马铃薯块茎蛾幼虫致病黏质沙雷氏菌的分离鉴定及杀虫活性

从马铃薯田自然罹病马铃薯块茎蛾幼虫上,分离到1株对马铃薯块茎蛾幼虫具有较强致病作用的菌株ML-1,通过形态及16S rRNA序列测定分析,确定该菌株ML-1为黏质沙雷氏菌Serratia marcescens。采用饲喂法分别测定了该菌株ML-1菌悬液、发酵液及发酵上清液对马铃薯块茎蛾初孵3日龄幼虫的毒力。结果表明,用ML-1菌悬液、发酵液及发酵上清液饲喂后第7 d时,马铃薯块茎蛾3日龄幼虫的累积校正死亡率分别为63.16%、80.70%和49.12%,在3.0×10⁹ cfu/mL浓度下的LT₅₀分别为4.71、3.04和6.47 d,在发酵液处理后第3、5和7 d的LC₅₀分别为9.784×10¹⁰、1.855×10⁸和5.434×10⁵ cfu/mL。综上所述,黏质沙雷氏菌ML-1菌株对马铃薯块茎蛾幼虫有较强的毒力,在马铃薯块茎蛾绿色防控中具有一定的开发潜能。     

基于年龄-阶段两性生命表的不同寄主对马铃薯块茎蛾生长发育和繁殖力的影响

为生态调控马铃薯块茎蛾Phthorimaea operculella,在室内测定取食马铃薯和烟草后马铃薯块茎蛾的各生长发育指标,并利用年龄-阶段两性生命表计算取食这2种植物后马铃薯块茎蛾的存活率、繁殖力、寿命期望、繁殖值和种群参数,并分析不同寄主之间各参数的差异。结果表明,取食烟草的马铃薯块茎蛾卵发育历期、幼虫发育历期、蛹发育历期、雌成虫寿命和雄成虫寿命分别为5.0、18.6、5.7、41.2和40.9 d,均显著大于取食马铃薯的马铃薯块茎蛾(分别为4.1、16.7、3.6、37.2和36.7 d),取食马铃薯的马铃薯块茎蛾的每日单雌产卵量、内禀增长率、周限增长率和净增殖率分别为130.2粒、0.138 d-1、1.15 d-1和49.5,均显著高于取食马铃薯的马铃薯块茎蛾(分别为49.1粒、0.086 d-1、1.09 d-1和17.5);取食马铃薯的马铃薯块茎蛾幼虫、蛹、新孵化个体到雌成虫和新孵化个体到雄成虫的存活率分别为93.4%、63.0%、38.0%和45.0%,也高于取食烟草的马铃薯块茎蛾(分别为65.6%、59.0%、26.0%和28.0%);取食马铃薯的马铃薯块茎蛾其平...     

利用线虫防治马铃薯块茎蛾

S.carpocapsae隶属于能侵染4目100多种昆虫(包括马铃薯块茎蛾)的Sfeinernema线虫科。以其幼虫肠中共生的细菌(Achromobacter nematopnilus)进入昆虫血淋巴后引起败血病死亡。紫外线可制约其效果。每块茎蛾幼虫上的致病体120个以上时,3天内可使该幼虫死亡率达97.8％,从每蛾幼虫产生的有侵染力线虫的幼虫数最高达1.3万～1.7万个。     

马铃薯块茎病原真菌拮抗菌株筛选及优良拮抗菌株鉴定

从马铃薯块茎上分离内生细菌,以块茎病原真菌为指示菌,采用平板对峙法筛选拮抗菌株,并利用形态学特征和16S rDNA基因序列分析对优良拮抗菌株进行鉴定。结果表明,从定西马铃薯块茎中共分离得到72株内生细菌,其中19株对5种块茎病原真菌的抑菌率均高于51.87%,特别是内生细菌6-5和5-6分别对马铃薯炭疽病菌Colletotrichum coccodes和马铃薯黑痣病菌Rhizoctonia solani的抑菌率达85.82%和72.18%,且具有固氮和产吲哚乙酸(IAA)功能,其产IAA量分别为3.37 mg/L和19.25 mg/L;根据形态特征及16S rDNA基因序列将菌株5-6鉴定为萎缩芽胞杆菌Bacillus atrophaeus,菌株6-5鉴定为贝莱斯芽胞杆菌Bacillus velezensis。     

