New sources of resistance to Fusarium wilt and sterility mosaic disease in a mini-core collection of pigeonpea germplasm

Fusarium wilt (FW) and Sterility mosaic disease (SMD) are important biotic constraints to pigeonpea production worldwide. Host plant resistance is the most durable and economical way to manage these diseases. A pigeonpea mini-core collection consisting of 146 germplasm accessions developed from a core collection of 1290 accessions from 53 countries was evaluated to identify sources of resistance to FW and SMD under artificial field epiphytotic conditions during 2007–08 and 2008–09 crop seasons. Resistant sources identified in the field were confirmed in the greenhouse using a root dip screening technique for FW and a leaf stapling technique for SMD. Six accessions (originated from India and Italy were found resistant to FW (<10% mean disease incidence). High level of resistance to SMD was found in 24 accessions (mean incidence <10%). These SMD resistant accessions originated from India, Italy, Kenya, Nepal, Nigeria, Philippines and United Kingdom. Combined resistance to FW and SMD was found in five accessions (ICPs 6739, 8860, 11015, 13304 and 14819). These diverse accessions that are resistant to FW or SMD will be useful to the pigeonpea resistance breeding program.     

Quantification of Wheat spindle streak mosaic virus and Soil borne cereal mosaic virus in resistance testing of field samples of triticale using real-time RT-PCR

Journal of Plant Diseases and Protection - Triticale, a cross between rye and wheat, is a crop important for animal feed and the production of biogas and ethanol. Soil-borne viruses found in wheat...     

A viral disease of broad bean caused by a non-aphid-transmissible strain of turnip mosaic virus

A viral disease of broad bean ( Vicia faba ) was observed in Jiangsu, Zhejiang and Sichuan Province, the People's Republic of China. Its typical symptom on infected leaves was a white mottle, and, rarely, red necrotic lesions on several broad bean cultivars. A non-aphid-transmissible strain of turnip mosaic virus (TuMV) was identified as the causal agent of the disease on the basis of biological properties, particle morphology, seed and aphid transmission and serological tests. The virus could not be transmitted by aphids in the non-persistent manner.     

甘蔗花叶病抗病性鉴定接种新技术研究

研究了甘蔗花叶病抗病性鉴定的一种新技术—甘蔗生长期切茎接种法。此法和传统苗期手指摩擦接种法相比,接种后发病率极显著地高于手指摩擦接种法,且发病均匀、结果稳定,可以有效地区分不同甘蔗品种(材料)之间对病害的抗感性。比较11个甘蔗品种材料生长期切茎接种法和田间自然感病法对SrMV-HH1的抗性鉴定,结果表明:两种方法发病率呈正相关,且相关程度极密切,相关系数达0.9997,鉴定所得的抗病性和抗病等级结果完全一致,说明切茎接种法鉴定结果能真实反映甘蔗品种材料的自然抗感性;此外该方法简便实用、可操作性强、接种工效高,因此可以对大批量材料进行鉴定和筛选。     

烟草品种对烟草花叶病毒病和黄瓜花叶病毒病的抗性鉴定

由烟草普通花叶病毒(TMV)和烟草黄瓜花叶病毒(CMV)引致的烟草病毒病是世界烟草主产区普遍发生且危害严重的侵染性病害,每年给烟叶生产造成了重大的经济损失。本文采用温室苗期接种鉴定的方法,对16份烟草种质进行了TMV和CMV的抗病性鉴定。结果表明:不同的烟草品种对TMV和CMV的抗病性存在较大差异。在供试种质中,对TMV表现免疫的有‘牛耳烟’、‘8301’、‘台烟7号’、‘三生-NN’共4份材料;表现抗病的有‘吉烟5号’、‘双抗70’、‘大护脖香’、‘秦烟95’共4份材料;表现中抗的有‘铁把子’、‘中烟15’、‘秦烟98’、‘中烟98’共4份材料;表现中感的有‘NC89’、‘翠碧1号’、‘云烟97’共3份材料;表现感病的只有‘秦烟97’。对CMV表现中抗的材料有1份,是‘铁把子’;表现中感的有‘秦烟95’、‘三生-NN’、‘8301’、‘牛耳烟’、‘翠碧1号’共5份材料;表现感病的有‘秦烟98’、‘云烟97’、‘中烟98’、‘NC89’、‘大护脖香’、‘双抗70’、‘秦烟97’、‘中烟15’、‘台烟7号’、‘吉烟5号’共10份材料。研究发现,‘铁把子’是兼抗这两种病毒病的材料。本研究明确了我国16个烟草品种资源的抗病性水平,为抗耐病品种的利用与品种合理布局提供科学依据,同时为烟草抗病毒病育种的亲本选择提供抗源信息。     

