Mosaic Virus Symptoms in Potato Crops and the Occurrence of Growth Cracking in Tubers

Infection of potato plants by viruses causing mosaic symptoms may result in a reduction in crop yield, depending on severity of symptoms and incidence. In 2004 and 2007, an investigation was undertaken to examine the relationship between plants with mosaic symptoms and the occurrence of growth cracking in daughter tubers. Samples of pairs of plants affected by mosaic symptoms and plants with no symptoms were collected from nine potato crops, of which seven were cv. Estima, containing at least 20% mosaic-affected plants. Growth cracking was more prevalent on mosaic-affected plants of cv. Estima than on plants with no symptoms. The incidence of growth cracking was much greater on plants showing mosaic symptoms caused by a mixed infection of Potato virus A and Potato virus V together than on symptomatic plants infected by either virus alone. The presence of virus in plants with no symptoms did not affect the incidence of tubers affected by cracking. In a crop of the advanced selection Blue Tzar, plants with mosaic symptoms caused by Potato virus Y ^N produced more tubers with cracking than plants with no symptoms. Growth cracking did not occur in the one sampled crop of cv. Désirée infected by Potato virus A.     

我国马铃薯病毒的种类及脱毒种薯生产过程中病毒的检测

对近年来我国各马铃薯产区病毒发生情况进行分析,详细列出马铃薯主产区病毒病种类及各主要马铃薯病毒的分布情况。分析表明,我国很多马铃薯产区尚缺少全面、系统的马铃薯病毒调查。同时比较了我国各地区马铃薯脱毒种薯生产过程中对病毒的检测规程,并分析了马铃薯A病毒(PVA)的检疫风险。     

马铃薯病毒的RT-PCR检测技术评述

对应用于马铃薯病毒检测中9种不同形式的RT-PCR检测技术进行评述,重点讨论常规RT-PCR、多重RT-PCR、Real-time RT-PCR等方法。分析了RT-PCR在同种病毒不同株系鉴定中的应用效果及建立系统进化树时应注意的问题。对RT-PCR技术在马铃薯病毒检测中可能出现的问题也进行了分析,并提出了应对策略。     

Assessing Potato Psyllid Haplotypes in Potato Crops in the Pacific Northwestern United States

The potato psyllid, Bactericera cockerelli (?ulc), is a vector of the bacterium ‘Candidatus Liberibacter solanacearum’ (Lso) that has been linked to the economically devastating zebra chip disease of potato. To date, four haplotypes of the potato psyllid have been identified and include Central, Western, Northwestern, and Southwestern haplotypes. Zebra chip was reported in potato crops in the Pacific Northwestern United States for the first time in 2011, and the Lso-infected psyllids collected from zebra chip-affected fields were identified as the Western haplotype. Additional studies have reported a mix of the Western and Northwestern psyllid haplotypes in the Pacific Northwest. The present study further examined psyllid population dynamics over the duration of the 2012 potato season in the Pacific Northwest by haplotype analysis of 864 potato psyllids collected from potato fields in Washington, Oregon, and Idaho. In the Yakima Valley of Washington and the lower Columbia Basin of Washington and Oregon, the Northwestern haplotype was predominant (78 %), and was detected earlier in the season than the Western haplotype. Interestingly, in south-central Idaho, all four psyllid haplotypes were identified, but the predominant haplotype was the Western haplotype (77 %). Here, Northwestern psyllids were detected early in the season from June to mid-August, whereas Central psyllids were detected in late July and thereafter. These results suggest that haplotype composition of psyllid populations in potato fields throughout the 2012 growing season in south-central Idaho differed greatly from those in Washington and Oregon. Additionally, all psyllids were analyzed for the presence of Lso, and no Lso-positive psyllids were found in Washington and Oregon, whereas Lso-positive psyllids were found in south-central Idaho. These Lso-positive psyllids consisted of the Western, Northwestern, and Central haplotypes.     

