257份小麦品种资源中矮秆基因的分子检测

矮秆基因Rht-B1b、Rht-D1b和Rht8等的广泛利用,不仅增强了小麦的抗倒性,而且提高了产量。明确矮秆基因的分布,可以为小麦矮化育种提供分子信息。采用STS和SSR标记检测257份小麦品种资源中Rht-B1b、Rht-D1b和Rht8基因的分布情况。结果表明,257份材料中,Rht8基因分布频率最高(106个品种,41.2%),Rht-D1b次之(88个品种,34.2%),Rht-B1b最低(70个品种,27.2%)。此外,部分材料中含有不同类型的矮秆基因组合,且分布频率不同,其中Rht-D1b+Rht8(25个品种,9.7%)>Rht-B1b+Rht8(24个品种,9.3%)>Rht-B1b+Rht-D1b(9个品种,3.5%)>Rht-B1b+Rht-D1b+Rht8(5个品种,1.9%)。上述结果为小麦抗倒伏育种以及矮化育种提供了重要的参考信息。     

黄淮麦区部分小麦种质资源中矮秆基因的分布

选用254份黄淮麦区小麦品种(系),利用BFMR1,DFMR2和微卫星xgwm261标记检测了矮秆基因Rht-B1b,Rht-D1b和Rht8的分布.结果表明,在254份材料中,含有Rht-B1b,Rht-D1b和Rht8基因的材料分别有84,171和178份,平均株高分别为80.7,78.5和80.7 cm.只含有Rht-B1b,Rht-D1b和Rht8基因的材料分别有15,36和31份,平均株高分别为83.8,80.1和86.2 cm.只含Rht-B1b和Rht-D1b基因有16份,平均株高为73.7cm,Rht-B1b和Rht-D1b基因具有累加效应,两个基因同时存在时株高降低幅度会更大.只含Rht-B1b和Rht8基因的有94份,只含Rht-D1b和Rht8基因的有28份,同时含有Rht-B1b,Rht-D1b和Rht8基因的有25份,同时不含这3个矮秆基因的有9份,说明黄淮麦区小麦品种(系)中绝大部分品种均含有不同种类的矮秆基因.微卫星WMS 261及基于PCR的2个STS标记可以分别用于对品种(系)中Rht8,Rht-B1b和Rht-D1b基因型的鉴定以及育种世代该基因型的筛选.     

中国小麦主要矮秆基因的分布及其对株高的影响

为了了解矮秆基因在中国冬麦区的分布及利用情况和明确矮秆基因对小麦株高的影响,进一步提高小麦的水肥利用效率,利用前人开发的矮秆基因分子标记和收集的210份冬小麦材料研究矮秆基因RhtB1b、Rht-D1b和Rht8在中国冬麦区的分布和利用情况。结果表明:210份冬小麦材料含有矮秆基因RhtB1b的材料有51份,占总材料的24.3%;含有矮秆基因Rht-D1b的材料有40份,占19.0%;含有Rht8矮秆基因的材料有94份,占44.8%。含有Rht-B1b的小麦材料平均株高为84.0cm,不含有Rht-B1b的小麦材料的平均株高为93.7cm;含有Rht-D1b的小麦材料平均株高为77.9cm,不含有Rht-D1b的小麦材料的平均株高为94.6cm;含有Rht8的小麦材料平均株高为90.0cm,不含有Rht8的小麦材料的平均株高为92.5cm;Rht-B1b、Rht-D1b和Rht8对小麦平均株高的降秆作用分别为9.7cm、16.7cm和2.5cm。进一步分析不同矮秆基因组合的联合分布情况,同时分析不同矮秆基因的联合降秆作用,结果表明3个矮秆基因的联合降秆作用大于2个矮秆基因的降秆作用,2个矮秆基因的联合降秆作用大于单个矮秆基因的降秆作用;另外还对分子标记在小麦矮秆基因的选择利用方面进行了探讨。     

