噻虫嗪对白背飞虱试验种群繁殖力的亚致死效应

为探究噻虫嗪对白背飞虱的亚致死效应,采用稻茎浸渍法以噻虫嗪亚致死浓度LC_(10)和LC_(25)胁迫白背飞虱3龄若虫,测定了F_0代和F_1代若虫的存活率、雌成虫寿命和产卵量,并组建了F_1代种群相对适合度生命表。结果表明,经噻虫嗪亚致死浓度胁迫后,F_0代白背飞虱若虫的发育历期延长,存活率降低,并且LC_(10)处理组的F_0代雌成虫寿命比对照组显著延长,而成虫产卵量无显著变化;F_1代的若虫发育历期比对照组显著延长,且产卵量有所减少,LC_(10)处理组雌成虫产卵量比对照组减少了22.24,LC_(25)处理组比对照组减少了69.96,且差异显著;LC_(10)和LC_(25)亚致死浓度处理后F_1代的种群增长趋势指数均下降,种群相对适合度分别下降了0.12和0.36。研究表明,噻虫嗪亚致死浓度胁迫均可抑制白背飞虱的种群增长。     

伪钝绥螨的花粉饲养研究

在饲养伪钝绥螨的10种植物花粉中,核桃、洋槐、贴梗海棠、仙人球、迎春和卷心菜等可使其取食并完成发育,前4种还可使其产卵。花粉粒的外部形态结构,是影响该螨能否取食的重要因素之一。用桃、苹果花粉饲养伪钝绥螨,对其F_1代生活力有明显的不良影响。取食桃花粉的F_1代,幼螨间相互残杀,并取食未孵化的卵,使成活率降低。取食苹果花粉的F_1代可正常完成发育,但成螨性比降低,产卵时自食其卵。试验表明,单纯喂食桃或苹果花粉难以进行伪钝绥螨的累代饲养。     

小麦品种对条绣病抗病性遗传规律研究初报

对133个小麦品种间杂交组合的观察结果指出,凡有免疫品种为亲本的组合,其 F_1抗病性表现显性的机率都很高,而其机率的高低又与另一亲本抗病性的强弱呈正相关。对24对正反交组合的 F_1代,8对的 F_2代和2对的 F_3代作比较观察的结果表明用免疫品种作父本与母本,对后代抗病性的表现和分离并无不同影响。根据田间调查结果,看出杂种后代中底部叶片轻微发病的植株其抗病性稳定程度和遗传力低于“全株免疫株”;用底部叶片发病,中上部叶片表现免疫的品种作抗病亲本,F_1代的中下部叶片发病比较普遍;而用全株免疫的品种作抗病亲本,F_1代一般没有发病现象。试验结果证明 F_1代和 F_2代中的“少茎病株”(同一植株中多数分蘖免疫,个别或少数分蘖感病),其后代(F_2和 F_3)分离出的免疫株率与全株免疫株差别不明显。感病分蘖与同株免疫分蘖的后代在抗病性的分离上也无显著差别。石特14×胜利组合 F_2免疫株的后代(F_3)中有15.8%的株系全部植株免疫;“0;”型和“1”型 F_3植株分离出的免疫株率各达到80.3%和55.5%,但汉有出现免疫的株系。     

用茶毛虫核型多角体病毒防治茶毛虫

茶毛虫(Euproctis pseudoconspersa)是茶树的主要害虫之一,全国茶区均有发生,造成巨大经济损失。我们试用茶毛虫核型多角体病毒(EpNPV)防治茶毛虫,获得结果如下: 试验材料和方法 茶毛虫NPV为四川大学生物系毒株。经室内感染,收集染病死虫,用差速离心法分离纯化病毒多角体(PB)。田间防治浓度为5×10~5PB/ml和1×10~6PB/ml,相当于每亩用     

用ELISA检测人血清中茶毛虫核型多角体病毒

用间接ELISA法,以109份人血清作为抗原及抗体,与茶毛虫核型多角体病毒及其抗血清进行检测,以确定茶毛虫核型多角体病毒对人群的安全性,结果均呈阴性反应。试验说明,茶园应用茶毛虫核型多角体病毒杀虫剂对人群无害。     