马铃薯主要病毒侵染不同品种症状及对产量的影响

马铃薯病毒病严重影响马铃薯产量和质量,因此,在马铃薯生产中防控马铃薯病毒病尤为重要。用马铃薯A病毒(Potato virus A,PVA)、马铃薯Y病毒(Potato virus Y,PVY)、马铃薯X病毒(Potato virus X,PVX)、马铃薯M病毒(Potato virus M,PVM)、马铃薯S病毒(Potato virus S,PVS)、PVY+PVA、PVY+PVX、PVY+PVS以及PVY+类病毒(Potato spindle tuber viroid,PSTVd)共9种病毒或病毒(类病毒)组合于苗期接种黑龙江省10个马铃薯主栽品种,调查这些品种的株高、产量、大薯率和植株症状的变化。结果表明,复合侵染中PVY和PSTVd和单一侵染中PVY对马铃薯品种高度影响最大。10个供试马铃薯品种对含有PVY侵染的5个处理(PVY、PVY+PVX、PVY+PVA、PVY+PVS、PVY+PSTVd)均表现出了明显的症状。PVY+PVX和PVY+PSTVd复合侵染对10个马铃薯品种的产量和大薯率影响较大。调查了生产中常见病毒病和类病毒在黑龙江省主栽品种上造成的症状和危害,有助于在生产中对病害的识别和防控,降低病害的危害,提高马铃薯的质量和产量。     

马铃薯茎尖脱毒培养方法优化研究

以甘肃省主栽品种陇薯6号为材料,研究了茎尖大小及培养基中激素和活性炭对马铃薯茎尖培养成活的影响。结果表明,叶原基数为2的茎尖脱毒效果最好;MS培养基中加入0.5 mg·L~(-1)6-BA、0.1mg·L~(-1)GA_3和0.1 mg·L~(-1) NAA有助于陇薯6号茎尖分生组织分化;加入0.05%活性炭,茎尖成苗时间提前了13 d,成苗率增加了7.5%。     

分子生物学技术在马铃薯病毒检测中的应用

直接应用于马铃薯病毒检测的分子生物学技术主要有 :RT PCR检测技术、指示分子 NASBA检测技术、核酸杂交检测技术三大类 ,以RT PCR技术应用最为广泛。另外病毒外壳蛋白基因的克隆与表达、DNA介导的抗体制备及病毒单链抗体片段筛选等技术在马铃薯病毒免疫学检测技术中也有成功的应用 ,并解决了传统免疫学方法难以解决的抗原制备问题 ,使后者更具应用前景。     

马铃薯病毒分子检测技术研究进展

对种子、苗木和无性繁殖材料以及在发病早期对植株进行快速准确地检测尤为重要。目前国内外马铃薯病毒分子检测技术的研究,主要涉及以蛋白质和核酸为基础的检测方法。以蛋白质为基础的检测方法主要根据免疫学原理,包括酶联免疫吸附反应测定法、直接组织斑免疫测定法和胶体金免疫层析法。以核酸为基础衍生的检测方法较多,主要有RT-PCR检测技术、免疫捕捉-RT-PCR检测技术、核酸杂交检测技术、指示分子NAS-BA技术、实时荧光定量PCR技术和基因芯片技术。     

马铃薯茎尖脱毒效果影响因素的研究

以克新2号、克新16号和克新17号等8个马铃薯品种为试验材料,对马铃薯茎尖脱毒效果的影响因素进行了研究。结果表明:不同种类的植物生长调节剂对茎尖的生长有不同的影响,茎尖在⑤号培养基(MS+1.0mg·L-1KT+0.5mg·L-1IAA+0.5mg·L-1GA3)上可不产生愈伤组织,直接成苗,是最适宜的培养基;6～8℃低温预处理和37℃热空气处理对茎尖脱毒有利;茎尖取材来源对成苗率没有影响,对脱毒效果影响较大,但脱毒效果依品种而异;为避免造成损失,需在15个月内准备出用于更换的基础苗。     