宁夏春小麦矮秆基因分子标记检测分析

[目的]分析宁夏春小麦育种材料常用矮秆基因的分布,为本地小麦改良株高性状提供理论依据。[方法]以宁夏大学小麦遗传育种实验室212个(其中54个材料由中国农业科学院引进)春小麦育种亲本为材料,调查其株高、穗长、穗下茎节等农艺性状,利用分子标记检测分析材料中常用矮秆基因Rht-B1b(Rht1)、Rht-D1b(Rht2)和Rht8的分布。[结果]中国农业科学院引进材料的株高、穗长、穗茎节的平均值(分别为69.2、7.8、28.5 cm)明显低于现有亲本材料(分别为83.6、11.1、32.0 cm)。矮秆基因检测发现166份材料携带Rht-B1b基因,占总检测材料的75.1%;88份材料含有Rht-D1b基因,占39.8%;191份材料含Rht8基因,占总检测材料的86.4%。携带Rht-D1b基因的9个材料同时含有Rht-B1b和Rht8基因。其中,引进材料中Rht8、Rht-B1b、Rht-D1b分别占85.1%、72.0%、33.3%,与整体材料中各矮秆基因分布相似。[结论]目前宁夏春小麦育种材料中普遍含有矮秆基因Rht8,其次是Rht-B1b,但主栽品种和主推品种以及核心育种亲本材料均含有Rht-D1b,即现有亲本材料中含Rht8+Rht-B1b的材料所占比例较Rht8+Rht-D1b多,但新培育的品种以含有Rht8+Rht-D1b为主。这可能是主栽品种宁春4号(Rht8+Rht-D1b)在当地长期种植,并作为育种骨干亲本被长期利用的结果。     

小麦矮秆基因导入八倍体小黑麦研究初报

采用NCⅡ设计,用6个不同株高类型(高、中、矮各2个)八倍体小黑麦作母本,用含Rhtl,Rht2,Rht3,Rht10,和RhtlRht2Rhty的5个小麦矮源作父本配制30个杂交组合,通过F_1的显性度(D值)、降秆强度(R值)及F_2株高分布频率,分析了Rht基因在不同株高类型八倍体小黑麦中的反应。主要结果为:1)不同矮秆基因对高、中、矮秆小黑麦降秆趋势一致,即对高秆小黑麦降秆效果最强,中秆次之,矮秆最弱,而不同矮秆基因降秆作用大小顺序为:Rht10>Rht3>Rht1Rht2Rhty>Rht1Rht2.2) 各矮秆基因在F_2染色体数分布不平衡的遗传背景下表达基本正常,Rht10、Rht3显示以矮秆为主的高低峰分布,农林10号、OlesenDwarf显示正态分布,3)连续回交能提高矮秆小黑麦株的选择效率。     

赤霉素敏感性不同矮秆基因对小麦胚芽鞘长度和株高的效应

 【目的】明确赤霉素敏感性不同的矮秆基因对小麦株高和胚芽鞘长度的效应,促进小麦不同矮秆基因的合理利用。【方法】利用分子标记和系谱分析相结合,对中国小麦主产区部分小麦品种及品系中所含的矮秆基因Rht-B1b、Rht-D1b和Rht8进行分类,结合田间株高和室内胚芽鞘长度调查,比较赤霉素（GA3）敏感性不同的矮秆基因对胚芽鞘长度和株高的效应。【结果】分子标记检测结合系谱分析对129份供试品种进行分类,含有矮秆基因Rht-B1b的小麦品种58份,含有Rht-D1b的24份,含有Rht8的73份。其中35份品种含有2个矮秆基因Rht-B1b和Rht8,16份品种含有Rht-D1b和Rht8。赤霉素敏感性检测发现含有矮秆基因Rht-B1b或Rht-D1b的小麦品种多对赤霉素反应不敏感,含有矮秆基因Rht8的小麦品种多对赤霉素反应敏感,而同时含有2个矮秆基因Rht-B1b+Rht8或Rht-D1b+Rht8的小麦品种绝大多数对赤霉素反应不敏感。赤霉素不敏感的矮秆基因Rht-B1b和Rht-D1b以及同时含有赤霉素不敏感和赤霉素敏感2个矮秆基因的小麦品种（Rht-B1b+Rht8和Rht-D1b+ Rht8）降低株高的效应较大,分别为24.6%、30.4%、28.2%和32.2%,而赤霉素敏感的矮秆基因Rht8降低株高的效应为14.3%。赤霉素不敏感的矮秆基因Rht-B1b、Rht-D1b以及Rht-B1b+Rht8和Rht-D1b+Rht8在降低株高的同时,也缩短了胚芽鞘长度,其效应分别为25.4%、31.3%、28.4%和31.3%,而赤霉素敏感的矮秆基因Rht8缩短胚芽鞘长度的效应较小,仅为6.0%。【结论】以上分析结果表明,赤霉素不敏感的矮秆基因Rht-B1b和Rht-D1b在降低株高的同时也限制了胚芽鞘的伸长,不适于旱地小麦改良利用,而赤霉素敏感的矮秆基因Rht8既降低了株高又不影响胚芽鞘长度,是旱地小麦改良中比较理想的矮秆基因。     

多分蘖矮秆水稻突变体的农艺性状及遗传分析

多分蘖矮秆水稻‘tdr(t)’是在半矮秆籼稻品系‘E20’中发现的一份突变体.与野生型‘E20’相比,‘tdr(t)’主要表现为植株矮化,分蘖增多,育性降低,各节间所占株高比例与野生型基本一致,属于矮秆突变体中的dN型.用5个株高正常的半矮秆水稻品种(系)与其杂交,对F1、F2、和BC1F1的遗传分析表明,‘tdr(t)’矮生性是由一对隐性核基因控制.‘tdr(t)’表现矮秆和多分蘖,是研究株高与分蘖发育机理关系的一份较好的材料.     

