3种安息香属植物的根尖染色体核型分析

Karyotype Analysis of Root Chromosome in Three Species of Styrax

2013年9月和10月,在浙江省杭州市采集芬芳安息香Styrax odoratissimus,越南安息香S.tonkinensis和赛山梅S.confusus种子,砂藏至翌年发芽,待根长至3~5 cm时,对3种安息香属植物的根尖进行染色体制片和核型分析。结果显示,3树种均为二倍体,体细胞染色体数均为2n﹦2x﹦16。芬芳安息香核型公式为2n﹦16﹦10 m+6 sm(2 sat),核不对称系数为58.20%,染色体核型为2A型;越南安息香核型公式为2n﹦16﹦12 m(1 sat)+4 sm(2 sat),核不对称系数为53.27%,染色体核型为1A型;赛山梅染色体核型公式为2n﹦16﹦12 m(1sat)+4 sm,核不对称系数为56.54%,染色体核型为1A型。表明越南安息香和赛山梅核型较为类似,亲缘关系较近,与芬芳安息香之间差别较大,芬芳安息香比越南安息香和赛山梅进化程度较高。3种安息香属植物染色体核型均为A型,表明其进化地位较低,植物较为原始。

Seeds of Styrax odoratissimus,S.tonkinensis and S.confusus were collected on September and October of2013in Hangzhou,Zhejiang province.They were treated by sand storage until the next spring.When seeds germinated and root had3-5cm,the apices of three species were used for chromosome sectioning and karyotype analysis.The results showed that the tested species were diploid,and their genome chromosome number was2n=2x=16.Karyogram of S.odoratissimus was2n=16=10m+6sm(sat),nuclear asymmetry index was58.20%,and karyotype was2A.Karyogram of S.tonkinensis was2n=16=12m(1sat)+4sm(2sat),nuclear asymmetry index was53.09%,andt karyotype was1A.Karyogram of S.confusus was2n=16=12m(1sat)1+4sm,nuclear asymmetry index was56.54%,and the karyotype was1A.The test concluded that karyotypes of S.tonkinensis and S.confusus were similar,but different with that of S.odoratissimus,indicating that the chromosome evolution of three species was low,and they were primitive.