33个杨柳品种指纹图谱构建

Construction of fingerprints for 33 varieties in Salicaceae

【目的】构建杨树与柳树优良品种的指纹图谱,对不同品种进行准确鉴定。【方法】利用柳树EST-SSR标记对33个杨树与柳树优良品种进行通用性检测及基因分型,通过核心引物间的组合构建品种指纹图谱。同时采用非加权组平均法进行聚类,分析各品种间亲缘关系。【结果】12个EST-SSR标记共扩增出97条等位片段,每个位点等位基因数5~13个不等,平均为8.1个。12个位点的多态信息含量(PIC)变化范围为0.637 2~0.834 8,平均为0.781 7。优选的3对核心引物中,SALeSSR0340与SALeSSR0346组合可完全区分12个杨树品种,而SALeSSR0259、SALeSSR0340与SALeSSR0346的组合可完全区分所有的33个品种。聚类分析显示33个品种间的遗传相似系数为0.68~0.96,并分成杨属与柳属两大类,与传统的杨柳科系统分类学一致。各品种间亲缘关系聚类结果与遗传背景相吻合。【结论】对33个杨柳树优良品种进行指纹图谱构建与亲缘关系分析,表明EST-SSR标记可有效反映品种间的差异,建立的基因分型体系准确、高效,可为杨树与柳树品种鉴定、保护与推广工作提供科学依据。

【Objective】Populus and Salix are members of Salicaceae family. They are dioecious catkin-bearing woody plants that propagate easily, grow fast, and serve as an important source of wood(for furniture), plywood, fiberboard, and pulp and paper industries. In recent years, numerous Populus and Salix varieties have been selected and widely used for afforestation. However, the morphological characteristics among the varieties of Populus and Salix are quite similar, making it difficult to popularize and protect them. To precisely identify different varieties of Salicaceae, a fingerprint for improved varieties of Populus and Salix was established in this study. 【Methods】 A total of 38 pairs of expressed sequence tag-derived simple sequence repeat(EST-SSR) markers with high polymorphism information content(PIC) derived from Salix in a previous study were selected randomly to evaluate the transferability of 33 varieties of Salicaceae, of which 12 were genotyped using the fluorescence dUTP method. The fingerprint of different varieties was constructed by the combination of the core primers. To elucidate the genetic relationship between the different varieties, the unweighted pair group method arithmetic average(UPGMA) was used for clustering analysis. 【Result】 Among the 38 EST-SSR markers, transferability was 68.4% and 57.89% across all the Populus and Salix varieties, respectively. After genotyping, a total of 97 alleles were detected by 12 pairs of EST-SSR markers, and the number of alleles per locus ranged from 5 to 13, with an average of 8.1 alleles. The PIC of the 12 loci varied from 0.637 2 to 0.834 8, with an average of 0.781 7. Among the three optimal pairs of core primers, the combination of SALeSSR0340 and SALeSSR0346 completely distinguish 12 Populus varieties, and the combination of SALeSSR0259, SALeSSR0340, and SALeSSR0346 completely identified all the 33 varieties used in our study. Cluster analysis demonstrated that the similarity coefficient for the 33 improved varieties ranged from 0.68 to 0.96, and all the improved varieties could be separated into two clades, namely, the genera Populus and Salix, which consisted of the traditional taxonomy of Salicaceae. The clustering result of the genetic relationship of each variety also corresponded with the genetic background. 【Conclusion】 In this study, the fingerprints of 33 improved varieties of Salicaceae were constructed and their genetic relationships were evaluated. The divergences between varieties could be effectively screened by the EST-SSR markers, and the genotyping system established in this study was also accurate and efficient. These results can provide scientific evidence for the identification, protection, and popularization of improved varieties of Populus and Salix.