Lettuce (Lactuca sativa) is a leafy vegetable that belongs to the family Asteraceae. It is widely cultivated and consumed around the world. In May 2022, lettuce plants (cv. 204) showing soft rot symptoms were observed in greenhouses in Fuhai District (25°18'N, 103°6'E), Kunming City, Yunnan Province, China. The disease incidence in three greenhouses (0.3 ha in size) was between 10% to 15%. The lower parts of the outer leaves showed brown and water-soaked symptoms, but at the same time the roots were asymptomatic. Sclerotinia species can cause soft decay on lettuce leaves, known as lettuce drop, which can produce symptoms partially resembling those of bacterial soft rot (Subbarao 1998). The absence of white mycelium or black sclerotia on the leaf surfaces of diseased plants indicated that Sclerotinia species were not responsible for the disease. Instead, it is more likely that bacterial pathogens were the cause. Fourteen diseased plants were sampled from three greenhouses, and potential pathogens were isolated from the leaf tissues of six plant individuals. Leaf samples were cut into pieces ca. 0.5 cm in length. The pieces were then surface-sterilized by dipping in 75% ethanol for 60 sec, followed by three successive rinses using sterile distilled water. The tissues were immersed in 250 µl of 0.9% saline in 2 mL microcentrifuge tubes and gently pressed down with grinding pestles for 10 sec. The tubes were let stand still for 20 min. Aliquots (20 μl) 100-fold dilutions of the tissue suspensions were plated onto Luria-Bertani (LB) plates and incubated at 28°C for 24 h. Three single colonies were picked from each LB plate and restreaked five times for purity. After purification, eighteen strains were obtained, and nine of these were identified by 16S rDNA sequencing using the universal primer pair 27F/1492R (Weisburg et al. 1991). Six out of nine strains (6/9) belonged to the genus Pectobacterium (OP968950-OP968952, OQ568892- OQ568894), two strains (2/9) belonged to the genus Pantoea (OQ568895 and OQ568896), and one strain (1/9) belonged to Pseudomonas sp. (OQ568897). Since the Pectobacterium strains shared identical 16S rDNA sequence, strains CM22112 (OP968950), CM22113 (OP968951) and CM22132 (OP968952) were selected as representative strains for further testing. The 16S rDNA sequences of Pectobacterium strains were 100% identical to that of the P. polaris strain NIBIO 1392 (NR_159086.1). To identify the strains to the species level, multilocus sequence analysis (MLSA) was performed using sequences of six housekeeping genes acnA, gapA, icdA, mdh, proA and rpoS (OP972517-OP972534) (Ma et al. 2007; Waleron et al. 2008). Phylogenetic analysis showed that the strains clustered with P. polaris type strain NIBIO1006T (Dees et al. 2017). They were all capable of utilizing citrate, which is an important biochemical feature in distinguishing P. polaris from its most closely related sister species P. parvum (Pasanen et al. 2020). Lettuce plants (cv. 204), at the rosette stage, were inoculated with the strains CM22112 and CM22132 by injecting 100 µl of bacterial suspensions (107 CFU·mL-1) into the lower parts of the leaf; for the controls, 100 µl of saline was used instead. Inoculated plants were incubated at room temperature (23°C) and 90% relative humidity. Five days after inoculation, only the bacteria-inoculated lettuce showed severe soft rot symptoms. Similar results were observed in two independent experiments. Bacterial colonies were obtained from the infected lettuce leaves, which showed identical sequences to P. polaris strains CM22112 and CM22132. Therefore, these strains fulfilled Koch's postulates for lettuce soft rot. P. polaris is prevalent on potato in many countries (Dees et al. 2017). To our knowledge, this is the first report of P. polaris causing soft rot on lettuce in China. This disease could seriously affect the appearance and saleability of lettuce. Further research on the epidemiology and management strategies of the disease is needed.

