The Use of Mineral Oil in Potato Protection: Dynamics in the Plant and Effect on Potato Virus Y Spread

The focus of this study was to evaluate two mineral oils (Superior 70 and Vazyl-Y) in reducing the seasonal spread of Potato Virus Y (PVY). Three concentrations of oil (0, 5, and 10 L ha^?1 of Superior 70; 0, 7.5, and 15 L ha^?1 of Vazyl-Y) and three spray regimes for both oils (every 3–4, 7, and 10–11 days) were tested. Two weeks after top-kill, two tubers from each of 49 plants free of virus at emergence were harvested from treatment plots, sprouted, and tested for PVY with enzyme-linked immunosorbent assay (ELISA). Results revealed that in the case of Superior 70, PVY spread in mineral oil treated plots ranged from 2.1 to 12.2 %, while in the control plots it ranged from 20.4 to 37.7 % across three cultivars. In the case of Vazyl-Y, PVY spread in mineral oil treated plots ranged from 2.1 to 26.5 %, while in the control plots it ranged from 49.9 to 85.7 % across three cultivars. These data show that there was a significant reduction in PVY due to spray of mineral oils. In addition, mineral oil was quantified in plants from the Superior 70 treated and the control plots to understand the dynamics of mineral oil during the season. While there was little to no oil measured in the leaves at the early stages of plant growth, a considerable amount of mineral oil was detected close to plant maturity. A basic model of the concentration of oil in the treated foliage was formulated to confirm our understanding of the factors at play. The model could explain from 50 to 90 % of the variation in oil content observed in the field. Plant growth and size are important factors affecting oil content in mineral oil treated foliage.     

马铃薯植株感染Y病毒后生理指标变化与抗病性的关系

本研究分别以对PVY感病、过敏和极端抗性的品种脱毒试管苗为材料,比较了接种PVY后不同时间内超氧化物歧化酶(SOD)和游离脯氨酸含量2个指标的变化。从整体上看,未接种PVY条件下,感病品种(Superior)植株的SOD活性较极端抗性品种(IVP35)和过敏型品种(Desiree)低。接种后,IVP35的SOD活性下降;Desiree在接种前期0.5～1 d SOD的活性下降,2～7 d后SOD活性上升,再后7～14 d又下降;Superior接种PVY后,SOD活性有上升趋势,且在接种2～3 d变化率出现最大值。另外,IVP35和Desiree在接种PVY后SOD变化率小,变化范围分别为-13.4%～4.6%和-17.8%～8.7%;Superior接种PVY后,SOD活性变幅较大,范围为5.1%～79.2%。被测的3个品种无论接种与否,极端抗性品种和过敏型品种其植株内部游离脯氨酸含量均明显高于感病品种。正常情况下,IVP35和Desiree的游离脯氨酸含量为41.39～48.77μg.g-1干重和33.42～39.11μg.g-1干重,而Superior仅为8.91～10.72μg.g-1干重。接种PVY后,Superior的游离脯氨酸含量明显上升,达到11.23～21.54μg.g-1干重;虽然IVP35和Desiree的游离脯氨酸含量也呈上升趋势,但上升幅度小,含量分别为48.92～72.13μg.g-1干重和42.46～71.34μg.g-1干重。     

马铃薯Y病毒研究进展

马铃薯Y病毒(Potato virus Y,PVY)是危害马铃薯的重要病毒之一,在全球广为传播,并造成了严重经济损失。因此深入研究PVY及其与马铃薯的相互作用有助于控制病毒,减轻危害。根据初始寄主植物,PVY可分为以马铃薯为初始寄主的株系群体和以非马铃薯物种为初始寄主的株系群体。以马铃薯为初始寄主的株系群体,依据指示寄主植物(马铃薯品种,烟草)反应,进一步分为PVYO、PVYN、PVYNTN及PVYC等几种类型。依据血清学反应,PVY分成PVYO/C血清型和PVYN血清型。依据基因序列和基因组学,PVY分为PVYO,PVYN,PVYC及一系列PVYO/PVYN重组型如PVYNTN和PVYN:O。症状是寄主与病毒之间复杂的相互作用的结果。一些病毒蛋白和寄主蛋白的相互作用已被证实或逐渐认识到。证据显示HC-Pro起到转录后基因沉默抑制子的作用,从而提高病毒复制能力。马铃薯对PVY的抗性分为极端抗性和高敏抗性两类,多个极端抗性基因(即Ry基因)和过敏抗性基因(即Ny基因)被定位在第9,11和12号染色体上。PVY与植物的分子互作和抗PVY基因资源挖掘与利用将是今后几年的研究重点。     

