橡胶树重要品系对胶孢炭疽菌抗性评价

橡胶树抗性种质的鉴定与利用是控制橡胶树炭疽病的一项重要措施。采用室内离体橡胶叶接种法、田间种质圃人工接种和自然发病条件下定期田间病害调查方法, 2011-2012年在海南省儋州开展46份重要橡胶树种质对胶孢炭疽菌病抗性鉴定和评价。把抗炭疽病程度划分为高度抗病(HR)、抗病(R)、中度感病(MS)、感病(S)和高度感病(HS)共5个级别,根据抗性评价结果分析得出：高度抗病(HR)类型的0份;抗病(R)类型8份, 占17.39%; 中度感病(MS)类型19份,占41.30%;感病(S)类型16份,占34.78%;高度感病(HS)类型3 份,占6.52%。筛选出的抗病品种,是今后可利用的抗性种质资源。本研究结果为炭疽病抗性种质资源的利用、培育及病害管理提供参考数据。     

青稞种质资源对条纹病的抗性鉴定

条纹病是青藏高原青稞生产上的重要种传病害之一, 常采用药剂拌种防治，但培育和推广抗病品种是防控该病害最经济有效的措施。为发掘抗条纹病的优良青稞种质资源, 本研究以田间鉴定和利用2个菌株室内人工接种鉴定相结合的方法, 对231份青稞种质资源进行了抗条纹病评价, 获得免疫性遗传资源材料20份, 高抗类型材料18份, 中抗类型材料44份, 分别占鉴定总资源数的8.7%、7.8%、19.1%;其他149份青稞资源材料对条纹病表现为感病, 其中36份材料为中度感病类型, 113份材料为高度感病类型, 感病材料占总鉴定材料的64.5%。     

人工合成小麦新种质抗条锈性鉴定与Yr18基因检测

对97份来自CIMMYT的人工合成小麦新种质进行了主要农艺性状考察、Yr18分子检测和成株期田间抗锈性接种鉴定。结果表明:参鉴种质间主要农艺性状变异程度较大,尤其千粒重普遍偏高,有30份材料千粒重达50 g以上、占30.9%;利用csLV34标记检测到合成20和合成43携带Yr18,占2.1%;鉴选出成株期呈抗性反应的材料30份、占30.9%,高度慢条锈材料19份、占19.6%,其中合成2、5、14、60、75、76、78、82、83、84计10个合成种同时表现高抗和高度慢锈。这些大粒、抗条锈或慢条锈合成小麦种质的鉴定筛选,为选育小麦新品种提供了优异资源。     

国内橡胶树主要种质对棒孢霉落叶病的抗性评价

棒孢霉落叶病是近年来我国橡胶树新发病害, 发生面积和危害程度有逐年加重的趋势, 已经成为相关产业发展的潜在限制性因素。培育和种植抗病种质是防治该病最经济有效的控制措施, 而育种材料的抗性评价是相关工作的前提。在前期工作基础上, 本研究通过4种方法对国内46份橡胶树主要种质进行了抗病性评价。结果发现, 不同接种方法获得的抗病性评价结果基本一致, 且抗感种质间的差异达到了极显著水平。在供试的46份橡胶种质中, 高抗(HR)种质3份, 占6.52%, 中抗(MR)种质13份, 占28.26%, 轻感(S)和中感(MS)种质各11份, 分别占23.92% , 高感(HS)种质8份, 占17.40%。     

小豆种质资源对锈病的抗性评价

为筛选小豆(Vigna angularis)抗锈病性资源,本研究以54份小豆种质资源为材料,通过室内接种豇豆单胞锈菌(Uromyce vignae)菌株ZXL01,并分析叶片表面花斑轻重和每1.5 cm~2夏孢子堆的数量,以评价小豆种质资源对锈病的抗性。结果表明,供试材料对小豆锈病的抗性存在明显差异。15份种质资源表现抗病,其中,吉林373和QH2对锈病表现免疫,占供试品种的3.7%;龙垦早红、北4、LZX031、建37、建265和QH1高抗锈病,占供试品种的11.1%;保M908-15、极旱红小豆、吉红6号、北12、湾选1号、保8824-17和北10为中抗种质资源,占供试品种的12.9%。其余39份种质资源均对小豆锈病表现感病。本研究筛选获得小豆抗锈病资源可为田间生产和抗病品种培育提供重要参考。     