番茄潜叶蛾与马铃薯块茎蛾形态特征及为害症状的比较

番茄潜叶蛾Phthorimaea absoluta Meyrick是一种重要的世界性检疫性害虫。2017年8月入侵我国,现已扩散蔓延至我国多个省市,对露地和保护地鲜食番茄生产构成了严重威胁。在田间种植的番茄和马铃薯上,番茄潜叶蛾与同科的马铃薯块茎蛾常混合发生,且形态与取食为害特征相似,较容易混淆,给田间识别带来困难。本文详细描述和比较了番茄潜叶蛾和马铃薯块茎蛾成虫、卵、幼虫和蛹的外部形态及幼虫为害症状。本文将为番茄潜叶蛾和马铃薯块茎蛾的准确识别及田间调查提供指导,还可为这两种害虫的精准测报奠定基础。     

湖北保康马铃薯块茎蛾的发生及防治

湖北保康马铃薯块茎蛾的发生及防治刘远康（湖北省保康县农业局４４１６００）马铃薯块茎蛾又名烟潜叶蛾,属鳞翅目麦蛾科,是全国性检疫对象,其喜食作物有烟草,茄子和马铃薯。一、危害状该虫危害马铃薯、烟草等植物叶片,多沿叶脉蛀入,取食叶肉,仅留上、下表皮,呈半...     

马铃薯块茎蛾综合防治技术

马铃薯块茎蛾是一种危害马铃薯生产和储藏的检疫性害虫,在我国多个省区发展迅速已经严重制约当地马铃薯生产。本文针对马铃薯块茎蛾的生物学特性和发生规律,提出综合运用药剂防治、栽培管理及收获措施等技术减轻马铃薯块茎蛾的发生与危害。     

马铃薯块茎蛾生物防治研究进展与展望

马铃薯块茎蛾是马铃薯上重要的世界性害虫,会对马铃薯造成毁灭性的危害,该害虫目前已成为影响马铃薯产业发展的重要因素.化学农药的过度使用造成了马铃薯块茎蛾的抗药性增强,使用单一的化学防治并不能对该虫进行长久有效的控制.因此,近年来生物防治逐渐引起了研究人员的重视.本文从马铃薯块茎蛾的天敌种类、昆虫病原物、昆虫性信息素和植物...     

球孢白僵菌对马铃薯块茎蛾的毒力及其与常用农药的生物相容性测定

室内测定了从云南分离的7株球孢白僵菌对马铃薯块茎蛾幼虫的毒力,结果表明,在接菌孢子浓度为10⁵个/mL和10⁷个/mL下,接种后7d马铃薯块茎蛾幼虫累积死亡率分别为23.3%～70.0%和33.3%～86.7%,添加吐温80的清水对照死亡率仅为3.3%。筛选出毒力较高的Bb7001、Bb7004、Bb8001 3个菌株,其中菌株Bb8001对马铃薯块茎蛾幼虫的毒力最高,在孢子浓度1×10⁵、1×10⁷个/mL下,第7天的累计死亡率分别为70.0%和86.7%,其毒力回归方程Y=0.366X+3.409(R=0.956),剂量效应LC₅₀=2.24×10⁴个/mL,孢子浓度10⁷个/mL下的LT₅₀为4.3d。测定了毒力较高的菌株与12种农药的生物相容性,结果表明在供试农药推荐用量及其101、00倍稀释液下,球孢白僵菌Bb7001、Bb7004、Bb8001的3个菌株孢子在含所选农药的营养液中生物相容性良好的农药有:苏云金芽孢杆菌可湿性粉剂(Bt)、10%吡虫啉可湿性粉剂、2.5%菜喜悬浮剂及松毛虫病毒可湿粉剂,可配伍使用;而阿维菌素、农安、卡死克、抑太保对球孢白僵菌有很强的抑制作用,应避免配伍使用。     

