染色体之间的互作导致五倍体小麦农艺性状与DNA变异  

Agronomic Trait and DNA Variation of Artificial Pentaploid Wheat Caused by Interaction of Homologous Chromosomes

作　　者：魏怡婷 陈晨慧 宣旭娴 姜露萍 戎均康 Wei Yiting;Chen Chenhui;Xuan Xuxian;Jiang Luping;Rong Junkang(The Key Laboratory for Quality Improvement of Agricultural Products of Zhejiang Province,Hangzhou,311300;College of Agriculture and Food Science,Zhejiang A&F University,Hangzhou,311300)

机构地区：[1]浙江省农产品品质改良技术研究重点实验室,杭州311300 [2]浙江农林大学农业与食品科学学院,杭州311300

出　　处：《分子植物育种》2021年第8期2704-2711,共8页Molecular Plant Breeding

基　　金：国家重点研发计划项目(2016YFD0102002);国家自然科学基金项目(31671684)共同资助。

摘　　要：为了揭示普通小麦进化过程中分化后的同源染色体结合到一个细胞核后是否会发生互作导致DNA水平的变异并引起表型变化,本研究以天然六倍体普通小麦品种‘中国春’(CS, AABBDD, 2n=6x=42)和人工合成四倍体小麦(AADD, 2n=4x=28)为材料,杂交产生五倍体小麦(AABDD, 2n=5x=35),并研究其与亲本在表型与DNA水平上的变化。结果表明:五倍体与亲本之间,以及不同五倍体个体之间在株高、抽穗期、芒长和小穗密度等表型上存在显著差异;利用30个SSR (Simple Sequence Repeat)标记进行检测,发现部分五倍体小麦植株DNA序列的碱基数发生了变化,同CS相比最多增加有67个碱基对。同时还发现五倍体减数分裂中期I染色体配对紊乱,存在高频率的单价体,且大多数五倍体小麦的花粉败育。上述结果表明六倍体普通小麦中的A和D组染色体与其二倍体祖先A和D组各自经过长期的进化,已积累了较多变异,使得同源染色体DNA间存在很大的差异,当结合到一起时会发生相互作用,从而导致表型变异。To reveal the DNA variation and phenotypic changes during the wheat evolution caused by the incorporation of differentiated homologous chromosomes into one nucleus. The natural hexaploid common wheat variety ’Chinese Spring’(CS, AABBDD, 2 n=6 x=42) was crossed by a synthetic tetraploid wheat(AADD, 2 n=4 x=28) to produce pentaploid wheat(AABDD, 2 n=5 x=35) for studying their changes in phenotypes and DNA levels. The significant variations were found in phenotype such as plant height, heading date, awn length and spikelet density among the pentaploid plants and compared to their parents. Analysis of 30 SSR(Simple Sequence Repeat) markers showed the variation of DNA fragments in some pentaploid plants, being a maximum of 67 base pairs more than in CS. In addition, pentaploid plants also displayed the disorder in chromosome pairings during meiosis of pollen mother cell at the Metaphase I, carrying more univalent than those expected. The pollen of most pentaploid plants was detected to be abortive. These results indicated that the A and D chromosomes of the hexaploid common wheat and the ones of their diploid ancestors had accumulated many changes during long-term evolution, which caused great differences between homologous DNAs. When the two sets of chromosomes reunited, they interacted with each other and subsequently resulted in phenotypic variations.

关 键 词：远缘杂种 DNA变异 农艺性状 染色体配对 

分 类 号：S512.1[农业科学—作物学]