应用三重RT-PCR技术检测三种马铃薯病毒

马铃薯X病毒(PVX)、马铃薯M病毒(PVM)和马铃薯A病毒(PVA)是导致马铃薯种薯退化的重要病毒,有时复合侵染,因此建立快速、准确检测体系尤为重要。试验从中、英文文献中查找引物,通过筛选和综合评价,每种病毒确定1对特异性引物,再通过对PCR部分Mg2+、d NTPs、Taq DNA聚合酶浓度梯度优化,最终建立了稳定的三重RT-PCR反应体系,得到长度分别为711、520、273 bp的特异性条带。应用该体系和DAS-ELISA方法同时对田间150份马铃薯毒源样品进行检测,两种方法检测结果吻合,三重RT-PCR体系的灵敏度更高、特异性更强,可以用于马铃薯田间样品检测。     

浅谈异境保存对热带作物种质资源的影响

异境保存是目前热带作物种质资源的主要保存形式.本文在介绍异境保存概念及其对种质资源遗传多样性影响的基础上,提出见解和建议:对生长不良的种质资源采取人为主动淘汰;对生长良好的种质资源可以采集种子播种,通过自然选择建立稳定种群;对于我国野生的资源,宜保存进化显著单元.     

Potato Ring Rot in Norway: Occurrence and Control

Potato ring rot, caused by the bacterium Clavibacter michiganensis subspecies sepedonicus, is considered to be one of the internationally most important seed potato diseases (Smith et al.; Eur J Plant Pathol 107:739–748, 2001) and has been a problem in Norwegian potato production since its first detection in 1964. Since 1965, Norway has had its own national legislation for the control of the disease. In recent years, this legislation has evolved to be more similar to the EU Commission Directive 2006/56/EC. In 1999, the Norwegian Food Safety Authority initiated an eradication program for potato ring rot with the aim of selling potatoes to other European countries. During the project period (1999–2008), efficient systems for sampling, analysis and eradication measures were built. From 1999 to 2002, the occurrence of potato ring rot in commercial potato production was monitored in all counties. Sampling was carried out according to the instructions of the Norwegian Food Safety Authority, while testing of samples was (from 2000 onwards) carried out by Bioforsk laboratories with modern serological and molecular detection methods. When ring rot was detected in a potato lot, the grower had to implement strict eradication measures. The survey was followed up with two monitoring periods, 2003–2004 and 2005–2008. During the project period, 328 cases of potato ring rot were found. The counties Hedmark, Nordland, Troms, and Tr?ndelag accounted for most of these. The main objectives of this study were to describe the occurrence of potato ring rot in Norwegian potato production and to evaluate the effectiveness of the eradication measures employed for the control of the disease. This survey showed that the overall ring rot situation did improve considerably during the project period (1999–2008), both in relation to prior periods, and when comparing the surveying and monitoring periods. Problem areas where monitoring must be continued remain.     

马铃薯瓢虫发生规律及防治方法

马铃薯瓢虫在绵阳市主要危害马铃薯、茄子、辣椒、玉米等作物,在马铃薯上危害盛期被害株率最高可达100%,百株虫口密度达95～480头,单株虫口数高的可达200头,产量损失15%～30%.马铃薯瓢虫一年发生两代,危害盛期为5月中下旬和7月中下旬.农业防治应重点抓住越冬期防治,药剂防治应在卵孵化盛期进行.     

