228份引进大蒜资源的表型多样性分析及适应性初步评价

为了解引进大蒜资源遗传多样性和引进后的适应性,对国家无性繁殖及多年生蔬菜种质资源圃从34个国家引进的228份大蒜(Allium sativum L.)资源进行了表型性状评价。结果表明:13个数量性状的变异系数分布在18.94%～56.36%之间,质量性状中除叶形仅一种表现型,其他质量性状表型丰富;25个性状的多样性指数分布在0～2.03之间,遗传多样性指数高,类型丰富。通过聚类分析,将引进的大蒜资源分为3个类群,类群Ⅰ地上部分植株矮小、细弱,叶片短而细,鳞茎表现较差,为丰产性较差的类群;类群Ⅱ鳞茎横茎小,鳞芽数少,鳞茎形状为高圆型;类群Ⅲ植株高大开展,叶片长且宽,鳞茎重且鳞茎横茎大。主成分分析中,选取累积贡献率为69.94%的3个因子来评价该批资源。大蒜鳞茎部分性状的相关分析表明,鳞茎横径、鳞茎高、鳞芽高、鳞芽背宽均与单头鳞茎重存在极显著的正相关关系,在选育高产大蒜品种时,这些性状将作为主要的目标性状;引种前后的鳞茎相关性状对比分析表明,不同种质在引种后的适应性表现差异较大,部分资源种植后鳞茎高和鳞茎横茎较引种时明显增大,表现出了较好的适应性。相关结果将为大蒜种质资源的利用及品种选育等提供重要参考。     

大蒜辣素UPLC检测体系优化及其在大蒜资源评价中的应用

大蒜是重要的调味蔬菜,大蒜辣素的含量是评价大蒜品质的最重要的一项指标.本研究通过对样品处理、提取方法和检测方法的研究,建立了完善的大蒜辣素超高效液相色谱(UPLC)检测方法:使用UPLC BEH C18色谱柱,流动相为甲醇∶水=1∶1,检测波长为254nm,进样体积为1μl,流速为0.3ml/min.大蒜辣素在2.04 ～ 510mg/L范围内呈良好线性关系(R2 =0.9991).利用建立的方法对212份大蒜鳞茎的大蒜辣素含量进行检测,发现供试212份大蒜资源的大蒜辣素含量差异显著,含量分布在0.82％ ～3.01％之间,最高含量与最低含量之间相差近4倍.     

蒜辣素UPLC检测体系优化及其在大蒜资源评价中的应用

大蒜是重要的调味蔬菜,大蒜辣素的含量是评价大蒜品质的最重要的一项指标。本研究通过对样品处理、提取方法和检测方法的研究,建立了完善的大蒜辣素超高效液相色谱(UPLC)检测方法:使用UPLC BEH C18色谱柱,流动相为甲醇∶水=1∶1,检测波长为254nm,进样体积为1μl,流速为0.3ml/min。大蒜辣素在2.04～510mg/L范围内呈良好线性关系(R2=0.9991)。利用建立的方法对212份大蒜鳞茎的大蒜辣素含量进行检测,发现供试212份大蒜资源的大蒜辣素含量差异显著,含量分布在0.82%～3.01%之间,最高含量与最低含量之间相差近4倍。     

基于表型性状的中国大蒜资源遗传多样性分析

对资源圃保存的212份大蒜种质资源的表型性状进行了系统鉴定,分析表明我国大蒜种质资源的表型变异丰富。主成分分析表明,29个性状可以归并为反映植株生长发育、产品特征和产量构成的8个主成分;进一步的聚类分析将所有资源分为特点明显的2类5亚类。为了避免质量性状在种质评价中的主导作用,与产量相关的鳞茎数量性状的主成分分析显示,前3个主成分累积贡献率达74.83%,第一主成分中鳞茎重、鳞茎直径、鳞茎高和鳞芽数是影响产量的主要因子。主坐标排序将所有资源分为6类。通过综合评价,将大蒜鳞茎产量分为6个级别,筛选出单产大于15 t/hm2的资源3份。     

小白菜种质资源对小菜蛾的抗性评价

本文就小白菜种质资源对小菜蛾的抗性进行室内鉴定,结果表明268份材料的虫害指数分布在18.10～100.00之间,种质资源间抗虫性差异达到显著水平.聚类分析将268份种质资源分为6大类,与高抗、抗、中抗、中感、感、高感相对应,其中筛选出高抗和抗性材料分别为6和11份.对268份材料的主要形态性状与虫害指数和抗性级别的相关分析表明,小白菜种质资源叶面的皱缩度与抗虫性存在一定的相关性,认为从叶面平滑型的种质资源中筛选抗虫性材料的可能性更大.     

