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.     

莰酮对蚜虫生物活性的研究

进行了樟树(CinnamomumcamphoraL.)中的莰酮(CamphorC10H160)对蚜虫的触杀、熏蒸毒力和拒食活性研究。结果表明,处理后24h莰酮对菜缢管蚜、桃蚜和棉蚜触杀作用的LD50分别为3.12×10-3,2.04×10-3,0.68×10-3 ng/头,熏蒸作用的LC50分别为3.44,2.56,1.06mg/L,拒食作用的AFC50分别为3.34,2.98,1.32mg/L。经回归和相关分析,处理浓度与作用效果相关性均达到极显著或显著水平。莰酮在田间防治菜缢管蚜的效果显著。     

抗蚜高产辣椒品种鉴定评价

为了有效满足海南辣椒产业发展需求,系统开展了适于海南种植的抗蚜辣椒品种鉴定与评价.抗蚜性鉴定结果表明,32个参试辣椒品种中,'猪大肠'石柱朝天红'博辣15号'辣丰三号'和'小米椒'5个品种对桃蚜表现为抗蚜,'福康8号'翡翠甜椒'翠玉甜椒'薄冠008'皇帝椒'新香2号'和'干辣3号'7个品种对桃蚜表现为感蚜,'大羊角椒'...     

Monitoring of inflights of green peach aphids,Myzus persicae (Sulzer), in New Brunswick potato fields by yellow pans from 1974 to 1983: Results and degree-day simulation

Based on 10 years of trapping with yellow pan traps it was determined that on the average inflights of green peach aphids,Myzus persicae (Sulzer), start July 26 and cumulative catches of more than five aphids August 8. The lack of significant differences in the timing of first and cumulative catches of aphids between the northern and the southern section of the potato production area is additional evidence thatM. persicae does not usually overwinter in New Brunswick. Important yearly variations in the timing of the first cumulative catch of more than 5 aphids can be simulated by the thermal summation of 1188 DD and forecasted by regression on the timing of first inflights. The use of these results to improve the extension program is discussed.     

Soluble protein electrophoretic patterns from two biotypes ofMyzus persicae (Sulzer), the green peach aphid

An SDS polyacrylamide disc gel electrophoretic study of the soluble hemolymph proteins from twoMyzus persicae (Sulzer) biotypes was conducted to determine if these biotypes could be distinguished from each other by their banding patterns. This study revealed that there were no differences between the two biotypes in terms of number and location of protein bands. Noticeable differences did occur between the biotypes in the intensity of specific bands. These differences could not be explained by proposed differences in the concentration of active enzymes regulating developmental rate in the biotypes.     

Propensity of the Tomato Leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), to Develop on Four Potato Plant Varieties

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is now considered to be one of the most damaging invasive pests of tomatoes in the world. Tomato is regarded as the main host of T. absoluta, but the pest can also feed, develop and reproduce on other cultivated Solanaceae, such as potato (Solanum tuberosum L). In the present study, we examined the ability of T. absoluta to develop on four commonly cultivated varieties of potato, under laboratory conditions. The survival rate of T. absoluta did not differ between the five tested host plants (tomato: Solanum lycopersicum cv. Moneymaker; and potato: Solanum tuberosum cv. Spunta, Charlotte, Nicola, and Bintje), but its development time (egg to pupation) was significantly affected. Compared to tomato, development times were longer on Bintje and shorter on Nicola, Charlotte, and Spunta. These results show the high capacity of T. absoluta to develop on potato crops.     

烟蚜与烟草黄瓜花叶病田间消长动态研究

为建立烟草黄瓜花叶病（CMV）的预测预报系统,对烟蚜、烟草黄瓜花叶病的田间消长动态进行调查．调查结果表明：烟蚜在田间洧长规律呈单峰型,有翅蚜峰日早于无翅蚜峰日10天,僵蚜峰日落后无翅蚜峰日5天;烟草黄瓜花叶病的发生与有趣蚜的迁入消长紧密相关．     

Insecticide toxicity to three strains of green peach aphid (Myzus persicae Sulzer) reared on resistant and susceptible potato cultivars

