小麦T型细胞质雄性不育恢复基因Rf1和f4的SSR标记分析

为进一步探讨小麦(Triticum aestivum L.)T型细胞质雄性不育(T-CMS)育性恢复的遗传机理,并为利用T型不育系选育强优势杂交小麦分子辅助育种提供理论与技术支撑,本研究以小麦ms(S)矮抗58/R113的F2代分离群体中的极端可育株和极端不育株分别建立恢复池和不育池,采用分布于小麦第一染色体群(染色体1A、1B和1D)及第六染色体群(染色体6A、6B和6D)上的196对SSR引物进行扩增筛选.结果表明,(1)位于1AS染色体上的3个SSR标记和位于6BS染色体上的4个SSR标记均在亲本和基因池间扩增出了稳定的多态性差异条带;(2)定位群体验证结果表明,恢复基因Rf1与1AS染色体上Xgwm136、Xgpw7062和Xgdm33标记的遗传距离分别为4.8、9.6和13.7 cM,3个标记与Rf1之间的顺序依次为Xgdm33、Xgwm136、f1、Xgpw7062; (3)恢复基因Rf4与6BS染色体上的Xgpw1079、Xgwm193、Xgpw7011和Xgwm508标记的遗传距离分别为3.4、6.8、13.7和21.5 cM,4个标记与Rf4之间的顺序依次为Xgpw 011、Xgpw1079、Rf4、Xgwm19和Xgwm508.研究还表明,T-CMS恢复系R113的育性是由Rf1和f4两对主效恢复基因和多对微效基因共同控制的,筛选的上述7个SSR标记可直接用于T型或者类似T型,如S型杂交小麦分子标记辅助育种,可有效提高对应恢复系的选择效率.     

小麦T型细胞质雄性不育恢复基因Rf1和Rf4的SSR标记分析

为进一步探讨小麦(Triticum aestivum L.)T型细胞质雄性不育(T-CMS)育性恢复的遗传机理,并为利用T型不育系选育强优势杂交小麦分子辅助育种提供理论与技术支撑,本研究以小麦ms(S)矮抗58/R113的F2代分离群体中的极端可育株和极端不育株分别建立恢复池和不育池,采用分布于小麦第一染色体群(染色体1A、1B和1D)及第六染色体群(染色体6A、6B和6D)上的196对SSR引物进行扩增筛选。结果表明,(1)位于1AS染色体上的3个SSR标记和位于6BS染色体上的4个SSR标记均在亲本和基因池间扩增出了稳定的多态性差异条带;(2)定位群体验证结果表明,恢复基因Rf1与1AS染色体上Xgwm136、Xgpw7062和Xgdm33标记的遗传距离分别为4.8、9.6和13.7 cM,3个标记与Rf1之间的顺序依次为Xgdm33、Xgwm136、Rf1、Xgpw7062;(3)恢复基因Rf4与6BS染色体上的Xgpw1079、Xgwm193、Xgpw7011和Xgwm508标记的遗传距离分别为3.4、6.8、13.7和21.5 cM,4个标记与Rf4之间的顺序依次为Xgpw7011、Xgpw1079、Rf4、Xgwm193和Xgwm508。研究还表明,T-CMS恢复系R113的育性是由Rf1和Rf4两对主效恢复基因和多对微效基因共同控制的,筛选的上述7个SSR标记可直接用于T型或者类似T型,如S型杂交小麦分子标记辅助育种,可有效提高对应恢复系的选择效率。     

小麦光温敏核雄性不育系BS20育性的QTL分析

以小麦(Triticum aestivum L.)光温敏不育系BS20×Fu3 DH群体的289个系为材料,于2005-2006年度种植于北京海淀和安徽阜阳,进行了育性(结实率和结实小穗率)的调查.利用SSR标记和分离群体分组分析法(BSA)分析该群体中与育性相关的分子标记,用128对SSR引物,初步构建BS20×Fu3群体的分子标记遗传连锁框架图.BSA的结果表明,与育性连锁的3个标记是Xgwm294、Xgwm374和Xgwm44,分别位于染色体2AL、2BS和7DS;采用混合线性复合区间作图法对小麦育性进行QTL分析,检测到6个QTL,分布在1AS、2BS、2DL、6AL、6BL和7DS染色体,贡献率为1.1%～12.5%,其中7DS上的QTL与2BS、6AL和6BL上的QTL存在显著的互作效应.综合BSA和QTL分析结果,确定染色体7DS和2BS上的QTL重复性较好、贡献率和互作效应较大,为小麦光温敏核雄性不育性状的重要QTL,标记区间分别为Xgum44-Xcfd14和Xgwm148-Xgwm374,贡献率分别为7.2%～12.5%和2.1%～2.5%.     

