Amoeboid organisms attacking larvae of the potato root eelworm (Heterodera rostochiensis Woll.) in England and the beet eelworm (H. Schachtii Schm.). in Canada

Samenvatting Amoebe-achtige organismen werden geïsoleerd uit grondmonsters, die cysten vanHeterodera rostochiensis bevatten en afkomstig waren van twee plaatsen in Feltwell Fen, Norfolk, Engeland en uit grond van een perceel in het Blackwell district, Essex County., Ontario, Canada, dat besmet was metH. schachtii. Deze organismen gelijken sterk opTheratromyxa weberi Zwillenberg, die bekend is als parasiet van het aardappelcysteaaltje in Nederland. Er werden enkele verschillen in gedrag tussen de in Engeland en Canada gevonden organismen enT. weberi waargenomen, maar deze kunnen het gevolg zijn van verschillen in kweekwijze.     

Problems of potato cyst nematode pathotypes in the Czech Republic

During 1983–1989 about 1,200 infested plots in the Czech republic were investigated for the occurrence of new pathotypes of the potato cyst nematodes (PCN) Globoderu rostochiensis and G. pallida. Only eight populations of the pest were suspected of containing another pathotype than Ro1. Glasshouse pot trials were performed with those eight natural populations, two populations of Ro1, 10 potato cultivars resistant to Ro1 and 10 cultivars resistant to more pathotypes, G. pallida included. The multiplication rates (Pf/Pi) showed that four of the PCN populations were probably mixtures, with pathotype Ro1 prevailing. Three populations were suspected of containing G. pallida , but their morphological characters corresponded only with G. rostochiensis. One population corresponded with pathotype Ro5. The extent of the occurrence of pathotypes or virulence groups different from Ro1 can be estimated at 0.3–0.4% of infested plots.     

A selective survey of potato cyst-nematode pathotypes in Great Britain

One hundred and forty-four samples of potato cyst-nematodes, the majority chosen to contain G. pallida , from England, Wales and Scotland were identified to pathotype. Where G. rostochiensis was present it proved to be pathotype Rol, there being no indication of other pathotypes of this species. Of G. pallida , a minority of samples incorporated pathotype Pa 1; many were pathotype Pa3 but distinction between Pa2 and Pa3 was unsatisfactory in many more. It is concluded that recognition of these latter two pathotypes is of little value. The proposed pathotype New Leake could not be recognized.     

干旱胁迫对马铃薯叶片超微结构及生理指标的影响

选用不耐旱品种‘费乌瑞它’、耐旱性较强品种‘东农308’和耐旱品种‘晋薯2号’的脱毒试管苗为材料,利用含有20%PEG-6000的MS液体培养基进行水分胁迫处理,研究干旱胁迫对马铃薯叶片细胞超微结构和生理指标的影响。结果表明:叶绿体对干旱胁迫反应最为敏感且受损伤最重,胁迫后叶绿体外形肿胀变圆,片层开始松散,间隙增大,甚至出现孔洞。线粒体次之,外膜破坏,嵴减少。对细胞核的影响相对较小。‘费乌瑞它’超微结构损伤最严重,‘东农308’次之,‘晋薯2号’伤害最轻。超微结构发生变化的同时,各项生理指标也随之改变。3个品种丙二醛(MDA)含量升高48.89%~243.27%,并且都达到极显著水平;过氧化物酶(POD)活性升高2.06%~32.98%,‘费乌瑞它’和‘晋薯2号’分别达到极显著和显著水平;不同品种的超氧化物歧化酶(SOD)活性和叶绿素含量变化趋势不一致。上述指标中,丙二醛含量和叶绿体超微结构变化显著,并能较好地表现出不同品种之间抗旱性的差异。     

