宁夏马铃薯主栽品种对黑痣病的抗性鉴定

为明确宁夏马铃薯主栽品种对黑痣病的抗性水平,利用田间和室内接种相结合的方法对供试马铃薯品种的抗病性进行评价。室内接种试验表明,供试的20份马铃薯材料中没有免疫及高抗品种,接种量与抗性水平呈负相关,其中‘陇薯7号’,‘黑美人’,‘青薯9号’在接种量为5~15g水平上表现为中抗。通过聚类分析,接种量为5g和10g时,以欧式距离13作为最佳聚类分割点,供试品种可分为3个类群。田间接种综合评价分析表明,不同品种间抗性存在显著差异,通过聚类分析,以欧式距离13作为最佳聚类分割点,试验品种可分为4个高感品种、11个中感品种和5个中抗品种。     

大麦条纹病菌致病性分析及抗性种质精细鉴定

为探明大麦条纹病菌Pyrenophora graminea的致病性差异,鉴定筛选抗病大麦种质材料,将15株大麦条纹病菌菌株通过三明治法种子幼芽接种至5个鉴别品种,分析菌株的致病性分化情况;通过在田间孢子喷雾穗部接种和三明治法种子幼芽接种对145个田间种植表现抗病品种进行抗条纹病精细鉴定。结果显示,15株菌株对5个鉴别品种致病性有一定差异,可划分为9个致病类型,其中致病类型Ⅱ、Ⅲ和Ⅳ为优势致病类型,每个致病类型菌株数均占总菌株数的20.0%,其它致病类型的菌株均占总菌株数的6.7%;致病类型Ⅰ菌株致病力最强,对5个鉴别品种表现高感。孢子悬浮液喷雾接种田间试验结果显示,90个大麦品种表现为抗病,占总数的62.1%,其中表现免疫的品种12个、高抗品种26个、中抗品种52个,分别占总数的8.3%、17.9%、35.9%。种子幼芽接种温室条件下发病鉴定结果显示,90个抗病品种接种致病类型ⅢP05菌株,对其表现抗病的品种有28个,占供试品种总数的31.1%,表现免疫的品种10个、高抗品种7个、中抗品种11个,分别占供试品种总数的11.1%、7.8%、12.2%;接种致病类型ⅠP01菌株,对其表现抗...     

不同小麦品种资源苗期和成株期麦长管蚜抗性鉴定和分析

为明确小麦苗期和成株期与麦长管蚜抗性的关系,2010—2012年采用蚜量比值法对94个小麦品种进行了温室苗期人工接种和田间成株期自然感蚜麦长管蚜抗性鉴定。结果表明,43个品种连续3年在成株期对麦长管蚜表现不同程度的抗性,其中高抗品种2个,中抗品种8个,低抗品种33个;45个品种在苗期对麦长管蚜表现不同程度的抗性,其中高抗品种5个,中抗品种16个,低抗品种24个;30个品种在苗期和成株期同时表现抗蚜,占供试品种的31.91%,其中C273和兰麦（陕西柞水）在苗期和成株期均表现为高抗;小麦品种在温室苗期人工接种和田间成株期自然感蚜的蚜量比值呈极显著正相关,苗期和成株期麦长管蚜抗性表现一致的共有66个品种,占供试材料的70.21%。研究表明温室苗期人工接种是快速鉴定小麦品种麦长管蚜抗性的有效方法。     

芝麻抗棒孢叶斑病种质资源评价及利用分析

为明确芝麻种质资源对棒孢叶斑病的抗性水平,本试验采用田间人工接菌方法对174份芝麻种质资源抗病性进行评价。田间试验结果表明,供试芝麻材料中没有免疫及高抗品种,通过聚类分析可将供试品种分为5个类群,其中抗病品种32个、中抗品种17个、中感品种69个、感病品种30个、高感品种26个,占参试品种的比例分别为18.39%、9.77%、39.66%、17.24%、14.94%。经亲本系谱分析,抗棒孢叶斑病品种的亲本对棒孢叶斑病也表现良好抗性,说明抗病基因资源的利用对芝麻品种选育至关重要,在育种工作中应加强品种系谱分析,充分利用抗病基因资源。     

30个水稻品种抗稻曲病的田间抗性评价

通过自然诱发与人工辅助接种相结合的方法,测定了30个湖南省主栽水稻品种对稻曲病的田间抗病性。结果表明,30个品种中,没有高抗品种,抗性品种有7个,占23.3%,中抗品种8个,占26.7%,中感品种11个,占36.7%,感病品种3个,占10%,高感品种1个,占3.3%。     

