复合光触媒防治烟草花叶病效果初探

在浏阳点和湖南农业大学点,通过分别在烟苗5叶期,移栽后10,25,40d喷施0．2％,0．5％,1％,2％的复合光触媒防治烟草花叶病效果的小区试验和浏阳点喷施0．5％,1％,2％的复合光触媒大田试验示范结果表明,与对照相比,复合光触媒对烟草花叶病有明显防治效果,并随喷施浓度提高烟株的发病率和病情指数降低加快。在不同喷施时期处理中,以移栽后10d的喷施效果最佳。综合试验结果和复合光触媒的成本,在大田生产上推广应用时以移栽后10d,喷施1％的复合光触媒对烟草花叶病的效果可能更好。     

棉花轮纹斑病成株期田间消长动态研究

为了明确棉花轮纹斑病成株期田间消长动态,在廊坊实验基地对不同品种（系）棉花轮纹斑病田间发病动态进行了系统研究。结果表明,不同品种棉花轮纹斑病的发病严重程度存在一定差异,棉花品种对轮纹斑病的抗性存在差异。田间消长动态表现为：子叶期即开始出现,进入8月份后,病害发生加快,8月6日至9月6日病害迅速发展,9月26日病情指数达到最高峰,病害的发生具有普发性、爆发性的特点。     

茶尺蠖成虫消长动态及其预测

茶尺蠖(Boarmia obliqua hypulina Wehrli)是茶树主要食叶害虫之一,在国内分布较广,尤其在苏、浙、皖等省发生最为普遍,为害严重。该幼虫喜食幼嫩芽叶,造成直接的经济损失严重,广大茶区对该虫的防治都比较重视。     

红麻胚胎发育过程中叶绿素的消长动态

对红麻胚胎发育过程中叶绿素消长的动态进行了观察，发现红麻早期胚胎已开始形成叶绿素，随着胚的发育，叶绿素逐渐增多，至鱼雷胚时期（授粉后２０天左右），叶绿素含量达到高峰。此后，随着子叶的迅速生长，叶绿素逐渐减退，到胚分化成熟时，叶绿素全部消失。不论红麻青皮３号，还是金钱吊芙蓉，叶绿素均呈有规律的消长。     

不同生物防治技术对烟草烟蚜和烟青虫及斜纹夜蛾的防治效果

为减少烤烟生产中化学农药的使用量,提高烟叶安全性,通过田间试验研究了烟蚜茧蜂、赤眼蜂、生物农药及性诱剂等防治技术对烟草蚜虫、烟青虫和斜纹夜蛾的防治效果。结果表明,烟蚜茧蜂对烟蚜的防治效果较好;与化学防治相比,赤眼蜂防治烟青虫处理与赤眼蜂防治斜纹夜蛾处理的田间被害株率分别降低了28.5%～84.2%、33.4%～100%,虫口减退率最高达25.6%;生物农药对烟蚜和烟青虫的防治效果与当地常规化学农药的防治效果相当,田间烟蚜与烟青虫的虫口减退率分别比化学农药防治低89.31%～91.45%、43.75%～54.55%;性诱剂对斜纹夜蛾的诱蛾效果良好,单个诱芯每5 d的平均诱捕量为28头,最高可达52头,但对烟青虫的诱蛾效果不理想。     

玉米蚜田间发生消长规律研究

玉米蚜田间发生消长规律研究王存晋（辽宁省经济作物研究所辽阳１１１０００）玉米蚜在我国北方玉米产区早有发生。自８０年代初玉米蚜在辽宁省普遍发生，一些年份部分地区危害尤其严重，对农业生产威胁很大。从８０年代初到１９９６年，经１１年我们分别在康平、辽阳、黑...     

