Variation in the ribosomal RNA units of the genera Lens and Cicer

• Published in: Euphytica 1995-01, Vol.83 (1), p.33-42
• Main Authors: PATIL, P. B, VRINTEN, P. L, SCOLES, G. J, SLINKARD, A. E
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; arn ribosomal; arn ribosomial; Biological and medical sciences; carte genetique; cicer; Cicer arietinum; Classical and quantitative genetics. Population genetics. Molecular genetics; Fundamental and applied biological sciences. Psychology; Generalities. Genetics. Plant material; genetic maps; genetic variation; Genetics and breeding of economic plants; lens; Lens culinaris; lens genus; Lens nigricans; mapas geneticos; Molecular genetics; Plant material; ribosomal rna; Taxonomy; variacion genetica; variation genetique
• ISSN: 0014-2336; 1573-5060
• DOI: 10.1007/BF01677858

Investigation of the organization of the tandemly repeated 5S and 18-25S ribosomal RNA (rRNA) genes was carried out on members of the genera Lens and Cicer using restriction endonuclease digestion and Southern hybridization. The 5S rRNA unit (gene + spacer) in Lens (0.38 to 0.50 kb) and Cicer (0.40 to 0.44 kb) is the largest among the legumes. In L. nigricans and L. culinaris ssp. odemensis a second repeat size was detected. Restriction maps for the 18-25S units of Lens and Cicer species were developed. The 18-25S rRNA unit varied from 8.3 to 9.8 kb in Lens and 10.5 to 11.4 kb in Cicer. The only detectable variability in the Lens and Cicer 18-25S rRNA unit was in the length of the intergenic spacer (IGS) region, except for a HindIII site in the IGS region of L. nigricans ssp. nigricans and all Cicer species. Similarities in the size of both 5S and 18-25S rRNA units were noted between L. culinaris ssp. culinaris and L. culinaris ssp. orientalis, which supports previous evidence that L. culinaris ssp. orientalis is the progenitor of the cultivated lentil. Differences in the arrangement of both 5S and 18-25S rRNA units were noted between L. nigricans ssp. nigricans and L. nigricans ssp. ervoides, indicating either divergent evolution of these subspecies or alternatively incorrect taxonomy. On the basis of the size of the 5S rRNA unit, C. bijugum, C. chorassanicum and C. echinospermum formed a group with a slightly smaller unit than the other Cicer species. Similarities in the length of both 5S and 18-25S rRNA units of C. arietinum and C. reticulatum possibly confirm C. reticulatum as the progenitor of C. arietinum. Cicer cuneatum has a smaller 18-25S rRNA unit than the other Cicer species as a result of a smaller intergenic spacer.