Priming Potato with Thiamin to Control Potato Virus Y

Potato virus Y (PVY) is a major potato pathogen affecting potato yields worldwide. Thiamin, a water-soluble B vitamin (vitamin B₁) has been shown to boost the plant’s immunity, thereby increasing resistance against pathogens. In this study, we tested different concentrations of thiamin (1 mM, 10 mM, 50 mM, 100 mM) and multiple thiamin applications (once, biweekly and monthly) on potato resistance to PVY in Ranger Russet potatoes. Plants were mechanically inoculated with PVY^N:O. This PVY strain is known for causing well-defined foliar symptoms. We collected leaflets weekly through April and May 2015 and tested them with an enzyme-linked immunosorbent assay specific to PVY as well as by real time quantitative RT-PCR. These assays allowed us to determine the presence and level of PVY in different parts of the plants. We found that the highest thiamin concentration treatment (100 mM) produced the lowest virus level in potatoes across all dates and leaflet samples. Also, it was found that multiple applications of thiamin had a positive effect on reducing virus level, especially when thiamin was applied every four weeks.     

马铃薯PVY和PLRV病毒的TC-RT-PCR检测

传统的RT-PCR技术检测病毒需提取总RNA,RNA容易降解。利用试管捕捉反转录扩增(Tube cap-ture RT-PCR,TC-RT-PCR)方法检测了PVY和PLRV 2种病毒,实现了不需提取总RNA也可在同一反应中同时检测2种病毒。根据已报道的引物用TC-RT-PCR的方法对PVY和PLRV的外壳蛋白基因进行了检测。结果表明,TC-RT-PCR能够成功的检测出感染PVY或PLRV以及2种病毒共同侵染的样品,扩增产物序列长度均与设计片段的长度相符,分别为781和364 bp,2种病毒扩增产物的测序结果同Gene Bank中已知的序列比对后的同源性均高达97%以上。该技术为单独或复合感染的马铃薯病毒的检测提供了更加方便、高效的方法。同时测得试验PVY病毒样本属于PVYNW株系。     

NCM-ELISA检测马铃薯Y病毒(PVY)技术的研究及应用

血清学方法是病毒检测的主要手段。本试验通过对马铃薯Y病毒(PVY)的提纯,免疫家兔制备PVY抗血清,并提取PYV免疫球蛋白IgG作为NCM-ELISA反应为一抗,以市售羊抗兔抗血清为二抗,在硝酸纤维素膜(NCM)上进行NCM-ELISA反应检测PVY,建立PVY NCM-ELISA检测反应体系。试验结果显示,NCM-ELISA具有反应特异性强,灵敏度高的优点,检测植物叶片样品的最高稀释度可达到1:250。通过对田间40份样品的NCM-ELISA和DAS-ELISA检测比较,其检测结果吻合率达到100%。由于NCM-ELISA方法可以将样品点在硝酸纤维素膜上,并且可贮存几个星期或将膜送到其他实验室进行检测,因此具有操作简单,使用方便,检测成本低等优点。     

马铃薯抗Y病毒资源材料的鉴定与筛选

用洋酸浆(Physalis floridana)、A6(Solanum demissum×Aquila)的后代、黄苗榆烟(Nicotianatabacum)、鲁特格尔斯番茄(Lycopersicon esculentum cv.Rutgers)4种指示植物汁液摩擦接种法,对55份马铃薯普通栽培种进行Y病毒的带毒鉴定试验,选出33份不带马铃薯Y病毒的材料;用接种过的番茄为砧木,以不带马铃薯Y病毒的材料为接穗进行嫁接传毒试验;对嫁接后能正常生长30 d以上的材料又回接了该种病毒病的寄主进行抗性鉴定试验。通过试验筛选出10份抗马铃薯PVY病毒的材料,其中免疫的有1份,过敏的有9份,从而为马铃薯抗Y病毒育种提供资源材料。     

野生马铃薯抗PVY材料的鉴定与筛选

通过人工接种的方法对5类野生马铃薯材料进行了马铃薯Y病毒(PVY)的抗性鉴定和筛选。它们对PVY抗性存在明显的差异,其中Solanum stoloniferum(S.A2)×S.stenotomum(104)和S.stoloniferum(S.A5)×S.stenotomum(105)组合抗性最强,属于抗病群体,S.chacoense×S.stenotomum(103)组合属于中抗群体,S.chacoense(102)和S.demissum(101)组合属于感病群体。并从中筛选出一批抗PVY的育种材料:0级抗性材料108份,1级抗病材料56份,3级抗病材料94份。     

PVY株系间的分子变异及分子鉴定方法

马铃薯Y病毒(Potato virus Y,PVY)株系分化现象明显,难于准确鉴定.本研究利用核酸序列分析工具对PVY主要株系的全基因组序列、cp基因序列和P1基因序列进行了系统分析,探明了PVY主要株系的分子特征.结果表明,具有PVYN株系血清型的PVYN、PVYNIN株系与具有PVYO株系血清型的PVYO、PVYN...     

