近年我国重要苹果病害发生概况及研究进展

苹果是我国最重要的经济作物之一,截至2015年我国苹果种植面积达到232万hm~2,总产量超过4 200万t。各种病害仍是困扰我国苹果产业健康发展的限制性因素。腐烂病和枝干轮纹病依然是我国苹果最重要的枝干病害,斑点落叶病和白粉病连年发生,危害加重;霉心病在一些产区成为产业发展的限制性因素。病毒病病原种类还在增加,发生程度不断加重,已经上升为苹果主要病害。随着老果园重建的大范围开展,再植病害已经成为苹果产业可持续发展的障碍;缺素、裂果和冻害等非侵染性病害虽然不具传染性,但近年来发生面积不断扩大,对苹果产量的威胁在某些年份甚至较侵染性病害更为严重。本文系统总结了自2013年以来这些苹果主要病害的发生概况及研究进展,并分析了目前存在的问题,提出了相应的建议。     

草莓真菌病害

草莓真菌病害叶斑病、腐烂病、枯萎病、白粉病等种种真菌病害草莓栽培带来巨大有损失。这些病菌削弱植株的生长势，降低浆果产量，损害果实品质。为了及时识别这些病害、采取必要措施减轻其危害，就必须熟悉这些病害的特征。在夏季凉爽而多雨的年份，灰腐病的蔓延几乎可以...     

云南昭通苹果早期落叶病流行动态

苹果早期落叶病是影响苹果生产的重大病害,据报道苹果早期落叶病是褐斑病[Marssonina coronaria(Ell.et Davis)Davis]、斑点落叶病(Alternaria mali Roberts)、灰斑病(Phyllosticta pirinaSacc.)等多种病害的统称。通过在云南昭通系统调查影响苹果早期落叶病的主导因素品种及栽培模式,检测和统计病原菌种类及数量,调查早期落叶病发病率和病情指数,结果表明云南昭通苹果产区早期落叶病主要包括由M.coronaria引起的褐斑病和由A.mali引起的斑点落叶病,没有发现由P.pirina引起的灰斑病和其他病害。早期落叶病发病时间与品种关系密切,‘金帅’从5月下旬开始发病,8月初为发病高峰,9月底病害结束。‘红富士’则5月中旬开始发病,8月底达到发病高峰,10月底结束。不同品种和栽培方式对早期落叶病的发生程度有显著影响。     

百合主要病害及其防治措施

百合属百合科百合属 ,多年生宿根植物 ,又名野百合、药百合。由于百合具有较高的食用、药用及栽培价值 ,是滋补上品及高档名花 ,因此近年来种植面积逐年扩大 ,发展很快。但百合栽培过程中常常遭受多种病害的威胁 ,主要有百合疫病、叶枯病、鳞茎基腐病、病毒病等 ,这些病害常常混合发生 ,加重了危害的程度。１百合几种常见的主要病害１．１百合疫病导致百合茎叶腐烂 ,植株倒伏 ,影响产量。主要危害茎和叶片 ,叶片上产生水渍状灰绿色至褐色大斑 ,无明显边缘。发病严重时 ,花、鳞茎呈现水渍状褐色斑 ,腐烂 ,天气潮湿时病部长出稀疏的白色霉层。…     

兰花病害及防治

兰花是我国和世界的名贵花卉 ,近年来 ,“兰花热”风靡世界 ,兰花的炒作使许多花卉爱好者又增添了一个花卉品种。然而 ,要栽培兰花 ,纵使精心养护 ,也难免病害侵扰。如何防治兰花病害发生呢 ?这就要了解病因 ,对症下药 ,根据植物病害分类法 ,现将兰花病害分为细菌性病害、真菌性病害和病毒病害。1　细菌性病害有兰花腐烂病。根据发病部位不同 ,把兰花腐烂病分为蘖腐病和软腐病。症状 :蘖腐病症状——蘖芽基部呈水渍状绿豆大小的病斑 ,后成为暗绿色烫伤状大斑块 ,蔓延到芽鞘外部 ,呈深褐色腐烂 ;软腐病症状——在叶的末端出现水浸状的暗绿色…     

水稻细菌性病害发生特点及防控技术

以条斑病、基腐病、白叶枯病为代表的水稻细菌性病害在我省多地均有发生,面积逐年扩大,危害不断加重,严重威胁我省水稻生产和粮食安全。因此,必须了解水稻细菌性病害的发病规律以及综合防控技术。     

