桑属ITS,TrnL-F,rps16序列分析及12个特殊桑资源评鉴

 【目的】分析桑属ITS,TrnL-F,rps16序列，探讨系统学价值，建立系统进化树，并对12个特殊桑资源进行评鉴，为开发利用提供理论依据。【方法】用67份桑资源，经DNA提取、PCR扩增、测序，测序结果用软件拼接、比对、除去非序列碱基，计算长度、G+C%含量、变异位点、信息位点、以构树、柘树为外类群，MP分析，根据分析结果，结合桑资源研究积累，对12个特殊桑资源进行评鉴。【结果】桑ITS(包括5.8S)基本序列576 bp ,变异范围576-590 bp，G+C% 59.55-62.25，40个信息位点；TrnL-F（包括tRNA-Leu内含子）基本序列923 bp , 变异范围920-924 bp, G+C%33.69-34.13，23个信息位点；rps16内含子基本序列929 bp ，变异范围923-929 bp，G+C%32.51-32.72，17个信息位点。最适碱基进化模型分别为(GTR+G),(GTR),(GTR+G),可能的分支概率，混合卡方概率值分别为0.000001 ,0.027175,0.000222, 三片段合并最适进化模型(GTR+G)，基于模型，MP分析， 2538个位点，80个信息位点。分支图首先将黑桑M. nigra分出，其它桑种分成两支，第一支桑(mulberry)，包括长穗桑、瑞穗桑、蒙桑、鬼桑、鸡桑、山桑、白桑、广东桑，第二支乔木桑(arbor)，包括华桑、奶桑、川桑。12个特殊桑资源，神农华桑♀（优质木材桑）分在第二支，乔木特性，其它11个特殊桑资源分在第一支，具桑(mulberry)特性。【结论】桑属TrnL-F;rps16序列信息位点有限，单独研究桑属系统学，价值不大，与ITS序列合并，能增加分支图的信息位点，使分支图更具客观性，更近于似然。基于ITS,TrnL-F;rps16序列MP分支图，新疆黑桑为最原始类型，乌克兰等栽培种是进化类型。桑属可根据分支的亲缘关系，结合桑资源研究积累，评鉴特殊桑资源。

Morus ITS, TrnL-F, rps16 sequence analysis and evaluation of 12 special mulberry resources

【Purpose】In this research ,we analyzed the sequences of Morus ---ITS, TrnL-F and ps16, for the value of phylogeny. And with evaluation of 12 special mulberry resources, it can be the theoretical basis for development and utilization.【Method】A total of 67 mulberry genotypes were analyzed (DNA extraction, PCR amplification, sequencing, software splicing, alignment, removing non-sequence bases, analyzing Length and G + C% content, Informative sites), and B. papyrifera and C. tricuspidata worked as outgroup. A cladogram ,generated using MP, was built.【Result】Mulberry ITS (including 5.8S) the length of basic sequence is 576 bp, variation range of 576-590 bp, G + C% 59.55-62.25, 40 informative sites; Mulberry TrnL-F Intergenic sequence(including the tRNA-Leu intron)，the length of basic sequence is 923 bp, variation range of 920-924 bp, G + C% 33.69-34.13, 23 informative sites; rps16 intron ,the length of basic sequence is 929 bp, variation range of 923-929 bp, G + C% 32.51-32.72, 17 informative sites. The most possible evolutionary models were (GTR + G), (GTR) and (GTR + G) respectively. And the optimal evolutionary model of the 3-segment-combined analysis was (GTR + G). In the cladogram , Morus nigra is separated first, the rest is divided into two branches. BranchⅠis mulberry, including M.wittorum, M. mizuho M.mongolica, M.mongolica var.diabolica, M. Australis, M. Bombycis, M. Alba and M. atropurprea. BranchⅡ is arbor, including M. cathayana, M. Macroura, M. notabilis. Shennongjia of M.cathayana♀ (high-quality mulberry wood) falls under Branch Ⅱ, and other 11 Mulberry special resources fall under BranchⅠ.【Conclusion】TrnL-F and rps16 sequence information sites of Morus is limited, but combined with the ITS sequences, it can improve the branch map information sites, and make branch map more reliable. Based on ITS, TrnL-F; rps16 sequence MP, M. nigra (Xinjiang) is divided into a single branch, as the most primitive type. So we can evaluate special mulberry resources through cladogram building.