广藿香^(60)Co-γ诱变体植株遗传多样性的ISSR分析

ISSR Analysis of Plant Genetic Diversity of ^(60)Co-γ Induced Mutants of Pogostemon cablin

从广藿香的同一大田植株上取外植体构建了一批无菌材料。将这批无菌材料分别经过0,45,60,75,90 Gy的^(60)Co-γ射线辐照诱变处理,获得了172份Co-γ射线诱变体材料和1份对照无菌材料(CK;0 Gy)。分别提取这173份无菌材料的基因组DNA,用14条ISSR有效引物对173份种质材料的基因组DNA进行PCR扩增,共获得297条扩增产物,其中多态性条带为68条,诱变材料的多态位点比率PPB为43.13%,观测等位基因数Na=1.431 3,有效等位基因数Ne=1.257 3,Nei's基因多样性H=0.146 5,Shannon信息指数I=0.217 5。173份供试材料之间遗传关系系统树由UPGMA法,根据所得遗传相似系数矩阵构建。系统树图表明,当GS(遗传相似系数)值取0.09<GS<0.42时,可以把供试的173份材料划分为2个类群:即Ⅰ类群和对照(CK);当GS=0.44时,可把Ⅰ类群分为2个亚类群,即Ⅱ类群和90 Gy-43号材料;当GS值取0.46<GS<0.48时,又可把Ⅱ类群分为2支,即Ⅲ类群和75 Gy-13号材料。虽然有部分不同辐射剂量处理的诱变植株聚类在一起,但是总体上是,相同辐射剂量处理组的诱变植株聚为一类。结果表明,广藿香无菌材料经用^(60)Co-γ射线辐照诱变后发生变异频率较大,为此,^(60)Co-γ射线辐照诱变可作为广藿香种质创新的一种有效手段。

A number of germfree materials were obtained from explants of the same field plant of Pogostemon ca- blin （Blanco） Benth. These germfree materials were irradiated by 60Co-γ/ray irradiation at a respective dose of 0, 45, 60, 75 or 90 Gy, from which 172 pieces of 60Co-γ/ray mutant material and 1 piece of germfree control ma- terial （CK; 0 Gy） were produced. The genomic DNAs of 173 germfree materials were extracted and amplified by using PCR with 14 ISSR primers. A total of 297 amplified products were produced, of which there were 68 poly- morphic bands, the percentage of polymorphic bands（PPB） was 43.13%, the observed number of alleles （NA） was 1. 431 3, the effective number of alleles （Ne） was 1. 257 3, the Nei＇ s gene diversity （H） was 0. 146 5, and Shannon index was 0. 217 5. According to the obtained genetic similarity coefficient matrix, a phylogenetic tree showing genetic relationships among the 173 materials tested was constructed by UPGMA. This phylogenetic tree diagram showed that at the genetic similarity coefficient （GS） range of 0.09 〈 GS 〈 0.42 the 173 materials could be divided into two groups： Group I and CK, that at the GS of 0.44, the Group I could be divided into two sub- groups ： Group II and material 90 Gy-34, and that at the range of 0.46 〈 GS 〈 0.48, the Group II could be divid- ed into two branches： Group III and material 75 Gy-13. Although some of the mutagenie plants induced by radia- tion at different doses were clustered together, the mutant plants induced at the same radiation dose were generally clustered into the same group. The results showed that 60Co-γ/-ray irradiation had significant mutagenic effect on the mutants of P. cablin （Blanco） Benth. Mutation with 60Co-γ ray could be used as an effective method for germ- plasm innovation of P. cablin （Blanco） Benth .