黄瓜品种苗期抗黑星病筛选初报

黄瓜品种苗期抗黑星病筛选初报李宝栋，冯东昕（中国农科院蔬菜花卉研究所北京１０００８１）黄瓜黑星病（ＣｌａｄｏｓｐｏｒｉｕｍｃｕｃｕｍｅｒｉｎｕｍＡｒｔｈ．ｅｔＥｌｌ．）是一种世界性病害，对黄瓜危害很大，近年未，我国北方一些省市曾一度严重流行。黄瓜植株...     

辽宁梨黑星病的防治

辽宁省是我国主要梨产区之一,近年发展尤为迅速,总株数近4000万株,年产量32万余吨。近几年,梨黑星病发生十分普遍,为害相当严重。防治该病已成为梨树生产上的一项重要工作。1 症状梨黑星病主要为害叶片及果实,其症状特点是在病部产生黑色霉状物。叶片受害多先发生于叶背面,在叶脉上形成长条形黑色霉斑。在叶表面的叶脉间产生近圆形褪绿斑,不久病斑上长出初为绿褐色后变黑色的霉状     

花期前喷药防治梨黑星病

为了防止梨黑星病早期发生,我们试验在梨树开花前喷波尔多液,有显著效果。 试验是在东代固大队,27年生梨园内进行,品种为鸭梨,树势衰弱,1963年感黑星病较重,病果率为75％。处理方法见下表:     

防治梨黑星病的技术要点

为防治梨黑星病，各个果园都投入了大量人力、物力进行多次施药，但有的果园并未取得好的防效。究其原因有多种可能：①用药不当，未在关键时期施药，病害失控；②病菌对有些杀菌剂已有抗性，虽按要求施用，防效下降；③对新的高产内吸杀菌剂品种应用技术未能深刻领会。实质是对病原菌的越冬、早春初发生、流行的气候条件等所知不多，抓不住防治关键，再加上对药剂使用技术不精等原因综合而成的结果。     

河北廊坊市鸭广梨暴发梨黑星病

固安县北义后村是一个有百余年生产历史的鸭广梨产区,有混植梨园1000余亩。其中鸭广梨树占梨树总数的80％,其产量产值占梨产量产值总数的90％以上。另外零星分布有少量鸭梨、京白梨等。是一个以盛产鸭广梨为特点的果树专业村。1982-1989年,该村的鸭梨、京白梨每年都因梨黑星病发生造成不同程度损失:而鸭广梨很少见到病果,果实商品率一般可达90％以上。1990年该     

无公害药剂防治梨黑星病药效试验

莱阳梨肉嫩质细,清脆可口,香浓味美,驰名中外。梨黑星病Venturia Pirina(Cooke) Aderh是莱阳梨的重要病害之一,每年受害面积达1667hm2,占全市栽培梨园面积的90%以上。梨黑星病主要危害叶片和果实,叶片受害后,在叶片背面产生圆形或不规则淡黄色病斑,潮湿环境下,产生黑色霉层。果实在直径1cm大小就可受害,病斑圆形,随着果实的增长,     

梨黑星病发生的主要诱因分析

梨黑星病一直是陕西梨产区的主要病害.自 1998年暴发以来,梨农始终将该病害的防治当作头等大事来抓,有的已经形成一种习惯,每年都要定期喷药防治.从减少农药残留,保护环境安全,依据实情防治,节支、增效的角度考虑,每年用 5～ 7次药剂防治一种病害,是很不科学的.为了科学指导防治,我们从弄清梨黑星病发生的主要诱导因子入手,对该病暴发后几年来的气象条件进行跟踪分析,发现降雨和温度是引起该病流行的关键因子.据此,本文加以分析,以便对植保人员及梨农今后管理该病有所裨益.     