甘薯种质资源对甘薯瘟的抗病性测定

用甘薯瘟 2个致病型的代表菌株对 259份甘薯品种分菌系接种鉴定 ,结果依据两者间的互作反应归类为 ,1 感病型 :对 2个菌系皆表现中感—高感的品种有180份 ,占69.5% ;2 专化抗病型 :表现高抗Ⅰ型菌 ,中感—高感Ⅱ型菌的品种有59份 ,占22.8%。表现抗—中抗Ⅱ型菌 ,而感—高感Ⅰ型菌的品种有4份 ,占65% ;3 抗病型 :对Ⅰ型菌表现高抗 ,且兼抗—中抗Ⅱ型菌的品种有7份占2.7%。对 2个菌系皆表现抗—中抗的品种有9份,占3.5%。     

糯玉米种质资源对纹枯病的抗性评价

为了明确糯玉米种质资源对玉米纹枯病的抗病性,2014—2015年连续2年对广西83个糯玉米农家品种进行田间接种纹枯病菌鉴定。田间接种鉴定方法:以纹枯病麦粒培养菌物在玉米拔节期进行田间人工接种,按照国内通用的病害分级评定方法进行鉴定评价。结果表明,广西糯玉米农家品种间的抗感性存在差异;同一品种在同一年度内病害的表现春植和秋植没有差异。在83个品种中没有发现免疫和高抗的品种,其中抗病品种占所鉴定品种总数的42.2%,中抗水平占40.9%,感病占13.3%,高感占3.6%。     

内蒙古自治区主栽马铃薯品种对黄萎病的抗性鉴定

为明确内蒙古自治区主栽马铃薯品种对黄萎病的抗性情况,于2016年分别在内蒙古自治区乌兰察布市凉城县、锡林郭勒盟正蓝旗、锡林郭勒盟多伦县3个试验田对16个马铃薯品种抗性进行鉴定。试验采用室内与田间鉴定相结合,通过调查地上部植株和地下部块茎的发病程度评价马铃薯品种的抗性。室内抗性鉴定结果显示,在所测定的16个马铃薯品种中,抗病品种有3个(10≤病情指数20),占总品种的18.75%;中抗品种有8个(20≤病情指数35),占总品种的50.00%;感病品种有5个(病情指数≥35),占总品种的31.25%,未发现免疫和高抗品种。田间人工病圃和自然病圃抗性鉴定结果显示,部分品种在不同地区的抗性表现不稳定,其中合作88在不同地区的抗性水平较强,适合在黄萎病流行地区种植,从而达到防病增产的目的。     

不同百合品种对百合灰霉病的抗病性鉴定

为明确不同百合品种对灰霉病的抗病能力,本试验采用离体叶片菌丝块接种和田间孢子液喷雾2种方法测定了百合7个不同品种对百合灰霉病的抗病性。离体测定结果表明,供试的7个品种对百合灰霉病的抗病性存在显著差异,其中‘法兰西’和‘罗蒂娜’为高感品种,‘康斯坦萨’和‘索邦’为高抗品种,‘马可波罗’、‘提拔’和‘西伯利亚’为中抗品种;田间接种发病的测定结果除‘西伯利亚’为高抗品种外其余结果与离体接种结果一致;离体接种和田间接种发病情况的系统调查分析得知,感病品种‘法兰西’和‘罗蒂娜’发病早,病情发展速度快,病情指数高;‘提拔’、‘康斯坦萨’、‘西伯利亚’和‘索邦’等抗病品种发病晚,病情发展缓慢,病情指数低;随着品种抗病性的增强,发病速度和病情指数逐渐降低。     