马铃薯根系分泌物组分对不同种植模式的响应

作物根系分泌物与作物连作障碍密切相关,为寻求减小作物连作障碍的途径,在轮作(大豆-马铃薯)、固定间作(马铃薯/大豆)和马铃薯连作3种种植模式下,分离鉴定了马铃薯根系分泌物的主要组分。结果表明:与轮作处理相比,固定间作和连作处理马铃薯根系分泌物种类分别增加了13.79%和17.24%,烷烃类物质的相对含量分别增加了52.17%和52.60%,酸类物质的相对含量分别增加了65.41%和14.79%。连作处理马铃薯根系分泌物中鉴定出乙胺、N-乙基吗啉和邻苯二甲酸二丁酯的相对含量分别为1.46%、2.87%和5%,而在轮作和间作处理中均未检测到。与轮作处理相比,间作和连作处理N,N-二乙基乙酰胺相对含量分别高出123.29%和47.95%,棕榈酸相对含量分别高出23.18%和40.0%,硬脂酸相对含量分别高出27.36%和39.80%。说明大豆-马铃薯轮作可有效降低马铃薯根系分泌物组分的种类和含量。因此,生产实践中,可通过大豆-马铃薯轮作克服因某一种马铃薯化感物质累积而造成的毒害作用。     

陇中旱农区不同品种马铃薯水氮利用效率研究

以12个马铃薯品种为研究对象,连续2 a（2022—2023年）设置不施氮(0 kg·hm^-2)和施氮(180 kg·hm^-2) 2个施氮水平,分析不同品种马铃薯产量和水氮效率特征,并采用隶属函数法对各马铃薯品种进行综合评价。结果表明：品种、氮水平和品种×氮水平都对晚熟马铃薯产量均具有极显著影响,而氮水平×品种对中熟品种无显著影响。连续2 a供氮条件下中熟品种产量变幅为8 289.39~22 011.61 kg·hm^-2,晚熟品种产量变幅为8 192.57~20 308.58 kg·hm^-2。基于2 a施氮和不施氮条件下各品种块茎产量,将不同马铃薯品种按照不同氮效率划分为4种类型,即双高型（‘京张薯1号’、‘陇薯20号’、‘青薯9号’、‘陇薯15号’、‘陇薯16号’）、低氮高效型（‘V7’、‘陇薯14号’）、高氮高效型（‘陇薯10号’）和双低型（‘冀张薯12号’、‘希森6号’、‘定薯3号’、‘陇薯22号’）。相关性分析结果表明：氮素吸收效率、氮肥表观利用率与产量呈极显著正相关关系（R²=0.4438^**,R²=0.4211^**）,马铃薯产量与块茎含氮量间呈极显著正相关关系（R²=0.5302^**,R²=0.4357^**）,说明在施氮和不施氮条件下,马铃薯块茎含氮量越高则其产量越高。隶属函数分析结果表明：中熟品种‘京张薯1号’（D_i=0.90）、晚熟品种‘青薯9号’（D_i=0.90）和‘陇薯10号’（D_i=0.87）具有较高的综合水氮效率和产量表现,可作为水氮高效品种在陇中旱作区进行推广。     

The effect of different dosages of aldicarb on the multiplication at small population densities of Globodera rostochiensis on potato in rotavated and non-rotavated plots

