摘要： 对紫萍〔Spirodela polyrhiza （Linn.） Schleid.〕3个克隆和兰氏萍〔Landoltia punctata （G. Meyer） Les et D. J. Crawford〕3个克隆的所有克隆分株的单株叶状体数，单叶状体的根数、总根长和平均根长以及叶状体的长度和宽度进行分析，基于微卫星标记扩增结果对6个克隆在各微卫星位点的基因型进行分析，并对各微卫星位点与2种浮萍生长性状的关联性进行分析，还对2种浮萍各微卫星位点不同基因型间的生长性状进行多重比较。结果表明：紫萍单叶状体的根数、总根长和平均根长及叶状体宽度在3个克隆间以及兰氏萍各生长性状在3个克隆间均存在显著（P＜0.05）差异。紫萍3个克隆在Sp25、Sp30、Sp47和Sp53位点的基因型不同，兰氏萍3个克隆在Sp10、Sp14、Sp16、Sp42、Sp47、Sp51、Sp52和Sp53位点的基因型不同；紫萍3个克隆在Sp6、Sp14、Sp16、Sp25、Sp36、Sp45、Sp47和Sp51位点的基因型和等位基因与兰氏萍不同；2种浮萍6个克隆在Sp4、Sp12、Sp28、Sp29和Sp43位点的基因型相同。Sp25、Sp30、Sp47和Sp53位点与紫萍单叶状体的根数、总根长和平均根长的关联性极显著（P＜0.01），Sp30位点与其叶状体的长度和宽度的关联性显著，Sp25位点与其叶状体宽度的关联性也显著。Sp10、Sp14、Sp16、Sp42、Sp47、Sp52和Sp53位点与兰氏萍单株叶状体数和单叶状体根数的关联性极显著，Sp10、Sp14、Sp42、Sp47、Sp51、Sp52和Sp53位点与其叶状体的长度和宽度的关联性显著或极显著，Sp16、Sp51及Sp53位点与其单叶状体的总根长和平均根长的关联性极显著。Sp47和Sp53位点BD基因型紫萍的根明显偏多且偏长，Sp51和Sp53位点AD基因型兰氏萍的根明显偏长；并且，Sp25位点CE基因型紫萍的叶状体最多且最大，其根也最多且最长。研究结果显示：供试的微卫星标记具有属间标记通用性，可用于紫萍和兰氏萍基因型分析；Sp25、Sp30、Sp47和Sp53位点与紫萍根的长度和数量密切相关，而Sp10、Sp14、Sp16、Sp42、Sp47、Sp51、Sp52和Sp53位点与兰氏萍叶状体的数量和大小以及根的数量密切相关。

Number of frond per plant， number， total length and mean length of root per frond， and length and width of frond of all clonal ramets of 3 clones of Spirodela polyrhiza （Linn.） Schleid. and 3 clones of Landoltia punctata （G. Meyer） Les et D. J. Crawford were analyzed， and genotypes of 6 clones at each microsatellite locus were analyzed based on microsatellite marker amplification result. In addition， associations of each microsatellite locus with growth traits of 2 duckweeds were analyzed， and multiple comparisons on growth traits of different genotypes of 2 duckweeds at each microsatellite locus were conducted. The results show that there are significant （P＜0.05） differences in number， total length and mean length of root per frond and width of frond of S. polyrhiza among 3 clones， and in each growth trait of L. punctata among 3 clones. Genotypes of 3 clones of S. polyrhiza are different at loci of Sp25， Sp30， Sp47 and Sp53， and those of 3 clones of L. punctata are different at loci of Sp10， Sp14， Sp16， Sp42， Sp47， Sp51， Sp52 and Sp53； genotypes and alleles of 3 clones of S. polyrhiza are different from those of L. punctata at loci of Sp6， Sp14， Sp16， Sp25， Sp36， Sp45， Sp47 and Sp51； genotypes of 6 clones of 2 duckweeds are the same at loci of Sp4， Sp12， Sp28， Sp29 and Sp43. Associations of loci of Sp25， Sp30， Sp47 and Sp53 with number， total length and mean length of root per fond of S. polyrhiza are extremely significant （P＜0.01）， those of locus of Sp30 with length and width of its frond are significant， and that of locus of Sp25 with its width of frond is also significant. Associations of loci of Sp10， Sp14， Sp16， Sp42， Sp47， Sp52 and Sp53 with number of frond per plant and number of root per frond of L. punctata are extremely significant， those of loci of Sp10， Sp14， Sp42， Sp47， Sp51， Sp52 and Sp53 with length and width of its frond are significant or extremely significant， and those of loci of Sp16， Sp51 and Sp53 with total length and mean length of its root per frond are extremely significant. Roots of S. polyrhiza of genotype of BD at loci of Sp47 and Sp53 are evidently more and longer， and those of L. punctata of genotype of AD at loci of Sp51 and Sp53 are evidently longer； in addition， fronds of S. polyrhiza of genotype of CE at locus of Sp25 are the most and the largest， and its roots are also the most and the longest. It is suggested that the microsatellite markers tested have cross-genera amplification， and can be used to analyze genotypes of S. polyrhiza and L. punctata； loci of Sp25， Sp30， Sp47 and Sp53 are closely associated with length and number of root of S. polyrhiza， while loci of Sp10， Sp14， Sp16， Sp42， Sp47， Sp51， Sp52 and Sp53 are closely associated with number and size of frond and number of root of L. punctata.