河北省小豆种质资源遗传多样性分析

通过26个性状分析河北省385份小豆种质资源的遗传多样性及优异资源分布,结果表明,5个质量性状中粒色的遗传多样性指数最高,结荚习性的遗传多样性指数最低;数量性状中百粒重的遗传多样性最高,但15g以上的大粒优异资源较少;抗性性状中芽期抗寒的遗传多样性指数最高,锈病抗性遗传多样性指数最低;抗叶斑病、抗锈病和抗蚜虫资源缺乏高抗类型.11个地市中承德的材料份数及遗传多样性指数最高,且有野生资源分布,推断其为河北省小豆遗传多样性中心.     

小麦种质对麦长管蚜的抗性鉴定与评价

2002-2005年连续4年,选用蚜情指数法对小麦种质进行麦长管蚜田间自然感蚜抗性鉴定,从2000份小麦种质中筛选出不同抗性材料34份,占总鉴定材料的1.7%,其中高抗种质5份、抗性种质9份、中抗种质20份。利用苗期室内接虫法,对部分抗感小麦种质进行鉴定,结果表明,苗期的抗性表现与成株期基本一致。对杂交组合临远207(抗)×Witchita(感)的F1、F2的抗性遗传分析表明,临远207对麦长管蚜的抗性由1对显性单基因控制。     

花生种质资源果腐病的抗性评价

花生果腐病是一种由真菌引起的世界性的严重病害,直接影响花生的产量及品质。通过田间自然发病对引进的77份美国资源和39份国内资源进行连续2年的鉴定,筛选抗果腐病的花生种质资源,为花生抗果腐病育种提供优异材料。结果表明:供试花生材料间的受害指数差异极显著(P0.01),两年间的差异也达到显著水平(P0.05)。根据受害指数的聚类分析将供试花生材料的果腐病抗性分为高抗、抗、中抗、感病和高感病5组,该结果作为花生果腐病抗性评价标准,能够明确评价供试花生材料对果腐病的抗性。综合两年抗性表现较一致的96份种质,筛选到高抗材料2份,平均受害指数分别为16.67和21.91;抗性材料6份,平均受害指数分布在26.33~42.41之间;中抗材料32份,平均受害指数在45.19~60之间;感病材料34份,平均受害指数在60.87~74.39之间;高感材料22份,平均受害指数在75.27~83.34之间。该结果为评价花生果腐病抗性和合理利用种质资源进行花生抗病品种遗传改良提供了参考和优异材料。     

大蒜种质产量和品质性状主成分聚类分析与综合评价

以40个大蒜品种为供试材料,依据数值分类学的性状选择原则,分别于大蒜生长期和采收后进行农艺性状指标的采集。估算40个大蒜品种16个农艺性状及4个品质指标的主成分,并以前3个主成分和遗传相似性系数为基础,分别作二维散点图和系统聚类分析。40份大蒜品种前7个主成分累计贡献率达85%。根据品种性状主成分表现,评选出性状优良的大蒜品种共10个。在聚类图中,在0.14的遗传相似性水平上可以把40份品种分成4类,即由5份种质组成的类群Ⅰ;由28份种质聚成的类群Ⅱ;由改良蒜等4份种质组成的类群Ⅲ,及苏联蒜等3份种质组成的类群Ⅳ。全部种质的遗传相似性系数在0.07～0.64之间,很好地揭示了品种类群间存在的亲缘关系。     

240份玉米自交系纹枯病抗性鉴定与评价

在人工接种条件下,连续3年对240份玉米自交系纹枯病抗性进行鉴定和评价,分析了玉米纹枯病抗性与主要农艺性状的相关性。结果表明,玉米纹枯病抗性资源较为缺乏,240份自交系中无免疫或高抗的材料,有中抗自交系4份、感病自交系18份、高感自交系218份。旅大红骨、Reid、PA和塘四平头类群自交系中未发现玉米纹枯病抗源,PB类群和Lancaster类群自交系纹枯病抗性相对较好,今后应主要从这两类种质中寻找玉米纹枯病抗源。玉米纹枯病病情指数与株高、穗位高、穗位高/株高、穗下节间数和穗下平均节间长均呈极显著负相关,这些表型可以作为非接种条件下筛选抗玉米纹枯病种质的参考指标。     

