抗条锈病小麦-滨麦衍生后代的分子细胞遗传学鉴定

为了有效挖掘滨麦优异的基因资源,利用形态学、细胞学、荧光原位杂交(FISH)、基因组原位杂交(GISH)和分子标记等技术,对小麦-滨麦衍生后代M13063-3-3进行了鉴定。结果表明,M13063-3-3的染色体构型为2n=44=22Ⅱ。以滨麦基因组DNA为探针的原位杂交结果显示,二条染色体有杂交信号,且能配对,表明两条外源染色体是滨麦的一对同源染色体。SSR、EST和PLUG标记分析表明,M13063-3-3附加的滨麦染色体归属于第6部分同源群染色体。A-PAGE电泳分析表明,M13063-3-3在α区具有滨麦染色体特征带,进一步验证了附加的滨麦染色体与小麦第6部分同源群染色体有部分同源关系。田间条锈病调查结果表明,M13063-3-3对条锈菌生理小种条中31号、条中32号和条中33号混合菌种表现高抗。因此,M13063-3-3是一个附加了一对滨麦第6部分同源群染色体的抗条锈病的普通小麦材料,为小麦抗病育种提供了新的种质资源。     

抗条锈病小麦-滨麦Lm#3Ns二体异附加系的分子细胞遗传学鉴定

滨麦(Leymus mollis)是小麦的三级基因源,具有改良小麦所需的许多优良性状。为了将滨麦中的优异基因导入到普通小麦中,通过远缘杂交获得小麦-滨麦异附加系、异代换系、易位系,以选自普通小麦7182与滨麦衍生后代M42(2n=54)F_6代的株系M11005-1-2-7-10-1-1(M11005A)为供试材料,对其进行了形态学、细胞学、原位杂交、分子标记、抗病性等综合鉴定。细胞学观察结果显示,M11005A有44条染色体且配对良好,可以稳定遗传。原位杂交及分子标记结果表明,M11005A含有42条普通小麦染色体和1对来自滨麦Lm#3Ns的染色体,并且用Oligo-pTa535探针得到了Lm#3Ns的FISH核型;筛选出6个EST及8个PLUG特异分子标记可以用来鉴定Lm#3Ns染色体,其中只有1个EST和4个PLUG标记可以同时在M11005A中扩增出滨麦和华山新麦草的条带,说明滨麦的Lm#3Ns染色体与华山新麦草的3Ns基因组之间存在差异。M11005A的穗长、穗型、小穗数、千粒重与亲本7182无显著差异,但分蘖数较7182显著增加,株高显著降低。抗条锈病鉴定结果显示,苗期M11005A对条锈菌生理小种CYR29和CYR34表现高抗,对CYR32表现高感,成株期对CYR32和CYR33混合小种表现高抗,推测滨麦的Lm#3Ns染色体携带对CYR29和CYR34小种的抗性基因,又携带了成株期对CYR32和CYR33的抗性基因。因此,M11005A可以作为抗源应用于小麦的条锈病抗性改良中。     

小麦-滨麦附加易位系DM 5911的创制及其细胞遗传学鉴定

滨麦(Leymus mollis(Trin.)Pilger,NsNsXmXm,2n=28)具有抗旱、耐寒、抗多种真菌和细菌病害、茎秆粗壮、大穗多花等特性,是麦类作物品种改良的优异种质资源。本研究采用细胞遗传学方法对由八倍体小滨麦M842-16与硬粒小麦品种D 4286杂交F6代选育出的1个附加易位系DM 5911进行了鉴定和农艺性状分析。细胞学镜检显示,DM 5911的染色体构型为2n=44=22Ⅱ;根尖体细胞原位杂交鉴定显示,DM 5911含有2条完整的Ns染色体和2条易位的Ns染色体;花粉母细胞原位杂交鉴定显示,DM 5911的2条完整Ns染色体和2条易位Ns染色体可以进行正常的联会配对和遗传。表明DM 5911是1个遗传稳定、包含1对完整的Ns染色体和1对易位Ns染色体的小滨麦附加易位系。形态学调查显示,DM 5911在株高和分蘖数等农艺性状方面得到了明显的改善。该附加易位系作为进一步创制小滨麦小片段染色体易位系的重要种质材料,可用于小麦染色体工程育种与遗传改良。     