普通小麦-柔软滨麦草易位系M8657-1抗条锈病基因遗传分析与SSR标记

为明确小麦(Triticum aestivum)-柔软滨麦草(Leymus mollis(Trin.)Hara)易位系M8657-1的抗条锈性,用中国小麦条锈菌(Puccinia striiform f.sp.stritici)流行小种条中30号、条中31号、水源11-4和水源11-11生理小种,对M8657-1和铭贤169的杂交后代进行苗期抗条锈性遗传分析.结果表明,易位系M8657-1对条中30号和水源11-11的抗条锈性均1对隐性核基因控制;对条中31号的抗条锈性由2对显性核基因(互补作用)控制;对水源11-4的抗条锈性由1对显性核基因控制.将控制水源11-4抗病性的基因暂时命名为YrElm1-4,以接种水源11-4的F2正交群体为研究对象,应用BSA法进行了SSR分析.从320对SSR引物组合中筛选到3个与主效抗病基因YrElm1-4连锁的多态性微卫星标记,它们分别是Xgwm636、Xwmc522和Xwmc453,根据3个微卫星标记位点的染色体位置,推出YrElm1-4位于小麦2AS染色体上,这3个标记可用丁分子标记辅助育种.     

甘蓝Ogura胞质雄性不育基因的RAPD标记筛选*

有关利用RAPD[1]技术进行分子标记的研究报道很多,如王俊霞等[1]对甘蓝型油菜Pel CMS育性恢复基因和王晓武等[2]对甘蓝的一个显性核雄性不育基因均进行了RAPD标记.我们经过多年的选育,已经成功把外源胞质雄性不育基因转育到甘蓝自交不亲和系上,现已成功选育出不育性稳定和经济性状优良的甘蓝雄性不育系.为了更深入的研究其不育机理,利用RAPD分子标记技术对其不育基因进行了标记,为以后开展甘蓝杂优育种提供标记基因打下基础.     

小麦-柔软滨麦草易位系M853-4抗条锈病基因的遗传分析和SSR标记定位

用中国小麦条锈菌(Puccinia stniform f.sp.stritici)流行小种条中29号、条中30号、条中31号和水源11-11生理小种,对小麦(Triticum aestivum)-柔软滨麦草(Elymus mollis)易位系M853-4和铭贤169的杂交后代进行苗期抗条锈性遗传分析.结果表明,易位系M853-4对条中29号、条中30号和条中31号的抗病性均由1对显性核基因控制;对水源11-11的抗病性由1对显性和1对隐性基因共同控制.将控制条中31号抗病性的基因暂时命名为YrElm4.以接种条中31号的F2正交群体为研究对象,应用BSA法进行了SSR分析.从320对SSR引物组合中筛选到3个与主效抗病基因YrE1m4连锁的多态性微卫星标记,它们分别是Xwmc654、Xgwm304和Xgwm129,与YrE1m4的遗传距离依次为5.8、7.1和10.3 cM,并将YrE1m4定位于小麦5AS染色体,这3个标记可用于分子标记辅助育种.     