水稻白叶枯病抗性基因在不同载体品种上及杂种F_1的抗性研究

本研究测试了八个水稻白叶枯病抗性基因Xa3、Xa4、xa5、Xa7、Xa10、Xa11、Xa14和Xa23在相应载体品种上对华南白叶枯病优势致病菌系Ⅳ型菌和强毒菌系Ⅴ型菌的抗性反应;分析了Xa4、xa5、Xa7和Xa23抗病基因与不同感病品种杂交组合F_1的抗性表达模式以及显性抗病基因Xa7和Xa23在杂交水稻上的利用价值。结果表明:大部分抗性基因在不同载体品种上抗性表达一致,但也有少数基因在不同载体品种上抗性表现不一,甚至截然相反,说明不同遗传背景对抗性表达有影响,而这种影响因不同抗性基因而异。隐性抗病基因xa5(IRBB5)和显性抗病基因Xa23(CBB23)与感病亲本组合的F_1代分别表现感病和抗病,符合隐性基因或显性基因的抗性表达模式;而2个显性抗病基因Xa4(IRBB4))和Xa7(IRBB7)与感病亲本组合的F_1代,有部分组合的F_1代表现抗病,符合显性基因的抗性表达模式,有部分组合的F_1代表现感病,不符合显性基因的抗性表达模式。在杂交水稻上的利用价值方面,Xa7与2个不育系组合的F_1代均表现高感,不宜在杂交水稻上利用;Xa23(CBB23)与4个感病亲本,无论是不育系还是常规稻组合的4个F_1代全部表现抗病,抗性在F_1充分表达,在杂交水稻上有重要的利用价值。     

小麦秆锈菌鉴别寄主品种Orofen对小种21C3和34C2抗病基因的单体分析

用中国春单体系列和二体中国春作为母本与Orofen杂交。选择出所有类型的单体杂种F_1植株,令其自交结实。在温室内(10—25℃)用秆锈菌小种21C3和34C2的单孢菌系分别接种鉴定各杂交组合的F_2代苗期的抗性分离表现。对小种21C3,除2D和6D之外,其它单体类型和二体对照的F_2代都符合抗病15:1感病的分离比例;对小种34C2,除2D之外,其它单体类型和二体对照的F_2代都符合抗病3:1感病的分离比例。用Orofen与含有国际上已定位于2D和6D染色体上的已知Sr基因的品系(或品种)杂交。对小种21C3,Orofen与含有Sr5和Sr6的单基因系的杂交F_2未分离出感病的植株;对小种34C2,只有与含有Sr6的单基因系的杂交F_2代未分离出感病的植株。这表明,Orofen在2D染色体上含有Sr6,它兼抗小种21C3和34C2,分别提供0—1;1~( )x~-和;1—;1~( )x~-的抗性效应;而在6D染色体上携带抗病基因Sr5,它只抗小种21C3.控制0—;1~-的侵染型。对无毒性的小种,Sr5对Sr6的抗病效应是上位的。     

茶毛虫低位侧向分布习性及其在防治中的应用

在茶毛虫(Euproctis pseudocospersa Strand)生态学研究中,观察到阶梯形茶园中的茶毛虫四龄前幼虫有规律地分布在茶丛两侧中下部叶片背面。在近20多天内,其垂直和水平活动范围相对稳定。以茶毛虫侧向分布规律为依据,设计了茶毛虫低位侧向快速喷药防治技术,改进了过去全丛喷雾为两侧中下部快速喷雾,并根据茶丛高度及幼虫龄期调节步速和喷幅,以提高防治效果。测定了5种杀虫剂不同剂量对茶毛虫及蜘蛛的影响和茶丛不同部位雾滴密度,建立了实施快速喷雾防治技术。可减少用药量约3/4;降低茶蓬面芽叶受药量;与常规方法防治效果相当,而工效提高约3倍。经3年小区试验和大面积推广示范,证明较经济有效,适于山区茶园应用。     

新农药介绍

中文通用名称:磺草灵英文通用名称:asulam农药登记名称和商品名称:33.3%磺草灵水剂(剑锄)理化性质:磺草灵原药(含量≥95%)外观为棕色固体颗粒.熔点:142℃~144℃;溶解度(g/L,20℃~25℃);水中4,丙酮中300,甲醇中290。在常温下贮存稳定。化学名称:对氨基苯磺酰氨基甲酸甲酯。化学结构式:毒性:磺草灵原药对小鼠急性经口和经皮LD50均>10000mg/kg。未见致敏反应,为弱致敏感物。致突变试验:Ames试验,小鼠骨髓细胞微核试验,小鼠睾丸细胞染色体畸变试验均为阴性。大鼠90天喂饲亚慢性试验的最大无作用剂量为55.6mg/kg。33.3%磺草灵水剂对大鼠急性经…     