小麦-滨麦衍生系18DM134的分子细胞遗传学及赤霉病抗性鉴定

滨麦[Leymus mollis(Trin.) Pilger]作为小麦的野生亲缘种之一,具有抗寒、抗旱、耐盐碱等优良特性,同时对多种小麦病害具有良好抗性,是小麦遗传改良的重要基因资源。本研究前期从八倍体小滨麦M842和硬粒小麦D4286的杂交后代中筛选出一个抗赤霉病的衍生系18DM134,为给该材料的利用提供依据,本研究利用细胞遗传学、原位杂交、液相芯片、分子标记等技术对其染色体组成进行鉴定,并对其农艺性状和赤霉病抗性进行调查。细胞学观察结果显示,18DM134的染色体构型为2n=42=21Ⅱ。原位杂交结果显示,18DM134含有38条小麦染色体、2条完整的Ns染色体以及2条易位染色体,其中整条6A染色体和5DS染色体缺失,2条Ns染色体片段易位到3DS染色体,2条3DL染色体易位到5DL染色体。液相芯片和分子标记分析结果显示,18DM134中来自滨麦的6Ns染色体替换了小麦6A染色体,部分5Ns染色体片段与3DS染色体发生了易位,5DS染色体缺失。因此,18DM134为小麦-滨麦代换易位系,其染色体组成为12A+14B+10D+2(6Ns)+2(T3DS-5Ns片段)+2(T3DL-...     

抗条锈病普通小麦-中间偃麦草7St二体异附加系的分子细胞遗传学鉴定

中间偃麦草（Thinopyrum intermedium）携带很多优异基因,是小麦重要的三级基因库。为了将中间偃麦草的优异基因导入小麦,以普通小麦品种阿勃的缺体系为母本,以普通小麦-中间偃麦草部分双二倍体远中4为父本,通过远缘杂交,获得普通小麦-中间偃麦草衍生系ES-24,并对其进行形态学、细胞学、原位杂交、分子标记、抗病性等综合鉴定。细胞学观察结果显示,ES-24有44条染色体,其减数分裂中期I染色体构型为2n=22Ⅱ, 且在减数分裂后期Ⅰ可均等分离,表明其可以稳定遗传。原位杂交和分子标记结果表明,ES-24含有42条普通小麦染色体和1对来自中间偃麦草的7St染色体,并利用Oligo-pTa535得到了7St染色体的FISH核型。条锈病抗性鉴定表明,ES-24在苗期和成熟期均对条锈病表现为高抗。综上结果表明,ES-24是高抗条锈病的普通小麦-中间偃麦草7St二体异附加系,可以作为小麦抗病育种的潜在中间材料。     

普通小麦-滨麦及其衍生系的染色体组成分析

滨麦[Leymus mollis(Trin.)Pilger,NsNsXmXm,2n=28]属禾本科(Poaceae)小麦族(Triticeae)大麦亚族(Hordinae)赖草属(Leymus Hochst.)的一个多年生四倍体植物,蕴含着丰富的小麦改良优异基因,是小麦育种的重要三级基因资源。为给普通小麦-滨麦种质类型的创制、筛选和鉴定提供参考依据,本研究通过细胞学观察、顺序荧光原位杂交(fluorescence in situ hybridization,FISH)-基因组原位杂交(genomic in situ hybridization,GISH)及分子标记等技术分别对普通小麦7182、滨麦及其高世代衍生系的染色体组成进行了研究。采用寡核苷酸探针pSc119.2和pTa-535相结合的技术绘制出普通小麦7182所有染色体的FISH标准核型图。初步推断出滨麦的染色体核型公式2n=4x=28=22m(6sat)+6sm。同时通过FISH-GISH技术鉴定出两种类型的普通小麦-滨麦高世代衍生系M47和M39,染色体组成分别表示为2n=56=42T.a+14L.m、2n=56=44T.a+12L.m。     

