特色桑品种资源ITS、TrnL-F和rps16序列与亲缘关系分析

Analysis of ITS,TrnL-F,rps16 Sequence and Genetic Relationship of Characteristic Mulberry Resources

为了更好地开发利用特色桑树品种,分析了龙桑、龙须桑等12个特色桑资源ITS、TrnL-F、rps16碱基序列的长度、G＋C含量、亲缘关系、遗传距离及信息变异位点。结果表明,ITS间隔区（包括5.8S）全长为576-590 bp,G＋C含量59.38%-60.17%;TrnL-F间隔区（包括TrnL内含子）全长为920-923 bp,G＋C含量为34.02%-34.24%;rps16内含子全长为929-947 bp,G＋C含量为32.51%-33.26%。亲缘关系分析显示,分支图首先将外类群—构树分出,紧接着分出的是新疆黑桑。再依次为咸丰长穗桑、钦州长果桑、神农华桑、广东大10、雅安白桑、斯里兰卡1号、湖北蒙桑4号、龙桑、和田白桑,龙须桑、剑持、小冠桑在分支树的最顶层。根据外类群确定法,新疆黑桑为原始类型,龙须桑、剑持、小冠桑为最进化类型。遗传距离分析显示,新疆黑桑、剑持、咸丰长穗桑、钦州长果桑、小冠桑与其他桑属材料的遗传距离分别为1.0-1.3、0.2-0.3、0.1-0.4、0.1-0.2、0-0.3,龙桑、斯里兰卡1号、雅安白桑、和田白桑、广东大10、龙须桑、湖北蒙桑4号与其他桑属材料间遗传距离差异不大。信息变异位点分析显示共有14个信息位点,占总位点数的0.5564%。变异主要发生在外类群—构树和新疆黑桑,且变异大多集中在ITS区域。ITS、TrnL-F和rps16三片段分析桑属的亲缘关系,信息位点不足,有待深入研究。

In order to understand the characteristics of mulberry resources,we analyzed the sequences of ITS,TrnL-F,and rps16 including the length,G ＋ C content,genetic distance,and parsimony informative sites using 12 characteristic mulberry resources. The results indicated that the length of mulberry ITS sequence（ including 5. 8S）was 576- 590 bp with G ＋ C content of 59. 38%- 60. 17%. The length of TrnL-F sequence（ including TrnL intron） was 920- 923 bp with G ＋ C content of 34. 02%- 34. 24%. And the length of rps16 intron was 929- 947 bp with the G ＋ C content of 32. 51%- 33. 26%. In the Cladogram built by mrbayes software,Broussonetia papyrifera was separated first,the remainders were arranged in the following order： Xinjiang M. nigra,Xianfeng M. mizuho,Qinzhou M. macroura,Shennong M. cathayana,Guangdong da shi,Ya＇an M. alba,Sri LankaNo. 1,Hubei M. mongolica No. 4,M. alba var. Tortuosa,Hetian M. alba,M. alba var. pendula Jianchi,Xiao guan sang,located in the topmost of the cladogram. Based on the outgroup,Xinjiang M. nigra was a primitive type,while M. alba var. pendula,Jianchi and Xiao guan sang were the most evolutional type. The genetic distances between Xinjiang M. nigra,Jianchi,Xianfeng M. wittiorum,Qinzhou M. macroura,Xiao guan sang and others was 1. 0- 1. 3,0. 2- 0. 3,0. 1- 0. 4,0. 1- 0. 2,0. 0- 0. 3,respectively. And the genetic distances of M. alba var. Tortuosa,Sri Lanka No. 1,Ya＇an M.alba,Hetian M. alba,Guangdong da shi,M. alba var. pendula and Hubei M. Mongolica No. 4 to others was almost the same. There were 14 parsimony information sites,which accounted for 0. 5564% of all sites. Variations occurred in Broussonetia papyrifera and Xinjiang M. nigra,and they were mostly concentrated in ITS regions. However,the parsimony information sites were insufficient to analyse the genetic relationship among Morus with three segments（ ITS,TrnL-F,rps16）,suggesting more work should be done to resolve the problem.