Three green peach aphid (GPA) strains, Myzus persicae (Sulzer) (Homoptera: Aphididae) obtained from New York, Puerto Rico and Minnesota, were reared on resistant potato hybrid D888-4 and a susceptible cv. Red Pontiac. No significant differences in GPA mortality were observed when aphids were reared on either the resistant or susceptible potato cultivars and later exposed to methamidophos 4EC, pirimicarb 50 WP, azinphos-methyl 2EC or permethrin 2EC. The interaction between the four insecticides × three GPA strains was significant. Of the three aphid strains, those from Minnesota had the lowest susceptibility to permethrin, pirimicarb and azinophos-methyl. No mortality was observed in this GPA strain when tested with azinphosmethyl.     

Identification of the Population Structure of Myzus persicae (Hemiptera: Aphididae) on Peach Trees in China Using Microsatellites

In this study, we characterized the genetic structure of Myzus persicae (Sulzer) (Hemiptera: Aphididae) populations in China using microsatellites. We expected that these data will reveal the genetic relationships among various populations of M. persicae and will be of value in the development of better methods for pest control. Four hundred sixty individuals from 23 areas over 13 provinces were collected in the early spring of 2010, all from their primary host, Prunus persicae. The markers analyzed were highly polymorphic, as demonstrated by the expected heterozygosity value (H_e = 0.861) and the Polymorphism Information Content (PIC = 0.847), which indicated that M. persicae maintains a high level of genetic diversity. Analysis of molecular variance revealed an intermediate level of population differentiation among M. persicae populations (F_ST = 0.1215). Geographic isolation existed among these populations, and, consequently, the genetic structure of the populations was split into a southern group and a northern group divided by the Yangtse River.     

Effect of repeated applications of insecticides to potatoes on numbers of Myzus persicae (Sulzer) (Hemiptera: Aphididae) and on the frequencies of insecticide-resistant variants

Numbers of Myzus persicae on potatoes (Solanum tuberosum) receiving three insecticide regimes were recorded in 1985 and 1986. Frequencies of insecticide-resistant variants were determined using an immunoassay for esterase-4 (E4), the enzyme responsible. M. persicae was more abundant at the end of the season on plots sprayed alternately throughout the experiment with a mixture of pyrethroid with oil and pirimicarb, than on those treated with pirimicarb alone. Frequency distributions of E4 activity showed that very resistant variants intermediate between R₂ and R₃ levels accounted for >50% of the populations. Further samples of aphids, collected on separate farms from defoliated patches in late-growing potato crops where repeated spraying had failed to control aphids, showed that these highly resistant variants had again been selected. Possible reasons for the observed increase in numbers of M. persicae following pyrethroid/oil treatment and consequences for virus control are discussed.     

Rate of spread of PVYn by alateMyzus persicae (Sulzer) from infected to healthy plants under laboratory conditions

Summary Alate green peach aphids,Myzus persicae (Sulzer), tested in a flight chamber during their maiden flight period displayed behaviours ranging from repeated trivial flights to settling on the plants. The interaction of alate vector density and PVYⁿ spread was dichotomous, virus spread was significantly related to vector density in some trials but virus spread was nil or limited and not significantly dependent on vector density in others. The green peach aphid colony used in these experiments provided a mixture of active and highly active alate populations. Results suggest that inactive and active vectors came from the active and highly active alate populations, respectively. Therefore, winged aphids within a species cannot all be attributed the same vector efficiency unless known to originate from the same population. At a 15% inoculum level the intercept for the regression model for the spread of PVYⁿ was 5.03% indicating that there is a significant probability of propagation at aphid densities as low as one. However, over the range of aphid densities tested, the rate of spread per aphid was low, 0.08%, suggesting that reinfection of newly infected plants or movement interference between aphid vectors rapidly became important factors negatively affecting virus spread. Although these results cannot be directly transferred to field conditions they provide confirmation that lowM. persicae numbers can transmit unacceptable levels of mosaic and that low inoculum levels are required to decrease the risk of transmission by the small aphid numbers which cannot be realistically controlled.     

The interaction of temperature and biotype on development of the green peach aphid,Myzus persicae (Sulz.)