10种寄主植物挥发物对马铃薯块茎蛾产卵的引诱作用

为了筛选寄主植物挥发物中引诱马铃薯块茎蛾产卵的活性成分,在室内利用选择性产卵试验方法分别测定了寄主植物的10种挥发物：α-蒎烯、β-蒎烯、α-石竹烯、β-石竹烯、P-聚伞花素、柠檬烯、壬醛、月桂烯、α-松油烯和烟碱各自不同浓度（0.00075～0.012g.L-1）的溶液对马铃薯块茎蛾产卵选择的影响。结果表明：α-蒎烯、α-石竹烯、β-石竹烯、柠檬烯、月桂烯和烟碱均在浓度范围内（0.00075～0.012g.L-1）分别对马铃薯块茎蛾的产卵有极显著的引诱作用;β-蒎烯、α-松油烯在浓度范围（0.00075～0.012g.L-1）内分别对马铃薯块茎蛾的产卵有显著的引诱作用;P-聚伞花素、壬醛在浓度范围（0.0015～0.012 g.L-1）内对马铃薯块茎蛾的产卵有极显著的引诱作用。本文供试的10种挥发物均对马铃薯块茎蛾有产卵引诱效果。     

Effects of different potato cultivars on life history and demographic parameters of Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae)

Potato tuber worm, Phothorimae operculella Zeller (Lepidoptera: Gelechiidae) is a common pest of potato which causes a heavy loss in yield either in fields or storage. The effect of six potato cultivars (Agria, Florida, Impala, Picasso, Satina, and Sprint) were evaluated on the life history, life table and demographic parameters of P.operculella under laboratory conditions, which could be appropriate indices in resistance and susceptibility evaluation of potato cultivars. The longest development time was on Picasso (28.76 ± 0.36d) cultivar. The male longevity ranged from 4.83 ± 0.44d on Sprint to 7.45 ± 0.60d on Picasso. Impala and Satina with 53.22 ± 7.78 and 28.74 ± 3.54 eggs/individual had the highest and the lowest net reproductive rates (R₀). The highest values for the intrinsic rate of increase (r_m) and finite rate of increase (λ) were on Impala (r_m: 0.119 day^?1, λ: 1.75 day^?1), and the lowest value was on Sprint (r_m: 0.090 day^?1, λ: 1.01 day^?1). The results indicated that Sprint was the most resistant cultivar for the feeding of P.operculella, which could be useful in the development of integrated pest management programs for this pest.     

Evidence for presence of the founder Ia mtDNA haplotype of Phytophthora infestans in 19th century potato tubers from the Rothamsted archives

Late blight remained a significant disease for potato growers in Europe long after the famine of the 1840s. Of the four mitochondrial haplotypes of Phytophthora infestans, only the Ia mitochondrial DNA (mtDNA) haplotype has been identified previously in infected potato leaves from famine‐era herbarium specimens collected in England, Ireland and Europe in the 19th century. Long‐term soil fertility experiments were conducted on potato between 1876 and 1901 in Rothamsted to investigate effects of combinations of organic manures and mineral fertilizers on disease and yield. This report identifies for the first time the same Ia mtDNA haplotype of P. infestans in three diseased tubers from 1877 from the long‐term Rothamsted trials, thus providing the earliest evidence of the presence of the founder Ia mtDNA haplotype of P. infestans in potato tubers in England. Soil amendments had a significant impact on disease and yield. A real‐time PCR assay was used to detect and quantify P. infestans in tubers. The level of pathogen DNA was greatest in tubers from highest yielding plots that received combinations of inorganic nitrogenous and mineral fertilizers and least in tubers from plots with organic farmyard manures or non‐nitrogenous mineral fertilizers. The Ia mtDNA haplotype was also confirmed from diseased potato leaves during the same time period. Thus, the founder Ia mtDNA haplotype survived in potato tubers after 1846 and was present over 30 years later in the UK.     

Monitoring populations of Phthorimaea operculella in potato fields and in storage in Senegal