萝卜种质资源对黑腐病的抗性鉴定与筛选

对40份初选萝卜种质分别接种Xcc8004和XccBJ两个菌株,进行黑腐病苗期抗性鉴定,对其中8份代表性萝卜种质肉质根切片接种Xcc8004进行抗性鉴定和27份萝卜种质幼苗接种8个效应物基因进行过敏反应鉴定。结果表明:不同萝卜种质苗期对黑腐病的抗性存在显著差异,筛选出高抗Xcc8004的材料3份、抗病1份、中抗4份,高抗XccBJ的材料1份、抗病2份、中抗5份。萝卜苗期对Xcc8004和XccBJ的抗病性极显著相关,幼苗和肉质根对Xcc8004的抗病性极显著相关。筛选出17份对不同效应物表现过敏反应的萝卜种质。对效应物XC₀241表现过敏反应的种质数最多,对XC₀542和XC₀541表现过敏反应的种质数次之。不同抗源对不同效应物的过敏反应程度有所不同。稳定可靠抗病资源的获得为萝卜抗病育种和抗病机理的深入研究提供了基础材料。     

海南普通野生稻稻瘟病抗性资源调查和鉴定

为挖掘海南普通野生稻稻瘟病抗性资源,2010年诱发鉴定了41个居群410份材料苗期叶瘟,2011年接种稻瘟病菌（YC25）鉴定了37个居群121份材料穗颈瘟,2012年调查了80个居群2461份材料田间自然状态的抗病性。结果表明：苗期叶瘟抗性鉴定有21份高抗、117份抗病。苗期抗、高抗叶瘟性的138份材料中穗颈瘟鉴定4份高抗和3份抗病,14份表现为田间自然抗病。苗期叶瘟鉴定不抗病或未作此鉴定材料中,4份表现为抗穗颈瘟和田间自然抗病。这些抗性材料来自海口、文昌、万宁、三亚、澄迈、东方等地。本研究为海南普通野生稻资源进一步研究和抗稻瘟病育种利用提供参考     

茄子种质资源抗青枯病的鉴定与评价

对304份茄子种质资源进行抗青枯病苗期人工接种鉴定,筛选出免疫材料10份,高抗材料51份,抗病材料35份,中抗材料32份,感病或高感材料176份,分别占鉴定材料的3.3%、16.8%、11.5%、10.5%和57.9%.茄子野生近缘种Solanum sisymbriifolium和S.torvum对青枯病有较强的抗病性,可作为茄子青枯病的抗源材料.获得4份抗青枯病的种间体细胞杂种.茄子对青枯病的抗性遗传较为复杂,主要由多基因控制.     

Resistance to cyst nematode (Heterodera cajani) in pigeonpea cultivars and in wild relatives of Cajanus*

Heterodera cajani is an important nematode pest of pigeonpea in India. Evaluation of 58 pigeonpea cultivars and 61 accessions of Cajanus acutifolius, C. cajanifolius, C. grandifolius, C. lanceolatus, C. lineatus, C. mollis, C. pla-tycarpus, C. reticulatus, C. scarabaeoides, C. sericeus, C. volubilis, Flemingia macrophylla, F. stricta, F. strobilifera, Rhynchosia aurea, R. bracteata, R. cana, R. densiflora, R. minima, R. rothii, R. suaveolens and R. sublobata revealed that the tested pigeonpea cultivars lacked resistance to H. cajani. Eight accessions of wild relatives were resistant and 20 accessions were moderately resistant. Based on the white cyst number on roots and low plant-to-plant variation, two accessions of C. scarabaeoides (ICPWs 111 and 128), three accessions of Flemingia spp. (ICPWs 194, 202 and 203), and one accession each of R. rothii (ICPW 257), R. densiflora (ICPW 224), and R. aurea (ICPW 210) were identified as resistant and promising for use in intergeneric hybridisation programmes.     

Natural variation in the Arabidopsis response to the avirulence gene hopPsyA uncouples the hypersensitive response from disease resistance

The plant hypersensitive response (HR) is tightly associated with gene-for-gene resistance and has been proposed to function in containing pathogens at the invasion site. This tight association has made it difficult to unequivocally evaluate the importance of HR for plant disease resistance. Here, hopPsyA from Pseudomonas syringae pv. syringae 61 is identified as a new avirulence gene for Arabidopsis that triggers resistance in the absence of macroscopic HR. Resistance to P. syringae pv. tomato DC3000 expressing hopPsyA was EDS1-dependent and NDR1-independent. Intriguingly, several Arabidopsis accessions were resistant to DC3000(hopPsyA) in the absence of HR. This is comparable to the Arabidopsis response to avrRps4, but it is shown that hopPsyA does not signal through RPS4. In a cross between two hopPsyA-resistant accessions that differ in their HR response, the HR segregated as a recessive phenotype regulated by a single locus. This locus, HED1 (HR regulator in EDS1 pathway), is proposed to encode a protein whose activity can cause suppression of the EDS1-dependent HR signaling pathway. HED1-regulated symptomless gene-for-gene resistance responses may explain some cases of Arabidopsis resistance to bacteria that are classified as nonhost resistance.     