唐山秋瓜口感清脆爽口,营养丰富,市场需求量大,效益较高,种植面积逐年扩大,已成为冀东、东北地区广泛种植的特色优势作物,唐山地区常年种植面积达到1.2万hm2[1,2],日光温室以越冬茬和早春茬为主,冷棚以春茬和秋茬为主.近年来,强雌性品种和吊蔓夹的普及,增加了坐瓜数量,保障了中后期植株长势,延长了采摘期,大幅提高了产量和品质,增加了瓜农收益,种植积极性不断增加[3].

Pectobacterium brasiliense is a worldwide distributed bacterial pathogen causing soft rot and blackleg of a wide range of economically important crops. Here, we present the complete, high-quality genome of P. brasiliense strain TS20HJ1, which was isolated from a ginger ( Zingiber officinale) rhizome showing soft rot symptoms. The genome assembly consists of a circular 4,766,353-bp chromosome with 52.1% GC content. The genome harbors 4,128 protein-coding genes, 22 rRNA genes, and 77 tRNA genes. We believe that the complete genome sequence of P. brasiliense TS20HJ1 will provide a valuable resource for understanding the molecular basis of host adaptation and evolution of pathogenesis. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

芫荽,伞形科,又称香菜、香荽等,是做面煲汤常用的提味蔬菜之一[1,2].近几年大叶型香菜品种作为涮菜广受欢迎,需求量不断增加[3].芫荽生长期短,耐低温,适合冷凉气候地区种植[4].冀东地区种植秋季露地芫荽多年,通过冬储供给京津冀和东北地区冬春市场.近年冷库凭借温度稳定、存储损耗小、省时省工的特点逐渐取代了传统的埋土法,储藏方式升级大幅提高了经济效益,助推生产规模不断扩大.但冀东地区特殊的气候条件,加之连年重茬种植造成芫荽容易出现徒长、红叶和重茬病害3方面问题,围绕本地芫荽生产中的实际问题,总结了 3项冀东地区秋季露地芫荽栽培关键技术,有效地控制了病虫害的发生,避免了株高超标或红叶造成的产量和品质下降,增加了菜农收入.该技术通过多年的集成熟化、示范应用,在唐山地区累计推广超过0.67万hm2,具有良好的应用前景,希望这3项关键技术可以为其他芫荽产区提供技术支持.

Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is a devastating disease of soybean. Biological control is a potential alternative to chemical fungicides for disease management, and provides broad benefits to the environment, farmers and consumers. Herein, we established a field application technique for biocontrol of Sclerotinia stem rot in soybean using wuyiencin, expanding on a previous study showing biocontrol potential. We used wuyiencin to reduce sclerotia in soybean seed, and disease incidence analysis by seed bioassay revealed an optimal wuyiencin seed soaking concentration of 12.5 μg/mL. We found that different application methods had different effects on soybean plant growth. Soybean pot experiments showed that 100 μg/mL wuyiencin was obtained a significant disease protection effect and promote soybean growth through root irrigation, and the optimal concentration for wuyiencin spraying was 100–200 μg/mL. We tested the efficacy of applying wuyiencin under field conditions, and the protection effect of 200 μg/mL wuyiencin sprayed three times was the best (64.0%), but this was slightly inferior to the protection effect of 200 μg/mL dimethachlon (77.6%).