梨黑星病流行动态模拟模型程序设计

梨黑星病流行动态模拟模型(PSSM)能以一日为一个步长模拟整个生长季节梨黑星病的流行动态。PSSM的计算机程序采用了面向对象的程序设计。模型中,梨园每一天的状态,如寄主、病原物的相对数量,果园环境的温度、湿度,果园管理措施等,由一个果园状态对象表示。果园状态对象由18个子对象和10个子模型构成。18个子对象分别表示寄主、病原物的相对数量、果园环境条件和管理措施等。10个子模型模拟孢子传播、侵染、病斑显症等病害流行动态过程。模型运行时,子模型根据果园前期状态和当日环境,计算获得数据,创建表示当日果园状态的对象,并依次类推。程序结构清晰自然,能较好地再现病害发生与流行的生物学过程。     

防治香蕉黑星病药剂筛选试验

香蕉黑星病,又名黑斑病,是香蕉常见的病害,近几年来,发生日趋严重,已上升为香蕉最主要病害之一。此病大大影响香蕉果外观、品质及产量,降低其商品价值、经济效益。为了经济、有效、安全地控制香蕉黑星病的发生,我们于2004年进行防治香蕉黑星病药剂筛选试验,旨在指导蕉农科学用药提供依据。1试验条件1.1试验地点、作物试验在长泰县武安镇溪东村和兴片区香蕉园进行,试验地为平地,土壤为沙壤土,土质肥沃,排灌条件良好。香蕉品种为台蕉2号,抽蕾结果期,株高2.5m~3m,长势良好,香蕉黑星病中偏重发生。1.2防治对象香蕉黑星病1.3气象条件试验期间天气…     

世高等药剂防治梨黑星病药效观察

梨黑星病是南方梨树主区的主要病害 ,常造成早期大量落叶 ,对树势、产量、品质影响较大。为了筛选高效、低毒的农药 ,并在生产上广泛的应用 ,达到理想的防治效果。作者于２００１年５～６月在修文县扎佐镇梨树上进行了世高、霉能灵等药剂防治梨黑星病药效试验 ,现将结果报告如下 :１材料与方法１．１供试药剂及使用浓度①１０ %世高ＷＧ５０００倍 ,有效成分 :恶醚唑 ,瑞士诺华公司 ;②５ %霉能灵ＷＰ８００倍 ,有效成分 :酰胺唑 ,日本北兴化学工业株式会社 ;③４０ %福星ＥＣ８０００倍 ,有效成分 :氟硅唑 ,上海杜邦农化有限公司治效果。２…     

Polygalacturonase-inhibiting protein (PGIP) from Japanese pear: possible involvement in resistance against scab

Venturia nashicola is the causal agent of scab, a fungal disease affecting Asian pears. The Japanese pear cv. ‘Kousui’ is highly susceptible to the race 1 of this fungus whereas the cv. ‘Kinchaku’ and the non-host European pear cv. ‘Flemish Beauty’ are resistant. The aim of this work is to investigate the role of polygalacturonase-inhibiting proteins (PGIPs) of pear during the interactions with V. nashicola leading to susceptibility or resistance. PGIP protein was detected from immature fruit of Kousui and Kinchaku. It showed a molecular mass of 42 kDa that shifted to 35 kDa after chemical deglycosylation. The gene pgip was amplified by PCR using genomic DNA and/or cDNA from young leaves of Kousui, Kinchaku, and European pear cvs. Flemish Beauty, ‘Bartlett’, and an Asian wild pear strain ‘Mamenashi 12’, then sequenced after sub-cloning. Some conserved variations were identified in the sequence indicating that gene family also exists in pgip of Japanese pear and confirmed by Southern blot analysis. The expression of PGIP was studied in scab-inoculated leaves of the susceptible Kousui and the resistant Kinchaku and Flemish Beauty. pgip Gene and its encoding protein were highly and rapidly activated in these resistant plants. In addition, PGIP extracts derived from Kinchaku and Flemish Beauty partially inhibited the activity of polygalacturonase (PG) from V. nashicola suggesting a possible role of PGIP in limiting fungal growth frequently observed in these resistant cultivars.     