黏类小麦CMS不育基因rfv1的分子细胞遗传学跟踪鉴定及定向转育研究

为了实现黏类小麦雄性不育基因rfv1的定向转育,创制优良的黏类非1BL/1RS小麦雄性不育新保持系,本研究以1BS上带有不育基因rfv1的非1BL/1RS小麦变种SP4、莫迦小麦为供体材料,以杀雄剂途径培育的小麦强优势组合西杂1号和西杂5号杂交小麦新品种的母本西农Fp1和西农Fp2为受体材料,采用专一核置换回交转育方法,同时结合根尖细胞学镜检、复合引物PCR及SDS-PAGE和A-PAGE技术,进行不育基因rfv1定向转入的鉴定,旨在育成既携带rfv1不育基因,又具有西农Fp1和西农Fp2核遗传背景的黏类非1BL/1RS小麦雄性不育新保持系。结果如下：（1）根尖体细胞随体鉴定和复合引物PCR分析表明,该法不仅能准确鉴定出1BL/1RS纯合易位系,还可鉴定出1BL/1RS·1BL/1BSrfv1 易位杂合体,两者结果一致。其中复合引物PCR更适合于回交后代中大量目标植株的筛选,为小麦雄性不育基因rfv1定向转移到1BL/1RS易位系提供了准确的鉴定方法与依据;（2）利用SDS-PAGE技术对供试材料进行高低分子量麦谷蛋白亚基的分析表明,在低分子量谷蛋白D亚基区存在莫迦小麦和SP4的特征带;而SP4的高分子量谷蛋白亚基区的6+8亚基,也可以作为示踪小麦雄性不育基因rfv1定向转移到非1BL/1RS易位系的特征亚基条带;（3）A-PAGE技术对醇溶蛋白的分析表明,在ω-醇溶蛋白区也发现莫迦小麦和SP4不同于西农Fp2的特异蛋白条带,也可作为示踪小麦雄性不育基因rfv1定向转移到非1BL/1RS易位系的特征蛋白条带。本研究成功地将小麦杂种优势利用中的杀雄剂法和三系法相结合,促进了小麦杂种优势利用新技术体系的建立。同时该方法亦可应用于黏类小麦雄性不育恢复基因Rfv1的定向转育,进而可实现小麦由生理型不育向遗传型不育的定向转化,以探索一套杂交小麦强优势组合多途径利用的新方法。     

普通小麦-华山新麦草易位系H9020-20-12-1-8抗条锈病基因SSR标记

H9020-20-12-1-8是一个通过杂交和回交选育的普通小麦（Triticum aestivum L.）华山新麦草（Psathyrostachys huashanica Keng.）易位系,苗期对中国小麦生产上流行的条锈菌（Puccinia striiforms f.sp.tritici）生理小种CYR32表现良好抗性。遗传分析表明,H9020-20-12-1-8对CYR32的抗病性是由1对显性基因YrHy（暂命名）独立控制的,通过对H9020-20-12-1-8和感病品种铭贤169杂交F2分离群体进行SSR分子标记,从305对SSR引物组合中筛选到3个与抗病基因YrHy紧密连锁的微卫星标记Xgwm429、Xwgm770和Xwmc154,与YrHy的遗传距离分别为5.4、6.4和11.3cM,将YrHy定位于小麦2BS染色体上。系谱分析及分子检测等结果表明,YrHy是一个源于华山新麦草的新抗条锈病基因。     

小麦抗叶锈病基因Lr2c的SSR标记

选取抗叶锈病基因位于2D染色体上的TcLr2c等7个小麦（Triticum aestivum）近等基因系、感病亲本Thatcher及215株TcLr2c与Thatcher杂交F2代为材料,研究抗叶锈病基因Lr2c SSR分子标记。从筛选的29对位于小麦2D染色体的SSR引物中获得4对能够揭示Lr2c多态性的分子标记,通过215株TcLr2c × Thatcher F2群体验证,结果表明Xgwm261和Xgwm296与Lr2c紧密连锁,其距目的基因的遗传距离分别为1.9和3.6 cM,可用于小麦抗叶锈病分子辅助育种。     

基于一致性QTL区段四川小麦地方品种产量和品质相关性状的遗传分析

普通小麦(Triticum aestivum)地方品种具备了对当地自然生态条件的较强适应性和与之相对应的生产潜力.因此,从地方小麦品种中挖掘产量、品质、抗病虫及耐逆等优良基因资源,扩大当前小麦育种亲本的遗传基础,历来受到小麦遗传育种学家的高度重视.本研究通过对64个四川小麦地方品种进行了2年3个环境的表型精准鉴定,并利用231个小麦产量与品质相关性状的一致性QTL区段中的SSR标记,通过关联分析揭示四川地方品种产量和品质相关性状的遗传特征.表型鉴定结果显示,这些地方小麦品种具有多花多粒、分蘖能力强、成穗率高等特性,总体上属于中筋或弱筋小麦,且有效分蘖数、株高、小穗密度、穗长、可育小穗数、沉降值等性状遗传力较高,达50％以上.关联分析鉴定出18个多环境下稳定表达的SSR位点,与产量和品质性状极显著关联,其中1个(Xgwm372)同时与产量性状和品质性状关联,4个(Xwmc112,Xcfd5,Xwmc317和Xgwm372)最为稳定,3个(Xcfd5,Xgwm328和Xbarc181)关联到新的产量性状.相关分析表明,穗长与小穗密度呈极显著负相关,且有2个共同关联标记(Xgwm328和Xcfd5).还鉴定出2A染色体上的Xgwm448-Xgwm328-Xgwm3 72区段(8.0 cM)在多环境下与穗长显著关联.上述SSR标记位点和区段为通过分子标记辅助选择手段利用和发掘四川小麦地方品种产量和品质优异相关基因或区段提供理论指导.     

