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。     

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.     

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.     

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。     

马铃薯块茎休眠及休眠调控研究进展

系统介绍了马铃薯块茎休眠的总体特征以及休眠块茎在细胞生理学方面的研究进展.同时还论述激素对马铃薯块茎休眠的调节作用,并提出了一些打破休眠的方法。     

Glycoalkaloid Concentration in Potato Tubers Related to Storage and Consumer Offering

Steroidal glycoalkaloids (SGA) are unwanted potato constituents for consumers because they are highly toxic and therefore have to be controlled in the food chain. Three experiments were carried out focusing on storage aspects and on exposure to artificial light at the point of sale. The experiments showed that an elevated temperature (10 °C) during long-term storage without sprouting inhibitors led to an increase in SGA contents (up to 518 mg SGA kg⁻¹ dry matter) in two of three investigated cultivars independent of the sprouting level. Cold storage (4 °C) slightly enhanced SGA contents in two cultivars. Sprout control resulted in a tendentious decrease in SGA contents in a set of another three cultivars. Growing location and wet and cool seasons had an influence too. Moderate exposure to light resulted in an increase in SGA in autumn, but in a decrease in spring time. Again, cultivars tested responded differently. The addressed factors have to be considered when developing strategies in minimising SGA level in table potatoes.     

Mineral Oil Inhibits Movement of Potato Virus Y in Potato Plants in an Age-Dependent Manner

Potato Virus Y (PVY) is one of the most devastating pathogens threatening potato production worldwide. It is a RNA virus that is disseminated by aphids in a non-persistent manner. Regular application of mineral oil on potato fields is known to reduce the number of PVY-positive tubers in post-harvest testing. The mechanism of this phenomenon is not well understood, but it is hypothesized to influence the virus-vector-plant relationships. Here, we present data from greenhouse and field trials that shed light on the effect of mineral oil on local and systemic accumulation of PVY^O in susceptible Shepody and Russet Burbank. The data suggests that mineral oil did not influence PVY^O levels in mechanically-inoculated leaves nor tubers of plants with a secondary infection. However, a reduction in systemic PVY^O levels was observed in mineral oil-treated older plants but not in younger plants, suggesting that mineral oil inhibits PVY^O movement in an age-dependent manner.     

热处理防治马铃薯卷叶病毒的研究

播种前对马铃薯种薯进行热处理可有效防治马铃薯卷叶病毒 (PLRV )发生。经试验 ,温度 38℃、时间 2 4d、相对湿度 75 %～ 85 %时 ,效果尤为明显。处理后的种薯在温室种植 ,PLRV呈阴性 ,田间感病明显降低 ,且出苗整齐 ,生长旺盛 ,产量增加 14 8%。     

Susceptibility to Pressure Flattening Correlates with Texture Analysis of Potato Tubers

The physiological disorder referred to as pressure flattening is a cause of significant economic losses in the storage of Irish potatoes (Solanum tuberosum L.) intended for use in the fresh market. As the flattened area on each tuber becomes larger in diameter or becomes more depressed the USDA quality grade, and therefore the market value of the potatoes is reduced. Experiments were conducted to identify at-harvest which potato lots within and among cultivars were likely to pressure flatten earlier or more severely. The use of an instrumented penetrometer or texture analyzer to measure peak load required for periderm deformation at harvest appears to anticipate correctly the majority of fields from which tubers are more likely to have severe pressure flattening at six months’ storage duration. At-harvest texture analysis appears to segregate varieties according to susceptibility to deformation based on cultivar specific factors that play a role in pressure flattening development during storage. The Pearson correlation coefficient (R²=0.5481) indicates that there is a correlation between tuber texture at harvest and pressure flattened area on the tuber following storage. Testing of tubers from different fields and cultivars as the potatoes are loaded into storage, may allow growers to identify and ship potatoes that are more susceptible before they develop significant pressure flattening.     

马铃薯不同品系贮藏期品质分析

马铃薯秋天入窖后,测定不同品系的还原糖含量、可溶性糖含量、淀粉含量,其结果为:还原糖含量入窖后到次年3月份逐渐升高,之后又快速下降,6-21还原糖含量最低,小白花还原糖含量最高;可溶性糖含量较稳定,只是不同品系表现趋势不同,6-21可溶性糖含量最低,1-38可溶性糖含量最高;淀粉含量也较稳定,6个品系总趋势为逐渐下降;1-38淀粉含量最高;大多数马铃薯品系的还原糖与可溶性糖呈正相关,可溶性糖与淀粉、还原糖与淀粉呈负相关。     

大生M-45防治马铃薯晚疫病药效试验

选用大生M-45防治马铃薯晚疫病,结果表明,田间三次施药,600倍液行间喷雾,对马铃薯晚疫病有较好的防治效果,防效达80.5%,马铃薯可增产27.5%。     

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。     

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。     

Pomerelle Russet: an Early Maturing Potato Variety with High Yields of U.S. No. 1 Tubers Suitable for Fresh Market and mid-Storage Processing and Tolerance to Potato Mop-top Virus

