抗条锈病小麦中间偃麦草二体异附加系的选育和鉴定

利用普通小麦-中间偃麦草杂交,然后回交自交,从其BC2F5中选育出一份小麦新种质AF-2。从形态上AF-2表现出硬颖、蜡质、秆细等稳定的与中间偃麦草类似的农艺特征;田间调查与接种都发现AF-2表现出对现今流行的条锈病和白粉病免疫。细胞学检测该品系根尖细胞染色体数目为44条,花粉母细胞减数分裂中期Ⅰ均为二价体,染色体配型为2n=22Ⅱ,细胞学上已十分稳定;GISH结果显示该抗条锈病品系AF-2附加了两条来自中间偃麦草E染色体组的染色体,结合其表现出的农艺性状特征表明AF-2附加的可能是中间偃麦草2E染色体;遗传研究表明抗病基因可能位于附加的E染色体上,随后在供试的160对SSR中,其中引物Xgwm382能在中间偃麦草和AF-2中稳定地扩增出一条大约90 bp的特异条带,而小麦亲本中不能扩增出该条带,因此Xg-wm382可作为兼抗小麦条锈病和白粉病新种质AF-2所附加的染色体的特异分子标记。     

中间偃麦草和偃麦草苗期耐盐性评价

比较不同NaCl浓度(0、0.4%、0.6%、0.8%、1.0%、1.2%)(盐浓度)下,中间偃麦草和偃麦草苗期的生长情况。结果表明:低盐浓度下,对中间偃麦草和偃麦草的生长没影响,盐浓度大于0.6%时,株高、分蘖数、存活苗数和生物量随浓度的增高呈下降趋势,中间偃麦草所受的影响小于偃麦草;中间偃麦草能抗1.2%的盐浓度,而偃麦草在0.8%的盐浓度下严重受到盐害,植株已枯黄死亡。2种牧草相比,苗期的耐盐性中间偃麦草高于偃麦草。     

中间偃麦草优良基因向小麦的转移利用

综述中间偃麦草的生物学特性、染色体组成及其优良基因向小麦中的转移、利用与鉴定等,并展望中间偃麦草的利用前景。     

3个抗条锈病小偃麦附加系中偃麦草染色体同源性鉴定

已经建立了3个抗条锈病小偃麦二体附加系,分别编号为 A1,A2和 A3。它们衍生于铭贤169与中4的杂交后代。铭贤169是一个普通小麦品种,它对我国现有全部条锈菌小种均高度感染。中4是人工合成的异源八倍体新种,含有全套小麦染色体和7对中间偃麦草染色体,对目前我国所有条锈菌小种均免疫或高抗。将铭贤169与中4杂交、用铭贤169回交、回交后代自交及抗病性鉴定得到了 A1,A2和 A3。为了搞清这3个附加系所附加染色的异同,将A1,A2和A3两两杂交,检查其 F_1植株减数分裂过程中染色体配对情况。在 A1×A2和 A2×A3的 F_1小孢子母细胞中出现了两个单价体染色体,在 A1×A3的 F_1中未发现单价体。这表明,A1与 A3所附加的是同一对中间偃麦草染色体,A2所附加的则是另一对。结论是,已经从中4鉴定出两种抗条锈病的中间偃麦草染色体,这两对染色体之间不具有同源性。     

3个抗条锈病水偃麦附加系中偃麦草染色体同源性鉴定

已经建立了３个抗条锈病小偃麦二体附加系，分别编号为Ａ１，Ａ２和Ａ３。它们衍生于铭贤１６９与中４的杂交后代。铭贤１６９是一个普通小麦品种，它对我国现有全部条锈菌小种均高度感染。中４是人工合成的异源八倍体新种，含有全套小麦染色体和７对中间偃麦草染色体，对目前我国所有条锈菌小种均免疫或高抗。将铭贤１６９与中４杂交、用铭贤１６９回交、回交后代自交及抗病性鉴定得到了Ａ１，Ａ２和Ａ３。为了搞清这３个附加系所附     

