抗黄矮病小麦种质的遗传分析

以抗黄矮病小麦种质为母本、丰产性品种为父本配制杂交组合,鉴定所有F1代及保留组合6个世代的抗病性,运用不完全双列杂交模式和加权最小二乘法分析抗病基因的遗传效应,根据Castle-Wright方法估计抗病种质的最小抗病基因数目。结果表明:抗黄矮病遗传不符合加性-显性模型,以加性效应为主,抗病基因间存在明显的互作效应,表现为加性×加性和加性×显性;黄矮病抗性遗传力较高,变幅为69.15%～97.75%;抗病种质"02R084"和"02R493"分别含有1对抗病基因,且在不同遗传背景中基因互作方式存在差异。     

水稻功米3号高抗性淀粉性状的遗传分析

抗性淀粉具有降低糖尿病患者饭后血糖值、减少肠机能失调及结肠癌发病率、提供能量以及防止脂肪堆积等重要生理功能。为了了解水稻(Oryza sativa L.)中抗性淀粉含量这一性状的遗传特点,本研究以高抗淀粉水稻品种籼稻(indica)功米3号和粳稻(japonica)日本晴的正、反交组合F1及其自交后代F2、F2∶3群体为研究材料,分别测定各单株的抗性淀粉含量以分析其遗传特点。结果显示,正、反交组合的F1抗性淀粉含量及淀粉颗粒形态均表现出与相应母本相似的遗传现象,但是正、反交组合F2的抗性淀粉含量没有显著差异,而且F2∶3发生性状分离,说明这一性状受母性效应的影响。通过对功米3号/日本晴F2∶3群体的群分离体混合分析,在1号和6号染色体上分别筛选出3对和6对可能与抗性淀粉含量位点连锁的微卫星标记;利用QTL(quantitative trait locus)作图软件检测到3个抗性淀粉含量QTL(qRS6-1、sqRS6-2和qRS6-3),均分布在6号染色体上,其中qRS6-2和qRS6-3可解释表型变异分别为20.36%和40.13%,同时检测到1号和6号染色体之间存在着1对上位性QTLs。以上结果说明,抗性淀粉含量这一性状是由少数主效基因和多个微效基因以及非等位基因间互作所控制的数量性状(QTL)。以上结果为高抗性淀粉水稻育种的母本选择提供了理论依据,为精确定位抗性淀粉含量相关的主效基因提供了基础资料。     

中国小麦地方品种籽粒强休眠特性的主效基因鉴定

前人研究表明,我国一些小麦地方品种籽粒休眠性强,穗发芽抗性好,可能受1～2对主效基因控制.本文利用小麦(Triticum aestivum)2个重组自交系群体(RILs,万县白麦子/京411,万县白麦子/中优9507)进行2点4年的田间试验,以期发掘控制我国小麦地方品种(万县白麦子)籽粒休眠的主效QTL位点.通过复合区间作图进行分析,分别在3AS和3BL染色体上鉴定出2个主效QTL,前者分布在Xbarc57和Xbarc294标记区间(在2个RILs群体中遗传距离分别为5.8和8.5 cM),在多年多点的实验中可解释25.6%～48.3%的表型变异;后者分布在Vp1和Xwmc446标记区间,在万县白麦子/中优9507群体中的遗传距离为8.1 cM,可解释23.5%～37.8%的表型变异.上述研究表明,我国小麦地方品种万县白麦子籽粒强休眠特性主要受Osd.ahau-3A、Qsd.ahau-3B这两个主效基因控制,在不同环境中表现出较好的遗传稳定性.可通过聚合育种的方法获得籽粒休眠性强、穗发芽抗性好的小麦新品种.     

玉米品种抗顶腐病遗传多样性分析及其应用

经鉴定和调查, 从25个玉米品种中选择抗病性较稳定的14个品种为材料, 其中6个品种包括病、健株, 共20个样品, 进行抗病遗传多样性的RAPD分析.结果表明, 不同品种的抗性遗传背景丰富, 20个样品经PCR扩增聚类后, 以遗传距离15划分, 可分为7个类群, 同一类群内的品种在抗病性方面有较强的相似性;同一品种的健株与病株间能产生特异性条带, 且存在一定的遗传距离, 说明植株感病后, 其遗传特性会发生改变.田间试验表明, 遗传特性差异大的感病品种与抗病品种轮作对顶腐病有较高的防效, 可一定程度缓解生产中倒茬难而造成病害流行的难题.     

玉米品种抗顶腐病遗传多样性分析及其应用

经鉴定和调查, 从25个玉米品种中选择抗病性较稳定的14个品种为材料, 其中6个品种包括病、健株, 共20个样品, 进行抗病遗传多样性的RAPD分析。结果表明, 不同品种的抗性遗传背景丰富, 20个样品经PCR扩增聚类后, 以遗传距离15划分, 可分为7个类群, 同一类群内的品种在抗病性方面有较强的相似性;同一品种的健株与病株间能产生特异性条带, 且存在一定的遗传距离, 说明植株感病后, 其遗传特性会发生改变。田间试验表明, 遗传特性差异大的感病品种与抗病品种轮作对顶腐病有较高的防效, 可一定程度缓解生产中倒茬难而造成病害流行的难题。     