The effect of 0.35, 0.5, 0.7, 1, 1.4 and 2 g aldicarb/m², applied at planting time, on the multiplication of small densities ofGlobodera rostochiensis on potato was investigated in an experiment on sandy loam. The chemical was applied broadcast to the soil and rotavated into the top 15 cm on half the plots of each treatment. The plots were ridged three times, the first time immediately after the planting of the potatoes. Nematodes multiplied at the same rate in the top 20 cm of the soil on rotavated and non-rotavated plots treated with the same dosage of the chemical. The relation between log dosage and probit reduction of the multiplication rate in the top 20 cm after the plots had been levelled was linear between 0.35 g and 1.4 g aldicarb/m². The dosage-increase efficiency was 0.3 probit units per doubling of the dosage and the reduction of the multiplication rate at 0.5 g aldicarb/m² 76%, whereas 2 g aldicarb/m² was not more effective than 1.4 g. However, multiplication rates in the centre of the ridges of rotavated plots were reduced by 96.5% at 1 to 2 g aldicarb/m² but only by about 60% below the furrows and by 60% to 80% below the ridges. The latter reduction was the greater the larger the dosage of the chemical.The observations were in accordance with the supposition that multiplication of nematodes was totally inhibited in the top 20 cm of plots treated with 1.4 g and 2 g aldicarb/m² and that postharvest populations there consisted entirely of non-hatched eggs of the pre-plant population. The poor performance of the chemical in the deeper layers of the soil makes application less effective in reducing population build-up than in preventing yield losses.Samenvatting Het effect van 0,35, 0,5, 0,7, 1, 1,4 en 2 g aldicarb/m², toegediend vlak voor het poten, op de vermenigvuldiging vanGlobodera rostochiensis op aardappel werd onderzocht in een veldproef op zavel. Het middel werd breedwerpig over de oppervlakte van de grond verdeeld. Daarna werd de helft van de met elke dosis behandelde en van de onbehandelde veldjes gefreesd tot 15 cm diepte. Er werd drie maal aangeaard. Er was geen verschil in de vermenigvuldiging van de aaltjes in de bovenste 20 cm van de grond tussen wel en van het middel van probit vermindering van het vermenigvuldigingsgetal van het aaltje ten opzichte van onbehandeld in de bovenste 20 cm van de grond was rechtlijnig tussen 0,35 g en 1,4 g aldicarb/m². Het effect van dosisvergroting was 0,3 probit eenheid per verdubbeling van de dosis en de vermindering van het vermenigvuldigingsgetal bij 0,5 g aldicarb/m² 77%. Het effect van 1,4 g en 2 g aldicarb/m² was gelijk. De resultaten zijn in overeenstemming met de veronderstelling, dat in de met 1,4 en 2 g aldicarb/m² behandelde veldjes de vermenigvuldiging van de aaltjes in de bovenste 20 cm van de grond geheel was verhinderd. Met een voor praktische toepassing aanvaardbare dosis aldicarb kon een sterke vermeerdering van aardappelcystenaaltijes beneden 20 cm onder de oppervlakte van de grond niet worden voorkómen. Daardoor is de bruikbaarheid van dit systemische nematicide (en van overeenkomstige middelen) in een bestrijdingssysteem, dat streeft naar het (zeer) laag houden van dichtheden van aardappelcystenaaltjes, problematisch.     

不同马铃薯品种干旱适应性与其钾素营养特性的关系

采用盆栽试验,通过对5个马铃薯品种(‘V7’、‘大西洋’、‘实验二号’、‘大丰八号’和‘京张三号’)、2个水分条件(保持80%~85%土壤最大田间持水量,3轮干旱-复水)和2个钾肥水平(0 kg·hm^-2和180 kg·hm^-2)的三因素裂区试验,研究不同马铃薯品种的干旱适应性与其钾素营养特性之间的关系。结果表明：各品种马铃薯的干旱适应能力表现为‘实验二号’>‘V7’>‘大丰八号’>‘大西洋’>‘京张三号’,且干旱适应性与钾素营养特性呈显著正相关关系。钾素利用效率、植株钾素吸收量、块茎钾素吸收量和钾素吸收效率对马铃薯干旱适应性的贡献度分别为28.44%、15.08%、14.01%和8.55%。正常水分条件和干旱处理下的马铃薯水分利用效率与钾素利用效率、植株钾素吸收量和块茎钾素吸收量均呈显著正相关关系(P＜0.05),且与钾素利用效率的相关性最强,在正常水分条件和干旱处理下相关系数分别为0.97和0.96,推测钾素利用能力强的马铃薯品种可通过提高水分利用效率增强其对干旱的适应能力。研究结果表明,‘实验二号’更适合在北方旱区推广种植。     

