Fluorescence In Situ Hybridization (FISH) played an essential role to locate the ribosomal RNA genes on the chromosomes that offered a new tool to study the chromosome structure and evolution in plant. The 45S and 5S rRNA genes are independent and localized at one or more loci per the chromosome complement, their positions along chromosomes offer useful markers for chromosome discriminations. In the current study FISH has been performed to locate 45S and 5S rRNA genes on the chromosomes of nine Lathyrus species belong to five different sections, all have chromosome number 2n=14, Lathyrus gorgoni Parl, Lathyrus hirsutus L., Lathyrus amphicarpos L., Lathyrus odoratus L., Lathyrus sphaericus Retz, Lathyrus incospicuus L, Lathyrus paranensis Burkart, Lathyrus nissolia L., and Lathyrus articulates L. The revealed loci of 45S and 5S rDNA by FISH on metaphase chromosomes of the examined species were as follow: all of the studied species have one 45S rDNA locus and one 5S rDNA locus except L. odoratus L., L. amphicarpos L. and L. sphaericus Retz L. have two loci of 5S rDNA. Three out of the nine examined species have the loci of 45S and 5S rRNA genes on the opposite arms of the same chromosome (L. nissolia L., L. amphicarpos L., and L. incospicuus L.), while L. hirsutus L. has both loci on the same chromosome arm. The other five species showed the loci of the two types of rDNA on different chromosomes. The detected 5S and 45S rDNA loci in Lathyrus could be used as chromosomal markers to discriminate the chromosome pairs of the examined species. FISH could discriminate only one chromosome pair out of the seven pairs in three species, in L. hirsutus L., L. nissolia L. and L. incospicuus L., and two chromosome pairs in five species, in L. paranensis Burkart, L. odoratus L., L. amphicarpos L., L. gorgoni Parl. and L. articulatus L., while it could discriminate three chromosome pairs in L. sphaericus Retz. these results could contribute into the physical genome mapping of Lathyrus species and the evolution of rDNA patterns by FISH in the coming studies in future.

中文翻译：

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通过 FISH 进行山黧豆属染色体上的核糖体 DNA 定位


荧光原位杂交（FISH）在染色体上定位核糖体RNA基因方面发挥了重要作用，为研究植物染色体结构和进化提供了新工具。 45S 和 5S rRNA 基因是独立的，位于每个染色体补体的一个或多个基因座上，它们沿染色体的位置为染色体区分提供了有用的标记。本研究通过FISH技术对属于5个不同组的9个山黧豆属物种的染色体上的45S和5S rRNA基因进行了定位，所有山黧豆属的染色体编号为2n=14，山黧豆 (Lathyrus odoratus L.)、山黧豆 (Lathyrus sphaericus Retz)、山黧豆 (Lathyrus incospicuus L)、山黧豆 (Lathyrus paranensis Burkart)、山黧豆 (Lathyrus nissolia L.) 和山黧豆 (Lathyrus mannsolia L.)。 FISH 检测物种中期染色体上 45S 和 5S rDNA 位点如下：除L. odoratus L.、L. amphicarpos L. 和L. sphaericus Retz L. 具有2 个5S rDNA 位点外，所研究的物种均具有1 个45S rDNA 位点和1 个5S rDNA 位点。九个检查物种中的三个在同一染色体的相对臂上具有 45S 和 5S rRNA 基因位点（L. nissolia L.、L. amphicarpos L. 和 L. incospicuus L.），而 L. hirsutus L. . 两个基因座位于同一染色体臂上。其他五个物种则显示出两种类型的rDNA位于不同染色体上的位点。检测到的山黧豆5S和45S rDNA位点可作为染色体标记来区分受检物种的染色体对。 FISH 只能区分 3 个物种（L. hirsutus L.、L. nissolia L. 和 L. incospicuus L.）七对染色体中的一对，以及 5 个物种（L. paranensis Burkart、L.）的两对染色体。香玉兰 L.，L. amphicarpos L.，L.gorgoni Parl。和 L. articulatus L.，而它可以区分 L. sphaericus Retz 的三对染色体。这些结果可能有助于未来研究中山黧豆属物种的物理基因组图谱以及通过 FISH 进行的 rDNA 模式的进化。