大麦抗条纹病基因的定位分析

为发掘大麦中抗条纹病的新基因,采用三明治法通过人工接种大麦条纹病菌Pyrenophora graminea强致病力菌株QWC对甘啤2号(免疫)与Alexis(高感)杂交F_1代及F_2代分离群体进行抗性遗传分析,利用群体分离分析法鉴定与抗病基因连锁的SSR标记,并通过QTL IciMapping软件构建遗传连锁图谱完成对抗病基因的定位。结果显示,甘啤2号与Alexis杂交F_1代对大麦条纹病菌强致病力菌株QWC表现为免疫,F_2代表现3∶1抗感分离,表明甘啤2号对菌株QWC的抗性由1个显性抗性基因控制,将该抗病基因暂命名为Rdg3;该基因位于大麦7H染色体上的SSR标记Bmag206和Bmag7之间,与二者的遗传距离分别为1.78 cM和2.86 cM。经与已定位于7H染色体上的抗病基因比较,发现Rdg3是一个新的抗条纹病基因,可作为大麦抗病育种的新种质资源。     

Transmission, Field Spread, Cultivar Response, and Impact on Yield in Highbush Blueberry Infected with Blueberry scorch virus

Scorch disease caused by Blueberry scorch virus (BlSV) spreads rapidly and radially from foci of infection. Healthy potted blueberry plants became infected when placed next to diseased field bushes from early May through mid-August. The aphid Fimbriaphis fimbriata, collected from infected field bushes, transmitted BlSV to healthy blueberry plants in controlled tests and was regarded as the most important means by which bushes in commercial fields became infected. The rate of spread in the symp-tomless cv. Stanley appears to be the same as the rate of spread in the cv. Pemberton, which exhibits blight and dieback. Most field bushes showed symptoms during the year following inoculation, but a few did not show symptoms until the second or third year. Many (30 out of 59) cultivars and selections infected with BlSV exhibited severe blighting of flowers and young leaves and dieback of twigs. Three cultivars showed only chlorosis of leaf margins. The virus was also detected in numerous cultivars (26 out of 59) that exhibited no symptoms, and they were considered tolerant of BlSV. The virus had no effect on germination of pollen from several cultivars. BlSV reduced yield in 'Pemberton', with the loss being related to the number of years bushes displayed symptoms. Yield was reduced by more than 85% in the third year of symptom expression. The virus did not significantly reduce the yield of six tolerant cultivars that were infected with the virus but displayed no symptoms.     

Tomato Breeding Lines Resistant and Tolerant to Tomato Yellow Leaf Curl Virus Issued from Lycopersicon hirsutum

ABSTRACT Two tomato yellow leaf curl virus (TYLCV)-resistant plants from accessions LA1777 and LA386 of the wild tomato species Lycopersicon hirsutum have been crossed. The resulting resistant F1 plants were crossed with the domesticated tomato L. esculentum, and a series of selfing was performed. At each generation, individuals were selected for resistance (no symptoms and undetectable viral DNA) and tolerance (no symptoms but with detectable viral DNA) following controlled massive and repeated inoculations with viruliferous whiteflies. A stable BC1F4 line (denominated 902) that does not segregate for resistance was obtained. This line does not support virus accumulation, even upon extensive whitefly-mediated inoculation of young seedlings, and does not need protection with nets or insecticides. Another stable BC1F4 line (denominated 908) was tolerant to the virus. Both lines have good horticultural characteristics and bear 80- to 120-g red fruits. Analysis of segregation of susceptibility, tolerance, and resistance during the BC1F1 to BC1F4 crosses indicated that tolerance is controlled by a dominant major gene and resistance by two to three additive recessive genes. The resistant and tolerant lines do not need to be protected by insecticides or nets.     