浙江宁波雪里蕻花叶病病原鉴定及雪里蕻品种的抗病性测定

 从浙江宁波雪里蕻上获得97株呈花叶症状的病毒样品,利用三抗体夹心酶联免疫吸附测定(TAS-ELISA)在97株雪里蕻花叶样品中均检测到芜菁花叶病毒(Turnip mosaic virus,TuMV),所有的样品都没有检测到黄瓜花叶病毒(Cucumber mosaic virus,CMV)和烟草花叶病毒(Tobacco mosaic virus,TMV);利用免疫捕捉反转录PCR (IC-RT-PCR)对部分TuMV样品中的CP和HC-Pro基因进行了扩增,所有样品都得到约0.8kb和1.4kb的2条特异条带,因此宁波雪里蕻花叶病的主要病原是TuMV。对53个雪里蕻栽培品种在温室和大田进行了人工接种,共鉴定出抗病品种7个,耐病品种22个,感病品种24个,未发现高抗品种。总的来说,细叶型品种比花叶型和板叶型品种抗病。利用TAS-ELISA方法对接种的53个雪里蕻品种中的TuMV浓度进行测定,在接种后10、15、20和30d,TuMV检出率分别为45.28%、90.57%、100%和100%,大多数雪里蕻OD405值随接种后天数的增加而呈上升趋势,说明TuMV可以在雪里蕻抗性品种内繁殖,抗性品种的抗性主要表现为耐病。     

小麦对黄花叶病的抗性鉴定及典型品种的遗传分析

 本研究针对来自江苏、河南、四川、湖北、日本和美国的37个小麦品种,在进行小麦抗黄花叶病的抗病性鉴定、调查的基础上,结合分子生物学检测(RT-PCR和ELISA),证实小麦品种扬辐9311对小麦黄花叶病毒(WYMV)表现免疫。将该品种与表现高感的小麦品种进行杂交和回交,通过对其后代抗感分离的调查与分析,确定了小麦品种扬辐9311对黄花叶病的抗性受一对显性基因控制,并为寻找小麦抗黄花叶病基因的分子标记提供理论依据和实验材料。同时,本文对小麦抗黄花叶病表现的影响因素及宁麦9号的抗病性进行了分析和讨论。     

Components of resistance of cassava to African cassava mosaic virus

Components of resistance of cassava (Manihot esculenta) to African cassava mosaic virus (ACMV) and their interrelationships were confirmed and quantified in a series of experiments at Adiopodoumé (Ivory Coast, West-Africa). The response to virus infection and toBemisia tabaci infestation of a large collection of cassava, including local cultivars and others derived from inter-specificM. glaziovii hybrids was assessed. A consistent correlation was found between virus titre, symptom intensity, disease incidence and non-systemicity (recovery) which suggests that they are different expressions of the same genetic resistance. By contrast, there was no correlation between whitefly infestation and incidence of ACMV, suggesting that resistance to virus and vector are determined by two distinct genetic mechanisms. Several improved cultivars derived from inter-crossing cassava withM. glaziovii as well as some local cultivars were highly resistant and combined low susceptibility, low symptom intensity, low virus content and high level of recovery. Although yield losses ranged from 10% to 30% in such resistant cultivars, the combined effect of high field resistance and high rate of recovery lead to low disease incidence and limited yield losses, even in areas of high infection pressure such as Adiopodoumé.     