小偃6号抗条锈性遗传分析

【目的】小偃6号是20世纪70年代末利用长穗偃麦草基因育成的著名品种，具有高温抗条锈性，研究其抗条锈遗传规律，对揭示其抗病机制和培育持久抗病品种具有重要意义。【方法】在常温[（10±1）℃～（16±1）℃]下，以小偃6号和铭贤169的杂交群体为研究对象，分析遗传规律，利用中国春单体对抗条锈基因进行染色体定位，利用SSR对抗条锈基因进行分子标记。测定所用菌种为Cy28和Cy29-mut3。【结果】小偃6号对CY28、CY29 mut-3的抗病性均由1对显性核基因控制。该抗条锈基因定位在4B染色体上。用4B上的11对SSR引物对该抗条锈基因进行了分子标记，找到了一个与小偃6号抗条锈基因紧密连锁的SSR标记Xgwm 107，这个标记位于4B染色体的长臂上，连锁分析表明其遗传距离为7.08 cM。【结论】经典遗传学分析、单体分析、分子标记研究均支持将小偃6号的常     

4个小麦—柔软滨麦草易位系苗期抗条锈基因的遗传分析

旨在开发和利用柔软滨麦草的基因,丰富小麦抗条锈基因库。利用小麦条锈菌流行小种CYR32和CYR33对M851-1、M8724-1、M8725-2和M8657-2 4个小麦-柔软滨麦草易位系进行苗期抗条锈性遗传分析。结果表明,M851-1对CYR32的抗条锈性由1对隐性基因控制;M8724-1对CYR32的抗条锈性由2对隐性基因独立作用控制,对CYR33的抗条锈性由1对隐性基因控制;M8725-2对CYR32的抗条锈性由2对显性基因互补作用控制,对CYR33的抗条锈性由1显1隐2对基因独立控制;M8657-2对CYR32的抗条锈性由1对隐性基因控制,对CYR33的抗条锈性由2对显性基因独立作用控制。研究结果初步明确这4个小麦-柔软滨麦草易位系抗条锈性遗传规律,有助于进一步利用这些易位系进行小麦抗条锈病育种。     

小麦-中间偃麦草异代换系的细胞学和SSR标记鉴定

中间偃麦草含有丰富的优良基因,在小麦的遗传改良中具有重要利用价值。对从八倍体小偃麦TAI-7045与普通小麦复合杂交后代中选育的小麦种质系CH-9916进行细胞学鉴定,其根尖细胞染色体数目为2n=42,为六倍体普通小麦,在苗期和成株期CH-9916对条锈病均表现免疫,中抗白粉病。通过SSR标记鉴定分析,其可能是由偃麦草的染色体代换了小麦的2D染色体。以上结果表明,种质系CH-9916可能是一个异代换系。     

一个新的小麦-中间偃麦草异代换系的分子细胞学鉴定

以来源于中间偃麦草的八倍体小偃麦为桥梁亲本,通过回交转育的方法,将其所携带的中间偃麦草染色体转移到普通小麦中,从其BC1F6选系中选育出一个高抗小麦秆锈病、白粉病的优良品系CH08-141,并利用分子细胞学方法对其进行鉴定。以中间偃麦草基因组DNA为探针的GISH结果表明,CH08-141中包含1对来源于中间偃麦草的染色体,属于小麦-中间偃麦草异代换系;以平均分布于小麦基因组染色体上的48对SSR引物对CH08-141分子标记染色体定位,结果表明,CH08-141中的6B染色体被中间偃麦草的1对J组染色体所代换。新鉴定的异代换系含有来源于中间偃麦草的抗秆锈病和白粉病基因,是小麦抗病育种中不可多得的新抗源。     

Molecular Mapping of Two Novel Stripe Rust Resistant Genes YrTp1 and YrTp2 in A-3 Derived from Triticum aestivum × Thinopyrum ponticum