河北省苹果主要病虫害发生现状调查

在2007-2009年对河北省唐山、保定、邢台、石家庄、沧州、衡水、秦皇岛、张家口、廊坊、承德共10个地市200余个苹果园进行了问卷调查、实地重点考察和现场访谈,调查内容包括品种名称、树龄结构以及各种病虫害发生情况。结果表明:河北省苹果以‘富士’品种为主,占调查果园面积的58%,其次为‘元帅’;从树龄结构上看,树龄超过15年的果园占69%,说明河北省苹果园老化现象比较严重。苹果上常发生的病虫害有枝干轮纹病、腐烂病、斑点落叶病、褐斑病、锈病、苹果黄蚜、山楂叶螨、金纹细蛾、苹果绵蚜、桑天牛、枣尺蠖和黑蚱蝉共12种。其中枝干轮纹病、腐烂病和山楂叶螨是全省苹果产区发生普遍且较严重的病虫害。唐山市枝干轮纹病病株率高达92%,张家口市腐烂病病株率为72.67%,苹果黄蚜、锈病、褐斑病和金纹细蛾在不同地区发生程度不同。苹果绵蚜在河北省已普遍发生。品种以及地形对病虫害发生的影响也存在不同程度差异。本文根据对河北省苹果病虫害发生状况的调查结果,提出了通过加强栽培管理、病虫害预测预报、选用抗性品种与砧木以及化学防治为手段的病虫害防治对策。     

仿生农用杀菌剂银泰对苹果两种主要病害的防治效果

苹果腐烂病和轮纹病是苹果生产上两种重要的病害.苹果腐烂病在山东的发病株率为20%～100%,病情严重的果园,树干上病疤累累、树冠残缺不全、病株寿命缩短,甚至造成死树毁园.苹果轮纹病不仅可以危害枝杆,造成树势衰弱、枝干枯死,还常造成大量烂果,有些年份田间病果率可高达70%～80%,并且在贮藏期可继续发病.长期以来,苹果枝杆上的腐烂病和轮纹病主要以福美胂等药剂进行治疗,虽有一定的防治效果,但防治后的病疤不易愈合,还易得由于砷中毒而引起的粗皮病.果实上苹果轮纹病的防治主要以多菌灵、甲基托布津等药剂进行防治.为了有效地防治这两种病害、提高果品质量和环境安全性、减缓病原菌抗药性的产生,作者根据银杏Gingko biloba L.体内含有大量杀菌物质的报道,经过10余年的研究,从中筛选出了对植物病原真菌有较高生物活性的物质,以其化学结构为先导化合物仿生合成出了新型农用杀菌剂“银泰”.     

20％噻唑锌防治苹果病害田间试验

苹果斑点落叶病、轮纹烂果病是鲁中南地区为害苹果树叶片、果实的两大病害,常造成苹果早期落叶及果实腐烂。流行年份．可致叶片早落率30％、病果率25％以上．对树势、果品产量、质量影响甚大。为了探明20％噻唑类有机锌新型杀菌剂对苹果斑点落叶病、轮纹烂果病的防效。笔者进行了该项田间试验。试验结果表明．20％噻唑锌悬浮剂500倍液对苹果斑点落叶病的防效为81．39％．对轮纹烂果病的防效为91．14％．对苹果果实品相及叶片光泽均有一定的改善作用。     

福建省泉州市花生茎腐病的发生与防治

花生茎腐病俗称烂脖子病、枯萎病、倒秧病、烂腰病、掐脖瘟,是一种暴发性病害,依据近几年的调查,发现花生茎腐病呈现逐年加重趋势.该病主要危害茎秆,造成花生茎秆腐烂而枯死,植株早期感病后很快枯萎死亡,后期感病者果荚常腐烂或种仁不饱满,严重影响花生的产量和品质.     

Infection and colonization of melon roots by Monosporascus cannonballus in two cropping seasons in Arizona and California

Although canopy collapse of melons (one of the above-ground symptoms of vine decline caused by Monosporascus cannonballus ) occurred late in the growing season, the onset of root infection occurred much earlier. In three early winter-spring and two late winter-spring crops, the onset of root infection occurred 47–65 and 35–36 days after planting, respectively. In contrast, in four summer-autumn crops, the onset of root infection occurred within 9–17 days after planting. Vine decline occurred commonly in winter-spring crops, but did not occur in any of the summer-autumn crops. Following the onset of root infection, the percentage of plants infected increased at rates of 0·031–0·036 and 0·038–0·070 per unit per day for winter-spring and summer-autumn crops, respectively, based on the monomolecular disease progress model. Root lesions were first observed 14–42 days after the onset of infection in winter-spring crops, and 14–28 days after the onset of infection in summer-autumn crops. Pathogen reproduction occurred primarily at the end of each growing season.     