A strategy to identify sources of quantitative resistance in pathosystems involving disease escape and physiological resistance: the case study of rice sheath blight

An epidemiology‐based strategy using rice sheath blight (ShB) as a biological model was developed that enables identification of sources of resistance. A set of 163 cultivated rice genotypes, including genotypes which had been reported to express partial resistance to ShB, and a few genotypes reported as very susceptible, were assessed using two complementary methods. First, microfield experiments allowed measurement of disease intensification at, and spread from, inoculated sources, along with morphological traits of each genotype. Secondly, detached tiller tests allowed measurement of the physiological resistance to the disease under conditions where morphology does not come into play. Multivariate analysis involving hierarchical cluster analysis, followed by multiple correspondence analysis, indicated that levels of physiological resistance, groups of plant morphology and disease levels in microfields were associated. Results from logistic regressions further indicated that a decreased number of lesions measured on detached tillers increased the odds of a rice genotype belonging to the group with low disease intensity in microfields. The combined results from microfield and detached tiller tests allowed identification of 23 genotypes with low level of disease intensity, which may be used as sources of resistance to ShB in breeding programmes. The results suggest that this strategy, which combines the crop stand and the individual tiller scales, may be applied to the identification of sources of resistance to a range of diseases with similar life cycle traits.     

Use of detached tomato leaves to test for resistance to tomato mosaic virus

Samenvatting Een methode werd ontwikkeld om de resistentie van in de kas geteelde tomateplanten tegen tomatemozaïek virus (ToMV) te bepalen. Bladeren van een vatbare en een resistente cultivar werden afgesneden en geïnoculeerd met ToMV. Na 6, 10 en 17 dagen werden de geïnoculeerde bladeren getoetst op de aanwezigheid van virus met ELISA en door inoculatie van bladeren vanNicotiana glutinosa. Met beide toetsmethoden kon de virustoename in de vatbare cultivar al vroeg na inoculatie duidelijk worden aangetoond. In de bladeren van de resistente cultivar was een zeer kleine hoeveelheid virus pas laat na de inoculatie aantoonbaar. Met deze methode is het mogelijk om de resistentie tegen ToMV te bepalen, tevens zaad te winnen en landbouwkundige eigenschappen te evalueren, zonder de plant te infecteren.     

Assessment of inoculation methods to identify resistance to Fusarium crown rot in wheat

Journal of Plant Diseases and Protection - Crown rot, caused by Fusarium culmorum and Fusarium pseudograminearum, is one of the most pervasive diseases of wheat throughout the world. Fusarium...     

壳寡糖诱导烟草抗烟草花叶病毒的超微结构研究

 电镜检查表明,接种烟草花叶病毒(TMV)表现系统侵染的烟草植株叶肉细胞和筛管内有大量病毒粒子和病毒结晶体,细胞质中出现髓鞘样结构、多泡体和次级囊泡。叶片薄壁细胞内叶绿体、线粒体等细胞器变形解体,膜结构增生。经壳寡糖(50 μg/mL)诱导处理的烟草,系统症状减轻,叶肉细胞和筛管中病毒粒子显著减少,偶见病毒结晶体;叶肉细胞中细胞器基本完好,但叶绿体内出现较大的淀粉粒;液泡内和细胞间隙出现大量电子致密物质。在未接毒和未经壳寡糖处理的植株中未见此种电子致密物,其产生可能与诱导抗病性表达有关。     

Quantitative trait Loci mapping of resistance to sugarcane mosaic virus in maize

ABSTRACT Sugarcane mosaic virus (SCMV) is an important virus disease of maize (Zea mays) in Europe. In this study, we mapped and characterized quantitative trait loci (QTL) affecting resistance to SCMV in a maize population consisting of 219 F(3) or immortalized F(2) families from the cross of two European maize inbreds, D32 (resistant) x D145 (susceptible). Resistance was evaluated in replicated field trials across two environments under artificial inoculation. The method of composite interval mapping was employed for QTL detection with a linkage map based on 87 restriction fragment length polymorphism and 7 mapped microsatellite markers. Genotypic and genotype x environment interaction variances for SCMV resistance were highly significant in the population. Heritabilities ranged from 0.77 to 0.94 for disease scores recorded on seven consecutive dates. Five QTL for SCMV resistance were identified on chromosomes 1, 3, 5, 6, and 10 in the joint analyses. Two major QTL on chromosomes 3 and 6 were detected consistently in both environments. Significant epistatic effects were found among some of these QTL. A simultaneous fit with all QTL in the joint analyses explained between 70 and 77% of the phenotypic variance observed at various stages of plant development. Resistance to SCMV was correlated with plant height and days to anthesis.     

