Yu J, Wang Y, Ru M, Peng L, Liang Z S
College of Life Sciences, Northwest A&F University, Yangling, China.
The Center of Soil and Water Conservation and Ecoenvironmental Research, Chinese Academy of Sciences, Yangling, China.
Genet Mol Res. 2015 Jul 3;14(3):7417-25. doi: 10.4238/2015.July.3.17.
Eucommia ulmoides Oliver, the only extant species of Eucommiaceae, is a second-category state-protected endangered plant in China. Evaluation of genetic diversity among some intraspecific hybrid populations of E. ulmoides Oliver is vital for breeding programs and further conservation of this rare species. We studied the genetic diversity of 130 accessions from 13 E. ulmoides intraspecific hybrid populations using inter-simple sequence related (ISSR) and sequence-related amplified polymorphism (SRAP) markers. Of the 100 ISSR primers and 100 SRAP primer combinations screened, eight ISSRs and eight SRAPs were used to evaluate the level of polymorphism and discriminating capacity. A total number of 65 bands were amplified using eight ISSR primers, in which 50 bands (76.9%) were polymorphic, with an average of 8.1 polymorphic fragments per primer. Alternatively, another 244 bands were observed using eight SRAP primer combinations, and 163 (66.8%) of them were polymorphic, with an average of 30.5 polymorphic fragments per primer. The unweighted pair-group method (UPGMA) analysis showed that these 13 populations could be classified into three groups by the ISSR marker and two groups by the SRAP marker. Principal coordinate analysis using SRAP was completely identical to the UPGMA-based clustering, although this was partly confirmed by the results of UPGMA cluster analysis using the ISSR marker. This study provides insights into the genetic background of E. ulmoides intraspecific hybrids. The progenies of the variations "Huazhong-3", "big fruit", "Yanci", and "smooth bark" present high genetic diversity and offer great potential for E. ulmoides breeding and conservation.
杜仲是杜仲科唯一现存的物种，是中国国家二级保护的濒危植物。评估杜仲种内杂交群体之间的遗传多样性对于该珍稀物种的育种计划和进一步保护至关重要。我们使用简单序列相关重复（ISSR）和序列相关扩增多态性（SRAP）标记，研究了来自13个杜仲种内杂交群体的130份材料的遗传多样性。在筛选的100条ISSR引物和100对SRAP引物组合中，使用了8条ISSR引物和8对SRAP引物来评估多态性水平和鉴别能力。使用8条ISSR引物共扩增出65条带，其中50条带（76.9%）具有多态性，平均每条引物有8.1个多态性片段。另外，使用8对SRAP引物组合观察到244条带，其中163条带（66.8%）具有多态性，平均每条引物有30.5个多态性片段。非加权组平均法（UPGMA）分析表明，这13个群体通过ISSR标记可分为3组，通过SRAP标记可分为2组。基于SRAP的主坐标分析与基于UPGMA的聚类完全相同，尽管基于ISSR标记的UPGMA聚类分析结果部分证实了这一点。本研究为杜仲种内杂交种的遗传背景提供了见解。“华中-3”“大果”“延慈”和“光皮”变异的后代具有较高的遗传多样性，为杜仲的育种和保护提供了巨大潜力。