临麦系列春小麦品种抗条锈性分析

小麦条锈病是发生于甘肃省临夏州小麦生产上的最主要病害,种植抗病品种是防治该病最经济有效且有利于保护环境的措施。作者于2013年在甘肃省农业科学院植物保护研究所兰州低温温室和甘谷试验站进行了苗期、成株期分小种接种鉴定,并于2010-2014年对临麦系列春小麦品种‘临麦32号’~‘临麦36号’在甘肃省不同生态区的8个试验点进行成株期抗条锈性分析,结果表明:春小麦品种‘临麦32号’苗期对所有供试菌系均表现感病,成株期对CYR29和CYR32表现中抗-中感;‘临麦33号’除对CYR29苗期表现免疫、成株期表现中抗-中感外,对其余供试菌系均表现感病。对自然诱发的条锈病,两品种也表现感病;‘临麦34号’和‘临麦36号’除对新菌系G22-9、G22-14表现感病外,对其余菌系表现抗病,但自2013年开始两品种在田间也表现感病;‘临麦35号’全生育期对接种及自然诱发的条锈菌均表现抗病。苗期选用24个国内外供试条锈菌单孢菌系进行基因推导分析,发现供试临麦系品种抗性谱与已知基因载体品种的抗性谱均不一致,初步推测供试临麦系品种含有未知抗条锈基因。     

湖南白菜和红菜薹根肿病菌生理小种鉴定

为了弄清湖南省白菜和红菜薹根肿病菌生理小种组成和分布,2013年采集长沙、湘潭、益阳、怀化4个地区的十字花科作物白菜、红菜薹根肿病株27个,用Williams根肿病鉴别品种对其进行生理小种鉴定。初步鉴定出5个生理小种,即1号、5号、8号、9号和11号,它们在湖南病区中出现的频率分别为22.3%、18.5%、14.8%、33.3%和11.1%。按寄主生理小种组成,湖南白菜根肿病菌生理小种有1号、5号、9号、11号,红菜薹根肿病菌为8号、9号和11号;按地区生理小种分布,长沙白菜根肿病菌生理小种为5号和9号,湘潭白菜和红菜薹根肿病菌生理小种分别1号、8号和11号,怀化白菜根肿病菌为生理小种9号;益阳白菜和红菜薹根肿病菌分别为生理小种1号、11号、8号和9号。目前,在湖南4个市白菜和红菜薹根肿病菌生理小种是9号。     

Effects of growing leafy daikon (Raphanus sativus) on populations of Plasmodiophora brassicae (clubroot)

Control of some soilborne pathogens may be achieved by use of decoy or catch crops. These stimulate the germination of resting spores, resulting in limited expression of disease symptoms. Results achieved using this approach are reported here using leafy daikon (radish, Raphanus sativus var. longipinnatus ) for control of Plasmodiophora brassicae , the cause of clubroot disease of Brassicaceae. Disease indices of Chinese cabbage plants grown in pots that had previously contained leafy daikon were lower compared with pots where no plants had been grown before (control pots). Numbers of resting spores of P. brassicae in soil in pots after cultivation with leafy daikon were reduced by 71% compared with control pots when resting spores were recovered and counted directly. In a field experiment, numbers of resting spores were reduced by 94% compared with the start of the experiment when leafy daikon was grown in advance of Chinese cabbage, but there was no reduction in disease severity in the Chinese cabbage. Plasmodiophora brassicae infected the root hairs of leafy daikon and those of Chinese cabbage, but no clubs were found on leafy daikon roots. The results from pot trials indicate that leafy daikon may be useful as a decoy crop for the control of clubroot disease in field crops.     

Eradication of Plasmodiophora brassicae during composting of wastes

Survival of infectious inoculum of the clubroot pathogen Plasmodiophora brassicae was assessed following bench-scale flask composting experiments and large-scale composting procedures. Clubroot-affected material was provided by artificial inoculation of Chinese cabbage or naturally infected Brussels sprout and cabbage roots. Both sets of diseased material were used in flask experiments, and the latter in large-scale windrow and aerated tunnel experiments. Municipal green wastes, onion waste and spent mushroom compost were evaluated in flask experiments with varying temperature, aeration and moisture conditions. Green wastes were used in larger-scale composts. Within the limits of a Chinese cabbage seedling bioassay, both temperature and moisture content were critical for eradication of P. brassicae spores extracted from composted clubroot-affected residues. Incubation in compost at 50°C for 7 days or 1 day at 60°C with high moisture levels (= −5 kPa matric potential or 60% w/w moisture content) eradicated inoculum from artificially inoculated Chinese cabbage roots. In large-scale windrows and aerated tunnels, the pathogen was eradicated from naturally infected brassica wastes after 6–7 days at 54–73°C.     

