Molecular analysis of Kr1 gene responsible for crossability of common wheat with alien species

普通小麦是与水稻和玉米一样重要的作物之一。为了改良小麦品种，人们将黑麦属和山羊草属的外源基因导入普通小麦中，培育出了许多抗寒、抗病、抗虫和优质蛋白质的小麦品种。然而，在导入外源基因的情况下，小麦与外来物种的杂交一直是一个大问题。普通小麦与黑麦的可交配性位于普通小麦同源群5的染色体上。Kr基因的作用主要表现在柱头和胚珠上，抑制花粉管的穿透和伸长。本研究以阐明可交换性的机理为目的，试图分离Kr 1基因的DNA片段，并对其进行克隆和核苷酸序列鉴定。材料为20个重组自交系， ...更多信息 以中国春小麦（KR 1）与黑麦（Rye）的可交配性高的品种马拉（Mara）的5 B染色体代换系（KR 1）为材料，研究了它们的可交配性。这些品系根据它们与黑麦的可杂交性分类。在开花期，收集小麦品系的雌蕊并将其分为两组，并分离其bulkmRNA。通过反转录法合成cDNA，DD-RAPD和DD-AFLP方法检测多态性。DD-RAPD分析结果存在重复性差、不可靠等问题。在DD-AFLP的情况下，在使用1723个引物对的分析后，62个Kr 1系的特异性cDNA片段被鉴定。其中31个片段从凝胶上切下，得到24个克隆。核苷酸序列分析表明，它们与拟南芥双因子调控系统蛋白基因和半胱氨酸蛋白酶前体基因同源。在今后的研究中，北方分析将是研究小麦雌蕊组织特异性基因表达的必要手段。少

Common wheat is one of the most important crops as well as rice and maize. For the purpose of improvement of wheat cultivars, alien genes of the genus rye and Aegilops have been incorporated into common wheat, and many cultivars having cold resistance, desease and insect resistance, and high quality proteins have been produced. However, in the case of introduction of alien genes, hybridization between wheat and alien species have been a big problem. Crossability of common wheat with rye have been clarified to be located on the chromosomes of homoelogous group 5 of common wheat. The effects of Kr genes are expressed on the stigma and ovule, and inhibit the penetration and elongation of pollen tubes. In the present research, on the purpose of clarifying the mechanism of crossability, we tried to isolate the DNA fragments which are correspond to the Kr1 gene, and clone the fragments and identify the nucleotide sequences. Materials used are 20 recombinant inbred lines produces from the cro … More ssing between Chinese Spring wheat (kr1), which has high crossability with rye, and its 5B chromosome substitution line derived from cv.Mara (Kr1) which has low crossability. These lines were classified according to their crossability with rye. In the flowering period, pistils of wheat lines were collected and classified in to two groups and their bulked mRNAs were isolated. Through reverse transcription method, cDNAs were synthesized and polymorphism were detected by DD-RAPD and DD-AFLP method. The results from DD-RAPD has a problem on the repeatability and not reliable. In the case of DD-AFLP, after the analysis using 1723 primer pairs, 62 specific cDNA fragments for Kr1 lines were identified. Among them, 31 fragments were excised from the gel, and 24 clones were obtained. Nucleotide sequences of them showed that they were homologous to the genes for the protein of two factors control system of Arabidopsis thaliana and the precursor of cystein protenase. In the future, northern analysis will be necessary to examine the tissue specific gene expression in pistils of common wheat. Less