燕麦对冠锈病水平抗性的QTL定位

为了确定与燕麦冠锈病水平抗性基因相关的分子标记，建立了具水平抗病性的品系MN841801-1和感病品种Noble-2杂交的F8群体。该群体由158个重组自交系组成。用112个RFLP标记构建了其连锁图，该图由17个连锁群（A-Q）组成，另有23个位点未连锁，大约覆盖了燕麦基因组的1498.2cM。重组自交系群体的抗病性鉴定分别在温室和田间进行。用病斑面积占总叶面积的百分率（PPA）和病害发展曲线下的面积（AUDPC）作为抗病指标，在田间试验中分别探测到3个燕麦冠锈病水平抗性的QTL，依次命名为PRQ1，PRQ2和PRQ3。这3个QTL分别位于连锁群C，P和N上，总共可解释27%的表现型变量。在温室试验中只探测到PRQ1和PRQ2两个QTL，当用AUDPC和PPA分别作为抗病指标时，这两个QTL可分别解释32%和26%的表现型变量。     

小麦幼苗期秆锈病反应型与产孢量的关系

研究了温室条件下苗期小麦秆锈病反应型与产孢量间的关系，对同一反应型不同品种间，以及不同反应型间的产孢量差异进行了比较，同时对产孢量与产孢面积的关系也作了分析研究，拟合了各种反应型下日产孢量和单位面积日产孢量的变化曲线及春关系式。     

POD和PAL在小麦抗秆锈病中的动态变化

选用中国春(CS)和以它为背景的近等单基因系Sr11与小麦秆锈菌生理小种34MKG,分别组成亲和性互作CS/34MKG及高度非亲和性互作Sr11/34MKG,研究过氧化物酶(POD)和苯丙氨酸解氨酶(PAL)在小麦与小麦秆锈菌高度非亲和性互作中的变化规律.结果表明,接种后5 d内,POD和PAL的变化趋势基本一致,高度非亲和性互作接种处理在接种后72 h出现了POD和PAL的酶活最高峰,比其他处理早24 h,且酶活峰值稍高.     

中国小麦秆锈病研究进展

小麦秆锈病是在小麦茎叶部发生的一种病害,发病时严重影响小麦产量。在中国的小麦种植区内均有秆锈病发生。通过分析对小麦秆锈病的病原菌及发病症状、环境因素对秆锈病的影响、秆锈菌生理小种变化和鉴别寄主演变以及抗病育种的方法进行了综述。     

远中5号小麦及其变异系对秆锈病抗性机制初探

远中5号小麦对秆锈菌的抗性,是由来源于天兰偃麦草的 EE 或 FF 染色体组所携带的抗病基因,表达为莽草酸—苯丙氨酸代谢途径中的苯丙氨酸解氨酶和过氧化物酶活性的增强,苯丙氨酸解氨酶和过氧化物酶活性峰的时间顺序有协同变化。     

小麦抗秆锈病基因推导的计算机程序及应用

在小麦抗秆锈病基因推导中应用计算机分析代替人工分析,编制了基因推导的计算机程序。以１５个秆锈菌不同毒力基因型菌系和３３个抗秆锈病单基因系的体系对该程序进行了分析测试,推导出我国６９个小麦主栽品种可能含有的抗秆锈病基因型,其中有Ｓｒ５,６,７ａ,７ｂ,８ａ,９ｂ,９ｅ,１１,１６,１７,２１,２５,３２,３４,３６,３７,Ｇｔ等,为我国小麦品种的抗秆锈病基因合理布局和抗秆锈病基因库构建提供了理论依据。     

杨树的不同派别及杂交种对山、青杨锈病抗病差异

本文通过人工接种和146种树杨(包括杂交种)自然发病情况的调查,研究分析了杨树的不同派别和杂交后代对山杨锈病(Melampsora LaricisHart.)和青杨锈病(M. Laric-populina Kleb.)两种锈病的抗病差异。两种锈病的为害以派为界,寄生范围互补,不混同发生;不同派别的杨树对这两种锈病的感病性具有明显的差异。杂交杨只能感染这种锈病的一种,究竟感染那种锈病,关键看母本,与父本无关;感病程度则与父本和母本均有相关性。这一结论和文中所附的各种杨树的病情调查结果同相,为各地推广杨树优良品种和在培育抗锈品种如何选择亲本提供了有价值的参考依据。     