分子标记检测矮秆基因Rht-B1b、Rht-D1b和Rht8在我国小麦中的分布

利用分子标记检测矮秆基因在我国主要麦区的分布,有助于提高小麦产量和改良株高。本研究利用小麦矮秆基因Rht-B1b、Rht-D1b的4对特异性分子标记,BF与MR1、BF与WR1、DF与MR2、DF2与WR2,以及微卫星Xgwm261标记对我国小麦主产区小麦主栽品种中矮秆基因Rht-B1b、Rht-D1b和Rht8的分布情况进行了分子标记鉴定。结果表明:1)在鉴定的129个品种中,58份含有Rht-B1b基因,占45.0%;24份含有Rht-D1b基因,占18.6%;73份含有Rht8基因,占56.6%;35份品种含有2个矮秆基因Rht-B1b和Rht8,占27.1%;16份品种含有Rht-D1b和Rht8基因,占12.4%。本研究未检测到同时含有Rht-B1b、Rht-D1b和Rht8这3个矮秆基因的品种,以及同时含有Rht-B1b和Rht-D1b的品种;2)3个矮秆基因Rht-B1b、Rht-D1b和Rht8在各个生态区育成品种中的分布频率也不同。矮秆基因Rht-B1b和Rht8在黄淮冬麦区的分布频率较高,分别为55.4%和71.1%;Rht-D1b基因在西南冬麦区的分布频率较高,为37.5%;矮秆基因Rht8在不同的麦区都有广泛的分布,在不同的生态区具有广泛的适应性。     

矮秆小麦XN0004的矮秆基因Rht21的染色体臂定位

XNOOO4是青431与小偃6号杂交选育的一个新的具有部分矮秆显性效应的小麦新矮源品系。和高秆亲本相比,其杂种F_1代的降秆作用平均为13.8％,对外源赤霉酸反应不敏感,在杂种小麦研究中,其配合力优良,增产显著,穗粒数增加,抗倒能力增强,收获指数提高等,无某些矮源对杂种F_1产生的不良效应,是杂种小麦比较理想的矮秆亲本,可作为常规育种的优良矮秆品种资源。用中国春缺—四体和双端体分析的方法,对XNOOO4丰矮秆显性基因进行了染色体定位,证明其矮秆显性基因位于2A染色体的短臂上,是一个不同于世界上已定位的20个Rht基因的新矮源,故暂定名为显性矮秆基因Rht21。     

小麦新品种百农矮抗58及其亲本矮秆基因的检测

为探索百农矮抗58小麦所含的矮秆基因及其来源,应用赤霉素反应和分子标记检测了百农矮抗58及其亲本周麦11、豫麦49号、郑州8960的矮秆基因。结果表明:郑州8960为赤霉素敏感型,其他3个品种对赤霉素不敏感;分子标记检测显示,矮抗58、豫麦49号、郑州8960携带Rht-D1b基因,周麦11携带Rht-B1b基因,4个品种均没有扩增出Rht8基因的192bp标准带。     

The Effects of Dwarfing Genes （Rht-B1b,Rht-D1b,and Rht8） with Different Sensitivity to GA3 on the Coleoptile Length and Plant Height of Wheat