Genetic diversity of the D-genome in <Emphasis Type="Italic">T. aestivum</Emphasis> and <Emphasis Type="Italic">Aegilops</Emphasis> species using SSR markers

Simple sequence repeats (SSRs), highly dispersed nucleotide sequences in genomes, were used for germplasm analysis and estimation of the genetic relationship of the D-genome among 52 accessions of T. aestivum (AABBDD), Ae. tauschii (D^tD^t), Ae. cylindrica (CCD^cD^c) and Ae. crassa (MMD^cr1D^cr1), collected from 13 different sites in Iran. A set of 21 microsatellite primers, from various locations on the seven D-genome chromosomes, revealed a high level of polymorphism. A total of 273 alleles were detected across all four species and the number of alleles per each microsatellite marker varied from 3 to 27. The highest genetic diversity occurred in Ae. tauschii followed by Ae. crassa, and the genetic distance was the smallest between Ae. tauschii and Ae. cylindrica. Data obtained in this study supports the view that genetic variability in the D-genome of hexaploid wheat is less than in Ae. tauschii. The highest number of unique alleles was observed within Ae. crassa accessions, indicating this species as a great potential source of novel genes for bread wheat improvement. Knowledge of genetic diversity in Aegilops species provides different levels of information which is important in the management of germplasm resources.     

K-19小麦雄性不育-育性恢复体系的研究

该研究以粘果山羊草Ae.19(Ae.Kotschyi 19)为母本,中国春和云南铁壳小麦为桥梁亲本进行远缘杂交,获得雄性不育株,再用普通小麦品种(系)与其测交和连续回交,育成了具有粘果山羊草Ae.19细胞质普通小麦细胞核的K-19小麦雄性不育系,并选育出K-19农矮3号A等10余个优良K-19不育系,其不育性稳定,没有发现单倍体,综合性状好。从普通小麦品种(系)中发现了恢复力高的K-19小麦雄性不育恢复系(源),筛选出原KR_1等7个恢复系,国内法恢复度高达88.2％～96.9％,国际法恢复度高达116.4％～150.4％,其后代不产生单倍体或单倍体频率很低,综合性状好。K-19小麦雄性不育-育性恢复体系的建成,丰富了小麦杂优育种种质库,具有良好的生产利用价值。     

Powdery mildew resistance in Aegilops tauschii coss. and synthetic hexaploid wheats

Summary A collection of 400 Ae. tauschii (syn. Ae. squarrosa) Coss. accessions were screened for powdery mildew resistance based on the response patterns of 13 wheat cultivars/lines possessing major resistance genes to nine differential mildew isolates. 106 accessions showed complete resistance to all isolates, and 174 accessions revealed isolate-specific resistance, among which were 40 accessions exhibiting an identical response pattern as wheat cultivar Ulka/^*8Cc which is known to possess resistance gene Pm2. Expression of both complete and isolate-specific resistance from Ae. tauschii was observed in some synthetic hexaploid wheats derived from four mildew susceptible T. durum Desf. parents, each crossed with five to 38 resistant diploid Ae. tauschii accessions. Synthetic amphiploids involving different combinations of T. durum and Ae. tauschii generally showed a decrease in resistance compared with that expressed by the Ae. tauschii parental lines.     

RAPD polymorphisms in Aegilops geniculata Roth (Ae. ovata auct. non L.)