外源硅对锈菌诱导下豇豆叶片不同细胞器中抗氧化特征的影响

以长豇豆高抗锈病材料‘ZN016’和高感品种‘之豇282’为材料,通过基质栽培,研究锈菌胁迫下外源硅对长豇豆叶片细胞质、线粒体和叶绿体抗氧化酶活性与抗氧化物质含量的影响。结果表明:锈菌胁迫下,外源硅可显著提高豇豆细胞质、线粒体和叶绿体中过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)和苯丙氨酸解氨酶(PAL)的活性以及线粒体内的超氧化物歧化酶(SOD)活性;同时显著提高细胞质内的多酚含量和感病品种线粒体中抗坏血酸(AsA)的含量;外源硅可显著降低感病品种细胞质和叶绿体中的丙二醛(MDA)含量。推测锈菌胁迫下外源硅可能通过提高豇豆叶片细胞质和叶绿体的抗氧化能力,从而避免活性氧对细胞质膜和叶绿体膜系统的伤害,维持其正常的生理功能。     

广西桑树品种资源材料对赤锈病的抗性鉴定

【目的】测定广西桑树品种资源材料对赤锈病的抗性水平,为育种部门提供抗性材料。【方法】采用涂抹法和覆盖法接种桑赤锈病病菌,鉴定7个桑树品种资源材料对赤锈病的抗性;同时,对桑园赤锈病田间自然发病情况进行调查。【结果】测定的7个桑树品种材料均发病,其中伦教40发病相对较轻,其余6个品种发病较重。不同年份、季节、地势的桑树品种材料赤锈病发生程度不同;4月上旬为赤锈病始发期,10～11月为发生高峰期;旱坡地桑树赤锈病发病较轻,水田、低洼地发病较重。【结论】伦教40赤锈病发病较轻,抗病能力较强,可作为抗性育种中间材料或亲本加以利用。     

几个小麦持久抗条锈品种病情扩展动态研究

在我国小麦条锈病常发易变区的陇南,对抗条锈性上分属不同类型的9个品种进行田间成株期病害发生特点的比较研究。结果表明参试的9个品种条锈病的反应型均为感病类型,主要差别表现在普遍率和严重度上。Libellula和N. Strampelli的普遍率和严重度保持最低水平,咸农4号与清农3号保持低严重度与普遍率,但在发病20 d后普遍率有一快速上升,其它品种均在发病后10 d左右达到较高的普遍率与严重度。Libellula、N. Strampelli和咸农4号同为持久抗性品种,但抗病机制不同。感病反应型、低普遍率与低严重度是持久抗病性的表型特点,但反之是否成立,以及持久抗病性表现的分子机制等尚需深入研究。     

Progress in breeding for resistance to Ug99 and other races of the stem rust fungus in CIMMYT wheat germplasm

Races belonging to the Ug99 (TTKSK) lineage of the wheat stem rust fungus, carrying complex virulence combinations, and their migration to countries in Africa, Middle East and Asia continue to pose a significant threat to global wheat production. The rapid spread of additional races, e.g., TKTTF or the Digalu lineage, in several countries causing localized epidemics reminds us of the vulnerability of wheat germplasm to stem rust disease, a formidable foe referenced as early as biblical times. A global rust monitoring system reflecting increased surveillance efforts has identified 13 races within the Ug99 lineage in 13 countries and unrelated lineages are emerging, spreading and posing serious threats to wheat production. Race TKTTF has caused localized epidemics in Ethiopia and its variants have been recently implicated in stem rust outbreaks in Europe. Concerted research efforts have resulted in the identification of several new resistance genes and gene combinations for use in breeding. Combining multiple adult plant resistance (APR) genes in high-yielding backgrounds and discovery of new quantitative trait loci conferring stem rust resistance has progressed in the recent years, enhancing the durability of resistance. Effective gene stewardship and new generation breeding materials and cultivars that combine multiple race-specific or minor to intermediate effect APR genes, complemented by active surveillance and monitoring, have helped to limit major epidemics and increase grain yield potential in key target environments.     

Genetic analysis and SSR mapping of stem rust resistance gene from wheat mutant D51

Wheat (Triticum aestivum L.) stem rust caused by Puccinia graminis f. sp. tritici is one of the main diseases of wheat worldwide. Wheat mutant line D51, which forms a highly susceptive cultivar ‘L6239’ to the three races notated and cultured with immature embryos, shows resistance to prevailing races 21C3CPH, 21C3CKH, and 21C3CTR of P. graminis f. sp. tritici in China. In this study, the number and the expression stages of the resistance genes in mutant D51 were studied using inoculation identification and microsatellite (SSR) marker analysis. Two F₁ populations from the crosses of D51 × L6239 (60 individuals) and D51 × Chinese Spring (60 individuals), their F₂ populations (185 and 175 individuals respectively) at the seedling stage, and one F₂ population derived from the cross of D51 × L6239 (194 individuals) at the adult stage were inoculated with pathogen race 21C3CPH to test for resistance. All F₁ individuals of the two crosses were immune to stem rust at both seedling and adult stages. The response pattern of the three F₂ populations showed that the R:S segregation ratio was 3:1, suggesting that the stem rust resistance of D51 is controlled by a single dominant gene, and is expressed during the entire growth period. The identification of the stem rust resistance by the F₃ progeny test confirmed the credibility of the F₂ population test. Segregating populations and small population analyses were used to identify chromosomal regions and molecular markers linked to the gene by the SSR marker method. A total of 675 SSR markers and 185 individuals of the D516L6239 F2 population were used to search genetically linked markers to the target gene. Using Mapmaker 3.0 and Map-draw with Kosambi’s function and other options set at default values, molecular mapping revealed that the gene was located on chromosome 5DS, linked with and flanked by two SSR markers, Xgwm190 and Xwmc150, at 18.58 and 21.33 cM, respectively. It has been reported that only one stem rust resistant gene, Sr30, is located on the wheat chromosome 5DL, and that it has no resistance to 34C2MKK and 34C2MFK, while the parent L6239 of mutant D51 has no resistance to 21C3CPH, 21C3CTK and 21C3CTR, but has resistance to 34C2MKK and 34C2MFK. The results above indicate that the gene identified in the study might be a novel resistance gene to stem rust, tentatively designated as SrD51. __________ Translated from Acta Agronomica Sinica, 2007, 33(8): 1262–1266 [译自: 作物学报]     