This study provided information on periods of peak trapping for the potato tubermoth (Phthorimaea operculella) in potato fields and in storage facilities in the Niayes area of Senegal. Delta sticky traps baited with P. operculella synthetic pheromone, IT053 ISCA lure, were used to monitor adult male moth populations in 2011 and 2012. In each trapping year, four peaks were observed with the maximum number of moths recorded in February, 2012. A Weibull regression model was developed to predict the incidence of P. operculella in potato fields using the number of male adults caught in pheromone-baited traps. The Weibull model provided a good fit to percentage cumulative mean trap catches for both 2011 and 2012 (R² = 0.99; P < 0.0001). Based on the Weibull models for the sampling periods in 2011 and 2012, 50% of cumulative mean number of moths were trapped by day 85 (26 March) in both years, 63.2% (= α) were trapped by day 103 and 104 (13 April and 14 April), and 95% were trapped by day 179 and 190 (28 June and 9 July), respectively. Male moths continued to be trapped after potatoes were harvested, but the numbers decreased compared to captures before harvest. This information will be useful for predicting the most appropriate times to institute intervention measures to mitigate damage to potatoes by the moth. Laboratory investigation revealed that abandoned tubers in the field were the source of sustained incidence of the moth on farms following the harvesting of potatoes. The number of male moths trapped in stores tapered with the number of weeks the bagged tubers stayed in storage.     

Potential of a strain of Beauveria bassiana (Hypocreales: Cordycipitaceae) for the control of the potato tuberworm,Phthorimaea operculella (Zeller)

The potato tuberworm, Phthorimaea operculella (Zeller), is one of the most important pests of potato, Solanum tuberosum L., worldwide. We evaluated six Beauveria bassiana strains with potential for control of larvae. Strain SD was the most virulent, causing up to 98% mortality 10 days after inoculation of first instars. The other tested strains (HL, XJ, SC, JL and GZ) were only marginally virulent compared to the controls. In cage trials, SD strain applied to potato plants significantly reduced the survival of tuberworm larvae. Our results suggest that strain SD may be recommended for effective biological control of P. operculella.     

Phosphite compounds reduce disease severity in potato seed tubers and foliage

Phosphites (Phi) are alkali metal salts of phosphorous acid, with the ability to protect plants against different pathogens. In this research, the effect of Phi applied to potato plants on severity of three important potato diseases in Argentina was assessed. Seed tubers and foliage of potato cvs Shepody and Kennebec were treated with Phi to assess effects on resistance against Phytophthora infestans, Fusarium solani and Rhizoctonia solani. Protection resulting from Phi treatment in seed tubers was high against P. infestans, intermediate against F. solani, and low against R. solani. In addition, seed tubers treated with calcium or potassium phosphites (CaPhi and KPhi, respectively) at 1% of commercial product emerged earlier than untreated ones. When Phi were foliarly applied two or four times at different doses, high levels of protection against P. infestans were achieved in both cultivars. Higher protection was observed in Kennebec when CaPhi was applied, while in Shepody this was true for KPhi. Expression of β-1,3-glucanases was induced at different times after treatment but no correlation between β-1,3-glucanases expression and foliar protection level was found. On the other hand, Phi positive protection effects did not produce negative effects in plant growth. Leaves from CaPhi-treated plants showed a darker green colour than leaves from control plants; also an increase in Rubisco protein and a delay in crop senescence was observed.     

Involvement of Iron and Ferritin in the Potato–Phytophthora infestans Interaction

This work shows that the infection of potato (Solanum tuberosum) detached leaves by the late blight pathogen Phytophthora infestans, was drastically reduced by adding deferoxamine, an exogenous iron chelator. Reactive oxygen species in leaves inoculated with P. infestans were also reduced after adding deferoxamine. A leaf ferritin cDNA fragment was obtained by PCR and used as probe for screening a tuber cDNA library. A cDNA (named StF1) encoding the iron-storing potato ferritin was cloned. StF1 is 915 bp in length and has an open reading frame of 230 amino acids that contains the information for the mature 28 kDa subunit of potato ferritin. StF1 was used as probe in northern blot hybridizations to analyze expression of the ferritin gene. In leaves, ferritin mRNA accumulated in response to pathogen attack. In tubers, ferritin mRNA increased upon treatment with the elicitor eicosapentaenoic acid. These results suggest that iron plays a role in the potato-P. infestans interaction.     

