Physical localization of the 18S-5 center dot 8S-26S rDNA and sequence analysis of ITS regions in Thinopyrum ponticum (Poaceae : Triticeae): Implications for concerted evolution
文献类型: 外文期刊
第一作者: Li, DY
作者: Li, DY;Zhang, XY
作者机构:
关键词: Thinopyrum ponticum;Thinoprum elongatum;Thinopyrian bessarabicum;Pseudoroegneria;18S-5 center dot 8S-26S rDNA;fluorescence in situ hybridization (FISH);internal transcribed spacer (ITS);concerted evolution
期刊名称:ANNALS OF BOTANY ( 影响因子:4.357; 五年影响因子:5.488 )
ISSN: 0305-7364
年卷期: 2002 年 90 卷 4 期
页码:
收录情况: SCI
摘要: Fluorescence in situ hybridization was used in Thinopyrum ponticum, a decaploid species, and its related diploid species, to investigate the distribution of the 18S-5.8S-26S rDNA. The distribution of rDNA was similar in all three diploid species (Th. bessarabicum, Th. elongation and Pseudoroegneria stipifolia). Two pairs of loci were observed in each somatic cell at metaphase and interphase. One pair was located near the terminal end and the other in the interstitial regions of the short arms of one pair of chromosomes. However, all of the major loci in Th. ponticum were located on the terminal end of the short arms of chromosomes, and one chromosome had only one major locus. The maximum number of major loci detected on metaphase spreads was 20, which was the sum of that of its progenitor,. The interstitial loci that exist in the possible diploid genome donor species were probably 'lost' during the evolutionary process of the decaploid species. A number of minor loci were also detected on whole regions of two pairs of homologous chromosomes. These results suggested that the position of rDNA loci in the Triticeae might be changeable rather than fixed. Positional changes of 18S-5.SS-26S rDNA loci between Th. ponticum and its candidate genome donors indicate that it is almost impossible to find a genome in the polyploid species that is completely identical to that of its diploid donors. The possible evolutionary significance of the distribution of the rDNA is also discussed. Internal transcribed spacer (ITS) regions of nuclear DNA in Th. ponticum were investigated by PCR amplification and sequencing. The sequence data from five positive clones selected at random, together with restriction site analysis, indicated that the ITS repeated units are nearly homogeneous in this autoallodecapolypoid species. Combined with in situ hybridization results, the data led to the conclusion that the ITS region has experienced interlocus as well as intralocus concerted evolution, Phylogenetic analyses showed that the sequences from Th. ponticum have concerted to the E genome repeat type. (C) 2002 Annals of Botany Company.
分类号:
- 相关文献
作者其他论文 更多>>
-
Molecular and biochemical characterization of puroindoline a and b alleles in Chinese landraces and historical cultivars
作者:Chen, F;He, ZH;Xia, XC;Xia, LQ;Zhang, XY;Lillemo, M;Morris, CF
关键词:bread wheat (Triticum aestivum L.);kernel hardness;puroindolines;Pina and Pinb alleles
-
Combined amino acid mutations occurring in the envelope closely correlate with pathogenicity of EIAV
作者:Liang, H;He, X;Shen, RX;Shen, T;Tong, X;Ma, Y;Xiang, WH;Zhang, XY;Shao, YM
关键词:
-
An approach for isolating high-molecular-weight glutenin subunit genes using monoclonal antibodies
作者:Wang, HQ;Zhang, XY
关键词:wheat;HMW-GS;monoclonal antibody;immunoscreen
-
Genetic diversity and core collection evaluations in common wheat germplasm from the Northwestern Spring Wheat Region in China
作者:Hao, CY;Zhang, XY;Wang, LF;Dong, YS;Shang, XW;Jia, JZ
关键词:core collection;genetic diversity;microsatellite;wheat
-
Amino acid mutations of the infectious clone from Chinese EIAV attenuated vaccine resulted in reversion of virulence
作者:Shen, T;Liang, H;Tong, X;Fan, XJ;He, X;Ma, Y;Xiang, WH;Shen, RX;Zhang, XY;Shao, YM
关键词:EIAV;attenuated vaccine;mutated infectious clone
-
Molecular cytogenetic identification of a wheat-Thinopyron intermedium (Host) Barkworth & DR Dewey partial amphiploid resistant to powdery mildew
作者:Wang, HG;Zhang, XY;Li, XF;Li, DY;Duan, XY;Zhou, YL
关键词:genomic in situ hybridization (GISH);partial amphiploid;powdery mildew;Thinopyron intermedium;wheat
-
Quantitative trait loci (QTL) of stem strength and related traits in a doubled-haploid population of wheat (Triticum aestivum L.)
作者:Hai, L;Guo, HH;Xiao, SH;Jiang, GL;Zhang, XY;Yan, CS;Xin, ZY;Jia, JZ
关键词:basal internode traits;doubled haploids;quantitative trait loci (QTL);stem strength