追施氨基酸水溶性肥料对烟株生长发育及烟草花叶病发生的影响

以K326为材料,采用随机区组试验,研究了追施不同水平氨基酸水溶性肥料对烟株生长发育及旺长期烟草花叶病害的影响.结果表明:追施氨基酸水溶性肥的3个试验组烤烟生育期较对照组平均延长7d,旺长期较对照组延长4～8d;处理组在株高、节距、茎围及有效叶数等方面均优于对照组,且以T1(在当地追肥用量的100％基础上,追施3次氨基酸水溶肥)处理效果最为明显;T1、T2(在当地追肥用量50％基础上,追施3次氨基酸水溶肥)处理组在烤烟旺长期可有效降低烟草花叶病的发生率.     

Myzus persicae (Sulzer) in diffuse light and dark rustic storages and resultant PLRV transmission

Population levels ofMyzus persicae (Sulzer) were studied on potato tubers in diffuse light and dark rustic storage houses in Peru. No differences in numbers of aphids/sprouted eye on potatoes infested naturally during storage in diffuse light or darkness were observed. Significantly more alate aphids were observed on tubers stored in darkness than in diffuse light storage houses. Viral transmission was occurring during the storage period. The incidence of viral transmission was not significantly influenced by storing tubers in diffuse light or dark storages. There were significantly more plants infected with virus from tubers that had not been sprayed for aphid control than from tubers that had been sprayed     

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'...     

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。     

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.     

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.     

Behavioral Responses of Green Peach Aphid, Myzus persicae (Sulzer), to the Volatile Organic Compound Emissions from Four Potato Varieties

Green peach aphid Myzus persicae (Sulzer) is a serious pest of potato and causes severe yield loss to potato production worldwide. The volatiles emitted from potato plants influence host selection by M. persicae. A laboratory experiment was conducted to study how these volatile emissions vary among four potato varieties (IdaRose, Desiree, Chipeta and Russet Burbank) having different genetic backgrounds, and to compare the aphid responses to the volatiles emitted by these varieties. Results indicated that headspace volatiles detected, and aphid responses, differed significantly among the varieties. Myzus persicae arrestment was greater in response to Desiree and Chipeta than on Russet Burbank and arrestment on IdaRose was intermediate and did not differ significantly from any of the other varieties, but the arrestment was not related to the total concentration of volatiles released by these varieties. This indicates that the blend of volatiles was important for eliciting arrestment. Eigenvector weightings of principal component 1 were predominantly sesquiterpenes (especially caryophyllene, sesquiphellandrene, α-farnesene and longifolene), whereas those for principal component 2 were predominantly aldehydes and green leaf volatiles (n-hexana1, (Z)-3-hexenol, (E)-2-hexenal and nonanal. The pedigrees of the varieties are not associated with the volatile blends or aphid responses.     

海南胡椒中黄瓜花叶病毒分离物的分子鉴定

通过间接酶联免疫法,从海南罹病胡椒植株中检测到黄瓜花叶病毒(Cucumber mosaic virus,CMV).从病叶中提取总RNA,用巢式RT-PCR方法扩增获得657 bp的CMV CP基因片段,并与pMDl8-T载体连接和转入大肠杆菌克隆,然后进行测序.序列分析结果表明,该分离物与CMV亚组I、亚组II之间的核苷酸序列同源性分别为92.54%～99.09%和76.97%～77.42%,推导氨基酸序列同源性分别为98.17%～100%和81.74%～82.65%.该分离物CP基因与印度胡椒分离物同源性相对较低,应属不同株系.     

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.     

Population Growth of Myzus persicae on Potato Plants Infected with Different Strains and Variants of Potato virus Y

Potato virus Y (PVY) is one of the most economically important viruses affecting the potato crop. Several strains of the virus, including PVY^O, PVY^N, recombinant isolates; PVY^N:O (PVY ^N-Wi) and PVY^NTN and several variants of PVY^O have been reported from North American potato-production areas. The green peach aphid, Myzus persicae Sulzer, is a colonizer of potatoes and is considered the most important vector of PVY. The objective of this study was to measure the population growth of M. persicae on potato plants infected with different strains and genetic variants of PVY. The initial population of ten winged adults of M. persicae was allowed to develop on a potted plant for 12 days. Results clearly indicated that infections by different strains and genetic variants of PVY did not influence the population growth of M. persicae on potato plants during this period.     

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.