世玛和阔世玛防除冬小麦田杂草应用技术研究

按江苏省农林厅植保站的要求,用德国拜耳作物科学公司开发的世玛和阔世玛进行田间药效大区示范试验,以明确其对冬小麦田恶性禾本科杂草和阔叶杂草的防除效果,并观察对小麦的安全性,确定最佳使用剂量,为大面积推广应用提供技术依据。1材料与方法1·1试验作物及防除对象试验作物为冬小麦,品种为宁麦9号。防治对象为禾本科杂草和阔叶杂草。1·2试验田概况试验在江苏省宜兴市大浦镇张渎村小麦田高产示范区实施,土壤为白土,pH值6.32,土壤肥力中等偏上。前茬为水稻,于2004年10月25日收割。小麦种植方式为稻板田免耕直播,小麦品种为宁麦9号,播种期…     

Variation in the resistance of Vicia faba to Ascochyta fabae in relation to disease development in field trials

The epidemic development of Ascochyta fabae in artificially infected field trials was studied in order to define resistance criteria and assess the variation in resistance of infected lines of faba bean. Large differences were demonstrated among French winter lines during the 1985/86 and 1986/87 growing seasons. All the scoring systems allowed the differentiation of very susceptible and resistant material, but disease indices, which account for the number and intensity of lesions, were more precise. The different phases of the epidemic are described on the basis of the variation in disease incidence on foliage and on pods during the 1986/87 cropping season in Brittany. There were three phases in disease development: initiation, spread throughout foliage, and pod infection, and these were all influenced by host resistance. On a very susceptible line, the disease spread was seen as an increase in the number and size of lesions and rapidly developed up the plant. Low disease indices observed on the resistant line 29 H were due to the small size and low frequency of lesions, resulting in a reduced area of foliage affected.     

Metabolic profiling of virus-infected transgenic wheat with resistance to wheat yellow mosaic virus

Wheat (Triticum aestivum L.) is an important crop, and wheat yellow mosaic virus (WYMV) can cause a severe loss in wheat yield. A genetically modified (GM) wheat carrying a WYMV 72kD coding gene (Wheat 72kD) with resistance to WYMV has been constructed in a previous study. However, neither the influence of genetic modification on wild-type wheat (WT) metabolism nor the effect of WYMV-infection on the metabolic profiling in 72kD is clear. Gas chromatography-mass spectrometry (GC-MS) was used to detect the metabolic profiling in GM, WT, GM with WYMV-inoculation (GMV), WT with WYMV-inoculation (WTV) wheat, respectively. As a result, GM and WTV samples were close to each other on the principal component analysis (PCA) plot, indicating genetic modification and WYMV-infection might cause similar changes in wheat metabolism. Only 54 metabolites were annotated, and 16, 12, 17, and 14 metabolites were significantly different between GMV and GM, GMV and WTV, GM and WT, as well as between WTV and WT, respectively. Furthermore, overlapped metabolites were identified, including 3-chloro-4-hydroxybenzoic acid (CHBA), 3-sulfocatechol, S-mercaptocysteine, 1-chloro-2-nitrobenzene (2-chloronitrobenzene) and melarsoprol. In conclusion, genetic modification or/and WYMV-infection significantly affected the metabolism in wheat. This is the first report investigating the effects of WYMV-infection on metabolic profiling in GM wheat.     