HomePlant DiseaseVol. 106, No. 7First Report of Rhizome Rot Caused by Pectobacterium brasiliense on Ginger in China PreviousNext DISEASE NOTE OPENOpen Access licenseFirst Report of Rhizome Rot Caused by Pectobacterium brasiliense on Ginger in ChinaJinhui Wang, Yuxiang Lu, Wanxin Han, Lijun Fu, Xiaoqing Han, Jiehua Zhu, and Shangqing ZhangJinhui Wanghttps://orcid.org/0000-0002-4328-984XHebei Agricultural University, College of Plant Protection, Baoding 071001, China, Yuxiang LuTangshan Academy of Agricultural Sciences, Tangshan 063001, China, Wanxin Hanhttps://orcid.org/0000-0002-6037-8027Hebei Agricultural University, College of Plant Protection, Baoding 071001, China, Lijun FuTangshan Academy of Agricultural Sciences, Tangshan 063001, China, Xiaoqing HanTangshan Academy of Agricultural Sciences, Tangshan 063001, China, Jiehua Zhu†Corresponding authors: J. Zhu; E-mail Address: [email protected], and S. Zhang; E-mail Address: [email protected]Hebei Agricultural University, College of Plant Protection, Baoding 071001, China, and Shangqing Zhang†Corresponding authors: J. Zhu; E-mail Address: [email protected], and S. Zhang; E-mail Address: [email protected]Tangshan Academy of Agricultural Sciences, Tangshan 063001, ChinaAffiliationsAuthors and Affiliations Jinhui Wang1 Yuxiang Lu2 Wanxin Han1 Lijun Fu2 Xiaoqing Han2 Jiehua Zhu1 † Shangqing Zhang2 † 1Hebei Agricultural University, College of Plant Protection, Baoding 071001, China 2Tangshan Academy of Agricultural Sciences, Tangshan 063001, China Published Online:16 Jun 2022https://doi.org/10.1094/PDIS-10-21-2324-PDNAboutSectionsView articlePDFSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleIn August 2020, ginger (Zingiber officinale) rhizomes (cv. Mianjiang) showing soft rot symptoms were observed in a field in Tayang Village, Fengrun District, Tangshan, Hebei Province (North China). The disease incidence in that field (15 ha in size) was more than 20%. Symptomatic rhizomes (brown and water-soaked) were surface-sterilized in 75% ethanol for 60 s, followed by three successive rinses with sterile distilled water. Rhizomes were cut into pieces ca. 0.5 cm in length that were soaked in 500 µl of 0.9% saline for 20 min. Aliquots (20 μl) of three tenfold dilutions of the tissue specimen soaking solution were plated onto lysogeny broth (LB) medium and incubated at 28°C for 24 h. Five single colonies were picked from each LB plate and restreaked three times for purity. Endophytic bacteria were also isolated from asymptomatic rhizomes as a control. The bacterial gDNA was extracted using the EasyPure Bacteria Genomic DNA Kit (TransGen Biotech, Beijing, China). The 16S rDNA region was amplified by PCR using the universal primer pair 27F/1492R (Weisburg et al. 1991) and sequenced. The results of BLASTn against NCBI nr of the 16S rDNA amplicons suggested that most isolates (8/10) obtained from the rotten rhizomes belonged to the genus Pectobacterium, and a few isolates (2/10) were Enterobacter spp. Only Enterobacter spp. were isolated from asymptomatic rhizomes. Since all Pectobacterium isolates showed identical 16S rDNA sequences, only two isolates were selected for further analysis. Pectobacterium isolates TS20HJ1 and TS20HJ2 (MZ853520, MZ853521) represent isolates from two plant individuals. To determine the species of the rhizome rot Pectobacterium isolates, multilocus sequence analysis (MLSA) was performed with five housekeeping genes: acnA, icdA, mdh, proA, and rpoS (MZ994717 to MZ994726) (Ma et al. 2007; Waleron et al. 2008), and a phylogenetic tree was reconstructed using RAxML v8.2.12 (github.com/stamatak/standard-RAxML). No sequence variation was observed at any MLSA locus between the two isolates. The results of phylogenetic analysis showed that the ginger rhizome isolates clustered with Pectobacterium brasiliense type strain IBSBF1692T (Duarte et al. 2004; Nabhan et al. 2012). Ginger seedlings (cv. Mianjiang) were inoculated with the isolate TS20HJ1 by injecting 10 µl of bacterial suspension (108 CFU·ml−1) into the rhizomes or 10 µl of 0.9% saline solution as a control. The seedlings were grown at 28°C and 50% relative humidity. Ten days after inoculation, only the bacteria-inoculated rhizomes showed disease symptoms resembling those observed in the field. Bacterial colonies were obtained from the infected rhizomes and were identified with MLSA gene sequencing, fulfilling Koch's postulates. P. brasiliense causes soft rot of a wide range of economically important crops (Oulghazi et al. 2021). To our knowledge, this is the first report of P. brasiliense causing rhizome rot of ginger in China. The rhizome rot caused 20 to 25% yield loss on average in the Tangshan region in 2020, which poses a significant threat to local ginger farming. Further research on epidemiology and disease management options is needed.The author(s) declare no conflict of interest.References:Duarte, V., et al. 2004. J. Appl. Microbiol. 96:535. https://doi.org/10.1111/j.1365-2672.2004.02173.x Crossref, ISI, Google ScholarMa, B., et al. 2007. Phytopathology 97:1150. https://doi.org/10.1094/PHYTO-97-9-1150 Link, ISI, Google ScholarNabhan, S., et al. 2012. J. Appl. Microbiol. 113:904. https://doi.org/10.1111/j.1365-2672.2012.05383.x Crossref, ISI, Google ScholarOulghazi, S., et al. 2021. Microorganisms 9:106. https://doi.org/10.3390/microorganisms9010106 Crossref, Google ScholarWaleron, M., et al. 2008. Eur. J. Plant Pathol. 121:161. https://doi.org/10.1007/s10658-007-9260-3 Crossref, ISI, Google ScholarWeisburg, W. G., et al. 1991. J. Bacteriol. 173:697. https://doi.org/10.1128/jb.173.2.697-703.1991 Crossref, ISI, Google ScholarJ. Wang and Y. Lu contributed equally to this work.Funding: This research work was supported by the Agriculture and Rural Affairs Support Program of Hebei (HBCT-2018-030207) and High-level Talent Funding Project of Hebei (A202001094).The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 106, No. 7 July 2022SubscribeISSN:0191-2917e-ISSN:1943-7692 Download Metrics Article History Issue Date: 8 Jul 2022Published: 16 Jun 2022First Look: 16 Jan 2022Accepted: 10 Jan 2022 Page: 1978 Information© 2022 The American Phytopathological SocietyFundingAgriculture and Rural Affairs Support Program of HebeiGrant/Award Number: HBCT-2018-030207High-level Talent Funding Project of HebeiGrant/Award Number: A202001094KeywordsgingerMLSArhizome rotThe author(s) declare no conflict of interest.PDF download