利用细胞学和RAPD技术鉴定抗条锈病小滨麦易位系

为了了解来自八倍体小滨麦与普通小麦杂种后代的小滨麦种质系山农0096的染色体构型和抗锈性,在农艺性状综合评价的基础上,对该系进行了细胞学和RAPD鉴定。结果表明,山农0096对条锈病免疫,其根尖细胞染色体数为2n=42,花粉母细胞减数分裂中期 (PMCMI)染色体构型为2n=21 ;与小麦亲本的杂种F1PMCMI染色体构型平均值为2n=19 1 ;100个多聚体核苷酸随机引物中,有3个引物在山农0096中扩增出滨麦草的特异DNA带,它们分别记为S241250、S38750、S42640,初步确定山农0096是一个小滨麦易位系。     

小麦-华山新麦草易位系24-6的鉴定

为给小麦-华山新麦草远缘杂交育种提供材料和理论基础,对普通小麦与华山新麦草杂交后代中选育出的材料24-6进行了形态学观察、细胞学检测和原位杂交(GISH)分析。结果表明:(1)通过根尖细胞学鉴定,该材料染色体数为42条,2n=42;(2)以华山新麦草Ns基因组DNA为探针,普通小麦7182基因组DNA为封阻,根尖与花粉母细胞原位杂交(GISH)显示该材料携带有2条可以配对的华山新麦草染色体臂,确定24-6为稳定的小麦-华山新麦草易位系;(3)田间观察发现24-6植株紧凑,叶色深绿,籽粒白色、呈半角质,比其母本(普通小麦7182)株高略有降低,穗长、小穗数、穗粒数、千粒重、分蘖数都有所增加。     

小麦-中间偃麦草代换系中233的分子细胞学鉴定

为了从小麦-中间偃麦草衍生后代中获得具有优良性状的新种质,利用细胞学和分子标记技术对中间偃麦草衍生系中233进行鉴定。结果表明,中233的根尖细胞染色体数为2n=42,花粉母细胞减数分裂中期Ⅰ的染色体通常配成21个二价体。以中间偃麦草基因组DNA为探针、中国春基因组DNA为封阻进行基因组原位杂交(GISH)分析发现,中233含有2条中间偃麦草染色体和40条小麦染色体,在减数分裂中期I,两条中间偃麦草染色体可以正常配对。利用D基因组特异探针pAs1进行荧光原位杂交(FISH)分析发现,中233缺少了一对小麦的2D染色体。分子标记鉴定进一步表明,中233的1对小麦2D染色体被中间偃麦草染色体所代换。说明中233是一个细胞学稳定的小麦-中间偃麦草二体代换系,初步推断其可能携带有中间偃麦草的优异基因。     

普通小麦-中间偃麦草易位系08-738的鉴定

中间偃麦草(Thinopyrum intermedium,2n=42)具有大穗多花和抗多种病害等特性,是小麦育种的重要基因资源之一。为确定普通小麦川麦107与中间偃麦草杂交获得的遗传稳定品系08-738的染色体组成,采用形态学、细胞遗传学和SSR分子标记对其进行了鉴定。形态学分析表明,08-738具有植株较矮和小穗数较多的特点。细胞学观察表明,其染色体数目及构型为2n=42=21II。基因组原位杂交(GISH)和重复序列原位杂交(FISH)结果表明,08-738含有20对小麦染色体和1对小麦-中间偃麦草小片段易位染色体,易位位于小麦3DS的近末端,且该外源片段可能来源于中间偃麦草的Js染色体组。SSR标记分析显示,位于3DS 6-0.55-1.00之间的SSR标记xcfd141能在08-738和中间偃麦草之间扩增出一条特异条带,xcfd141可作为该中间易位片段鉴定和选择的标记。     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

