The cytological instability of common wheat-rye addition lines was investigated in the present study. The chromosome numbers of almost all addition lines were considerably stable, but those of CS ＋ 5R were very varia...The cytological instability of common wheat-rye addition lines was investigated in the present study. The chromosome numbers of almost all addition lines were considerably stable, but those of CS ＋ 5R were very variable. The rye chromosome added in this line was found to be much shorter than expected. Fluorescent in situ hybridization with 5S rDNA and the centromere-speciflc probes clearly revealed that the short rye chromosome contains only a short arm of chromosome 5R （5RS）. In this line, chromosome numbers of both 5RS and common wheat were changeable. The chromosome numbers ranged from 2n = 36 to 2n = 44 in the cells carrying two 5RS, and ranged from 2n = 31 to 2n = 44 in one 5RS cells. In addition to the chromosome instability, the muIticells wrapped in a sac-like structure were frequently observed in the root meristematic tissues of CS ＋5RS after the enzyme treatment for chromosome preparation. Genomic in situ hybridization with rye DNA as a probe showed that all cells in sacs investigated were at the interphase stage and contained one or two 5RS chromosomes. An electron microscopic analysis revealed that the cells of CS＋5RS, particularly in sacs, have abnormal （irregular and curved） cell walls. These results indicate that 5RS has （a） specific factor（s） influencing the cell wall development as well as the genome stability.展开更多
Using the nulUsomic back-cross procedure, four wheat-rye chromosome substitution 2R （2D） lines with different agronomic performance, designated WR02-145-1, WR01-145-2, WR02-145-3, and WR02-145-4, were produced from ...Using the nulUsomic back-cross procedure, four wheat-rye chromosome substitution 2R （2D） lines with different agronomic performance, designated WR02-145-1, WR01-145-2, WR02-145-3, and WR02-145-4, were produced from a cross between 2D nullisomic wheat （Triticum aestivum L. cv. ＂Xiaoyan 6＂） and rye （Secale cereale L. cv. ＂German White＂）. The chromosomal constitution of 2n=42=21 in WR02-145 lines was confirmed by cytological and molecular cytogenetic methods. Using genomic in situ hybridization on root tip chromosome preparations, a pair of intact rye chromosomes was detected in the WR02-145 lines. PCR using chromosome-specific primers confirmed the presence of 2R chromosomes of rye in these wheat-rye lines, indicating that WR02o145 lines are disomic chromosome substitution lines 2R （2D）. The WR02-145 lines are resistant to the powdery mildew （Erysiphe graminis DC. f. sp. tritici E. Marchal） isolates prevalent in northern China and may possess gene（s） for resistance to powdery mildew, which differ from the previously identified Pm7gene located on chromosome 2RL. The newly developed ＂Xiaoyan 6＂- ＂German White＂ 2R （2D） chromosome substitution lines are genetically stable, show desirable agronomic traits, and are expected to be useful in wheat improvement.展开更多
基金the National Natural Science Foundation of China (30771316)the State Key Basic Research and Development Plan of China(2006CB100201).
文摘The cytological instability of common wheat-rye addition lines was investigated in the present study. The chromosome numbers of almost all addition lines were considerably stable, but those of CS ＋ 5R were very variable. The rye chromosome added in this line was found to be much shorter than expected. Fluorescent in situ hybridization with 5S rDNA and the centromere-speciflc probes clearly revealed that the short rye chromosome contains only a short arm of chromosome 5R （5RS）. In this line, chromosome numbers of both 5RS and common wheat were changeable. The chromosome numbers ranged from 2n = 36 to 2n = 44 in the cells carrying two 5RS, and ranged from 2n = 31 to 2n = 44 in one 5RS cells. In addition to the chromosome instability, the muIticells wrapped in a sac-like structure were frequently observed in the root meristematic tissues of CS ＋5RS after the enzyme treatment for chromosome preparation. Genomic in situ hybridization with rye DNA as a probe showed that all cells in sacs investigated were at the interphase stage and contained one or two 5RS chromosomes. An electron microscopic analysis revealed that the cells of CS＋5RS, particularly in sacs, have abnormal （irregular and curved） cell walls. These results indicate that 5RS has （a） specific factor（s） influencing the cell wall development as well as the genome stability.
基金Supported by the National Natural Science Foundation of China （30471079）, National Key Technologies R ＆ D Program in the 10th Five-Year Plan （2004BA525B03）, and the Knowledge Innovation Proiect of the Chinese Academy of Sciences （KSCX2-SW-304）.
文摘Using the nulUsomic back-cross procedure, four wheat-rye chromosome substitution 2R （2D） lines with different agronomic performance, designated WR02-145-1, WR01-145-2, WR02-145-3, and WR02-145-4, were produced from a cross between 2D nullisomic wheat （Triticum aestivum L. cv. ＂Xiaoyan 6＂） and rye （Secale cereale L. cv. ＂German White＂）. The chromosomal constitution of 2n=42=21 in WR02-145 lines was confirmed by cytological and molecular cytogenetic methods. Using genomic in situ hybridization on root tip chromosome preparations, a pair of intact rye chromosomes was detected in the WR02-145 lines. PCR using chromosome-specific primers confirmed the presence of 2R chromosomes of rye in these wheat-rye lines, indicating that WR02o145 lines are disomic chromosome substitution lines 2R （2D）. The WR02-145 lines are resistant to the powdery mildew （Erysiphe graminis DC. f. sp. tritici E. Marchal） isolates prevalent in northern China and may possess gene（s） for resistance to powdery mildew, which differ from the previously identified Pm7gene located on chromosome 2RL. The newly developed ＂Xiaoyan 6＂- ＂German White＂ 2R （2D） chromosome substitution lines are genetically stable, show desirable agronomic traits, and are expected to be useful in wheat improvement.
