【摘要】 以国审高优势杂交棉中棉所47及其亲本苗期的根尖和顶尖叶为研究材料,采用差异显示技术(DDRT-PCR)分析了苗期杂种与亲本的根、叶基因表达差异,并结合中棉所47及其亲本的产量性状,分析了苗期基因表达差异与产量性状优势之间的关系。结果表明:(1)苗期根和叶基因表达有差异的带分别占总统计带数的38.8%和65.2%,叶基因表达有差异的带比根丰富得多,说明一些对杂种优势起作用的基因可能在叶中开始表达;(2)杂种和亲本间存在显著的基因表达差异,这些差异表达分为4种类型:I.双亲共沉默型;II.单亲表达沉默型;III.杂种特异表达型;IV.单亲表达一致型。在根中,这4种比例分别为6.5%、10.6%、6.5%和15.2%;在叶中,这4种类型比例分别为4.4%、17.9%、15.1%和27.8%,两器官基因差异表达的类型比例趋势基本一致,单亲表达一致型所占比例最高,说明苗期这种表达类型可能对杂种优势的形成起主要作用;(3)进一步分析中棉所47的产量构成因素,单株铃数增加是杂种高产主要原因,进一步表明,苗期单亲基因表达一致型可能对杂交种后期单株成铃数的增加有较大的贡献。上述结果表明,苗期基因表达差异与杂种优势的形成存在着密切关系。更多还原

【Abstract】 The patterns of gene differential expression in roots and leaves between CRI47 and its parents at seedling stage were analyzed by using DDRT-PCR, and the relationship between the hybrid yield traits and patterns of gene expression was also studied. The main results were as follows: (1) Differential expression bands in roots and leaves accounted for 38.8% and 65.2% of their total numbers of detected bands,respectively. The differential expression bands in leaves were richer than those in roots, which explained that some useful genes to heterosis maybe begin to express in seedling leaves. (2) Four types of differential expression were detected between the hybrid and its parents: I. Bands expressed in both parents but not in F1; II. Bands expressed in one parent but not in F1 and another parent; III. Bands expressed only in F1 but not in both parents; IV. Bands expressed in one parent and F1 but not in another parent. Percentages of the four types accounted for 6.5%, 10.6%, 6.5% and 15.2% in roots and 4.4%, 17.9%, 15.1% and 27.8% in leaves, respectively. The tendency of proportion in four types in roots and leaves was consistent, which indicated the type of bands expressed only in one parent and F1 played main role in CRI47 yield. (3) Increase of boll number per plant was the main cause of high yield formation in CRI47, which also indicated the type of bands expressed only in one parent and F1 contributed to CRI47 yield. These results showed that there were closely relationship between differential expression genes and heterosis at seedling stageof cotton.更多还原