Loss of variety resistance to stripe rust (Puccinia striiformis Westend f. sp. tritici) is an important factor causing massive periodical epidemic of rust in wheat production. Creation and development of new races of rust pathogen have led to serious crisis of resistance loss in widely planted varieties. This has quickened the search for new resistance resources.Molecular marker could facilitate the identification of the location of novel genes. A line A-3 with high resistance(immune) to currently epidemic yellow rust races (CY29, 31, 32) was screened out in offspring of Triticum aestivum ×Thinopyrum ponticum. Segregation in F2 and BC1 populations indicated that the resistance was controlled by two independent genes: one dominant and one recessive. SSR markers were employed to map the two resistant genes in the F2 and BC1 populations. A marker WMC477-167bp located on 2BS was linked to the dominant gene with genetic distance of 0.4 cM. Another marker WMC364-208bp located on 7BS was linked to the recessive-resistant gene with genetic distance of 5.8 cM. The two genes identified in this paper might be two novel stripe rust resistant genes, which were temporarily designated as YrTpl and YrTp2, respectively. The tightly linking markers facilitate transfer of the two resistant genes into the new varieties to control epidemic of yellow rust.     

中梁12小麦抗条锈病基因遗传分析与SSR分子定位

中梁12具有抗逆性强、适应性广、抗条锈性强等许多优良的生物学特性。为明确其抗条锈性及遗传规律,利用当前流行的中国条锈菌小种CYR30对抗病品种中梁12与感病品种铭贤169及其杂交后代代F1、F2、F3和BC1代进行苗期抗条锈性遗传分析,并对其抗条锈基因进行SSR分子标记。结果表明,中梁12对CYR30小种具有良好的抗性,由1对显性基因控制,暂命名为YrZh12。该基因与位于小麦7AL染色体上的4个SSR位点Xwmc695、Xcfd20、Xbarc121和Xbarc49连锁,其中最近的侧翼位点为Xcfd20和Xbarc121,其遗传距离分别是3.1cM和4.9cM。系谱分析YrZh12基因可能来自抗引655,由于7AL染色体上没有其他抗条锈病基因,YrZh12可能是一个抗条锈病的新基因。     

Molecular Mapping of Two Novel Stripe Rust Resistant Genes YrTp1 and YrTp2 in A-3 Derived from Triticum aestivum × Thinopyrum ponticum

Loss of variety resistance to stripe rust (Puccinia striiformis Westend f. sp.tritici) is an important factor causing massive periodical epidemic of rust in wheat production. Creation and development of new races of rust pathogen have led to serious crisis of resistance loss in widely planted varieties. This has quickened the search for new resistance resources. Molecular marker could facilitate the identification of the location of novel genes. A line A-3 with high resistance (immune) to currently epidemic yellow rust races (CY29, 31, 32) was screened out in offspring of Triticum aestivum × Thinopyrum ponticum. Segregation in F₂ and BC₁ populations indicated that the resistance was controlled by two independent genes: one dominant and one recessive. SSR markers were employed to map the two resistant genes in the F₂ and BC₁ populations. A marker WMC477-_167bp located on 2BS was linked to the dominant gene with genetic distance of 0.4 cM. Another marker WMC364-_{208 bp} located on 7BS was linked to the recessive-resistant gene with genetic distance of 5.8 cM. The two genes identified in this paper might be two novel stripe rust resistant genes, which were temporarily designated as YrTp1 and YrTp2, respectively. The tightly linking markers facilitate transfer of the two resistant genes into the new varieties to control epidemic of yellow rust.     