Thermal requirements per developmental stage, offspring production, and percent survival of three isolates of the green peach aphid,Myzus persicae (Sulz.), were determined over a range of constant temperatures from 12.4°–29.4°C. Isolates were collected from Pennsylvania, Maine, and Washington State potato producing regions. Offspring produced, survival, and thermal requirements were not different for all three isolates. Offspring production increased from 12.4°–15.6°C and then decreased as temperature increased. Percent survival averaged 78.2% except at 29.4°C where only 26.7% survived to reproduce. Thermal requirements, with 4°C as the lower developmental threshold, were 25.2, 27.1, 30.9, 30.7, 20.4, 74.2, 201.6 and 135.7 degree days, respectively, for instars 1–4, prereproductive adults, reproductive adults, longevity, and generation time. Data were used as the basis for a computer forecast system to predict aphid population development in potato fields.     

福建省茶小绿叶蝉抗药性的地区差异

采用浸梢法测定茶小绿叶蝉对8种杀虫剂的相对敏感基线,福建省不同地区茶小绿叶蝉对5种杀虫剂的药剂敏感性水平。结果表明,联苯菊酯、溴虫腈、三氟氯氰菊酯、吡虫啉、高效氯氰菊酯、啶虫脒、噻嗪酮、杀螟丹等药剂对小绿叶蝉均有较高的毒力,不同地区小绿叶蝉对药剂的抗性水平不同。福安茶场的小绿叶蝉种群对联苯菊酯、啶虫脒已经产生了高抗水平,抗性倍数分别达44.1和97.4倍,对吡虫啉达中抗水平,抗性倍数为11.8倍;北峰茶场的小绿叶蝉种群对杀螟丹的抗性水平为中抗,抗性倍数为16.4倍;武夷山茶场的小绿叶蝉种群对啶虫脒已经产生了高抗水平,抗性倍数为52.3倍。不同茶场的小绿叶蝉种群对溴虫腈表现敏感。     

上海地区四个水稻品种抗虫特性与螟害的关系

研究了上海地区20世纪80年代~90年代初的代表性栽培品种秀水04和3个当前推广品种（寒优香晴、98110、花育1号）对螟虫(主要指二化螟Chilo suppressalis、三化螟Scirpophaga incertulas)抗性的差异及其机理。结果表明：三化螟和二化螟对4个品种的为害率存在着显著差异,秀水04 的抗螟性明显高于其他3个近期品种。植株的组织学特征中,维管束间距大小与品种的螟虫侵入率表现出明显的负相关,秀水04的维管束间距显著小于其他3个品种;在无机化合物分析中硅的含量也以秀水04最高。     

Difference of Phytic Acid Content and its Relation to Four Protein Composition Contents in Grains of Twenty-nine japonica Rice Varieties from Jiangsu and Zhejiang Provinces, China

Twenty-nine japonica rice varieties collected from Jiangsu and Zhejiang Provinces, China were planted in Hangzhou, China, to investigate the phytic acid content in brown rice and its frequency distribution as well as the correlation among the contents of phytic acid, total protein and four protein compositions in brown rice. The phytic acid content in brown rice ranged from 0.699% to 1.034%, with a mean of 0.868% for the 29 tested rice varieties. Xiushui series rice varieties generally exhibited lower phytic acid level than Wuyujing and Huai series rice varieties. A rough normal distribution, with a mean of 8.722%, was observed for the total protein contents in the tested varieties. Of the four protein compositions, the glutelin, globulin and albumin contents had larger coefficient of variation than the prolamin content, although the difference in prolamin content was genotype-dependent. No significant correlation was found between the phytic acid and four protein composition contents, whereas the total protein content was significantly and positively related to the glutelin content in brown rice.     