大豆种质资源对大豆孢囊线虫3号和4号生理小种的抗性鉴定

选育和利用抗病品种是控制大豆孢囊线虫病的最经济有效方法.本研究通过测定国内外大豆种质资源对大豆孢囊线虫2个生理小种的抗性水平,以期获得抗大豆孢囊线虫的品种与种质资源.2009年9月-2010年6月,采用PVC柱法在温室内鉴定了300份大豆种质资源分别对大豆孢囊线虫(SCN)3号和4号生理小种的抗性.用3号生理小种测定得到了抗性表现免疫的种质资源12份,表现高抗的28份,表现中抗的39份,分别占测试材料的4.0％、9.3％和13.0％;用4号生理小种测定得到了免疫的种质材料8份,高抗的18份和中抗的51份,分别占测试材料的2.7％、6.0％和17.0％.对2个生理小种的毒力差异比较表明,20份大豆种质资源的抗性表现差异明显,4号生理小种的毒力比3号生理小种强.本研究所鉴定出的抗病品种与资源,不仅对农业生产中利用抗病品种合理布局具有指导意义,而且为大豆抗孢囊线虫病的品种培育提供了重要的抗源材料.     

云南野生稻和地方稻资源抗白叶枯病分析

为鉴定云南稻种质资源对水稻白叶枯病的抗性情况,于孕穗期采用剪叶接种方法,用水稻白叶枯病强致病型代表菌株BD8438、CN9404和X1接种云南野生稻和地方稻种质资源,以病斑长度大于6 cm为感病分界线,对其抗感表现型进行调查分析。结果显示,共鉴定出来源于云南省不同种植生态区的186份地方稻抗性材料和22个野生稻抗病居群。野生稻对水稻白叶枯病的抗病能力较地方稻强,其中疣粒野生稻的抗性最强,抗病等级为0~2;药用野生稻次之,抗病等级为1~2;普通野生稻相对较差,抗病等级为1~5。地方稻抗性资源来自于云南省各个传统水稻种植区,抗性1级的材料占17%,抗性2级的占2%,抗性3级的占81%;按照稻种质资源亚种类型、粘糯性和水旱性分类,各类型地方稻抗性材料所占比例分别为粳稻占61%、籼稻占39%;粘稻占66%、糯稻占34%;水稻占83%、陆稻占17%。从利用抗白叶枯病基因培育新品种的角度评价,这些抗性资源具有潜在的发掘利用价值。     

抗白粉病豌豆种质资源田间筛选

以国内外收集的436份豌豆资源为试验材料,在田间自然感病的条件下,每份材料选10株,每株调查上部10片叶的病情级别,计算病情指数,进行白粉病抗性鉴定。同时对鉴定出的抗白粉病豌豆材料进行主要农艺性状的调查记载,旨在筛选出抗白粉病的豌豆优良种质资源,为今后抗性材料的有效利用提供参考,以利于加速豌豆抗性遗传育种进程。鉴定结果显示,436份材料中,抗病资源35份,占8.03%,其中11份高抗(HR),占2.52%;6份抗病(R),占1.38%;18份中抗(MR),占4.13%。综合抗白粉病性与农艺性状优良性,筛选出半无叶型豌豆抗白粉病资源‘RZ-1-1’、‘X9002’、‘1702’、‘MP1811’,普通蔓生型豌豆抗白粉病资源‘DX23’、‘DX25’、‘定褐’、‘黑眉’、‘所427’、‘所430’可进一步加以利用。     

81份春小麦种质资源抗条锈病评价

本研究结合苗期分小种接种和大田成株期自然诱发条件下对供试的81份春小麦资源进行抗条锈病鉴定,分析其抗条锈病情况、抗病类型及抗病性关系,结果表明:具全生育期抗条锈病类型的资源有7份,具成株期抗条锈病类型的资源有39份,有30份资源为含有成株期和对部分小种失去抗性的全生育期抗病性的抗性类型;苗期分别接种7个小种后,表现抗病的资源数为9~25份不等,表现中抗的资源为2~6份不等,表现感病的有50~69份不等,成株期表现抗病的73份,表现中抗的3份,感病的5份,即供试种质资源大部分表现为苗期感病,而成株期具有抗病性。聚类分析结果表明,该81份种质资源抗性聚类相对分散,遗传多样性水平较高。研究结果为小麦育种提供优良的抗条锈性资源。     