化学农药的大面积推广应用,有效地控制了病虫害的发生,生产中高毒农药和不合理使用农药,导致了食品安全问题频发.本文综合了抗病品种、种植模式等农业措施,形成了一套农药减施技术措施,希望为农药的科学使用提供参考.

麦长管蚜具有远距离迁飞习性,其种群在小麦田发生、发展和消亡均可能受温度、湿度、风雨等气象因素的影响,而在麦长管蚜种群不同发育阶段出现不同的气象因素也将使其防治策略发生变化.重点分析5月温度、湿度、瞬时风速、降水量等对2019年河北省小麦田麦长管蚜种群发展动态的影响,以期明确影响河北省麦长管蚜种群发展的关键气象因子.小麦田麦长管蚜种群发展动态结果表明,河北省保定和唐山地区麦长管蚜在麦田快速发展时,当地小麦分别处于扬花后期至灌浆初期和小麦扬花期,而保定地区麦长管蚜至小麦乳熟后期才开始出现种群数量下降,唐山地区麦长管蚜却在小麦灌浆期出现了种群数量的快速下降.结合气象因素分析发现,在平均气温相近的情况下,保定和唐山地区最高气温均于5月22—24日出现了高于36℃的天气,而保定地区麦长管蚜种群数量于23日出现了急剧下降,可以确定与此次高温天气有关,但唐山地区麦长管蚜种群数量于19日便开始出现下降,与5月19—20日唐山地区小麦田出现的大风天气有关,当时风速为8.3～16.0 m/s,达到了5～7级,其中7级大风持续时间为3 h.而2地降水量和田间相对湿度的变化不是麦长管蚜种群数量下降的主要原因.