抗黑星病芽变鸭梨组织结构、生理生化与抗病性关系研究

对一株抗黑星病芽变‘鸭梨’的叶片组织结构和生理生化特性进行了研究,发现其叶片蜡质含量高、栅栏组织双层出现时间早、厚度大、海绵组织结构致密、气孔数目少,推断这些特性决定黑星病菌分生孢子不易侵入叶片内部;叶绿素含量高为植株抗病性提供了生理基础,可溶性糖含量低有可能抑制黑星病营养菌丝在细胞间的生长和扩展。通过研究该抗黑星病芽变‘鸭梨’的抗病机理,为‘鸭梨’抗黑星病育种提供了理论依据。     

Amplified fragment length polymorphism markers linked to a major quantitative trait locus controlling scab resistance in wheat

ABSTRACT Scab is a destructive disease of wheat. To accelerate development of scab-resistant wheat cultivars, molecular markers linked to scab resistance genes have been identified by using recombinant inbred lines (RILs) derived by single-seed descent from a cross between the resistant wheat cultivar Ning 7840 (resistant to spread of scab within the spike) and the susceptible cultivar Clark. In the greenhouse, F(5), F(6), F(7), and F(10) families were evaluated for resistance to spread of scab within a spike by injecting about 1,000 conidiospores of Fusarium graminearum into a central spikelet. Inoculated plants were kept in moist chambers for 3 days to promote initial infection and then transferred to greenhouse benches. Scab symptoms were evaluated four times (3, 9, 15, and 21 days after inoculation). The frequency distribution of scab severity indicated that resistance to spread of scab within a spike was controlled by a few major genes. DNA was isolated from both parents and F(9) plants of the 133 RILs. A total of 300 combinations of amplified fragment length polymorphism (AFLP) primers were screened for polymorphisms using bulked segregant analysis. Twenty pairs of primers revealed at least one polymorphic band between the two contrasting bulks. The segregation of each of these bands was evaluated in the 133 RILs. Eleven AFLP markers showed significant association with scab resistance, and an individual marker explained up to 53% of the total variation (R(2)). The markers with high R(2) values mapped to a single linkage group. By interval analysis, one major quantitative trait locus for scab resistance explaining up to 60% of the genetic variation for scab resistance was identified. Some of the AFLP markers may be useful in marker-assisted breeding to improve resistance to scab in wheat.     

与番茄枯萎病抗病基因I-1连锁的AFLP和SSR分子标记

本研究以番茄枯萎病抗病品种‘05045’与感病品种‘051451’为亲本配制杂交组合。用870对AFLP引物及319对SSR引物对348个F2代分离群体进行连锁分析,得到4个与番茄枯萎病抗病基因I-1连锁的AFLP标记和2个SSR标记,分别是E41M60-D、E41M62-C、E86M36-B、E32M44-E和SSR108、SSR276,与抗病基因I-1的连锁遗传距离分别为4.7、5.3、8.9、11.5cM和6.1、9.3cM。     

Effects of temperature, relative humidity and duration of wetness period on germination and infection by conidia of the pear scab pathogen (Venturia nashicola)

Experiments were conducted to determine the effects of temperature, relative humidity (RH) and duration of wetness period on in vitro germination of conidia and infection of detached pear leaves by Venturia nashicola , the causal agent of pear scab. Conidia germinated only in near-saturation humidity (RH > 97%). The final percentage germination (24 h after inoculation) at 100% RH without free water was less than half that in free water. Conidia germinated over the range of temperatures tested (5–30°C); the optimum temperature for germination was ≈21°C. Changes in percentage germination of conidia over time were fitted by logistic models at each individual temperature. Polynomial models satisfactorily described the relationships between two (rate and time to 50% of maximum germination) of the three logistic model parameters and temperature. The minimum length of the wetness period for successful infection of detached pear leaves by conidia was observed at several temperatures. The shortest length of wetness period required for infection was 7 h at 22°C. Two polynomial models fitted well the relationship between the minimum wetness duration required for infection, and temperature.     