Behavioral responses of adult potato psyllid, Bactericera cockerelli (Hemiptera: Triozidae), to potato germplasm and transmission of Candidatus Liberibacter psyllaurous

The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), is a major pest of potatoes that can cause yield loss by direct feeding on crop plants and by transmitting a bacterial pathogen, Candidatus Liberibacter psyllaurous (a.k.a. Candidatus Liberibacter solanacearum) associated with zebra chip disease of the crop. In recent years, there have been no studies regarding resistance of potato to the potato psyllid or the bacterial pathogen that the psyllid transmits. Thus, the objectives of this study were to determine the effects of potato germplasm on adult potato psyllid behavior and transmission of Ca. L. psyllaurous. A total of twenty-two potato (Solanum tuberosum L.) breeding clones and varieties were examined. Plant genotype significantly affected the occurrence and duration of psyllid probing, the duration of psyllid cleaning, resting and the amount of time psyllids spent off the potato leaflet as well as transmission of Ca. L. psyllaurous. For the potato genotypes in which there were significant decreases in transmission compared to controls, there was often an unclear relationship between the occurrences and duration of behaviors and subsequent bacterial transmission. We discuss the implications of our results for an integrated pest management program for the potato psyllid and Ca. L. psyllaurous control on potatoes.     

抗白背飞虱水稻品种挥发性次生物质的提取、组分鉴定与生测

采用水蒸汽蒸馏－乙醚同时萃取装置对抗白背飞虱品种ＲａｔｈｕＨｅｅｎａｔｉ（ＲＨＴ），ＩＲ６４，Ｎａｂｅｓｈｉ和感虫对照品种ＴＮ１稻株进行挥发性次生物质提取．浓缩所得精油，经“气谱－质谱”（ＧＣ－ＭＳ）联机检测出６４个有机的化学组分，其中３６种主要分子结构为：９种醇．９种醛．７种酮４种酯，３种烷烃．２种酸，烯烃和杂环化合物各１种。２－已烯醛、β－紫罗兰酮、叶醇（反式）、叶绿醇、３，５．５－三甲基－３－环已烯－１－酮和水杨酸甲酯的含量较高。将蒸馏提取物回喷在ＴＮ１稻株上，白背飞虱对抗虫和感虫稻株蒸馏提取物的趋性没有显著差异。嗅觉仪测定飞虱的趋性结果表明。单体化合物苯甲醇和已烯醛比对照丙酮更易吸引白背飞虱。在回喷ＴＮ１蒸馏提取物、丙酮溶液和未处理的ＴＮ１稻株上，白背飞虱分泌的蜜露量明显地较在Ｎａｂｅｓｈｉ和ＩＲ６４蒸馏提取物处理过的ＴＮ１稻株上分泌的高。白背飞虱从掺有蒸馏提取物和挥发物单体的营养液中吸食的量均比从单纯营养液中的少；抗虫品种ＲＨＴ蒸馏提取物对白背飞虱拒食作用最强，β－紫罗兰酮和已烯醛次之。     

抗白背飞虱水稻品种挥发生性次生物质的提取、组分鉴定与生测

 采用水蒸汽蒸馏－乙醚同时萃取装置对抗白背飞虱品种Rathu Heenati(RHT)，IR64，Nabeshi和感虫对照品种TN1稻株进行挥发性次生物质提取，浓缩所得精油，经“气谱－质谱”（GC-MS）联机机检测出64个有机的化学组分，其中366主要分子结构为：9种醇，9种醛，7种酮，4种酯，3种烷烃，2种酸，烯和杂环人经合物各1种。2-已烯醛，β-紫罗兰酮，叶醇（反式），叶绿醇，3,5,5-三甲-3-环已烯-1-酮和水杨酸甲酯的含量较高。将蒸馏提取物回喷在TN1稻株上，白背飞虱对抗虫和感虫稻株蒸馏提取物的趋性没有显著差异。嗅觉仪测定飞虱的趋性结果表明，单体化合物苯甲醇和己烯醛比对照丙酮更易吸引白背飞虱。在回喷TN1蒸馏提取物、丙酮溶液和未处理的TN1稻株上，白背飞虱分泌的蜜露量明显较Nabeshi和IR64蒸馏提取物处理过的TN1稻株上分泌的高。白背飞虱从掺有蒸馏提取物和挥发物单体的营养液中吸食的量均比从单纯营养液中的少；抗虫品种RHT蒸馏提取物对白背飞虱拒食作用最强，β－紫罗兰酮和己烯醛次之。