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【目的】深化烟草种质资源遗传多样性研究,为种质利用改良烟草提供科学依据。【方法】应用ISSR分子标记方法,以烟草属6个种共96份有代表性的种质为材料,进行遗传多样性与亲缘关系分析。【结果】(1)从90个ISSR引物中筛选出18个多态性引物对全部实验材料进行PCR扩增,共获得314条稳定的条带,其中多态性条带299条(占95.2%)。(2)应用Nei-Li相似系数法估算了96份材料间的遗传相似系数(GS),其GS在0.28～0.97之间,遗传多样性丰富。其中普通烟草栽培品种间的GS在0.62～0.98之间,平均为0.78,品种间的遗传基础相对狭窄,普通烟草栽培种与野生种及黄花烟的GS在0.28～0.58之间,平均为0.42,种间遗传差异较大;(3)对91份普通烟草栽培品种的分子系统聚类分析表明:地理来源相同的部分品种有相对聚合现象或少部分国内外品种和类型出现交叉聚类,与其亲缘关系较近有关;个别品种自行一类,与其特异的遗传基础差异较大有关。【结论】ISSR是一种较有效、稳定和可靠的分子标记,本研究可为烟草育种的亲本利用及开展烟草遗传连锁图的构建和核心种质指纹图谱的绘制提供重要的科学依据。
【Objective】 The purpose of this research is to deepen the genetic diversity of tobacco germplasm resources and provide a scientific basis for the improvement of tobacco utilization by germplasm. 【Method】 The ISSR molecular marker method was used to analyze the genetic diversity and genetic relationship in 96 representative indica germplasms of 6 species of Nicotiana. 【Result】 (1) Eighteen polymorphic primers were screened from 90 ISSR primers for PCR amplification of all the experimental materials. A total of 314 stable bands were obtained, of which 299 were polymorphic (95.2% ). (2) The Nei-Li similarity coefficient method was used to estimate the genetic similarity coefficient (GS) of 96 cultivars. The GS was between 0.28 and 0.97 and the genetic diversity was abundant. Among them, GS of common tobacco cultivars ranged from 0.62 to 0.98 with an average of 0.78. The genetic basis among breeds was relatively narrow. The GS of common tobacco cultivars and wild and yellow tobaccos ranged from 0.28 to 0.58 with an average of 0.42, (3) The molecular phylogenetic analysis of 91 common tobacco cultivars showed that some species with the same geographical origin had relative polymerization phenomena or a few cross-species clustered with varieties and types at home and abroad, The relationship between the close related; individual species of a class, and its specific genetic basis of the larger differences. 【Conclusion】 ISSR is a more effective, stable and reliable molecular marker. This study can provide important scientific evidences for the utilization of tobacco breeding parents and the construction of tobacco genetic linkage map and the mapping of core germplasm.