三尖杉种源遗传多样性

应用ISSR分子标记对我国三尖杉主要分布区16个地理种源的遗传多样性和遗传分化进行分析.结果表明,三尖杉具有丰富的遗传多样性,总的种源基因多样性为0.337 7.研究发现,不同种源的遗传多样性差异较大,遗传多样性较高的种源主要来自三尖杉自然分布区的东部和偏中东部地区.由于小种群效应, 以及缺乏有效的基因流和生境的片断化,三尖杉种源间的遗传分化较大,25.9%的遗传变异存在于种源间,而74.1%的遗传变异来自于种源内.聚类结果显示,来自东部和偏中东部、遗传多样性较高的种源聚成一支.该区域和边缘分布区种源间遗传多样性的差异在很大程度上可能归因于长叶和短叶2种类型三尖杉种源间的差异.研究还表明,种源间的遗传距离与其地理距离相关不显著.

Genetic Diversity for Different Provenances of Cephalotaxus fortunei

Genetic diversity and genetic differentiation of l6 Cephalotaxus fortunei provenances from main distribution area were analyzed using ISSR molecular markers.The result showed that there existed a high degree of genetic diversity for C.fortunei.Total gene diversity was 0.337 7.It was found that there was significant difference in genetic diversity among provenances.Provenances from the eastern and mid-eastern distribution area had higher genetic diversity.Small population effect,restricted gene flow and habitat fragmentation resulted in high genetic differentiation among provenances,which contributed to 25.9% of total genetic variation,and the differentiation within provenances contributed to 74.1% of total genetic variation.Analysis of Nei's unbiased genetic distance showed that provenances with higher genetic diversity from eastern and mid-eastern distribution area were aggregated.Genetic diversity difference between provenances from the central and the fringe distribution area might be attributed to difference between provenances of long-leaf types and short-leaf types.The test also showed there was no significant correlation between genetic and geographic distances among provenances.