Genomic and genic sequence variation in synthetic hexaploid wheat (AABBDD) as compared to their parental species  

作　　者：Lihong Nie Zongfu Han Lahu Lu Yingyin Yao Qixin Sun Zhongfu Ni 

机构地区：[1]Key Laboratory of Crop Heterosis and Utilization （ MOE） and State Key Laboratory for Agrobiotechnology, Key Laboratory of CropGenomics and Genetic Improvement （ MOA ）, BeO＇ing Key Laboratory of Crop Genetic Improvement, Department of Plant Genetics ＆ Breeding, China Agricultural University, Beijing 100094, China

出　　处：《Progress in Natural Science:Materials International》2008年第5期533-538,共6页自然科学进展·国际材料（英文版）

基　　金：This work was supported by the National Program on Key Basic Research Projects(2007CB109000); the National Natural Science Foundation of China(Grant No．30370878).

摘　　要：In order to understand the genomic changes during the evolution of hexaploid wheat, two sets of synthetic hexaploid wheat from hybridization between maternal tetraploid wheat (AABB) and paternal diploid goat grass (DD) were used for DNA-AFLP and single strand conformation polymorphism (SSCP) analysis to determine the genomic and genic variation in the synthetic hexaploid wheat. Results indicated that more DNA sequences from paternal diploid species were eliminated in the synthetic hexaploid wheat than from maternal tetraploid wheat, suggesting that genome from parental species of lower ploidity tends to be eliminated preferentially. However, sequence variation detected by SSCP procedure was much lower than those detected by DNA-AFLP, which indicated that much less variation in the genic regions occurred in the synthetic hexaploid wheat, and sequence variations detected by DNA-AFLP could be derived mostly from non-coding regions and repetitive sequences. Our results also indicated that sequence variation in 4 genes can be detected in hybrid F1, which suggested that this type of sequence variation could be resulted from distant hybridization. It was interesting to note that 3 out of the 4 genes were mapped and clustered on the long arm of chromosome 2D, which indicated that variation in genic sequences in synthetic hexaploid wheat might not be a randomized process.In order to understand the genomic changes during the evolution of hexaploid wheat, two sets of synthetic hexaploid wheat from hybridization between maternal tetraploid wheat （AABB） and paternal diploid goat grass （DD） were used for DNA-AFLP and single strand conformation polymorphism （SSCP） analysis to determine the genomic and genic variation in the synthetic hexaploid wheat. Results indicated that more DNA sequences from paternal diploid species were eliminated in the synthetic hexaploid wheat than from maternal tetraploid wheat, suggesting that genome from parental species of lower ploidity tends to be eliminated preferentially. However, sequence variation detected by SSCP procedure was much lower than those detected by DNA-AFLP, which indicated that much less variation in the genic regions occurred in the synthetic hexaploid wheat, and sequence variations detected by DNA-AFLP could be derived mostly from non-coding regions and repetitive sequences. Our results also indicated that sequence variation in 4 genes can be detected in hybrid F1, which suggested that this type of sequence variation could be resulted from distant hybridization. It was interesting to note that 3 out of the 4 genes were mapped and clustered on the long arm of chromosome 2D, which indicated that variation in genic sequences in synthetic hexaploid wheat might not be a randomized process.

关 键 词：Synthetic hexaploid wheat POLYPLOIDY GENOME Sequence variation 

分 类 号：S512.1[农业科学—作物学]