Isolation and characterization of bacterial isolates for biological control of clubroot on Chinese cabbage

Clubroot caused by Plasmodiophora brassicae is becoming an emerging threat to the production of crucifer vegetable crops in China. The aim of this study was to develop an effective biocontrol strategy against clubroot of Chinese cabbage. Results indicated that six out of fourteen bacterial strains that were isolated from vegetable rhizosphere soil reduced disease severity of Chinese cabbage by more than 50.% under greenhouse conditions.In greenhouse experiments, a soil-drench application of strain YFY 02, 13-1 and HY cell-free culture filtrate reduced the clubroot by 37.7-74.6 % relative to pathogen post-inoculation control on the highly susceptible Chinese cabbage cultivar. Seed treatment of strain YFY 02, 13-1 and HY cell-free culture filtrate reduced clubroot by 23.8-56.0 % in greenhouse experiments. In two field trials conducted at Tonghai and Lufeng sites, cell-free culture filtrates of three isolates reduced clubroot severity on Chinese cabbage by 62.4-76.8 % and 79.4 % -85.1 %, respectively. This efficacy was similar to fungicide Cyazofamid. Based on the sequence analysis of the 16S rDNA gene and identification of biochemical and physiologica criteria l(Biolog carbon source utilization analysis), the strains YFY 02 and HY were identified as Lysobacter antibioticus. To our knowledge, this is the first report of L. antibioticus strains being a promising candidate as a biological control agent against clubroot.     

江西省蔬菜根肿病菌致病性分化研究

正芸薹根肿病菌(Plasmodiophora brassicae)存在生理小种分化现象,国际上通常采用Williams鉴别系统~([1])和欧洲根肿病菌鉴别寄主(ECD)系统~([2])鉴定根肿病菌生理小种。我国尚没有研究出适合本国根肿病菌生理小种鉴定的鉴别寄主系统。国内学者研究根肿病菌生理小种通常采用Williams鉴别系统~([3])。为了明确江西省蔬菜根肿病菌致病性分化及病菌小种的变化趋势,作者采用     

Pathogenic and genetic diversity in Plasmodiophora brassicae (clubroot) from Japan

Clubroot disease, caused by Plasmodiophora brassicae Woronin, affects various cruciferous crops. Variations in pathogenicity and virulence are present among field populations of P. brassicae. Many races (pathotypes) have been reported in Japan as well as in other countries using various differential systems. Populations can be classified into four pathotypes using two clubroot-resistant (CR) cultivars of Chinese cabbage as differential hosts in Japan. However, it was recently indicated that each population is often heterogenic and composed of multiple genotypes (races or pathotypes). Breakdown in CR cultivars of Chinese cabbage is a problem in some areas of Japan and may contribute to the selective propagation of minor pathogenic genotypes on the CR cultivars. Clubroot has also been recorded on five species of cruciferous weeds in Japan. In particular, clubroot of Cardamine flexuosa is widely distributed in Japan. Some populations of C. flexuosa are often moderately pathogenic on Chinese cabbage and turnip. Therefore, the epidemiological relationship between clubroot of cruciferous crops and that of the weed has been noted but not thoroughly clarified. The relationship between pathogenic and genetic variations has also been examined among populations from cruciferous crops and weeds in Japan. The result implies an interesting genetic relationship among Williams’ races, among pathotypes determined using CR cultivars of Chinese cabbage and among populations from crops and C. flexuosa. This review includes an introduction of the status of studies on pathogenic and genetic diversity in P. brassicae from Japan.     

Characterization,genetic diversity and distribution of Xanthomonas campestris pv. campestris races causing black rot disease in cruciferous crops of India

Black rot, caused by Xanthomonas campestris pv. campestris (Xcc) is a disease of crucifer crops. The objective of this study was to characterize races of Xcc, their distribution and genetic diversity in India. Two hundred and seventeen isolates of bacteria were obtained from 12 different black rot‐infected crucifer crops from 19 states of India; these were identified as Xcc based on morphology, hrpF gene and 16S rRNA gene based molecular markers and pathogenicity tests. Characterization of races was performed by using a set of seven differential crucifer hosts, comprising two cultivars of turnip (Brassica rapa var. rapa) and cultivars of Indian mustard (B. juncea), Ethiopian mustard (B. carinata), rapeseed mustard (B. napus), cauliflower (B. oleracea) and Savoy cabbage (B. oleracea var. sabauda). Races 1, 4 and 6 of Xcc were identified and, among these races, race 1 followed by race 4 dominated most of the states of India. Genetic diversity of the Indian isolates of Xcc was analysed using repetitive sequence‐based PCR (rep‐PCR) including primers for REP (repetitive extragenic palindromic), ERIC (enterobacterial repetitive intergenic consensus) and BOX (amplifying with BOX A1 R primer) repetitive elements. This method of fingerprinting grouped the isolates into 56 different DNA types (clusters) with a 75% similarity coefficient. Among these clusters, DNA types 22 and 53 contained two different races 1 and 4, whereas DNA type 12 contained races 1, 4 and 6. However, no clear relationship was observed between fingerprints and races, hosts or geographical origin.     

