Jørgensen Stacy, Hamrick J L, Wells P V
Department of Geography, The University of Georgia, Athens, Georgia 30602 USA;
Am J Bot. 2002 May;89(5):792-800. doi: 10.3732/ajb.89.5.792.
Pinus flexilis (limber pine) is patchily distributed within its large geographic range; it is mainly restricted to high elevations in the Rocky Mountains and the Basin and Range region of western North America. We examined patterns of allozyme diversity in 30 populations from throughout the species' range. Overall genetic diversity (H(e) = 0.186) was high compared with that of most other pine species but was similar to that of other pines widespread in western North America. The proportion of genetic diversity occurring among populations (G(ST) = 0.101) was also high relative to that for other pines. Observed heterozygosity was less than expected in 28 of the 30 populations. When populations were grouped by region, there were notable differences. Those in the Basin and Range region had more genetic diversity within populations, a higher proportion of genetic diversity among populations, and higher levels of inbreeding within populations than populations from either the Northern or Utah Rocky Mountain regions. Patterns of genetic diversity in P. flexilis have likely resulted from a complex distribution of Pleistocene populations and subsequent gene flow via pollen and seed dispersal.
柔枝松（limber pine）在其广阔的地理分布范围内呈斑块状分布；主要局限于落基山脉以及北美西部盆地与山脉地区的高海拔地带。我们研究了该物种分布范围内30个种群的等位酶多样性模式。与大多数其他松树物种相比，总体遗传多样性（H(e) = 0.186）较高，但与北美西部广泛分布的其他松树相似。种群间遗传多样性的比例（G(ST) = 0.101）相对于其他松树也较高。在30个种群中的28个种群中，观察到的杂合度低于预期。当按区域对种群进行分组时，存在显著差异。盆地与山脉地区的种群在种群内具有更多的遗传多样性、种群间遗传多样性的比例更高，并且种群内的近亲繁殖水平高于来自北部落基山脉或犹他落基山脉地区的种群。柔枝松的遗传多样性模式可能是由更新世种群的复杂分布以及随后通过花粉和种子传播的基因流动所导致的。