为了明确200 g/L氟唑菌酰羟胺·苯醚甲环唑悬浮剂对黄瓜白粉病的防治效果,为其在黄瓜上推广和应用提供理论依据,进行了田间药效试验.试验结果表明,200 g/L氟唑菌酰羟胺·苯醚甲环唑悬浮剂能够快速控制白粉病的发生,具有良好的速效性;第2次药后3、5、7、10、14 d,该药剂130、200 mg/L 2个处理的防效均高于89％,且显著高于42.8％氟吡菌酰胺·肟菌酯悬浮剂、10％苯醚甲环唑水分散粒剂和25％乙嘧酚悬浮剂3种对照药剂.该药剂对黄瓜安全,结合成本核算,建议生产中使用200 g/L氟唑菌酰羟胺·苯醚甲环唑悬浮剂(有效成分130 mg/L)防治黄瓜白粉病.

为了提高吡噻菌胺对黄瓜白粉病的防治效果,筛选增效配方,降低抗性风险,为其应用提供理论依据.采用常规喷雾法进行田间防效试验.田间试验结果表明,20％吡噻菌胺SC+10％多抗霉素WP对黄瓜白粉病防效突出,第1次药后7 d防效为84.39％,第2次药后14 d防效高达97.48％.20％吡噻菌胺SC+10％多抗霉素WP增效作用明显,可以在黄瓜生产中推广应用.20％吡噻菌胺SC+30％苯甲·嘧菌酯SC对黄瓜白粉病也有较好的增效作用,可降低抗性风险,作为备选或轮换使用的方案.

草莓,原产南美洲,多年生草本植物.其品种资源丰富,口感酸甜各异,气味香甜浓郁,深受广大消费者喜爱.草莓喜低温冷凉气候,对设施条件要求不高,且植株低矮,便于休闲采摘,市场需求量大,收益较高,已逐步成为北方地区城市周边观光农业生产的首选品种.采摘种植的品种主要包括红颜、章姬、圣诞红、小白、雪兔、白雪公主、京藏香、粉红公主等,这些品种大多风味独特、颜色诱人,但果皮较薄、果实偏软,抗病能力不足,同时冬春季节日光温室内长期低温弱光、高湿,为病害的发生提供了条件,此外,观光采摘过程中,儿童因缺乏采摘经验易对秧苗和未成熟果实造成损伤,病菌会从伤口侵入,导致灰霉病大规模发生流行.

黑绒金龟,又称天鹅绒金龟子、东方金龟子等,属鞘翅目,鳃金龟科,分布于东北、华北、内蒙及华东部分地区,食性杂,喜食豆类农作物及杨树、柳树、榆树、苹果树等幼嫩枝叶.成虫是黑绒金龟危害虫态,生产上可根据黑绒金龟成虫的生活习性制定防治策略.成虫喜食大豆幼苗,冀东地区俗称黑豆虫,大豆出苗期常聚集危害,吃光子叶和芯叶,造成植株死亡.发生期一般田块 1 ～ 3 头 / m2,严重田块 4 ～ 10头/ m2,常因聚集性危害,使大豆田出现区域性无头苗,严重影响大豆生产,必须提前采取有效的防治措施.

[目的]筛选防治马铃薯早疫病的有效药剂,明确供试药剂对早疫病的防治效果.[方法]通过马铃薯早疫病田间防治效果试验,对比早疫病发病情况、药剂的安全性及产量等,综合评价药剂的防治效果.[结果]各药剂对马铃薯植株生长是安全的;第3次施药后7d,40％甲硫·氟啶胺SC、50％咪鲜胺铜盐SC、36％硝苯菌酯EC、22.5％啶氧菌酯SC、50％异菌脲WP、50％啶酰菌胺WG、40％腈菌唑WP以及70％丙森锌WP等对早疫病的防效分别为85.94％、91.73％、84.20％、91.19％、82.91％、89.93％、91.79％和89.49％,分别增产4.49％、20.61％、8.15％、18.50％、5.64％、8.07％、17.95％和8.46％.[结论]依据冀东地区马铃薯种植和杀菌剂使用现状,推荐使用50％咪鲜胺铜盐SC、22.5％啶氧菌酯SC及40％腈菌唑WP防治马铃薯早疫病.