Pomerelle Russet is an early maturing fresh potato variety, which produces moderately high early-season (95–110 days after planting) yields of long tubers with brown-russet skin. It is notable for its very attractive, smooth tubers and resistances to internal and external defects with a high percentage of U.S. No. 1 tubers. Fresh merit ratings for Pomerelle Russet in trials conducted in Idaho, Oregon and Washington were consistently higher than Russet Burbank and Russet Norkotah. Early harvest yields for Pomerelle Russet are generally comparable to Russet Norkotah with a higher percentage of U.S. No. 1 tubers. Compared to Russet Burbank and Russet Norkotah, Pomerelle Russet has greater resistance to Potato mop-top virus, soft rot, corky ringspot and tuber infections from late blight. It also has higher protein and vitamin C concentrations than Ranger Russet, Russet Burbank and Russet Norkotah, indicating that it can provide an enhanced level of dietary protein and vitamin C relative to these standard potato varieties. Pomerelle Russet has moderate specific gravity and good resistance to sugar ends. It also has moderately long dormancy, about 30 days shorter than Russet Burbank. Average post-harvest processing ratings for Pomerelle Russet were similar to Ranger Russet and greater than Russet Burbank. Pomerelle Russet also has maintained acceptable fry color for about 180–200 days in storage at 8.9 °C, indicating potential for processing out of mid-term storage, with improved fry color uniformity relative to industry standards. However, its primary use appears to be as a high quality, early fresh variety.     

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.     

Representation of Potato Virus Y Control Strategies in Current and Past Extension Literature

The aphid-vectored Potato virus Y (PVY) is currently seen as an important limiting factor in the production of potatoes in many countries. Using a content-analysis approach, we investigated the German extension literature for recommendations regarding the control of PVY. Media included articles from periodicals addressing farmers and agricultural textbooks published in the last five decades (1955–2004). In the current literature (1995–2004), the clearly dominating strategy was found to be insecticidal control, although this strategy has been subject to some criticism in the scientific literature. Over the last five decades we also found a strongly increasing representation of insecticidal strategies. Furthermore, over this period of time, information diversity, measured as the number of different strategies proposed per article or per textbook, decreased consistently. Electronic supplementary material The online version of this article () contains supplementary material that is available to authorized users.     

Resistance of Potato Tubers to a Highly Aggressive Isolate of Phytophthora infestans in Relation to Tuber Age

The goal of these studies was to evaluate the influence of tuber age on the expression of resistance to Phytophthora infestans in five selected potato genotypes (three cultivars and two clones) varying in tuber resistance and maturity type, and also to select the best time for testing potato tubers for resistance to blight. Resistance was evaluated by inoculating whole tubers at 13 different times as they progressively aged during growth and storage. Tuber age was expressed as weeks after planting. Tubers were rated from week 13 (late July) until week 43 (late February) for tubers planted on 27–28 April, over three consecutive seasons (2001–2003). Analysis of variance performed on tuber resistance data showed significant effects of genotype, year and tuber age. Significant contributions of genotype × year, genotype × tuber age, year × tuber age and year × genotype × tuber age interactions were also detected. A slight increase in tuber resistance with tuber age was observed for cvs Bzura, Sokół and Irga, while the opposite trend was observed for the clones 97-A-63 and DG 92-227. Changes in tuber resistance with age of tested genotypes were not related to their maturity type. The period of most stable expression of tuber resistance was observed when tubers were tested between the 16th and 28th week after planting.     

Sugar-Starch Metabolism and Antioxidant Potential in Potato Tubers in Response to Different Antisprouting Agents During Storage

Single applications of different antisprouting agents like hot water treatment, spearmint oil and clove oil were carried out on potato cultivar “Lady Rosetta” to compare their efficacy with that of synthetic chloro isopropyl N-phenyl carbamate (CIPC). The tubers were stored at ambient storage conditions (25?±?2 °C) for 81 days to assess changes in their sugar-starch concentrations and antioxidant potential. Antioxidant potential in the tubers was assessed as their total phenolic concentrations and radical scavenging activities. In addition, the enzymatic activities were also determined in order to evaluate the possible depletion of these antioxidants as substrate during storage. Results revealed significant response of stored potatoes to all antisprouting agents compared with the control (P?≤?0.05). CIPC and clove oil applications maintained tuber dormancy almost twice as long (81 days) as observed in the control (45 days). Application of spearmint oil and hot water treatment maintained tuber dormancy for almost 2 months. However, it was associated with an increased percentage sprouting during the last weeks of storage. At the end of storage, the highest starch (16.83%) and lowest sugar (0.99%) concentrations were estimated after CIPC application and maximum total phenolic concentration (143.57 mg gallic acid equivalent (GAE)/100 g), and highest antioxidant activity (39.73%) were found after clove oil application. Enzymatic activities were not statistically different between CIPC and clove oil application during most of the storage period. Results showed that efficient replacement of CIPC with clove oil in the premium potato cultivar might be useful; this may avert related food safety and environmental issues and would also ensure organic potato storage.