苜蓿菌核病的初步研究

对南京地区苜蓿菌核病进行了田间危害调查、病原菌分离培养和苜蓿品种抗病性评价。结果表明,该病的病原菌为三叶草核盘菌(Sclerotinia trifoliorum),主要发生在每年3月底至4月底,4月初为发病高峰期,造成整株枯死。三叶草核盘菌生长温度为5～30℃,最适生长温度15～25℃,菌丝扩展速度2.43～2.83 cm/d。苜蓿不同品种间抗病性有明显差异,抗病性极强的材料有WL414和WL325,抗性较好的材料有WL323、CS40A和CS40R。     

我国水稻黑条矮缩病和玉米粗缩病研究进展

上世纪60年代初我国华东和华北地区分别发现了水稻黑条矮缩病和玉米粗缩病,后来都分别发生了2次大流行,同时都以病害防治为目标分别开展了研究,探明了当地病害发生规律,提出了相应的防治方法,获得了不同程度的防病效果.80年代以来,水稻黑条矮缩病的发生报道仅限于华东地区局部地市,玉米粗缩病的发生涉及华北、东北、西北、西南和华中地区13个省市.根据各地对两病病原形态、寄主及症状、介体昆虫及传病特性等方面相似性的报道,提出了我国玉米粗缩病与水稻黑条矮缩病病原异同性问题.经近10年来对两病用生物学和分子生物学方法进行比较鉴定,证明我国玉米粗缩病和水稻黑条矮缩病病原同属水稻黑条矮缩病毒(RBSDV).同时基本探明了水稻黑条矮缩病在浙江杂交稻区和华北玉米区的再次流行成灾的原因,提出了相应的防治措施,并有效地控制了病害的流行危害.     

Relationship between the extent of colonization by Verticillium dahliae and symptom expression in strawberry (Fragaria × ananassa) genotypes resistant to verticillium wilt

Eleven strawberry (Fragaria × ananassa) genotypes from the University of California breeding programme known to be resistant to verticillium wilt were inoculated with Verticillium dahliae. Individual plants were given a resistance score based on the severity of visual symptoms, and the extent of colonization was quantified as the percentage of petioles not colonized by the pathogen. Both resistance scores and the percentage of pathogen‐free petioles decreased significantly from May to June (P < 0·05) during each of two growing seasons, indicating a progression of both colonization and symptom expression. Even the most resistant genotypes had plants with some infected petioles, and manifested some symptoms of verticillium wilt. Significant (P < 0·05) genotypic variance was detected for the percentage of pathogen‐free petioles, but not for resistance score. The percentage of pathogen‐free petioles had a strongly positive genotypic correlation (r_g = 0·77, P < 0·01) with resistance score, indicating that about 60% of the genotypic variation for visual symptoms in this set of resistant genotypes was explained by the extent of colonization of individual plants by V. dahliae. Conversely, the genotypic correlation between the percentage of pathogen‐free petioles and the resistance score for plants sampled in May (r_g = 0·74, P < 0·01) was smaller than that for plants harvested in July (r_g = 0·93, P < 0·01). Together, these results suggest that the overall performance of strawberry genotypes in the presence of V. dahliae can be enhanced by both resistance and tolerance, but that tolerance may be less stable over the course of a season. Distinguishing between these two mechanisms may require evaluations that supplement visual assessments of resistance.     

Characterization of Fusarium diseases on commercially grown orchids in Hawaii

A decline of unknown aetiology has become a major problem for commercial orchid production in Hawaii, one of the primary orchid‐producing states in the USA. The major symptoms of decline include root degradation, foliar blight, pseudobulb rot and sheath rot. It was unclear whether all these symptoms are caused by the same or different pathogens, but preliminary research indicated that Fusarium species may be involved. In this study, the incidence of Fusarium species was examined across 186 plants, from 29 orchid genera and intergeneric hybrids across three islands in the state of Hawaii. The main five species associated with diseased orchids were F. proliferatum (38% of samples), F. solani (16%), F. oxysporum (16%) and two previously undescribed species (8% for both species combined). The two undescribed species were similar in appearance to F. subglutinans, and were designated FS‐A and FS‐B. Pathogenicity tests established that both F. proliferatum and FS‐B caused foliar spots, foliar blight and pseudostem rot on Dendrobium orchids, and that F. proliferatum isolates from diseased tissue of several genera could also induce symptoms on Dendrobium orchids. Although orchids have increasing importance in floriculture, relatively little is known about orchid pathogens, and previous studies focused primarily on Cymbidium and Phalaenopsis. This study provides new information concerning Dendrobium orchid pathogens and suggests a much wider host range than previously recognized for the five Fusarium species recovered from tissue with symptoms. These findings can contribute to better management of Fusarium diseases, which represent a significant challenge to orchid production in Hawaii.     