Occurrence and Distribution of Potato Pests and Diseases in Kenya

Potato plays an important role in food security in Kenya but yields are low (<10 t/ha), and this is partly attributed to the lack of healthy planting material. This study is the first wide-scale survey to determine the occurrence and distribution of common potato pests and diseases in Kenyan seed (certified and quality declared) and ware crops. Potato crops growing on 101 farms in 21 districts were examined. Approximately 36% of plants in farmers’ fields sampled both during the long rains (main potato-growing season) and short rains seasons displayed virus-like disease symptoms. Six viruses (potato leafroll virus (PLRV), Potato virus A (PVA), potato virus M (PVM), potato virus S (PVS), potato virus X (PVX), and potato virus Y (PVY)) were detected using double antibody sandwich enzyme-linked immunosorbent assay in potato samples. Sequencing of polymerase chain reaction products from PVY-infected plants revealed the presence of recombinant strains of PVY (NTN and Wilga). Four aphid species, Macrosiphum euphorbiae, Aphis gossypii, Myzus persicae, and Aphis fabae, colonized potato in all districts, occurring in greater numbers west of the Great Rift Valley than to the east. There was a positive correlation between virus incidence and aphid numbers in the long rains (main) potato-growing season. PLRV, PVM, PVS, PVX, and PVY were detected in solanaceous weeds. Ralstonia solanacearum was detected in soils from 13 farms in 8 of the 18 districts surveyed. Approximately 38% of soil samples were infested with Meloidogyne spp. Phytophthora infestans isolates belonging to the US 1 and 2_A1 genotypes were identified. Although many economically important diseases are present in Kenya, the lower aphid incidence in districts east of the Great Rift Valley may indicate that these districts are more suitable for seed potato production.     

Optimization of a Chemiluminescent Dot-Blot Immunoassay for Detection of Potato Viruses

Vegetative propagation of potato leads to virus accumulation, resulting in significant yield losses and reduced quality. Virus identification is critical for developing disease management strategies and measuring seed lot health. The most widely used method of virus diagnosis in seed potatoes is a post-harvest test, for which the enzyme-linked immunosorbent assay (ELISA) is often used. ELISA was previously modified by substituting microtiter plates with membranes to develop a more flexible and inexpensive assay. We optimized a dot-blot immunoassay with viral proteins bound to a polyvinylidene fluoride (PVDF) membrane and detection of the proteins with alkaline phosphatase-labeled antibodies and a chemiluminescence reagent. The assay was tested for detection of viruses of seven genera. We have also altered the assay by spotting an antibody array onto a PVDF membrane and tested it for its potential uses as a diagnostic tool for Potato virus Y, Hosta virus X, and Potato leafroll virus.     

The Effect of Elevated Levels of Carbon Dioxide on Potato Crops

SUMMARY

Experiments, which have investigated the effect of elevated concentrations of atmospheric CO₂ on the physiology, growth and yield of potato (Solanum tuberosum L.), are reviewed. These studies were conducted in controlled environment chambers, in glasshouses, in open top field chambers as well as using free air carbon dioxide (FACE) exposure systems. In general, photosynthesis is stimulated by elevated CO₂ initially although long-term exposure leads to acclimation. The stomata of potato leaves partially close in response to elevated CO₂ and starch granules build up in the chloroplasts. Although above- and below-ground biomass production is stimulated, accelerated senescence limits growth towards the end of the growing season exposure to elevated CO₂ stimulates tuber yield, the magnitude of which depends on agronomic practise, cultivar choice and growing conditions. The beneficial effects of elevated CO₂ may be reduced by interaction with other components of climate change, such as drought stress. Modelling of the effects of climate change on potato yield has predicted an increase in yields in northern Europe with little change in central and southern Europe. It is suggested that further research is needed to understand the reasons for photosynthetic acclimation, field trials are also needed to understand and quantify the interaction between elevated CO₂ and drought stress.     

马铃薯茎尖培养脱毒研究进展

综述了马铃薯茎尖培养脱毒的原理 ,影响马铃薯茎尖培养脱毒的因素 ,马铃薯试管苗快繁技术与培养条件优化等方面的研究进展 ,指出了茎尖培养脱毒中尚存在的一些问题     

云南省宣威市马铃薯晚疫病发病规律研究

本研究用定点观察的方法,连续3年对云南省宣威市马铃薯种植田块中田间气候、种植习惯、品种等因素进行调查记录,同时观察记录该区域马铃薯晚疫病田间发生、发展情况。结果表明:马铃薯疫病在云南宣威市的发生与流行受主栽品种的抗性、种薯带菌率以及田间气候条件等多因素综合影响。新品种滇薯6号在当地表现出较好的抗性;种薯带菌率越高,田间晚疫病发生越重,流行越快;田间相对湿度高,对晚疫病发生与流行十分有利。