陕甘小麦品种及抗源的高温抗条锈性研究

小麦苗期接种条锈菌(PucciniastriiformisWest.)后,分别采用高温(21±1)℃和常温(14±1)℃处理,测定了陕西、甘肃两省主栽品种及抗源的高温抗条锈性。结果表明,陕927、陕897、兰天1号、豫麦21和钱保德等品种具有高温抗条锈性,陕农757、西植9420、M8003-06、绵阳11、繁6、天选36和里勃留拉等品种可能具有高温抗条锈性。     

意大利抗病小麦品种Pascal抗条锈性的遗传分析

在2000~2003年,以我国陇南重要外引小麦品种Pascal作母本,铭贤169作父本进行杂交,子代材料苗期分别接种条锈菌单孢菌系条中29号、洛13-Ⅲ、条中31号、条中32号和水14,抗性遗传结果表明,对条中29号,F1代植株抗感分离比为5∶12,BC1代植株全部为抗病株,F2代植株抗感分离比为46:31,符合理论比9:7,卡方测验结果也符合这一结果;对条中32号,F1代植株抗感分离比为6∶5,BC1代植株抗感分离比为4:4,F2代植株抗感分离比为24:49,符合理论比1:3;对洛13-Ⅲ,F2代植株抗感分离比为10:48,符合理论比1:3;对条中31号,F2代植株抗感分离比为20:55,符合理论比1:3;对水14,F2代植株抗感分离比为6:69,符合理论比1:15.卡方测验值均符合理论值.据此推知pascal对条中29号的抗性由2对显性互补抗性基因控制,对洛13Ⅲ、条中31号、条中32号的抗性均由1对隐性抗性基因控制,对水14的抗性由2对隐性抗性基因控制.     

Beneficial effects of silicon on photosynthesis of tomato seedlings under water stress

Silicon can improve drought tolerance of plants,but the mechanism still remains unclear.Previous studies have mainly concentrated on silicon-accumulating plants,whereas less work has been conducted in silicon-excluding plants,such as tomato(Solanum lycopersicum L.).In this study,we investigated the effects of exogenous silicon(2.5 mmol L~(–1))on the chlorophyll fluorescence and expression of photosynthesis-related genes in tomato seedlings(Zhongza 9)under water stress induced by 10%(w/v)polyethylene glycol(PEG-6000).The results showed that under water stress,the growth of shoot and root was inhibited,and the chlorophyll and carotenoid concentrations were decreased,while silicon addition improved the plant growth and increased the concentrations of chlorophyll and carotenoid.Under water sterss,chlorophyll fluorescence parameters such as PSII maximum photochemical efficiency(F_v/F_m),effective quantum efficiency,actual photochemical quantum efficiency(Ф_(PSII)),photosynthetic electron transport rate(ETR),and photochemical quenching coefficient(q_P)were decreased;while these changes were reversed in the presence of added silicon.The expressions of some photosynthesis-related genes including PetE,PetF,PsbP,PsbQ,PsbW,and Psb28 were down-regulated under water stress,and exogenous Si could partially up-regulate their expressions.These results suggest that silicon plays a role in the alleviation of water stress by modulating some photosynthesis-related genes and regulating the photochemical process,and thus promoting photosynthesis.     

普通小麦抗条锈新种质--WT212的抗性及遗传分析

对普通小麦抗条锈新种质——WT212的抗锈性及遗传学特性进行了分析。结果表明,WT212具有多小种抗性,参试的4个条锈菌生理小种的抗性受1对显性基因控制;细胞遗传学分析表明,WT212所携带的抗源不同于以1BL/1RS易位系为基础的"洛类"抗源,而是一种来自黑麦染色体组的抗条锈新抗源。初步断定WT212为可能只涉及1对染色体的小麦—黑麦易位系。