蔬菜产业是脱贫攻坚、农民增收的支柱产业之一.但蔬菜生产过程受气候因素影响较大,如突发性暴雨、洪涝、大风、冰雹以及持续连阴雨、低温冷害等极端灾害天气,造成蔬菜作物瞬间折损、浸泡甚至绝收毁种.基于各种极端灾害天气的不同特点,笔者归纳总结了近两年在生产一线对极端灾害性天气的应对措施及成功经验,以期为蔬菜生产提供参考.

唐山秋瓜为唐山地区传统黄瓜品种的总称,近年来在河北、山东及东北等地种植面积不断增加.为了适应冬春茬寒冷气候,延长采摘期,提高种植收益,2013年起选择强雌性系唐山秋瓜品种配合保温增温措施、吊蔓夹落秧、合理整枝疏瓜和病虫害保护性防控等技术措施,实现了唐山秋瓜冬春茬日光温室优质高产,采摘期延长至150d左右.由于该模式投入少,见效快,效益大幅提高,已成为冀东地区唐山秋瓜的主要栽培模式,可为菜农提供参考.

为综合防控唐山秋瓜的害虫和推广杀虫剂10％ 溴氰虫酰胺可分散油悬浮剂,采用田间小区试验,使用10％ 溴氰虫酰胺OD不同剂量在害虫发生初期进行喷雾处理,研究10％ 溴氰虫酰胺OD对日光温室唐山秋瓜3种主要害虫瓜绢螟、烟粉虱和美洲斑潜蝇的田间药效.结果表明:10％ 溴氰虫酰胺OD对瓜绢螟、烟粉虱和美洲斑潜蝇均具有良好的防治效果.试验剂量有效成分含量22.5和30.0 g·hm-2药后7 d防治效果达到最高,药后14 d对瓜绢螟的防治效果仍高于80％;试验剂量有效成分含量50.0和60.0 g·hm-2对药后7 d烟粉虱成、若虫防治效果达到最高,均高于88％,之后防治效果逐渐降低;试验剂量有效成分含量15.0,21.0,27.0 g·hm-2药后10 d防治效果均高于80％.10％ 溴氰虫酰胺OD可以兼治瓜绢螟、烟粉虱和美洲斑潜蝇,值得在唐山秋瓜生产中推广.

为促进冀东地区马铃薯的高产优质栽培,对冀东地区冷棚种植马铃薯各环节,包括冷棚的构建 、种薯的选择与处理 、覆膜栽培技术 、田间管控 、病虫害综合防治的相关技术进行了归纳总结,集成一套冀东地区马铃薯冷棚高产栽培的关键技术.

甜瓜是重要的水果之一,全球温带和热带地区广泛种植.在我国甜瓜种植历史悠久,是我国最早作为果品食用的瓜类,种植范围遍布全国.我国是世界甜瓜生产第一大国,截至2015年我国甜瓜播种面积达46.09万hm2,年总产量1 527.1万t.种植甜瓜已成为很多农民增收致富的不二选择.

为了应对当前番茄价格不断下降、农民收入得不到有效保障的问题,河北省蔬菜产业体系病虫害绿色防控岗位专家团队经过几年研究,探索出了日光温室秋延后番茄套种芹菜的栽培模式,并针对栽培模式改变后病害种类、发生规律的变化,提出了配套"三灌两喷"防控技术,控制番茄和芹菜病害的效果明显.

马铃薯(Solanum tuberosum L.),属茄科多年生草本植物,块茎可供食用,目前已成为全球第四大重要粮食作物.河北省是我国较早引进种植马铃薯的地区,目前马铃薯在河北省各地市均有种植,特别是由于马铃薯具有较强的耐寒性和耐贫瘠性,以及产量高、易管理、耐储存等特点,深受农民的喜爱,种植面积处于稳定增长的趋势,常年种植面积20万hm2以上,鲜薯总产量可达360多万t.