糯高粱种质资源对川南高粱丝黑穗病的抗性鉴定

为明确新选育和引进的糯高粱种质资源对川南高粱丝黑穗病菌主要生理小种的抗性,利用4个高粱鉴别寄主分别对2013年和2014年自川南泸州、宜宾、自贡3市高粱上采集的丝黑穗病菌Sporisorium reilianum进行生理小种鉴定,并于2014—2018年对新选育和引进的55份不育系、88份恢复系和20份常规品种糯高粱种植资源进行丝黑穗病抗性鉴定。结果表明,川南3市采集的高粱丝黑穗病菌生理小种均为1号生理小种。不育系糯高粱种植资源对丝黑穗病菌1号生理小种抗性较强,对丝黑穗病免疫材料有45份,87.3%不育系糯高粱种植资源为抗性材料。恢复系糯高粱种质资源抗丝黑穗病菌1号小种的能力弱于不育系,对丝黑穗病表现为免疫、高抗、抗病、中抗的种质资源分别为32、1、2和5份,抗病恢复系糯高粱种质资源占恢复系糯高粱种质资源总数的45.5%。糯高粱种质资源常规品种对丝黑穗病菌1号小种的抗性最差,抗病糯高粱种质资源常规品种占常规品种总数的45.0%,其中对丝黑穗病免疫的糯高粱种质资源常规品种仅有1份,为国窖红3号;对丝黑穗病高抗和抗病的糯高粱种质资源常规品种无,主要表现为中抗,应加强川南地区糯高粱常规品种的丝黑穗病抗性改良。鉴定的对丝黑穗病免疫的糯高粱不育系、恢复系和常规品种可作为川南高粱丝黑穗病病区主栽品种或抗丝黑穗病菌1号生理小种的育种材料。     

Pathogenicity of Rhynchosporium secalis isolates from Norway on 30 cultivars of barley

The pathogenic variability of the barley scald fungus, Rhynchosporium secalis , in central Norway was examined in 1994. The climate in this region is usually cold and wet during the growing season of spring barley. Leaf blotch is prevalent and causes significant yield losses. Forty-two isolates of the fungus, from naturally infected spring barley in four counties, were differentiated into 32 pathotypes by the standard differential set for R. secalis . All pathotypes were complex and had virulence for nine to 22 differentials. The cultivar Osiris was resistant to all isolates tested. The cultivars C.I.8162, Hudson, Atlas 46 and C.I.3515 were resistant to the majority of the isolates. Several differentials with various resistance genes were susceptible to up to 100% of the isolates. Isolates were derived from local cultivars with no known resistance genes, suggesting that R. secalis populations in central Norway are characterized by a high degree of seemingly unnecessary pathogenicity. Because of the great variability and complexity of the pathotypes, traditional breeding methods using single major genes are not likely to be effective in central Norway.     

A weed suppressive index for spring barley (Hordeum vulgare) varieties

A screening programme for crop variety competitiveness would ideally be based on only a few, non-destructive measurements of key growth traits. In this study we measured the weed suppressive ability of 79 varieties of spring barley in two ways: (i) directly, by weed coverage assessments under weedy conditions at three Danish locations in 2002–2004 and (ii) indirectly, by non-destructive measurements of varietal growth traits under weed-free conditions in 17 other experiments in Denmark in 2001–2003. Based on just four varietal growth traits (reflectance, leaf area index, leaf angle and culm length), we successfully developed a method for indexing the weed suppressive ability of spring barley varieties. The suppressive index ranged from 12% in Lux and 55% in Modena in proportion to the 90% quantile coverage of all varieties. The index was validated against independent data from two locations in 2005 with 14 and 24 varieties and was found valuable for future use in regular screening programmes.     