Mechanisms of woolly aphid [Eriosoma lanigerum (Hausm.)] resistance in apple

Abstract:  The sourcing of new resistant accessions and understanding their resistance mechanisms are significant aspects of a breeding strategy for durable resistance. Resistance of a number of apple accessions to the woolly apple aphid (WAA) [ Eriosoma lanigerum (Hausm.)] was assessed based on the biological parameters of the insect. Two experiments were conducted under glasshouse conditions in two consecutive years during January–February of 2002 and 2003. In Expt 1 in 2002, settlement, development and survival of the aphids were assessed on five apple accessions [Roter Eiserapfel (RE), Freiherr von Berlepsch (FvB), Braeburn (B), Willie Sharp (WS) and Royal Gala (RG)]. RG was the most susceptible and WS the most resistant accession to WAA. RG and WS were included as references in Expt 2 in 2003, with 11 further accessions ( Malus floribunda 821 OP (open-pollinated) G01-078 (MF), Korichnoe Polosatoje OP G01-104 (KP), Geneva (G), Raritan (R), Malus 6 (M-6), Twenty Ounce (TO), Winter Majetin (WM), Aotea (A), Irish Peach (IP), Court Pendu Plat (CPP) and Colonel Vaughan (CV). Daily reproductive rate and colony establishment were added to the three paramaters assessed in Expt 1. The overall results showed resistance in G, MF, WS and KP to settlement and development with low survival at the larval stage of the aphid, whereas R showed resistance in all the parameters tested. RG and CPP have proved to be susceptible while A, WM, TO, M-6, IP and CV were partially resistant.     

A glasshouse screening method to assess resistance in onions to damage by onion fly (Delia antiqua) larvae

Factors influencing the resistance of onion (Allium cepa) cultivars to onion fly (Delia antiqua) damage were investigated. These included different environments, methods of plant raising and egg inoculation, and plant size. A glasshouse compartment maintained at 14 to 37 °C was as satisfactory for assessing the resistance as a controlled environment. The basic test unit comprised 10 onion seedlings raised in a 400 × 50 × 50 mm deep plastic trough and inoculated with 50 onion fly eggs from a laboratory culture. Resistance was assessed by counting wilted plants every two or three days for 21 days after egg inoculation. The reciprocal of number of days for each plant to wilt (wilting rate) was an appropriate variate for statistical analysis, adjusted for the length of the longest leaf at the time of inoculation. The method enables cultivars or breeding lines of onion species to be reliably screened for resistance to larvae of this pest in a glasshouse so that only the most promising need be tested in the field.     

Search for partial resistance to leaf rust in a collection of ancient Spanish wheats

A collection of 917 accessions of Spanish durum and bread wheat was screened for resistance to leaf rust (Puccinia triticina) under field conditions at three locations. Resistance levels ranged from very low to very high, high susceptibility being most frequent. Relative disease severity (referred to the most susceptible accession = 100%) was lower than 20% in about 6% of the accessions in each location. In the collection most of the lines (84%) displayed a susceptible infection type. A final selection of seven accessions (one of them durum) displaying low severity level in the field and high infection type in a growth chamber was chosen for further studies. High levels of partial resistant with longer latency period and high percentage of early aborted colonies without necrosis were found. They might be used in breeding programmes.     

拟南芥对细菌性软腐病抗性变异分析

由胡萝卜软腐欧文氏菌胡萝卜软腐亚种 Erwinia carotovora subsp.carotovora （Ecc）引起的细菌性软腐病是世界性的重要流行病害,由于缺乏天然抗源,研究进展缓慢,拟南芥成为软腐病抗性研究的主要试材。本文选用 29 份拟南芥材料,制定了病情分级标准,以接种后 48 小时的病情指数作为软腐病抗性的鉴定指标,筛选出抗软腐病材料 CS906 和感病材料 CS20。通过分析抗、感材料接种 Ecc 后 AOS、ERF1-1、PR1、PDF1.2 和 PAL1 等 5 个基因的表达变化,发现 SA、ET 和 MJ 信号途径都参与了拟南芥对 Ecc 的防卫反应,且基因表达模式在抗、感材料中相似,差异体现在表达量上。本研究对深入探讨拟南芥软腐病抗病机制具有重要意义。