Identifying resistance in wild and ornamental cherry towards bacterial canker caused by Pseudomonas syringae

Bacterial canker is a major disease of stone fruits and is a critical limiting factor to sweet cherry (Prunus avium) production worldwide. One important strategy for disease control is the development of resistant varieties. Partial varietal resistance in sweet cherry is discernible using shoot or whole tree inoculations; however, these quantitative differences in resistance are not evident in detached leaf assays. To identify novel sources of resistance to canker, we used a rapid leaf pathogenicity test to screen a range of wild cherry, ornamental Prunus species and sweet cherry × ornamental cherry hybrids with the canker pathogens, Pseudomonas syringae pvs syringae, morsprunorum races 1 and 2, and avii. Several Prunus accessions exhibited limited symptom development following inoculation with each of the pathogens, and this resistance extended to 16 P. syringae strains pathogenic on sweet cherry and plum. Resistance was associated with reduced bacterial multiplication after inoculation, a phenotype similar to that of commercial sweet cherry towards nonhost strains of P. syringae. Progeny resulting from a cross of a resistant ornamental species Prunus incisa with susceptible sweet cherry (P. avium) exhibited resistance indicating it is an inherited trait. Identification of accessions with resistance to the major bacterial canker pathogens is the first step towards characterizing the underlying genetic mechanisms of resistance and introducing these traits into commercial germplasm.     

江西甘蔗花叶病田间调查

2007年9-10月对江西甘蔗花叶病(sugarcane mosaic disease)进行了多点田间调查,结果表明江西甘蔗普遍发生花叶病,其中红皮甘蔗花叶病重于青皮甘蔗,两者病丛率分别为59.8%和19.2%,赣北、赣中、赣南3大地区之间的甘蔗花叶病发生轻重无明显差异。     

甘肃省红豆草病原真菌鉴定及病害发生动态调查

为明确甘肃省红豆草的病害种类、发生动态和危害状况,采用病原物分离与培养、形态学及分子生物学鉴定和致病性测定确定红豆草病害种类,于2012—2013年在通渭、渭源、榆中和碌曲4县调查各病害的发病率以确定发生动态,观察病害田间发生特点并结合调查数据评价其重要性。结果表明,4县共发生真菌性病害12种,分别为大茎点霉叶斑病(病原为大茎点霉属真菌Macrophoma sp.)、壳针孢叶斑病(病原为歪头菜壳针孢Septoria orobina)、炭疽病(病原为白蜡树刺盘孢Colletotrichum spaethianum)、黑秆病(病原为红豆草壳二孢Ascochyta onobrychis、菠菜刺盘孢C.spinaciae和链格孢Alternaria alternata混合侵染)、壳二孢叶斑病、茎点霉叶斑病、尾孢叶斑病、柱格孢白斑病、匍柄霉叶斑病、链格孢黑斑病、锈病和白粉病,其中大茎点霉属真菌、白蜡树刺盘孢和菠菜刺盘孢在红豆草上首次发现;尾孢叶斑病和壳针孢叶斑病为甘肃新记录病害;大茎点霉叶斑病为世界新病害,仅于碌曲县发现。白粉病、锈病、链格孢黑斑病发生于红豆草生长后期,其它病害则始于6月;6—9月危害加重的为黑秆病和柱格孢白斑病,发病率最高达89.7%和96.0%;危害渐轻的为茎点霉叶斑病、壳二孢叶斑病和壳针孢叶斑病,发病率最高达88.7%、57.4%和45.1%。黑秆病和茎点霉叶斑病在甘肃省目前危害最重。     

江西省吉安、抚州两地区柑橘黄龙病发生调查

2005年至2008年,对江西省吉安和抚州两地区共20个县、区柑橘黄龙病发生情况进行了实地调查和病样室内诊断,结果表明抚州地区目前尚无柑橘黄龙病发生,吉安地区的吉安、永新、新干、峡江、安福、吉水、水丰也无黄龙病发生,而吉安地区的遂川、万安、泰和3县则已发现了黄龙病。柑橘品种对黄龙病抗病性存在差异,椪柑最感病,而南丰蜜橘则抗病。     

河北省主推番茄品种抗黄化曲叶病鉴定与筛选初报

采用田间自然鉴定方法对河北省42个番茄生产主推品种进行抗番茄黄化曲叶病鉴定。结果表明,‘迪芬尼’、‘74 589’、‘佳西娜’、‘格利’、‘74 587’、‘荷兰6号’、‘Ty204’等7个品种田间表现明显抗番茄黄化曲叶病,发病率分别为0、0、0、1.35%、1.32%、0、1.76%。其余35个品种田间均表现明显感病,发病率最高的品种为‘鲁寿巨粉’,发病率达到99.22%,各品种发病率差异显著。