先玉335、郑单958和京科968抗虫能力的比较研究

以先玉335、郑单958、京科968为材料,以玉米螟(Ostrinia furnacalis)、黏虫(Mythimna separata)和禾谷缢管蚜(Rhopalosiphum padi)为供试昆虫,探究玉米品系大喇叭口期对玉米螟和黏虫及抽雄期对禾谷缢管蚜抗性差异,测定其主要抗虫化合物丁布类物质的含量。结果发现,京科968对玉米螟及禾谷缢管蚜抗性均高于另外两个品系;对黏虫的抗性,郑单958和京科968高于先玉335。大喇叭口期京科968中丁布类物质含量最高,抽雄期郑单958和京科968中主要丁布成分含量均高于先玉335,上述组织中丁布合成相关基因在郑单958及京科968中的表达量也均高于先玉335。本研究揭示杂交玉米抗虫性与抗性相关化合物含量及其相关基因表达间存在正向相关关系,为抗虫玉米分子育种提供理论参考。     

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).     

Mineral composition of some traditional Mexican teas

Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Resistance to <Emphasis Type="Italic">Potato virus Y</Emphasis> in a Multitrait Potato Breeding Scheme without Direct Selection in Each Generation

In an experimental breeding scheme to improve late blight (Phytophthora infestans) and white potato cyst nematode (Globodera pallida) resistance of tetraploid potato over three generations of crossing and selection, 15 clones survived the final selection, and these were derived from 15 great-grandparents. There was no direct selection for resistance to Potato virus Y (PVY), but 14 out of the 15 great-grandparents were resistant to PVY and three had extreme resistance. Thirteen of the 15 descendants had PVY resistance and one extreme resistance. This was within the range expected for a random (unselected) sample from the genotypes of the great-grandparents. Hence, we found no evidence for any positive or negative association between PVY resistance and the attributes selected. The conclusion is that laborious selection is not required in every generation when many parents have PVY resistance, including some with more than one copy of a PVY resistance gene or resistance at more than one locus. However, in the future, determining the major virus resistance genes present in potential parents in each generation using diagnostic molecular markers would prevent susceptible × susceptible crosses being made and maximise the number of resistant × resistant ones.     

分子标记辅助小麦抗白粉病基因Pm21和Pm13聚合育种

为了获得同时具有抗白粉病基因Pm21和Pm13的材料,利用与抗白粉病基因Pm21和Pm13共分离或紧密连锁的分子标记SCAR1400、CINAU161650和SCAR564、BE398268,对分别含Pm21和Pm13的小麦品系杂交F2代进行检测。结果表明,在764个F2代单株中,能同时检测到显性标记SCAR1400和SCAR564的有404株,阳性率为52.9%,经标记CINAU161650和BE398268检测,同时携带纯合Pm21和Pm13的单株有47株,阳性率为6.15%,两个显性抗病基因在F2代群体中的分离比例符合孟德尔独立分配定律。获得的聚合单株可作为小麦抗白粉病育种的亲本资源。     

