Polyploidy and natural hybridization are considered as two major evolutionary processes involved in plant speciation and diversification. In conifers, natural hybridization has been noticed to be more frequent than polyploidy. Nevertheless, a few cases of polyploidy have been reported in the genus Juniperus. In this genus, a new variety Juniperus sabina var. balkanensis has been postulated to have arisen from an ancient hybridization between the tetraploid species Juniperus thurifera and the diploid species Juniperus sabina var. sabina. The genome size variation and the ploidy level of two J. sabina taxa were estimated by flow cytometry in a panel of 29 populations. All 13 populations of J. sabina var. sabina were diploid, with genome sizes ranging from 22.09 to 25.03 pg/2C, while the 16 populations of J. sabina var. balkanensis were tetraploid, with genome sizes ranging from 41.99 pg to 51.33 pg/2C. These findings open new venues towards the discovering of the polyploidization pathway of J. sabina var. balkanensis and to understand historical and ecological factors that explain its current geographical distribution.

多倍体和自然杂交被认为是植物物种形成和多样化的两个主要进化过程。在针叶树中，已经发现自然杂交比多倍体更为频繁。然而，在ipe属中已经报道了一些多倍体病例。在这个属中，新品种杜松变种。据推测，巴尔干是起源于四倍体物种杜鹃花与二倍体杜鹃花变种之间的古老杂交。萨宾娜。两个J. sabina的基因组大小变异和倍性水平通过流式细胞仪在29个人群中估计了分类单元。J. sabina var。的所有13个人口 sabina是二倍体，基因组大小范围为22.09至25.03 pg / 2C，而J. sabina var的16个种群。巴尔干是四倍体，基因组大小为41.99 pg至51.33 pg / 2C。这些发现为发现J. sabina var的多倍体化途径开辟了新的场所。balkanensis和理解解释其目前的地理分布的历史和生态因素。