Genetic diversity of eighteen accessions of Ae. geniculata (2n=28; UUMM) was assessed using the random amplified polymorphic DNA (RAPD) technique. We optimized RAPD conditions including the template DNA, the concentration of AmpliTaq DNA polymerase Stoffel fragment, and MgCl₂ concentration for revealing polymorphisms. Thirty-eight decamer oligonucleotides were individually used as primers under optimized conditions. Seventeen of these primers produced polymorphic RAPDs among the 18 accessions of Ae. geniculata. Polymorphisms were recorded by noting presence or absence of an amplification product from the total genomic DNA. Comparisons of unique and shared amplification products of each pair of accessions were used to generate genetic similarity coefficients (GSCs). These GSCs were used to construct a phenogram using an unweighted pair-group method with arithmetical averages (UPGMA). The phenogram shows that RAPD data is useful in the measurement of genetic variation or similarity within a species. It also indicates that we can select eight or nine accessions of the eighteen accessions to maintain at least 80% genetic variability of the Chinese collection of Ae. geniculata. Address for correspondence: Dr X-Y. Zhang, USDA-ARS-FRRL, Utah State University, Logan, UT 84322-6300, who is visiting the USA under an agreement between USDA-ARS and CMA-CAAS on germplasm resources.     

一例特异细胞质雄性不育小麦mtDNA特异片段的克隆和测序

以具有同质同核的二角型小麦花药外露不育系与花药不外露突变不育系为试材,对其mtDNA进行了RAPD分析,筛选出特异片段S32-1582、OPAA16-1753,并进行克隆与测序。结果表明:花药外露型不育系与花药不外露型不育系细胞质内mtDNA存在明显差异,而ctDNA之间不存在差异;二角型花药外露型不育系转化为花药不外露型不育系,很可能是由于mtDNA自发的重排引起的。其差异片段S32-1582、OPAA16-1753序列与核基因组上的序列具有同源性;供试线粒体基因组能够在较短的演化时间内发生变异,从而引起二角型花药外露型不育系向花药不外露型不育系的变异,其特异质核互作可能起重要作用。     

水旱稻根基粗、千粒重主效QTL近等基因系的构建及鉴评

近等基因系的选育是分子遗传图谱构建、数量性状基因定位及分子标记辅助育种的重要基础之一。本文利用分子标记辅助目标性状QTL前景选择及恢复轮回亲本基因组的背景选择，再结合表型选择获得了定位在水稻4号、6号染色体上根基粗、千粒重2个主效QTL的近等基因系。其中有9个系入选旱田根基粗主效QTL brt4.1的近等基因系，根基粗的表型值为1.07～1.16mm，较轮回亲本越富提高6.11％～15.18％，平均遗传背景恢复率达97.22％；千粒重主效QTL的近等基因系有11个系入选，千粒重的表型值为21.25～26.25g，较轮回亲本越富的增幅为7.05％～32.16％，平均遗传背景恢复率为95.97％。另外，本文还就分子标记辅助近等基因系选育中背景选择标记数的确定、基于QTL-NILs的基因克隆等进行了讨论。     

Collecting spanish populations of the genusAegilops L.

Summary Several expeditions were made to the greater part of Peninsular Spain and the Balearic Islands, in order to collect samples from populations ofAegilops spp. The result has been the compilation of a collection reflecting both the presence and the distribution of the genus in Spain. The localisation and collection of two populations ofAe. cylindrica is particularly noteworthy.Ae. ovata is found all over the Peninsula except in the north and northwest of the country. It extends also to the Balearic Islands, which lie within the same biogeographical region.Ae. triuncialis also has a widespread distribution though smaller than that ofAe. ovata. In the Balearic Islands it is found only in Mallorca. All other species were found in more localised areas.Ae. neglecta was found in regions of W and SW Spain with the limits of its distribution bordering those ofAe. biuncialis, which is found in central Spain and in the South.     