马铃薯Y病毒黑龙江分离物株系鉴定

通过生物学方法、血清学方法、RT-PCR方法对黑龙江省一个马铃薯Y病毒分离物进行株系鉴定。该病毒侵染洋酸桨产生枯斑,在黄苗榆烟上表现系统花叶,并伴有坏死症状,血清学反应强烈,三重PCR特异性条带清晰,鉴定该分离物为PVYN。     

Comparison of Straw Mulch,Insecticides, Mineral Oil,and Birch Extract for Control of Transmission of Potato virus Y in Seed Potato Crops

Potato virus Y (PVY) is a major pathogen of potato and transmitted non-persistently by aphids. Aphis fabae is the main vector of PVY in the High Grade Seed Potato Production Area (HG area) in Finland, where the number of aphids and infection pressure with PVY are rather low, but problems with PVY occur in PVY-susceptible cultivars. The aim of the study was to test straw mulch, mineral oil, birch extract, and insecticides for control of PVY in small-scale field experiments and, additionally, at farm level in growers’ fields in the HG area of Finland. The insecticide esfenvalerate reduced the incidence of PVY in the progeny tubers by 29% in one of the 3 years, whereas other chemical treatments or birch extract had no significant effect on PVY incidence. Spraying foliage with mineral oil (Sunoco 11 E/3) reduced the incidence of PVY in 2 years by 43 to 58%, respectively. Straw mulch spread to the field at the time of plant emergence reduced PVY incidence in all 3 years by 50–70%. At farm level, straw mulch reduced the incidence of PVY in the progeny tubers by 25–47%, respectively, in both years tested; however, combining application of straw mulch and mineral oil did not further reduce incidence of PVY. Successful control of PVY in the HG area of Finland using straw mulch may be explained by transmission of PVY early in the growing season at the time of plant emergence and the relatively low number of vector aphids.     

Genetic Resistances to Potato Leafroll Virus, Potato Virus Y, and Green Peach Aphid in Progeny ofSolanum etuberosum

Increasing prevalence of potato leafroll virus (PLRV) and potato virus Y (PVY) has been reported in seed and commercial potato production, resulting in the rejection of potatoes for certification and processing. Host plant resistance to PLRV and PVY and their primary vector, green peach aphid,Myzus persicae, could limit the spread of these viruses. Host plant resistance to PLRV, PVY, and green peach aphid has been identified in non-tuber-bearingSolanum etuberosum (PI 245939) and in its backcross 2 (BC₂) progeny. Resistance to green peach aphid involved a reduction in fecundity and adult aphid size. In addition, one BC₂ individual was identified as possessing a genetic factor that was detrimental to nymph survival. PVY resistance was identified in all five BC₂ progenies evaluated in a field screening under intense virus pressure. PLRV resistance was identified in two of the five BC₂ progeny. This resistance was stable in field and cage evaluations with large populations of viruliferous aphids. Based on the segregation of virus resistances in the BC₂ , PVY and PLRV resistances appear to result from the action of independent genetic mechanisms that reduce the levels of primary and secondary virus infection. Two BC₂ individuals, Etb 6-21-3 and Etb 6-21-5 were identified as having multiple resistances to PLRV, PVY, and green peach aphid derived fromS. etuberosum. This germplasm could prove useful to potato breeders in the development of virus-resistant cultivars.     

Cryotherapy of Potato Shoot Tips for Efficient Elimination of Potato Leafroll Virus (PLRV) and Potato Virus Y (PVY)

Viral diseases constitute a major constraint to high yield and high quality production of potato. Potato leafroll virus (PLRV) and Potato virus Y (PVY) are among the most damaging potato viruses and are prevalent in most potato growing areas. In the present study, attempts were made to eliminate PLRV and PVY by three cryogenic protocols, i.e., encapsulation-dehydration, encapsulation-vitrification and droplet. Results showed that both PLRV and PVY could be efficiently eliminated by cryogenic treatments with 83–86% and 91–95% of frequencies of virus-free plantlets obtained for the former and latter, respectively. Frequencies of virus-free plantlets produced by cryogenic treatments were higher than those by meristem culture (56% for PLRV and 62% for PVY) and thermotherapy (50% for PLRV and 65% for PVY), and similar to those by thermotherapy followed by meristem culture (90% for PLRV and 93% for PVY). Survival (75–85%) and regrowth (83–89%) from cryo-treated shoot tips were higher than those from meristem culture (50–55%) and thermotherapy followed by meristem culture (40–50%), but similar to those from thermotherapy (80–87%). The morphology of the plantlets regenerated from cryo-treated shoot tips was similar to that of non-treated plantlets. Thus, cryotherapy would provide an alternative method for efficient elimination of potato viruses, and can be simultaneously used for long-term storage of potato germplasm and for production of virus-free plants.     

