RESUMO
Rheum palmatum, one of the source plants of the traditional Chinese medicine rhubarb, is anendemic and endangered species. To our knowledge, this is the first report on the chromosome number and karyotype of this species. Sectioning combined with micrography was used to analyze the karyotype. The following results were obtained: R. palmatum had a stable chromosome number 2n = 22; the basic number of chromosomes was 11; karyotype formula is 2n = 22 = 20 metacentric + 2 submetacentric, belonging to Stebbins' 1A type; and karyotype asymmetry index was 55.39%. The present study showed that R. palmatum has a primitive type of karyotype.
Assuntos
Cromossomos de Plantas/genética , Espécies em Perigo de Extinção , Plantas Medicinais/genética , Rheum/genética , Cariótipo , Cariotipagem/métodos , Medicina Tradicional ChinesaRESUMO
The topmouth culter (Culter alburnus) is an economically important freshwater fish, which is widely distributed throughout large rivers, reservoirs, and lake areas of China. We report here the isolation and characterization of 32 new polymorphic microsatellite loci isolated from genomic DNA in this species enriched by (CA)12 and (GA)12 probes. The variability of these microsatellites was tested on 30 individuals cultured. The average allele number was 6.6 per locus, ranging from 3 to 12. The observed heterozygosity was from 0.4667 to 0.9000, and the expected heterozygosity was from 0.6163 to 0.9085. After using Bonferroni's correction for multiple tests, there was no evidence of linkage disequilibrium between pairs of loci, but deviations from Hardy-Weinberg equilibrium were found in 3 loci. These microsatellites can be used to study QTL of economic importance, population genetic diversity and the construction of genetic maps for C. alburnus in the future.
Assuntos
Peixes/genética , Loci Gênicos , Repetições de Microssatélites , Alelos , Animais , Peixes/classificação , Heterogeneidade Genética , Dados de Sequência MolecularRESUMO
Ion implantation, a new biophysically mutagenic technique, has shown great potential for crop breeding. To reveal the mutation effect of low-energy ion implantation on Baiyangdian red lotus, sequence-related amplified polymorphism markers were used to amplify and detect the DNA sequence differences in mutants induced by Fe(+) ion implantation. A total of 121 primer combinations were tested in 6 mutants and a control. Seven primer combinations (me1 + em3, me1 + em14, me9 + em3, me8 + em2, me6 + em1, me11 + em5, and me6 + em5) generated clear bands with high polymorphism and good repeatability. The results showed that among 15,317 bases cloned, 146 bases in 6 mutants were different from those of the wild type, showing a variation frequency of 0.95%. The types of base changes included deletion, insertion, transversion, and transition. Adenine was more sensitive to the irradiation than were the other bases. The results suggested that mutational "hotspots" probably exists in lotus and are induced by low-energy ion implantation.