9种金线莲资源的染色体倍性及其核型分析

Ploidy Study and Karyotype Analysis of 9 Anoectochilus roxburghii(Wall.) Lindl.

目的:通过对比研究,确定9种金线莲资源的染色体倍性及进行核型分析。为进一步大范围开展金线莲不同遗传资源亲缘关系研究提供了技术依据,同时,也为金线莲的优良资源筛选和品种鉴定奠定基础。方法:本研究选取福建等省广泛种植的9种金线莲资源,分别命名为GXHZ、GXJX、GXDY、FJQG、FJTN、FJTN1、FJCY、FJSM、FJJY,通过流式细胞术的方法详细鉴定不同金线莲资源的倍性特征。同时,采用改良后的酶解去壁低渗-火焰干燥法制备不同金线莲染色体标本,详细解析不同金线莲资源核型类型。结果:流式细胞术分析发现在以2倍体石斛为对照时,本研究所用的9种金线莲资源材料皆为4倍体。不同资源染色体制片观察结果发现9种不同金线莲的核型分类均属于2B型,其中,GXHZ的核型公式为2n=64m+16sm;GXJX为2n=78m+2sm;GXDY为2n=1st+20m+19sm;FJQG为2n=18m+22sm;FJTN/1为2n=68m+12sm;FJTN/2为2n=29m+11sm;FJCY为2n=38m+2sm;FJSM为2n=14m+26sm;FJJY为2n=74m+6sm。核型聚类9种不同金线莲似近系数范围介于0.027~0.107之间。结论:本研究所选取的金线莲为4倍体,核型聚类结果表明,本研究所选取的金线莲资源亲缘关系较近。

Objective： To provide the technological references for further identifying of different Anoectochilus roxburghii on large-scale levels and lay foundation for screening of genetic resources and identification of varieties,9 A. roxburghii（Wall.） Lindl. were studied particularly by ploidy study and karyotype analysis. Methods： The 9 A. roxburghii germplasms in Fujian and other provinces that named as GXHZ,GXJX,GXDY,FJQG,FJTN,FJTN1,FJCY,FJSM and FJJY respectively,were analysed by using chromosome karyotype technology and flow cytometry methods. The flow cytometry technology was used to identify the ploidy property of different A. roxburghii. Simultaneously,the modified flame-drying method,in which the cell wall from plant were digested with enzyme under low osmosis was used to reveal the karyotypes of different A. roxburghii. Results： 9 A. roxburghii were identified as tetraploid with comparison to the control（Dendrobium officinale Kimura et Migo） that were confirmed to be diploid based on flow cytometry analysis. Furthermore,the 9 A. roxburghii owned typical characteristics with karyotypes of 2 B type through the observations of chromosome tabletting method. Of which,the karyotype formulas were 2 n = 64 m ＋ 16 sm for GXHZ,2 n = 18 m ＋ 22 sm for GXJX,2 n = 1 st ＋ 20 m ＋ 19 sm for GXDY,2 n = 18 m ＋ 22 sm for FJQG,2 n = 68 m ＋ 12 sm for FJTN/1,2 n = 29 m ＋ 11 sm for FJTN/2,2 n = 38 m ＋ 2 sm for FJCY,2 n = 14 m ＋ 26 sm for FJSM,2 n = 74 m ＋ 6 sm for FJJY. Cluster analysis of karyotype showed that there were the near coefficients between any two of 9 A. roxburghii that ranged from 0. 027 to 0. 107. Conclusion： The chosen A. roxburghii were identified as tetraploid,and the karyotype resemblance-near coefficient indicated that there were similar genetic relationship presented among 9 A. roxburghii＇ s germplasms.