大麦白粉病抗性的遗传分析与QTL定位

为探究大麦白粉病抗性遗传,定位其抗性QTL,本研究以抗病品种Gairdner和感病品种扬饲麦1号杂交F₁花药培养构建的DH群体及亲本为材料,对大麦白粉病抗性进行鉴定与遗传分析,并利用91对在亲本间多态性好的SSR标记构建了群体的遗传连锁图谱,采用Windows QTL IciMapping 4.0软件中的完备区间-加性模型对大麦白粉病抗性QTL进行定位。结果表明,DH群体各系间存在丰富的大麦白粉病抗性遗传变异。共检测到5个与大麦白粉病抗性相关的QTLs。其中3个时期均检测到qPM-2Ha位于Bmag0711-AWBMS56区间,可解释的表型变异为7.48%~12.50%;qPM-4Ha位于EBmac0906-HVM68区间,可解释的表型变异为23.07%~32.09%;2个时期均检测到qPM-2Hb位于Bmag0749-GBM1475区间,可解释的表型变异为6.22%~8.13%。qPM-2Ha、qPM-4Ha及qPM-2Hb白粉病抗性基因均来源于抗病亲本Gairdner, qPM-3Ha和qPM-4Hb白粉病抗性基因来源于感病亲本扬饲麦1号,qPM-2Hb和qPM-3Ha可能是2个新的大麦白粉病抗性QTLs位点。本研究结果为大麦白粉病抗性基因的发掘、精细定位、克隆及分子标记辅助选择育种奠定了基础。     

玉米抗玉米蚜种质的鉴定与抗性位点的定位分析

玉米蚜是世界性的玉米害虫,利用玉米自身的抗性是控制玉米蚜虫危害的重要途径。为培育抗蚜新品种,提高玉米的抗性,首先需要鉴定筛选抗性种质,明确其抗性遗传模式,发掘抗性基因。本研究首先对新收集的国内外玉米种质资源进行抗玉米蚜鉴定,然后采用分离群体分组分析与高通量测序技术相结合的方法,对鉴定出的高抗蚜玉米自交系携带的抗性位点进行了定位分析。结果表明,在98份玉米种质资源中有5份表现高抗玉米蚜,其中高抗蚜自交系32t33的抗蚜性受多基因控制,表现数量遗传特征,测序分析在第3、第5染色体上获得了2个与抗蚜性状关联的区域,其大小分别为19.66和6.34 Mb,并在关联区域初步筛选出5个抗蚜候选基因。本研究结果丰富了玉米的抗蚜基因资源,为最终分离出抗性基因、明确抗蚜的遗传机制和培育抗蚜品种奠定了基础。     

鸡抗马立克氏病遗传机制的研究进展

鸡的马立克氏病(MD)遗传抗性是由多个基因控制着,其中主要组织相容性复合体(MHC)基因是最确定的抗性影响因素.遗传抗病性研究根据病毒的生活史可分为抗感染和抗发病两个阶段,鸡抗MD的遗传机制研究目前主要集中在抗发病阶段,主要包括抗性基因的选择、抗性基因的表达水平、抗病性的遗传力.文章对上述与鸡马立克氏病遗传抗性相关的各个因素的研究进展进行了综述.     

水稻抗瘟性与雄性不育性之间的遗传关系研究

以两个三系杂交水稻组合来测定水稻对稻瘟病的抗性与野败型雄性不育性的遗传关系,以一个二系杂交水稻组合来测定水稻抗瘟性与光敏不育性的遗传关系。结果表明,水稻抗瘟性（对８８－９菌株,ＺＢ１５小种）与野败不育性是独立遗传的;抗瘟性与光敏不育性是连锁遗传的,交换值接近４０．９０。     

33份黄瓜核心种质对枯萎病的抗性评价及遗传特性研究

以33份黄瓜核心种质为试材,通过苗期接种和成株期自然发病,调查黄瓜种质的生态类型、性型、瓜皮色、瓜形、瓜刺色、瓜瘤大小、瓜刺瘤稀密及枯萎病病情指数,分析了不同黄瓜种质对枯萎病的抗性及抗性分布频率。结果表明,在供试的33份黄瓜种质中,高抗种质3份,占9.09%;抗病种质占33.33%,中抗种质占21.21%;感病种质占30.30%,高感种质占6.06%。具有欧洲温室型亲缘关系的种质较华南型种质抗枯萎病,强雌黄瓜较雌雄黄瓜抗枯萎病,皮色较绿的黄瓜对枯萎病抗性较强,无瘤黄瓜较中瘤和大瘤黄瓜抗枯萎病,瓜刺瘤密种质较刺瘤稀的抗枯萎病。利用其中6份黄瓜自交系配制6份杂交1代,通过苗期和成株期抗性鉴定,表明黄瓜枯萎病抗性为数量性状遗传,抗性为显性基因控制,抗病与感病亲本的杂交1代抗病性介于双亲抗性均值与强抗病亲本之间,抗病性表现出中亲优势,没有发现超亲优势。     

低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响

【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。     

Biodiversity and ecogeography of wild Lactuca spp. in some European countries

Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.     

Pasture Vegetation Elemental Analysis by Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.     

Properties of anaerobically digested and composted municipal solid waste assessed by linking soil mesofauna dynamics and nitrogen modelling

We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass, soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration, N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially (<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils, indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea.     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.