烟草品种对烟草花叶病毒和黄瓜花叶病毒的抗性鉴定

 2010-2011年采用大田人工接种鉴定的方法,对生产中大面积推广使用的24份烟草品种进行了烟草花叶病毒（TMV）和黄瓜花叶病毒（CMV）的抗性鉴定。结果表明,供试品种对TMV和CMV的抗病性存在较大差异,对TMV表现抗病的有Coker86、吉烟5号、Coker176、CV87、辽烟8号、CV91、中烟90等7份材料;表现中抗的有秦烟98、双抗70、C151等3份材料;表现中感的有秦烟96、G80、金星6007、龙江981、K326、秦烟201、NC89等7份材料;表现感病的有G28、云烟97、净叶黄、红花大金元、RG11、云烟85、云烟87等7份材料。对CMV表现抗病的有Coker86、龙江981、C151、秦烟201、云烟87等5份材料;表现中抗的材料是金星6007;表现中感的有CV91、RG11、Coker176、中烟90、K326、红花大金元、净叶黄、G80、G28等9份材料;表现感病的有秦烟98、云烟85、秦烟96、NC89、双抗70、云烟97、CV87、辽烟8号、吉烟5号等9份材料。其中兼抗TMV和CMV两种病毒病的材料有2份,分别是Coker86和C151。同时研究还发现,抗病性不同的烟草品种在受到病毒危害以后,对烟叶的产量和品质的影响也不同。明确了中国24个烟草品种的抗病性水平,为抗病品种的利用与品种合理布局提供科学依据,同时为烟草抗病毒病育种的亲本选择提供抗源信息。     

Symptom severity of cassava mosaic disease in relation to concentration of African cassava mosaic virus in different cassava genotypes

The concentration of African cassava mosaic virus (ACMV) was assessed by enzyme-linked immunosorbent assay in relation to symptom severity among resistant, moderately resistant and susceptible cassava genotypes. Resistant genotype NR 8083 had significantly lower symptom severity scores ( P  < 0·05) than the susceptible genotype TMS 91934, but the two genotypes contained similar levels of virus concentration. The moderately resistant genotypes TMS 30572 and NR 8082 expressed significantly lower symptom severities ( P  < 0·05) than the susceptible genotypes TMS 91934 and TME 117, but they contained significantly higher virus concentrations ( P  < 0·05) than TMS 91934 and similar virus concentration as in TME 117. However, two other resistant genotypes, TME 1 and TME 8, had low symptom severity scores and virus concentrations. There was significant interaction ( P  ≤ 0·05) between cropping season and virus concentration in all the genotypes except TMS 30572. The resistant and moderately resistant genotypes that had high virus concentrations sustained storage root yield losses. The severity of symptoms expressed was not necessarily a reflection of the virus concentration in some of the genotypes. In addition to the use of symptom severity scores to group genotypes into resistant classes, it is recommended that virus concentration should also be considered. Genotypes displaying mild symptoms, but with high levels of virus accumulation, could be an important source of inoculum in the spread of ACMV by the whitefly vectors. This suggests that each genotype should be tested for virus accumulation prior to its release to the farmers.     

Identification of novel sources of resistance to Pea enation mosaic virus in chickpea germplasm

Chickpea can be seriously affected by Pea enation mosaic virus (PEMV) in the Pacific Northwest region of the USA and other areas of the world. Use of pesticides to manage PEMV vector transmission is ineffective and PEMV-resistant chickpeas have not been identified. Therefore, the Cicer core collection consisting of 499 wild Plant Introduction (PI) accessions and improved cultivars representing 25 countries and two chickpea phenotypes (Desi and Kabuli) was evaluated for resistance to PEMV based on a 1 to 5 scale where 1 = symptomless and 5 = severe mosaic and stunting. Eight accessions were considered resistant to PEMV based on mean disease severity values equal to or less than 1·9 in repeated greenhouse tests. All of the resistant accessions to PEMV were of the Desi type and all originated from Iran or India. PI 450763 was the only Kabuli accession that demonstrated tolerance to PEMV. PEMV resistance was not detected in commercial chickpea cultivars or advanced breeding lines currently grown in the USA and Canada. This is the first report of chickpea germplasm with resistance to PEMV.