玉米和马铃薯根系分泌物对马铃薯生长的影响

通过溶液培养法获取供体玉米和马铃薯根系分泌物,用来浇灌盆栽受体马铃薯“会-2号”,设单株马铃薯浇玉米根系分泌物（P+M-RE）、单株马铃薯浇马铃薯根系分泌物（P+P-RE）和单株马铃薯浇自来水（CK）3个处理,研究玉米、马铃薯根系分泌物对盆栽马铃薯生长的影响。结果表明：（1）盛花期和成熟期,P+M-RE处理的块茎生物量比P+P-RE增加了42.4%和28.5%,比CK增加了28.8%和8.2%,P+P-R比CK减少了23.7%和28.4%,差异分别为显著和极显著;（2）分枝期、盛花期和成熟期与CK相比,P+M-RE处理地上和地下部分生物量分别提高了8.3%~12.7%和7.5%~45.6%,P+P-RE处理分别降低了1.7%~12.9%和5.5%~20.9%;两处理的茎叶比均比CK低,根冠比在盛花期和成熟期比CK提高了64.1%、42.5%和56.8%、40.0%;(3)观测期内,P+M-RE处理叶片、茎秆、根系和块茎的化感敏感指数RI>0,表现为促进作用,敏感程度为根系>叶>块茎>茎秆;P+P-RE处理根系RI<0,叶片、块茎在分枝期和盛花期RI>0,成熟期为RI<0,整体表现为抑制作用;（4）盛花期马铃薯干物质转移率(DMME)及贡献率（DMCR）P+M-RE处理比CK分别提高了45.6%和48.0%,P+P-RE处理比CK分别提高了30.7%和43.9%。由此说明,玉米根系分泌物对马铃薯地上茎叶和地下根系及块茎生长具有净促进作用,有利于块茎的膨大,而马铃薯根系分泌物对自身地上和地下生长则具有抑制作用,影响了块茎膨大,这为揭示玉米||马铃薯体系增产机制提供了一定的理论依据。     

Distribution and frequency of occurrence of potato cyst nematode pathotypes in Northern Ireland

The distribution and frequency of occurrence of potato cyst nematodes, Globodera rostochiensis and G. pallida , were examined in Northern Ireland. Globodera rostochiensis (pathotype Rol) was the most abundant species, while Pal and Pa3 pathotype reactions could be discerned within G. pallida. Unlike other parts of the UK, species proportions appear not to have changed over the last 20 years, probably as a result of the legislative control currently practised combined with the limited use of Rol-resistant cultivars within the country. Differences in the geographical distributions of the three pathotypes were observed, and these are discussed in relation to original potato cyst nematode introductions and subsequent agricultural practices.     

A laboratory study on accelerated multiplication of virus-free potato material1

Various approaches have been tested for improving the production of usable microtubers in tissue culture propagation of virus-free potato material. Cultures in which microtubers are spontaneously produced under conditions when only vegetative growth should occur are generally not usable, either for further propagation or for microtuber production. Feeding with supplementary sucrose solution has been shown to stimulate such cultures to produce adequate quantities of usable microtubers. Use of a liquid medium instead of a solid medium was another method used to increase microtuber yield. An attempt was also made to increase efficiency by placing more transplants in each culture flask. Improvements were obtained by making various adjustments in the density of plants and the volume of medium, with supplementary feeding if necessary. The density could best be expressed in relation to total surface area of growth chamber used.     