Detection of the root lesion nematode Pratylenchus penetrans in potato tubers

The root lesion nematode Pratylenchus penetrans parasitizes a wide range of economically important crops, including potato (Solanum tuberosum). Damage by P. penetrans impacts not only the potato yield but can also reduce the tuber quality. Detailed information on tuber infection by P. penetrans is scarce for most cultivars and molecular detection of nematodes from infected tubers is needed. The objective of this study was to assess tuber symptomatology due to P. penetrans infection in 10 potato cultivars and to provide an accurate molecular methodology for nematode detection using tuber peels. Sprouts of certified potato seed from cultivars Agata, Agria, Camel, Désirée, Dirosso, Kennebec, Laura, Picasso, Royata, and Stemster were planted in 2 L pots, and soil was inoculated with 4 P. penetrans/g of soil. Sixty days after inoculation, tubers were harvested, inspected for lesions, and the number of nematodes/g of potato peel assessed. Observations of tubers with symptoms showed the presence of P. penetrans in superficial layers of peels around the lenticels and injured necrotic tissue. Different nematode stages were detected in tubers of all inoculated cultivars, varying from 4 to 46 nematodes/g of potato peel. Species-specific primers showed suitable sensitivity and reproducibility for the detection of P. penetrans in tuber potato peel samples. The molecular detection of P. penetrans directly from tuber peels can facilitate routine nematode inspections of potato seed tubers or cull potatoes for nematode detection, and prevent further dissemination of this species.     

取食不同寄主的草地贪夜蛾肠道微生物多样性分析

为绿色防控草地贪夜蛾Spodoptera frugiperda,基于16S rDNA和ITS高通量测序分析,对分别取食玉米、小麦以及田间常见杂草婆婆纳Veronica polita的草地贪夜蛾肠道细菌和真菌进行物种注释、多样性分析、物种组成分析及功能预测。结果显示,细菌注释共获得20门30纲72目106科164属214种,真菌注释共获得9门23纲46目90科154属237种。厚壁菌门、放线菌门和变形菌门为取食玉米、小麦和婆婆纳的草地贪夜蛾肠道优势细菌门,子囊菌门和担子菌门为取食玉米、小麦和婆婆纳的草地贪夜蛾肠道优势真菌门。肠球菌属Enterococcus为取食玉米、小麦和婆婆纳的草地贪夜蛾肠道细菌共同的优势属,相对丰度分别为70.86%、25.42%和72.02%;丝孢酵母属Tricho-sporon 和帚枝霉属 Sarocladium 为取食玉米的草地贪夜蛾肠道真菌的优势属,相对丰度分别为57.28%和17.38%,酵母菌目未分类属、小囊菌属Microascus和丝孢酵母属Trichosporon为取食小麦的草地贪夜蛾肠道真菌优势属,相对丰度分别为29.31%、27.01%和15.45%,双足囊菌科未分类属为取食婆婆纳的草地贪夜蛾肠道真菌优势属,相对丰度为61.79%。取食小麦的草地贪夜蛾肠道细菌群落的多样性最高,取食婆婆纳的草地贪夜蛾肠道真菌群落的多样性最高,取食婆婆纳的草地贪夜蛾肠道细菌和真菌群落的丰富度最高。取食玉米、小麦和婆婆纳的草地贪夜蛾肠道细菌群落功能主要与代谢通路相关,取食玉米、小麦和婆婆纳的草地贪夜蛾肠道真菌群落功能主要与基础代谢或生理功能相关。     

Evaluation of a diagnostic microarray for the detection of major bacterial pathogens of potato from tuber samples

Potato can be infected with many bacterial pathogens, the detection of which is necessary in seed certification. In this study, a diagnostic microarray previously tested for specificity of probes for detecting the potato bacteria causing blackleg and soft rot (Pectobacterium atrosepticum, Pectobacterium carotovorum, and Dickeya spp.), ring rot (Clavibacter. michiganensis subsp. sepedonicus), scab (Streptomyces scabies and Streptomyces turgidiscabies) and brown rot (Ralstonia solanacearum) from pure culture was evaluated for analytical sensitivity when testing directly from tuber samples. The microarray readily detected all the bacterial species when 100 ng of the target bacterial DNA from pure culture was mixed with DNA from soil microbes and potato. However, detection was inconsistent when total DNA isolated directly from infected tubers or enriched bacterial culture was used. While the high specificity of the probes could be confirmed from the results of the DNA cocktail experiment used as a control, the study demonstrated that the level of analytical sensitivity of the microarray under the tested condition was not sufficient to detect bacteria directly from tubers. Therefore, in addition to the cost and organizational complexities, the low analytical sensitivity and limited reproducibility of the microarray are constraints for establishing the platform for routine detection of potato bacterial pathogens from tuber samples.