Genetic structure of hybrid zones between Pinus pumila and P. parviflora var. pentaphylla (Pinaceae) revealed by molecular hybrid index analysis.
Genetic structure of hybrid zones between Pinus pumila and P. parviflora var. pentaphylla (Pinaceae) revealed by molecular hybrid index analysis.
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DOI：
10.3732/ajb.91.1.65
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发表时间：
2004
影响因子：
3
通讯作者：
Yasuyuki Watano;Akiko Kanai;N. Tani
中科院分区：
文献类型：
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作者：
Yasuyuki Watano;Akiko Kanai;N. Tani
松属物种有三种不同的遗传基因组：父本叶绿体，母本线粒体和双亲核。本文对高山白皮松与山地-亚高山小花松的杂交带进行了研究。pentaphylla证明了两个细胞质基因组的渐渗的对比模式，即，父本的cpDNA来自小花芍药P. parviflora var. pentaphylla向P. pumila的方向迁移，而母本mtDNA的迁移方向则相反。利用火炬松表达序列标签（EST）引物，通过聚合酶链反应（PCR）产物的单链构象多态性（SSCP）分析，建立了火炬松各亲本种的共显性核DNA标记。为了描述核基因的渐渗模式，分子杂交指数（MHI）显示的等位基因推断来自P. pumila的总比例被确定为每个植物收集在杂交区的山。旭岳山日本东和马。在Mt. Asahidake，MHI值根据植物采集的海拔高度而变化。然而，在Mt。东沼，有一个差距的MHI值的上方和下方的冷杉和铁杉林区（alt。1800-1900米）。这表明该区域在杂交区中对基因流动形成有效屏障方面发挥作用。
Pinus species have three differently inherited genomes: paternal chloroplast, maternal mitochondrial, and biparental nuclear. Our previous study on the hybrid zones between alpine Pinus pumila and montane to subalpine P. parviflora var. pentaphylla demonstrated contrasting patterns of introgression of two cytoplasmic genomes, i.e., the paternal cpDNA flowed from P. parviflora var. pentaphylla to P. pumila, and the maternal mtDNA flowed in the reverse direction. In the present study, we developed codominant nuclear DNA markers diagnostic or mostly diagnostic for each parental species by single-strand conformation polymorphism (SSCP) of polymerase chain reaction (PCR) products, using expressed sequence tag (EST) primers of Pinus taeda. To describe the introgressive patterns of the nuclear genes, the molecular hybrid index (MHI) showing the overall proportion of alleles inferred to be derived from P. pumila was determined for each plant collected in hybrid zones on Mt. Asahidake and Mt. Higashiazuma, Japan. At Mt. Asahidake, the MHI values changed clinally according to the altitudes at which the plants were collected. However, at Mt. Higashiazuma, there was a gap in the MHI values between the plants above and below the Abies and Tsuga forest zone (alt. 1800-1900 m). This suggested that the zone plays a role in creating an effective barrier to gene flow in the hybrid zone.