小麦品系西农1163-4抗叶锈病基因的遗传分析和分子作图#br#

【目的】小麦品系西农1163-4高抗小麦叶锈、条锈和白粉病,综合农艺性状良好。明确该小麦品系中所含的抗叶锈病基因及遗传特点,找到与其紧密连锁的分子标记,有利于抗病基因利用和培育抗病新品种。【方法】将西农1163-4与感病品种Thatcher杂交,获得F1、F2代群体,利用中国叶锈菌优势小种THTT进行苗期抗性鉴定和抗性遗传分析;采用SSR技术对西农1163-4所携带的抗叶锈基因进行分子标记研究,共筛选了1 273对SSR引物。【结果】小麦品系西农1163-4对多个叶锈菌小种具有良好的抗病性,对THTT的抗性是由1个显性基因控制,该基因暂命名为LrXi。获得了与LrXi紧密连锁的3个微卫星分子标记Xbarc8、Xgwm582、Xwmc269和1个STS标记(ω-secali/Glu-B3),将LrXi定位于小麦1BL染色体上。距离最近的2个微卫星位点是Xgwm582、Xbarc8,与抗叶锈基因间的遗传距离分别为2.3 cM和3.2 cM。【结论】LrXi位于1BL染色体,抗叶锈表现不同于所有已知抗叶锈病基因,该基因的发现将有利于丰富中国抗叶锈病基因资源,为培育持久抗病品种奠定基础。     

小麦品种贵农6号抗条锈病基因的SSR标记

用小麦条锈菌生理小种条中31号,对小麦抗病种质贵农6号和鲁麦17的杂交后代进行抗条锈性遗传分析.结果表明:贵农6号携带1个抗条锈病显性单基因,暂命名为YrGn6.利用分组分析法(BSA),并根据F2抗、感病单株分离比例组建抗感池,从93个SSR引物组合中筛选到1个与抗病基因YrGn6紧密连锁的微卫星标记Xpsp3000,遗传距离为3.9 cm;将YrGn6定位于小麦IBS上.分析基因所在染色体的位置及抗病性特征,认为:YrGn6可能是一个新的抗小麦条锈病基因,并可用于分子标记辅助选择.     

两个中国小麦品种中抗叶锈基因的遗传分析和基因定位

【目的】确定来自四川的两个小麦品种绵阳351-15和SW8588所携带的抗叶锈基因,为选育持久抗锈品种提供理论依据。【方法】在苗期用15个叶锈菌生理小种接种小麦品种绵阳351-15、SW8588和30个含有已知抗叶锈基因的近等基因系,推导2个材料中所含有的抗叶锈病基因,同时以小麦抗叶锈品种绵阳351-15和SW8588分别同感病品种郑州5389杂交获得F1和F2代群体,用叶锈菌小种FHTT接种各亲本及其杂交后代,进行抗叶锈遗传分析,并利用SSR和STS标记进行抗叶锈病基因的分子定位。【结果】经苗期基因推导发现SW8588中含有未知基因不同于已知抗叶锈病基因Lr1,绵阳351-15中可能含有已知抗叶锈病基因Lr1。用叶锈菌小种FHTT接种各F1和F2代群体,2个F2代群体抗感单株分离比例均符合3﹕1的理论分离比例,表明2个亲本对小种FHTT的抗病性均由1个显性基因控制。经过分子标记分析,在小麦材料绵阳351-15中发现该抗叶锈基因与位于5DL的SSR标记barc144和wmc765连锁,其遗传距离分别为8.9和20.8 cM,并同Lr1的STS标记WR003共分离,确定在小麦材料绵阳351-15中对小种FHTT的抗病性由抗叶锈基因Lr1提供;经分子标记检测SW8588中含有1对显性的抗叶锈病基因,暂命名为LrSW85,该基因位于5DL染色体上与Lr1的STS标记WR003共分离,该抗叶锈基因可能是Lr1的等位基因或紧密连锁基因。【结论】通过基因推导、遗传分析和分子标记等手段,确定小麦材料绵阳351-15中含有抗叶锈基因Lr1;小麦材料SW8588中含有抗叶锈基因LrSW85,该基因可能为Lr1的等位基因或紧密连锁基因。     

在小麦育种中利用偃麦草抗病特性的研究

为利用中间偃麦草的抗性基因改良普通小麦的抗病性,以八倍体小偃麦TAI7045为桥梁亲本,与小麦杂交、回交,通过异源染色体的细胞遗传学操纵,将偃麦草的抗条锈病基因转移给普通小麦,育成一批抗病性和农艺性状均已稳定的小偃麦易位系,并采用染色体分带和分子原位杂交技术,对它们的染色体组成进行了准确鉴定。抗病性的异地评价和接种鉴定结果表明,它们高抗我国小麦条锈病优势小种和新的流行小种。此外,还就防止或至少延缓抗病性丧失的有效途径、染色体小片段异源易位的诱导方法和外源基因的利用前景进行了讨论。     