Understanding the effects of wheat dwarfing genes on the coleoptile length and plant height is crucial for the proper utilization of dwarfing genes in the improvement of wheat yield. Molecular marker analysis combined with pedigree information were used to classify wheat cultivars widely planted in major wheat growing regions in China into different categories based on the dwarfing genes they carried. The effects of the dwarfing genes with different sensitivity to gibberellins （GA3） on the coleoptile length and plant height were analyzed. Screening of 129 cultivars by molecular marker analysis revealed that 58 genotypes of wheat contained the dwarfing gene Rht-B1b, 24 genotypes of wheat contained Rht-D1b gene and 73 genotypes of wheat possessed Rht8 gene. In addition, among these 129 cultivars, 35 genotypes of wheat cultivars contained both Rht-B1b and Rht8 genes and 16 genotypes of wheat cultivars contained both Rht-D1b and Rht8 genes. Wheat cultivars with the dwarfing genes Rht-B1b or Rht-D1b were insensitive to GA3, while the cultivars with the dwarfing gene Rht8 were sensitive to GA3. Most of the wheat genotypes containing combination of Rht8 gene with either Rht-B1b or Rht-D1b gene were insensitive to GA3. The plant height was reduced by 24.6, 30.4, 28.2, and 32.2%, respectively, for the wheat cultivars containing Rht-B1b, Rht-D1b, Rht-B1b ＋ Rht8, and Rht-D1b ＋ Rht8 genes. The plant height was reduced by 14.3% for the wheat cultivar containing GA3-sensitive gene Rht8. The coleoptile length was shortened by 25.4, 31.3, 28.4 and 31.3%, respectively, in the wheat cultivars containing Rht-B1b, Rht-D1b, Rht-B1b ＋Rht8 and Rht-D1b ＋ Rht8 genes, while the coleoptile length was shortened only by 6.2% for the wheat cultivar containing Rht8 gene. We conclude that GA3-insensitive dwarfing genes （Rht-B1b and Rht-D1b） are not suitable for the wheat improvement in dryland because these two genes have effect on reducing both plant height and coleoptile length. In contrast, GA3- sensitive dwarfing gene （Rht8） is a relatively ideal candidate for the wheat improvement since it significantly reduces the plant height of wheat, but has less effect on the coleoptile length.     

Studies of Multi-Allelic Polymorphism of Dominant Dwarfing Genes in Wheat

Dwarfing breeding of wheat in the world is confined to the exploitation of recessive dwarfing sources. None of the dominant dwarfing sources discovered in common wheat (Triticum aestivum L. ) has found wide exploitation in wheat breeding due to the extreme dwarfness of their plants (20 -55 cm). We found in our work that some stable mutant lines with their plant height enhanced to different extents could be obtained in large populations derived from the stock seeds of the dominant dwarfing sources Aibian1 carrying Rht10 on 4DS and being 20 - 55 cm tall and Aisu2 carrying Rht3 on 4BS and being 55 cm tall, or from their descendants of induced mutation treatments, or from the segregating descendants of their crosses with mid- or tall-statured genotypes. Subsequently, we studied these mutation-derived lines differing in plant height with near isogenic lines and observed that the character of their enhanced plant height bred true, each carrying a semidominant dwarfing gene for a definite height and that as the plant height of the mutation-derived lines increased, the yield-contributing characters of their near isogenic lines were significantly improved. When test crosses with marker genes and physiological and biochemical genetic marker tests were performed to re-localize the semi-dominant dwarfing genes carried by the mutation-derived lines, it was confirmed that they shared common loci with Rht10 and Rht3 and that they were all mutation-derived multiple alleles. It is thus speculated that dominant dwarfing genes are of "multi-allelic polymorphism". In other words, dominant dwarfing genes, which are ultra-dwarfing, are liable to develop by mutation into a group of multiple alleles with plant height enhanced to different extents and some may have a height close to the ideal plant height for wheat breeding. Therefore, these results offer a fundamentally new approach for the exploitation of dominant dwarfing sources in wheat breeding.     

小麦显性矮秆基因复等位多态特性研究

 世界小麦矮化育种主要使用隐性矮源。在普通小麦中发现的显性矮源均因导致植株极度矮化（20~55　cm）而未能在小麦育种中广泛应用。笔者发现,将显性矮源矮变1号（4DS携带Rht10,25~30 cm）及矮苏3（4BS携带Rht3,55 cm）的原种大群体种植或施以诱变因子并将其与中、高秆的小麦品种杂交、回交,从其分离世代的大群体中,均可选择到一些株高呈不同程度提升的稳定的突变株系。采用近等基因系法对不同株高突变衍生系的研究表明：其提升的株高真实遗传,各自均携带一个不同株高的半显性矮秆基因,随突变衍生系株高的提升,近等基因系的产量性状显著优化。采用标志基因测交法以及生理生化遗传标记对突变衍生系携带的不同株高的半显性矮秆基因重新进行了基因定位,确认它们分别与Rht10及Rht3的座位相同,因而均是其突变衍生的复等位基因。提出显性矮秆基因具有"复等位多态特性",即极度矮化的显性矮秆基因容易突变为一群株高提高程度不同的、可以达到小麦育种理想株高的半显性矮秆复等位基因。     