大麦Mlo近等基因系与叶枯病菌互作的细胞学研究

 本文对大麦品种Ingrid(Mlo)及Mlo基因功能丧失性突变的近等基因系(Ingrid mlo-3、Ingrid mlo-4和Ingrid mlo-5)与大麦叶枯病菌的互作进行了细胞学比较分析。结果发现,大麦mlo突变体mlo-3、mlo-4和mlo-5对叶枯病菌的抗病性显著增强,其抗病机制包括对病菌初侵染的乳突抗性和HR反应两个方面。Ingrid(Mlo)大麦的表皮细胞在受到病原菌侵染时,只有15%的有效乳突可成功抵抗病原菌对表皮细胞的侵染;而大麦mlo突变体mlo-3、mlo-4和mlo-5突变体大麦的有效乳突率则分别高达40%、38%和43%。随后,部分被病原菌成功侵入的寄主表皮细胞发生过敏性坏死,从而进一步抑制病原菌向相邻叶肉细胞的扩展。其中3个大麦mlo基因突变体平均67%的被侵染细胞坏死,而Ingrid仅为26%。因此,Mlo基因在调控大麦与不同病原菌互作中的作用是不同的。此外,本文发现该病原菌除气孔入侵外,还可直接穿透大麦表皮细胞;少量菌丝可以侵染进入叶肉细胞,甚至是活的叶肉细胞。     

春季储水灌溉条件下啤酒大麦节水增产机理研究

测定了不同春季储水灌溉定额下啤酒大麦出苗率、生长发育动态、土壤水分变化、耗水规律及水分利用效率,并结合气象资料比较不同灌水处理的优越性,分析不同春季储水灌溉定额对土壤水分、降水利用及作物产量的影响。结果表明,将冬季储水灌改为春季储水灌从技术层面上切实可行;在适宜灌水定额条件下,采用春季储水灌溉技术较冬季储水灌溉技术可减少储水灌灌溉水量75 mm,减少土壤蒸发37.4%,水分利用效率提高26.2%。在实际大麦种植生产中应以春季储水灌定额75 mm,生育期灌水5次,灌水定额75 mm为宜,这样不仅可节约有限水资源,还可提高地温及水分利用效率,达到节水、增效的目的。     

The effects of infection by barley yellow mosaic virus on the yield and components of yield of barley

Infection by barley yellow mosaic virus (BaYMV) was greater in a crop sown in October than in November and in cv. Maris Otter than in cv. Sonja. However, a greater proportion of plants of Sonja than of Maris Otter were infected, and more severely, with the soil-borne fungus vector of BaYMV. Polymyxagraminis. Indifferent years the yield of individual plants of Maris Otter was decreased by 15% and of Sonja by 40%. The spring barley cultivars Athos. Porthos. Georgie and Ark Royal were all infected with BaYMV when sown in autumn in infected soil. Infected winter barley cv. Igri lost up to 50% of yield when this was measured across a naturally infected patch of crop.     

THE EFFECT OF COMPETITION FROM CEREAL CROPS ON THE GERMINATION AND GROWTH OF AVENA FATUA L. IN A NATURALLY-INFESTED FIELD

Summary. The effect of winter wheat, winter rye, winter barley, spring barley, and fallow cultivated as for a winter cereal, on germination and growth of wild oats ( A. fatua ) was investigated on a naturally-infested field. Treatments were continued for 2 years on the same plots and in the third year all plots were cropped with spring barley. Wild oats were not allowed to shed seeds.
A. fatua was controlled by a dense crop of an autumn-sown cereal. The crop genus was unimportant provided it grew well on the site; its effectiveness depended on its density when the wild oats germinated in spring. Winter wheat and winter rye were equally effective. Even in a light crop of barley, wild oats grew much less vigorously than on the fallow plots. Beyond a certain crop density dependent on soil fertility, further increase in crop did not decrease the size of wild oats. The heaviest crop did not completely suppress the wild oats.
The crop affected the wild oats mainly by decreasing growth of the seedlings, but under winter wheat and winter rye some wild oat seeds may have remained dormant, germinating in the spring barley in the third year, perhaps because the crops decreased the soil moisture content. Nitrogenous fertilizer increased the weight of both crops and wild oats. Barley was more severely affected by soil acidity than wild oats and on acid areas of barley plots the wild oats were larger than where the pH was higher. In wheat and rye which were scarcely affected by soil acidity the size of the wild oat plants was unaffected by soil pH.
L'effet du competition des céréales sur la germination et le développement d' Avena fatua dans un champ naturellement infesté .     