小麦株高QTL的定位及对重要农艺性状的多效性分析

株高作为小麦育种的重要指标,对产量具有较大的影响。为进一步挖掘小麦株高的数量性状位点（quantitative trait loci,QTL）,本研究以扬麦12和偃展1号杂交得到的包含205个家系的重组自交系（recombinant inbred lines,RIL）群体为材料,利用小麦55K SNP芯片构建高密度遗传图谱,结合 3年共6个环境的表型数据对株高性状进行QTL定位分析。结果表明,在染色体2B（1）、4B（1）、4D（1）、5A（1）、5B（1）和7D（2）上共检测到7个与株高相关的QTL。QPh.yaas-4B、QPh.yaas-5A和QPh.yaas-7D.1的矮秆效应来源于扬麦12,其余4个QTL的矮秆效应来源于偃展1号。在6个环境下都能检测到的位点是QPh.yaas-4B和QPh.yaas-4D,对株高的贡献率分别14.50%~24.09%和19.01%~29.80%,经过比对发现,这2个QTL分别是Rht1和Rht2。QPh.yaas-5A在5个环境下被检测到,对株高的贡献率为3.29%~5.36%;QPh.yaas-2D和QPh.yaas-7D.2在4个环境中均被检测到,对株高的贡献率分别为3.45%~6.14%和3.16%~4.10%;QPh.yaas-5B和QPh.yaas-7D.1分别在2个和3个环境中被检测到,对株高的贡献率分别是2.27%~5.09%和2.72%~4.82%。QTL比较分析后发现,QPh.yaas-7D.1和QPh.yaas-7D.2可能是新的株高位点。研究Rht-B1和Rht-D1对千粒重、穗长和穗粒数的效应,发现Rht-B1位点对这些农艺性状无显著效应,Rht-D1位点仅对千粒重有显著效应,其株高增效等位变异可显著增加千粒重。在自然群体中验证Rht-B1和Rht-D1的效应结果与RIL群体结果一致。     

Effect of a continuous hot water treatment of potato tubers on seed-borne fungal pathogens

Summary The viability of five pathogens was decreased by treatment with hot water when tested in vitro.Polyscytalum pustulans was most sensitive andRhizoctonia solani least sensitive. Potato tubers were exposed to 55°C for 5 min in a commercial continuous hot water treatment plant using naturally contaminated seed tubers and tubers which had been inoculated by dipping in comminuted cultures. The frequency of eyes colonised byP. pustulans, Helminthosporium solani, andR. solani was reduced to virtually zero and the effect persisted on tubers subsequently stored at 4°C and at 15°C for up to 16 wk. Results withColletotrichum coccodes were inconclusive. Treatment suppressedPenicillium spp. which, however, rapidly recolonised the eyes during storage, leading to higher contamination levels in the treated than in the untreated tubers. With tubers inoculated withPhoma foveata, good control was achieved when the incubation period before treatment was 10 d but not when the period was 42 d.     

基因枪介导的小麦叶片瞬间表达体系的优化及应用

麦类作物的叶片单细胞瞬间表达是一种高效而快速的基因功能验证方法,尤其适用于麦类作物与白粉病菌的互作系统,但由于影响参数较多、参检基因表达频率低而尚未广泛应用。本研究使用绿色荧光蛋白(GFP)基因作为报告基因,对影响表达效率的多个转化参数进行优化,筛选出表达频率最高的参数组,即小麦叶片采用固体保鲜培养基固定,钨粉用量为每枪300μg,质粒DNA用量为每枪750ng,可裂膜氦压为1 350psi,可裂膜与受体膜距离6mm,受体与阻挡网距离6cm,与先前报道的方法相比表达频率有显著提高。应用上述参数在感病小麦品种离体叶片中过量表达一个已知具有抗白粉病功能的簇毛麦SGT1基因,结果表明该基因瞬间表达使互作细胞吸器指数降低,表现为对白粉病菌侵入和吸器形成具有抑制作用,在一定程度上增强了表达细胞对白粉病菌的抗性,使目标基因的抗性功能再次得到印证。本研究还进一步运用该优化体系开展瞬间表达介导的基因沉默(TIGS)实验,将携带抗白粉病基因Pm21的抗病小麦品种南农9918和感病小麦品种扬麦158中的内源SGT1和RAR1分别或同时沉默,结果显示南农9918的叶片表皮与白粉菌互作细胞的吸器指数增高,在一定程度上降低了表达细胞对白粉菌的抗性。而扬麦158中互作细胞的吸器指数较对照变化不显著。说明这两个基因均分别参与了Pm21介导的抗白粉病信号途径,且二者共同作用与白粉病抗性关系更加密切。