2002年黑龙江省部分稻区稻瘟病菌生理小种鉴定

用中国7个统一鉴别品种对2002年在黑龙江省部分地区采集的57个单孢分离菌株进行了生理小种鉴定。共鉴定出6群10个生理小种,即ZA17、ZA49、ZB1、ZB19、ZB25、ZC9、ZD1、ZD5、ZE1和ZF1生理小种,其中ZD1为优势小种,出现频率为36.8%。生理小种的组成由1996年商世吉报导的4群7个生理小种发展到6群10个生理小种,优势小种也由ZE1转变为ZD1。其中ZA17、ZA49强致病型的生理小种开始出现。所鉴定出的10个生理小种对4个粳稻鉴别品种有较强的致病力。地域较近的地区稻瘟病菌的生理小种群体组成也有较大差异。     

Variation in Virulence of Plasmodiophora brassicae in Japan Tested with Clubroot-resistant Cultivars of Chinese Cabbage (Brassica rapa L. ssp. pekinensis)

The differential hosts of Williams (1966) and the European Clubroot Differential (ECD) (Buczacki et al., 1975) have been used commonly to identify populations of Plasmodiophora brassicae, which causes clubroot disease in Brassica crops. However, some of these hosts showed intermediate and fluctuating scores to most populations from Japan. Therefore, these hosts could not be used to provide a clear classification in Japan. We have tried to clarify the genetic diversity in pathogenicity of P. brassicae in Japan using Japanese clubroot-resistant (CR) F₁ hybrid (F₁) cultivars and lines of Brassica rapa. The responses of some CR F₁ cultivars were very clear. Four groups of field populations in Japan were recognized using the CR F₁ cultivars. The clear response obtained here may depend largely on the genetic purity of the F₁ cultivars. Moreover, it is possible to classify some of these Japanese populations into the same race using the Williams set and ECD 01 to ECD 05. The present differential hosts may be useful in the study of European populations of P. brassicae. The response of the differential hosts suggests that there are several major CR genes in B. rapa. It is suggested that pyramiding CR genes would be useful in breeding CR cultivars that can overcome the breakdown of the present CR cultivars of Chinese cabbage.     

Effects of cyazofamid against Plasmodiophora brassicae Woronin on Chinese cabbage

Cyazofamid (4-chloro-2-cyano-N,N-dimethyl-5-p-tolylimidazole-1-sulfonamide) is a novel fungicide with high levels of activity against Oomycetes fungi and Plasmodiophora brassicae Woronin. The effects of cyazofamid were investigated against P. brassicae, the causal agent of clubroot disease in Chinese cabbage. Cyazofamid at 0.3 mg litre(-1) inhibited resting spore germination of this pathogen by about 80%. Cyazofamid at 3-10 mg litre(-1) exhibited fungicidal activity to resting spores of P. brassicae 1-10 days after treatment. When cyazofamid was applied to infested soil, both root-hair infections and club formation caused by P. brassicae were strongly inhibited at 1-3 mg kg(-1) dry soil. These results suggest that cyazofamid directly inhibits resting spore germination, thereby leading to the inhibition of root-hair infection and club formation. Cyazofamid at 3 mg kg(-1) dry soil also exhibited complete control of clubroot disease. The effect of broadcast soil application using a dust formulation at 2 kg AI ha(-1) (equivalent to 1.3 mg AI kg(-1) dry soil), and plug seedling tray application by a suspension concentrate formulation at 200 and 400 mg AI tray(-1) (30 x 60 x 4 cm3) against P. brassicae was also evaluated. Cyazofamid exhibited good efficacy against the pathogen. The sequential treatment including plug seedling tray application with cyazofamid and pre-plant broadcast soil application with the fungicide fluazinam also exhibited excellent levels of control. These results indicate that cyazofamid has a high potential to be an effective fungicide for the control of clubroot disease.