A Tal-Ph<Superscript>I</Superscript> wheat genetic stock facilitates efficient alien introgression

The genetic stock Chinese Spring Ph^I (refer as CS-Ph^I hereafter) with the Ph ^I gene (Ph gene inhibitor, introduced from a high-pairing accession of Aegilops speltoides) was crossed as a male parent to a Tai-gu genic male-sterile wheat with the Tal gene and backcrossed once to CS-Ph^I to develop the Tal-Ph^I genetic stock. The Tal-Ph^I stock, CS-Ph^I as well as Chinese Spring (CS), were test-crossed using Aegilops peregrina (syn. Aegilops variabilis) to test the effectiveness of the Ph ^I gene inducing homoeologous chromosome pairing in the Tal-Ph^I stock. At meiotic I(MI) of pollen mother cells (PMCs), the average chromosome pairing of the TC₁ testcrosses of TalCSPh^IC_08–4/Ae. peregrina, TalCSPh^IC_11–5/Ae. peregrina and CS/Ae. peregrina was 26.81 I + 3.64 II + 0.33  + 0.07 III + 0.01 IV, 24.75 I + 4.58 II + 0.25  + 0.21 III + 0.07 IV and 32.25 I + 1.38 II, respectively. These data indicated that the Ph ^I gene could promote homoeologous chromosome pairing in the Tai-gu male sterile background. In order to verify the introgression of the chromatin from Ae. speltoides into CS in the three CS-Ph^I lines, a total of 79 SSR primers located on group-3 chromosomes were used for PCR analysis using the genomic DNA of CS, Ae. speltoides and the three CS-Ph^I lines. Two markers Xwmc505 _-110 and Xwmc674 _-160 amplified S genome-specific fragments from Ae. speltoides in lines Ph^IC_04–13 and Ph^IC_11–5, providing molecular evidence for the introgression of Ae. speltoides-specific chromatin in the two lines. Furthermore, some 3D-specifc SSR markers were missing in line Ph^IC_04–13, indicating there might be a deletion of chromosome 3D in this line. In further experiments, a BC₁ population was produced from the cross of Tal-Ph^I/Triticum durum-Dasypyrum villosum amphiploid (AABBVV)//CS-Ph^I, and the progenies were further screened for chromosome recombination by GISH analysis. A homozygous translocation line T5VS·5VL-5DL was identified from the BC₁F₂ by genomic in situ hybridization, C-banding and SSR analysis. The results of the present study demonstrate the Tal-Ph^I is a useful genetic stock for transferring alien genes into common wheat.     

Inheritance in hexaploid wheat of genes for hairy auricles and hairy leaf sheath derived from Aegilops tauschii Coss.

Inheritance of genes for hairy auricles and hairy leaf sheath of Ae. tauschii in hexaploid wheat backgrounds (synthetic hexaploid wheat and common wheat varieties) was analyzed. The results indicated that hairy auricles and hairy leaf sheath of Ae. tauschii can be transferred and are expressed in hexaploid wheat. In a synthetic hexaploid wheat ('Ae. tauschii' 188) hairy auricles was proved to be controlled by a single dominant gene derived from Ae. tauschii, which was different from the Pa gene located on chromosome 4BS of common wheat. The hairy leaf sheath phenotype of 'Altar 84/Ae. tauschii 188' was also controlled by a single dominant gene derived from Ae. tauschii, which is obviously different from the Hls gene in T. dicoccoides. We suggest to designate the Ae. tauschii genes for hairy auricles and hairy leaf sheath as Pa2 and Hls2, respectively; such genes could be used as useful genetic markers in common wheat.     

Resistance to wheat leaf rust in Aegilops tauschii Coss. and inheritance of resistance in hexaploid wheat

A collection of 164 Aegilops tauschii accessions, obtained from Gatersleben, Germany, was screened for reaction to leaf rust under controlled greenhouse conditions. We have also evaluated a selection of synthetic hexaploid wheats, produced by hybridizing Ae. tauschii with tetraploid durum wheats, as well as the first and second generation of hybrids between some of these resistant synthetic hexaploid wheats and susceptible Triticum aestivum cultivars. Eighteen (11%) accessions of Ae. tauschii were resistant to leaf rust among which 1 was immune, 13 were highly resistant and 4 were moderately resistant. Six of the synthetic hexaploid wheats expressed a high level of leaf rust resistance while four exhibited either a reduced or complete susceptibility compared to their corresponding diploid parent. This suppression of resistance at the hexaploid level suggests the presence of suppressor genes in the A and/or B genomes of the T. turgidum parent. Inheritance of leaf rust resistance from the intercrosses with susceptible bread wheats revealed that resistance was dominant over susceptibility. Leaf rust resistance from the three synthetics (syn 101, syn 701 and syn 901) was effectively transmitted as a single dominant gene and one synthetic (syn 301) possessed two different dominant genes for resistance.