Genetic Analysis and Molecular Mapping of an All-Stage Stripe Rust Resistance Gene in Triticum aestivum-Haynaldia villosa Translocation Line V3

Triticum aestivum-Hayaldia villosa translocation line V3 has shown effective all-stage resistance to the seven dominant pathotypes of Puccinia striiforms f.sp.tritici prevalent in China.To elucidate the genetic basis of the resistance,the segregating populations were developed from the cross between V3 and susceptible genotype Mingxian 169,seedlings of the parents and F 2 progeny were tested with six prevalent pathotypes,including CYR29,CYR31,CYR32-6,CYR33,Sun11-4,and Sun11-11,F 1 plants and F 3 lines were also inoculated with Sun11-11 to confirm the result further.The genetic studied results showed that the resistance of V3 against CYR29 was conferred by two dominant genes,independently,one dominant gene and one recessive gene conferring independently or a single dominant gene to confer resistance to CYR31,two complementary dominant genes conferring resistance to both CYR32-6 and Sun11-4,two independently dominant genes or three dominant genes（two of the genes show cumulative effect） conferring resistance to CYR33,a single dominant gene for resistance to Sun11-11.Resistance gene analog polymorphism（RGAP） and simple-sequence repeat（SSR） techniques were used to identify molecular markers linked to the single dominant gene（temporarily designated as YrV3） for resistance to Sun11-11.A linkage map of 2 RGAP and 7 SSR markers was constructed for the dominant gene using data from 221 F 2 plants and their derived F 2：3 lines tested with Sun11-11 in the greenhouse.Amplification of the complete set of nulli-tetrasomic lines of Chinese Spring with a RGAP marker RG1 mapped the gene on the chromosome 1B,and then the linked 7 SSR markers located this gene on the long arm of chromosome 1B.The linkage map spanned a genetic distance of 25.0 cM,the SSR markers Xgwm124 and Xcfa2147 closely linked to YrV3 with genetic distances of 3.0 and 3.8 cM,respectively.Based on the linkage map,it concluded that the resistance gene YrV3 was located on chromosome arm 1BL.Given chromosomal location,the reaction patterns and pedigree analysis,YrV3 should be a novel gene for resistance to stripe rust in wheat.These closely linked markers should be useful in stacking genes from different sources for wheat breeding and diversification of resistance genes against stripe rust.     

A-3中抗条锈新基因YrTp1和YrTp2的分子标记定位分析

【目的】半个多世纪的中国小麦育种史基本是育种家与条锈病的赛跑史。因此，筛选、鉴定、储备和利用新抗源是我国育种和资源研究中的一个长远战略性课题。【方法】利用小麦条锈菌条中31、32号生理小种，对来自小麦与十倍体长穗偃麦草［Thinopyrum ponticum (Host) Liu & Wang］的杂交后代材料A-3进行抗性遗传分析。用荧光SSR分子标记技术，鉴定所携带抗条锈病基因是否为新基因，并对其进行染色体定位研究。【结果】遗传分析表明，A-3对条中31号和32号的抗性由一显一隐2对基因控制。经过对196对微卫星引物的筛选，发现2B染色体短臂上的WMC477-167bp与显性基因紧密连锁，遗传距离为0.4 cM,将该显性基因定位于2BS上；7B染色体短臂上的WMC364-208bp与隐性基因连锁，遗传距离为5.8 cM。图位比较、系谱分析和抗谱分析表明，A-3所含抗条锈基因不同于已知抗条锈基因，暂定名为YrTp1和YrTp2。【结论】可利用A-3中与条锈病抗性紧密连锁的分子标记YrTp1和YrTp2将抗性基因转移到主栽品种中，在小麦育种和生产上发挥作用。