免疫白粉病的小麦种内易位系的创制

以普通小麦Ａ５５２为父本、ＩＲＳ／ＩＢＬ黑麦和小麦易位系早抗为母本的杂种Ｓ３０６３,经Ｃ－分带和原位杂交鉴定,发现丢失了母本的黑麦成分,同时又发生了小麦种内易位,变成了５ＢＳ／７ＢＳ、５ＢＬ／７ＢＬ臂间双易位系。与此同时,白粉病抗性和一些农艺性状也发生了变化,此已己连续３年对白粉病免疫,且免疫条锈、叶锈和高抗黄矮病,每公顷５５２３千克,接近北京推广品种京冬６号     

小麦背景中黑麦1R染色体的遗传变异

运用细胞遗传学方法鉴定了来源于中国春×Ｍ２７（１Ｒ／１Ｄ代换系）的花粉植株和Ｆ２单株染色体组成。发现７个花粉植株中出现７种染色体组成变异类型,每株呈现一类变异;而２７个Ｆ２单株中,存在１１种染色体组成变异类型,变异频率仅为３７．０％,低于花粉植株。花粉植株群体中,观察到一个能稳定向后代传递的小麦／１Ｒ小片段易位,但Ｆ２群体中未检测到小麦／黑麦易位。表明常规染色体工程结合花药培养是有计划、有目的实现异源染色体小片段向小麦转移的简便、高效、快速途径。     

一个小麦/黑麦小片段染色体易位系的创制和鉴定

从来源于组合中国春×M27(1R/1D代换系)的8个花粉植株中,分离获得1个小麦/黑麦小片段染色体易位系WER-1-2。C-分带和荧光原位杂交结果显示,衍生出易位系WER-1-2的原始麦穗含有1条完整的1R染色体和1条长臂端部发生缺失的1R染色体,所缺失部分易位到1条小麦染色体上。推断该易位是在花药离体培养过程中经异常有丝分裂产生的,而非异常减数分裂的产物。表明花药培养是一条实现异源染色体小片段(基因)向小麦转移的快速而有效的途径。     

黑麦1R染色体特异性PCR引物的分子证据

根据黑麦（ＳｅｃａｌｅｃｅｒａｌｅＬ．）与小麦（ＴｒｉｔｉｃｕｍａｅｓｔｗｕｍＬ．）ｒＲＮＡ基因间隔区序列差异,按Ｋｏｅｂｎｅｒ设计的引物序列,合成了黑麦特异引物ＮＯＲ－Ｒ１。运用该引物对不同植物材料进行ＰＣＲ扩增,观察表明,含有黑麦１Ｒ染色体的植物均扩增出黑麦的特异带,但含有其他黑麦染色体的小麦种质,普通小麦品种及其近缘物种长穗偃麦草（Ａｇｒｏｐｙｒｏｎｅｌｏｎｇａｔｕｍ（Ｈｏｓｔ）Ｂｅａｕｖ）     

黑麦1R染色体特异性PCR引物的分子证据

Based on the differences of rRNA intergenic sequences between wheat ( Triticum aestivum L. ) and rye ( Secale cereale L. ), rye specific primer set NOR-R1 was synthesized according to Koebner' design. PCR analyses were carried out on different DNA substrates of common wheat and its relatives such as Agropyron elongataum (Host) Beauv., Haynaldia villosa Shur. and Hordeum vulgare L. The results confirmed that NOR-R1 primer set is specific to rye. It was found that PCR using DNAs from wheat materials containing 1R chromosome resulted in the specific amplification products of rye, whereas no amplification product was detected in PCR when using DNAs with other rye chromosomes. FISH (Fluorescent in situ Hybridization) further revealed that the binding sites for the primer set NOR-R1 were only on nucleolar organizing region of chromosome 1R. These results indicated that the primer set NOR-R1 provides a useful means for molecular tagging of rye chromosomes 1 R in wheat genetic background.