不同玉米品种对烟嘧磺隆的敏感性差异

烟嘧磺隆是玉米田重要的芽后除草剂,采用温室盆栽和皿内生测法比较了32种不同玉米品种对烟嘧磺隆的敏感性差异。温室盆栽测定结果表明,在烟嘧磺隆大田常规用量60g/hm2下,各品种对药剂的敏感性差异显著,泰玉2号(正交)、金珍珠、泰玉15号、紫糯等7个品种对烟嘧磺隆表现较为敏感,株高抑制率均在40.4%以上,鲜重抑制率在31.37%以上,表现为植株生长受到抑制、叶片黄化、新叶牛尾状扭曲不能正常抽出;淄玉2号、泰玉2号(反交)、聊玉18、鲁原单33、鲁原单14、郑单958等品种的株高抑制率在30.6%～38.1%,敏感性略低,植株外部形态无明显变化;而农大2008、农大108、鑫玉958和泰玉12号生长正常,耐药性相对较高,无明显药害症状。其它品种介于豫单2002和鑫玉958之间。皿内生测法测定表明,烟嘧磺隆对玉米幼苗主根长的抑制存在较大差异,根据IC50值,各品种敏感性依次为:泰玉2号(正交)>金珍珠>泰玉7号>紫糯>泰玉2号(反交)>泰玉15>费玉5号>新单23>户单2000>聊玉19>泰玉12>鲁原单33>聊玉18>农大108>农大2008。     

Co-evolution of potato cyst nematodes and their hosts: implications for pathotypes and resistance1

The co-evolutionary process is believed to have resulted, through interaction of wild populations of potato cyst nematodes and their hosts in geological time, in the resistant hosts now utilized in plant breeding programmes and in nematode populations with genes for resistance-breaking or virulence. It is argued that all such interactions between highly adapted, truly parasitic plant nematodes and their hosts are likely to be governed by gene-for-gene interrelationships. Practical implications of this hypothesis are that only pathotypes (resistance-breaking races) defined against identified resistance genes are scientifically sound and of practical value; that, in the case of potato cyst nematodes, other pathotypes (Ro2, Ro3, Ro5 and Pa2 and Pa3) should be abandoned; and that oligogenically based resistance to potato cyst nematodes, especially important in providing resistance to Globodera pallida, is non-durable. Working definitions of the terms ‘pathotype’, ‘host-race’ and ‘virulence’ are provided.     

History of potato wart disease in Europe – a proposal for harmonisation in defining pathotypes

Potato wart disease, caused by the chytridiomycete Synchytrium endobioticum, was first introduced into Europe in the late 19th century. It spread quickly, and today is reported in 15 European countries. Initially, only one pathotype was found, and the disease was efficiently controlled using resistant cultivars. In 1941, however, formerly resistant cultivars showed wart formation in the field simultaneously in Germany and South Bohemia (Czech Republic), indicating the occurrence of new pathotypes. New pathotypes have since been reported from Germany, The Netherlands, Czech Republic, Ukraine and Canada. Today the pathogen is present in The Netherlands (only in fields for ware and starch potatoes) but restricted to two demarcated areas and subject to official control. Outside these areas, the pathogen is absent. For pathotyping, different countries have used different sets of differential cultivars, and the usual system of numerical coding of pathotypes has not been consistently followed. In this review we propose a new standardised code to be used for the 43 pathotypes currently known and described in Europe. The code is a combination of a numerical and letter code, combining the two terminologies used by former West and East Germany, respectively. We also plead for harmonisation in the choice of differential cultivars used for pathotype identification. The set of differentials described in the international standard for diagnosis of S. endobioticum issued by the European and Mediterranean Plant Protection Organisation (EPPO), should serve as a basis. Through close collaboration of European countries dealing with new pathotypes of potato wart disease, a final agreed upon set of differentials, combined with a set of reference isolates, should ultimately be established, allowing a clear distinction between the most important pathotypes occurring in Europe.     