Identification of molecular markers linked to a gene conferring resistance to coffee berry disease (Colletotrichum kahawae) in Coffea arabica

Coffee berry disease (CBD) caused by Colletotrichum kahawae is a major constraint to Arabica coffee (Coffea arabica) production in Africa. One source of resistance to the disease is a natural interspecific hybrid between C. arabica and C. canephora and its derivatives. This study is aimed at deciphering the genetic basis of the host resistance and identification of molecular markers associated with it. CBD is a mature stage disease and in the absence of a mature mapping population, early detection of disease reaction phenotypes of mapping individuals is required. Two F₂ populations from crosses of cv. Catimor (resistant) and cv. SL28 (susceptible) were screened for resistance by a two step procedure. First, half of each population was screened 6 weeks after germination by inoculating hypocotyls with the pathogen. The surviving seedlings (G1) were considered to be resistant and were raised in a nursery together with the other unscreened halves (G2). Secondly, after one year, all the seedlings (G1 + G2) were screened by inoculation. Analysis of 57 microsatellites and 31 AFLP markers in 56 and 95 seedlings from G1 and G2, respectively, were performed. Eight AFLP and two microsatellites markers linked tightly to the resistant phenotype were identified and mapped to one unique chromosomal fragment introgressed from C. canephora. The gene conferring the resistance was localized within an 11 cM segment. It is concluded that the locus carries a major resistance gene designated Ck‐1, which is likely to be synonymous to the T gene described in previous studies.     

Ultrastructural study on scab resistance expressed in epidermal pectin layers of pear leaves

Proliferation and collapse of subcuticular hyphae of Venturia nashicola race 1 were studied ultrastructurally, after inoculation of susceptible Japanese pear cv. Kousui, resistant Japanese pear cv. Kinchaku, resistant Asian pear strain Mamenashi 12 and nonhost European pear cv. Flemish Beauty leaves, to understand the nature of the resistance mechanism. After cuticle penetration by the pathogen, the hyphae were observed at lower frequency in epidermal pectin layers and middle lamellae of leaves of the three resistant plants than in those of susceptible ones. This result suggested that fungal growth was suppressed in the incompatible interaction between pear and V. nashicola race 1. In the pectin layers of all inoculated plants, some hyphae had modifications such as breaks in the plasmalemma with plasmolysis, necrotic cytoplasm and degraded cell walls. More hyphae had collapsed in the leaves of the three resistant plants than in those of the susceptible cv. Kousui. In collapsed hyphae, the polymerized cell walls broke into numerous fibrous and amorphous pieces, showing that the scab resistance might be associated with cell wall-degrading enzymes from pear plants.     

小麦抗叶锈基因Lr 38的AFLP标记

 小麦叶锈病是小麦的重要病害之一,几乎在所有小麦种植区都有发生,严重时可造成5%~15%甚至更大的产量损失^[1]。小麦抗叶锈基因Lr38发现位于中间偃麦草(Agropyron intermedium)第7组的一条染色体上,并被标定在6 DL上^[2],是抗性很强的抗叶锈病基因,国内外至今尚未发现对Lr38有毒性的菌株,是一个应用潜力很大的抗病基因。     

亚麻品系9801-1抗白粉病基因的RAPD标记

 F2 populations were obtained from the cross between 9801-1 and DIANE.Bulked segregate and RAPD analyses were employed to identify molecules linked to the resistance to powdery mildew.OPP02 amplified about 792 bp polymorphic band in all individuals from 9801-1 and resistant bulk,but absent in all individuals from DIANE and susceptible bulk.By further analysis in F2 segregating population,the polymorphic band was found to be cosegregated with the resistant gene possibly.The fragment was sequenced,     

番茄黄萎病抗病基因Ve的AFLP和SSR分子标记

 本研究以番茄抗病品种05046与感病品种051355配制杂交组合,接种鉴定F1代及F2代分离群体的黄萎病发生情况,结果表明,番茄黄萎病属单基因显性遗传。用545对AFLP引物和101对SSR引物对两个亲本、抗感池及F2代分离群体进行AFLP和SSR分析,得到3个与番茄抗黄萎病基因Ve连锁的AFLP标记和1个SSR标记,分别是E66M84-A、E78M84-D、E66M40-A和SSR599,与抗病基因Ve的连锁遗传距离分别为10.3、14.2、30.5 和12.5 cM。