A survey of grass weeds in cereals in central southern England

A survey of grass weeds in cereals in nine areas of central southern England was made in summer 1981 with the primary purpose of determining the importance of Bromus sterilis. A total of 1477 fields of winter wheat, 715 of winter barley and 434 of spring barley were assessed by visually scoring the whole field for grass flower heads. In all, 19 species were found; their levels of infestation were scored. In winter cereals the most frequent species were Avena spp. in 32% of fields. Agropyron repens in 24%, Poa trivialis in 22% and Alopecurus myosuroides in 19%. Bromas sterilis was next most frequent in 9%. In spring barley the two most frequent species were Agropyron repens in 53% of the fields and Avena spp. in 52%. The third most frequent was Alopecurus myosuroides in 1 1%. Bromus sterilis was recorded in 12% of winter wheat and 4% of winter barley crops, but did not occur in spring barley. Of the 206 fields where it was present it occurred throughout the field in only 82 and it was confined to the headlands in the remainder.     

Yield Trends during Take-all Decline in Spring Barley and Wheat Grown Continuously1

The effects of take-all, nitrogen and cropping sequence on grain yield were compared for spring barley and spring wheat grown in extended monoculture. Initial crops showed least take-all and maximum yields. Yields fell to a minimum more rapidly in wheat than in barley while the take-all intensity increased to a maximum; take-all decline occurred and yields improved from the 4th and 5th years respectively. Without nitrogen, yields were at their lowest level; application of nitrogen increased yields considerably with responses in proportion to the rate applied. At optimum rates, yield losses were 33% for wheat and 11% for barley with maximum disease intensity but only 9% and 3% respectively with take-all decline. Potential maximum yields in the absence of take-all were calculated to be greater with barley than with wheat.     

SEED PRODUCTION OF AGROPYRON REPENS (L.) BEAUV. IN ARABLE CROPS IN ENGLAND AND WALES IN 1969

Summary. Spikes oi Agropyron repens (L.) Beauv. were collected from field crops (mostly spring barley and winter wheat) in England and Wales near the time of crop harvest. Seeds per spike were counted and their germination tested in soil in the glasshouse.
About 95% of the samples contained viable seeds; about one third of the samples had fewer than 5 viable seeds/spike, a third between 6 and 15 and a third more than 15. The average number of viable seeds/spike for all samples was 13. Spikes from spring barley (152 samples) had an average of 11 and a maximum of 51 viable seeds and those from winter wheat (42 samples), 20 and 48 respectively. Samples collected within 3 weeks after mid-July had fewer viable seeds/spike than those collected later. Samples containing morphologically-different spikes had more viable seeds/spike than apparently uniform samples, and spikes from dense field populations more seeds than those from sparse populations.     

A second survey of cereal weeds in central southern England

A survey of grass weeds of cereals in central southern England made in 1981 was repeated in 1982 between 28 June and 23 July. Dicotyledonous weeds were also assessed in 1982. A total of 1021 fields were surveyed, 702 in winter wheat. 198 in winter barley and 121 in spring barley. A total of twenty-four grass weeds were found and their levels of infestation were scored. The most frequently found grass weeds were the same as in 1981. In all cereals combined, these were Elymus (Agropyron) repens in 35% of fields, Avena fatua in 32%, Alopecurus myosuroides in 26% and Poa trivialis in 24%. Sixty-three species of dicotyledonous weeds were recorded and of these, eighteen species occurred in 2% or more of fields. The eight most frequent were Viola arvensis, Galium aparine, Stellaria media, Myosotis arvensis, Polygonum aviculare, Convolvulus arvensis, Bilderdykia (Polygonum) convolvulus and Lamium purpureum. Most species were fairly uniform in distribution, but Galium aparine, Convolvulus arvensis and Cirsium arvense were most frequent in the east while Viola arvensis was least frequent there. The cereals varied in weediness, 32% of winter barley, 23% of spring barley and only 7% of winter wheat fields had no weeds recorded.