马铃薯Y病毒一步RT-PCR检测试剂盒的研制

马铃薯Y病毒(Potato virus Y,PVY)对马铃薯的危害最大,可导致马铃薯退化,降低马铃薯产量。解决这一问题的重要途径就是培养脱毒种薯,但是否完全脱毒需要经过检测才能证实。本研究依据PVY CP基因序列设计合成了一对引物PY1、PY2,以带毒样品植物总RNA为模板,在同一个反应中同时加入反转录和PCR反应所需试剂,反应程序中包括反转录和PCR反应所需条件,进行反应扩增,带毒样品扩增得到340 bp的目的条带,而健康对照无此目的条带,从而建立了PVY的一步RT-PCR检测技术,并组装成试剂盒。该试剂盒具有良好的稳定性和特异性,灵敏度可以检测到带毒植物组织下限的6.25μg,高于ELISA(100μg)和NASH(15μg)的灵敏度,虽然和常规方法的灵敏度相同,但更为快速、简便、易于操作,适合脱毒苗和脱毒种薯生产单位做大量样品的检测。     

武汉地区马铃薯Y病毒株系的类型

马铃薯Y病毒(PVY)是严重危害我国马铃薯生产的主要病毒之一。本研究通过RT-PCR的方法,对依据症状采集的124份马铃薯叶片样品进行了病毒检测,并对其中PVY阳性样品进行了株系类型分析。结果显示,在93份PVY阳性样品中,PVYN/NTN/N??O类型株系占60.2%,而PVYO普通株系占20.4%,还有18个样品(19.4%)显示受到两种类型PVY的混合侵染。进一步分析表明,在PVYN/NTN/N??O类型株系中,PVYNTN、PVYN??O和PVYN三种株系分别占83.8%、12.2%和4.0%;而PVYO普通株系中,PVYO-FL和PVYO-RB两种变异型各占70.3%和29.7%。本研究结果显示,PVYNTN和PVYO-FL是检测样品中主要的PVY株系,该结果为指导马铃薯PVY的防治提供一定的依据。     

Potato Virus Y transmission efficiency for some common aphids in Idaho

Green tile pan trap counts during the potato-growing season showed thatCapitophorus elaeagni (32%),Diuraphis noxia (27.7%), andMetopolophium dirhodum (15%) were the most abundant aphid species in potato fields at Aberdeen, Idaho.Acyrthosiphon pisum (22%),C. elaeagni (19%), andMetopolophium dirhodum (19%) were the most abundant species in potato fields at Tetonia, Idaho potato seed production areas. Eight species of aphids found to visit potato fields (C. elaeagni, D. noxia, M. dirhodum, Myzus persicae, Rhopalosiphum maidis, Rhopalosiphum padi, Schizaphis graminum, andSitobion avenue) were tested for Potato virus Y (PVY) transmission efficiency by timed probe experiments. Four of these species (D. noxia, M. dirhodum, M. persicae, andS. aoenae) and an additional three (Diuraphis frequens, Diuraphis mexicana, andDiuraphis tritici) were tested using mass inoculations.Capitophorus elaeagni, M. persicae, R. maidis, R. padi, andS. graminum all transmitted PVY in the timed probe experiments.Myzus persicae andD. noxia transmitted PVY in the mass inoculation experiments.     

Age-Dependent Potato Tolerance to Herbivory in Different Nutrient Environments

Tolerance is a type of defense that allows plants to attenuate the negative effects of herbivory. Tolerance has been shown to be context-dependent, contingent on abiotic and biotic factors such as nutrients and plant age. Here, we determine the simultaneous effect of herbivory at different phenological stages and nitrogen regimen on the potato’s ability to tolerate herbivory. We subjected young and blooming plants of two potato varieties to 50% injury by Colorado Potato Beetle in low and high nitrogen environments to determine their effects on tuber yield and plant tolerance. All plants in the high nitrogen treatment expressed higher yield and tolerance compared to those in the low nitrogen treatment. Control plants expressed higher yield than plants in either herbivory treatment. There was a variety by phenological stage of herbivory interaction showing that phenological-based tolerance expression within species is genotype dependent.     

用指示植物分离鉴定马铃薯轻花叶病毒(PVX)的技术

试验研究指示植物培养、接种鉴定及分离马铃薯轻花叶病毒 (PVX)的方法 ,为马铃薯轻花叶病毒抗血清制备提供技术保证。