甘薯根腐病病原菌鉴定

采用形态学、分子生物学和柯赫氏法则验证技术,对引起内蒙古甘薯根腐病的腐霉菌进行了鉴定。2012年从内蒙古通辽市科尔沁左翼后旗甘薯种植区采集的病样中分离获得45个菌株,经形态学观察和rDNA-ITS序列分析,确定其中43个菌株为Pythium ultimum var.ultimum,分离频率高达95.6%。致病性测定结果表明,回接后观察到与田间自然发病症状相同,并从发病根部重新分离到初始接种的腐霉菌株。腐霉菌引起甘薯根腐病在内蒙古为首次报道。     

Morphometric and developmental consequences in Spodoptera litura due to feeding on three varieties of sweet potato plants (Ipomoea batata)

The tobacco caterpillar, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae), is a polyphagous pest defoliating sweet potato, Ipomoea batata (Lam) (Convolvulaceae), throughout Asia. The study of morphometric parameters of S. litura as a result of feeding on three varieties (RNSP1, KIRAN and RNSP3) of host plant revealed that a greater number of egg masses were laid on the KIRAN variety than on the others. I. batata varieties showed statistically significant effects on length, breadth and weight of different larval instars. KIRAN-fed larvae molted to bigger-sized pupae. S. litura larvae reared on KIRAN variety had the highest feeding index as well as growth index. The low concentrations of phenols and carbohydrates coupled with elevated levels of proteins and amino acids were found in KIRAN as compared with RNSP1 and RNSP3. Collectively, the results of this study revealed that KIRAN cultivar was the most suitable food plant for the development of S. litura. Concurrently, it is suggested that this cultivar is therefore least suitable for sweet potato cultivation.     

甘薯瘟菌系致病型与寄主品种的互作关系

阐述了甘薯瘟菌系致病类型、品种抗性分类、抗性遗传趋势和病菌潜伏侵染特征;介绍了近年来我国南方甘薯瘟病区菌系分布状况,抗病品种利用与抗病育种进展;讨论了病原菌与寄主相互作用中的遗传关系。     

不同紫花苜蓿品种特性分析

2001-2002年在渭北旱塬麟游县对苜蓿王、阿尔冈金、WL-323、WL-323HQ、WL-323ML、WL-324、农宝、巨人、金皇后、西香、西河、会宁等12个国内外紫花苜蓿品种的生长特性和生态适应性进行了田间定位研究。结果表明,苜蓿王、阿尔冈金、wL-323ML、西香苜蓿产草量潜力较大,再生性强、综合性状好,适宜在当地大面积推广种植;地方品种会宁在产草量、再生性、直立性等方面均处于劣势。     

35个马铃薯品种对镰刀菌干腐病优势病原的抗病性评价

为合理利用抗源,用菌株混合接种法分别接种接骨木镰刀菌Fusarium sambucinum和茄病镰刀菌F.solani,以DPS2000数据处理系统对接种块茎第15天腐烂斑的半径进行系统聚类分析,从而探讨35个马铃薯品种对镰刀菌干腐病优势病原的抗病性。结果表明:以接种接骨木镰刀菌的块茎其腐烂半径原始数值不转换、接种茄病镰刀菌的块茎其腐烂半径原始数值进行标准化转换、聚类方法均采用欧式距离、最长距离法,其聚类效果与接种结果的吻合度最好。接种接骨木镰刀菌后,以欧式距离21作为最佳聚类距离分割点,将试验品种分为11个抗病品种、17个中抗品种和7个感病品种;接种茄病镰刀菌后,以欧式距离3.0作为最佳聚类距离分割点,将试验品种分为13个抗病品种、14个中抗品种和8个感病品种。     

一种马铃薯根茎腐烂病病原鉴定

正马铃薯(Solanum tuberosum)为茄科茄属植物,是全世界广泛种植的重要粮食作物~([1])。马铃薯为人们提供了丰富的营养物质,如碳水化合物、多种微量营养素和有利于健康的膳食纤维~([2,3])。马铃薯根茎腐烂病由多种病原菌引起,是马铃薯采后的主要病害~([4])。甘薯长喙壳菌也引起多种植物果实腐烂,如巴西首次报道甘薯长喙壳菌侵染鸡蛋