic barriers among populations, gene drift, and limited gene flow caused by restricted pollen flow and seed flow. A Mantel test indicated that geographic distances were significantly correlated with genetic distances. The UPGMA phenogram based on Nei's unbiased genetic distances and the result of three-dimensional model plots performed by principal coordinate analysis also supported the correlation. Altitude, however, did not have any clear effect on genetic differentiation.
authors.affiliation: Institute of Botany, Northwest Normal University, Lanzhou, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Chen
authors.forename: Xue
authors.initials: X
authors.lastname: Su
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Kun
authors.initials: K
authors.lastname: Sun
authors.forename: Ruijun
authors.initials: R
authors.lastname: Ma
authors.forename: Xuelin
authors.initials: X
authors.lastname: Chen
mesh_terms: D016000:Cluster Analysis; D017753:Ecosystem; D014644:Genetic Variation; D005843:Geography; D031281:Hippophae / Q000235:genetics*; D010802:Phylogeny; D011157:Population Dynamics; D025341:Principal Component Analysis; D018609:Tibet