矮败小麦育种技术研究进展

矮败小麦是我国自主创制的小麦特异种质资源。其4D染色体上紧密连锁有显性矮秆基因Rht D1c和显性雄性核不育基因Ms2,因此,矮败小麦后代始终会分离出一半异交结实的矮秆不育株和一半自交结实的高矮秆可育株,是理想的遗传改良工具。经过多年研究与实践,建立了方便高效的矮败小麦育种技术体系,在我国小麦育种中发挥了重要作用。近年来,分子生物学研究的快速发展为矮败小麦育种技术的进一步提升提供了强有力的工具,同时,矮败小麦育种技术体系也为分子生物学研究成果在小麦育种中的应用提供了高效的技术平台。矮败小麦育种技术与现代分子育种技术结合,将为我国小麦育种技术的发展开辟新的途径。总结了矮败小麦育种技术研究进展,并对该项技术今后的发展趋势进行了讨论。     

257份小麦品种资源中矮秆基因的分子检测

矮秆基因Rht-B1b、Rht-D1b和Rht8等的广泛利用,不仅增强了小麦的抗倒性,而且提高了产量。明确矮秆基因的分布,可以为小麦矮化育种提供分子信息。采用STS和SSR标记检测257份小麦品种资源中Rht-B1b、Rht-D1b和Rht8基因的分布情况。结果表明,257份材料中, Rht8基因分布频率最高（106个品种,41.2%）,Rht-D1b次之（88个品种,34.2%）,Rht-B1b最低（70个品种,27.2%）。此外,部分材料中含有不同类型的矮秆基因组合,且分布频率不同,其中Rht-D1b+Rht8(25个品种,9.7%)＞Rht-B1b+Rht8(24个品种,9.3%)＞Rht-B1b+Rht-D1b(9个品种,3.5%)＞Rht-B1b+Rht-D1b+Rht8(5个品种,1.9%)。上述结果为小麦抗倒伏育种以及矮化育种提供了重要的参考信息。     

The Value of Different GA Insensitive Rht Dwarfing Genes in Winter Wheat Breeding

The value of different dwarfing genes in winter wheat breeding was studied using 6 nearisogenic lines carrying different Rht dwarfing genes over three years experiment.Results showed that both the Rhtl and Rht2 semi-dwarfing genes had significantly positive effects on kernel number and grain weight per spike, and had significantly negative effects on 1 000-grain weight comparing to the tall line(rht) and the Rht3 line.The Rht3 dwarfing gene had a significantly negative effect on kernel number per spike,and had positive effect on 1 000-grain weight. The combination of the Rht2 and Rht3 gene showed significantly negative effect on yield components. All of these 5 dwarfing or semidwarfing genotypes mentioned above had a significantly negative effect on plant height and no significant effect on the area of flag leaf, spikelets per spike and spike length.     

近等基因系法对小麦显性矮源的研究

【目的】开拓小麦育种新矮源，克服自小麦矮化育种“绿色革命”以来，仅使用Rht1、Rht2、Rht8等少数几个隐性矮源的局限性，为选育高度集约化的小麦新品种提供条件。【方法】将国内外已定名的5个显性矮源Rht10、Rht3、Rht12、Rht21、奥尔森矮（Olesen dwarf）和西南大学农学与生物科技学院培育与征集的7个致矮力弱的显性矮源回交导入4个中、高秆（85～105 cm）轮回父本品种（BC4F1），建立了4套矮秆基因的近等基因系。2005～2006两年，在非竞争群体条件下开展了近等基因系的多因素品系比较试验，研究矮源及轮回父本遗传背景两个主因素对近等基因系主要农艺性状的影响效应。【结果】12个显性矮源在本试验统一遗传背景条件下株高为37.9～74.3 cm，显性矮源的株高与其株粒重呈高度正相关（r=0.8884），株高每上升1 cm，则株粒重增加0.24 g。随显性矮源株高的提升、致矮力减弱，其近等基因系的农艺性状得到改善。显性矮源的株高提升到60 cm以上时，即有可能达到和超过中、高秆轮回父本的单株生产力，从而作为新型矮源应用于小麦矮化育种。此外，12个显性矮源具有一致的延迟早熟轮回父本抽穗以及降低轮回父本千粒重的多效性效应，这些不利的多效性效应可以通过轮回父本遗传背景的修饰作用加以改良。【结论】株高在50 cm以下的强致矮力显性矮源，难以直接用于小麦育种，但通过矮秆主基因突变以及特殊遗传背景的修饰等途径可以衍生出株高呈不同程度提升、以致达到70～80 cm理想株高的弱致矮力显性矮源。加强株高提升的弱致矮力显性矮源的研究是将显性矮源应用于小麦杂交育种的有效途径。推荐株高在60～75 cm的弱致矮力显性矮源SW07、SW05、女水妖矮、SW02、Rht21用于小麦矮化育种。