EFFECT OF TEMPERATURE ON THE ACTIVITY AND PERSISTENCE OF AMITROLE AND 2,4-D

Summary. One leaf of each of several tomato plants 5–6 weeks old maintained at 55, 70 or 85° F was dipped in 0.05 M amitrole or 0.005 M 2,4-D solution. The treated leaf was removed 1 week later. Scions taken from untreated plants were grafted to the treated plants at intervals up to 4 months after treatment.
Amitrole-treated plants maintained at 55° F were killed within 1 month but those at 70 and 85° F recovered.
Plants treated with 2,4-D showed typical symptoms when maintained at 70 and 85° F but no symptoms at 55° F. Scions grafted on plants maintained at 55, 70 and 85° F for 60 days after 2,4-D treatments exhibited typical symptoms. Grafts made more than 60 days following the 2,4-D application did not exhibit symptoms except a slight malformation on the plants held at 55° F.
New growth on the scions grafted up to 103 days after amitrole treatment on plants which had been maintained at 70 and 85° F exhibited typical amitrole symptoms (i.e. white foliage) but scions grafted after this lime did not. New shoots developing from buds on the treated plants also produced green growth 115 days after treatment but produced white foliage prior to that time.
Effet de la température sur l'activi'ité et la persistance de l'aminotriazole et du 2,4-D     

Interaction of Fusarium solani f. sp. glycines and Heterodera glycines in Sudden Death Syndrome of Soybean

ABSTRACT Sudden death syndrome (SDS) of soybean is caused by the soilborne Fusarium solani f. sp. glycines (synonym F. virguliforme). In a sequential approach, two multifactor factorial-design microplot experiments were conducted to investigate the effects of fungal infestation levels and soil moisture on both root necrosis and foliar SDS severity, and the interaction between F. solani f. sp. glycines and Heterodera glycines in fumigated versus nonfumigated soil. In 2003, soybean cv. Spencer was grown in nonfumigated or methyl bromide-fumigated soil and infested with increasing levels of F. solani f. sp. glycines, either under rainfall or irrigated after growth stage V6/R1. In 2004, interactions between F. solani f. sp. glycines and H. glycines were explored in a factorial inoculation design in fumigated or nonfumigated soil, planted to Williams 82 or Cyst-X20-18. In both years, higher levels of foliar SDS severity and root necrosis were found in F. solani f. sp. glycines-infested soils with H. glycines than in soils without the nematode on the soybean cultivars susceptible to both pathogens. Both natural infestations of H. glycines in 2003 and artificially amended populations of H. glycines in 2004 contributed to higher foliar SDS severity. More severe foliar SDS symptoms always were associated with more root necrosis, but elevated levels of root necrosis did not predict severe leaf symptoms. In contrast to the critical role of H. glycines, increasing fungal infestation levels had no significant effects on increasing either foliar SDS symptoms or root necrosis. Effects of moisture regime and fungal infestation levels also were examined in factorial greenhouse and growth chamber experiments. High soil moisture resulted in higher levels of SDS root necrosis. In the greenhouse, root necrosis increased at a higher rate in low soil moisture than the rate in high soil moisture. The two pathogens acted as a complex and the disease development was strongly dependent on high soil moisture.     

Response of UK winter wheat cultivars to <Emphasis Type="Italic">Soil-borne cereal mosaic</Emphasis> and <Emphasis Type="Italic">Wheat spindle streak mosaic viruses</Emphasis> across Europe.

Twenty-one UK winter wheat cultivars were grown over three seasons at sites with natural inoculum sources of Soil-borne cereal mosaic virus (SBCMV) and Wheat spindle streak mosaic virus (WSSMV) located in France, Italy and the UK. Plants were assessed visually for virus symptoms and leaf extracts were tested for the presence of each virus using enzyme-linked immunosorbent assays (ELISA). Cultivars showing little or no foliar symptoms and low levels of virus in leaf tissue were classified as resistant to each virus. All the trials were taken to harvest and agronomic data collected. At the most heavily infected sites, severe symptoms of SBCMV were observed in all UK cultivars except Aardvark, Charger, Claire, Cockpit, Hereward and Xi 19. The latter cultivars exhibited either light or no symptoms and little or no SBCMV infection in leaves. In fields with WSSMV, the virus failed to develop in Italy, but was detected in the leaves of all the susceptible control cultivars at a site in France. However, no UK cultivar tested positive for WSSMV. Multi-site analysis indicated that the presence of WSSMV did not increase the impact of SBCMV on the height, thousand-grain weight or yield of UK cultivars. The wheat cultivars on test gave a similar response to SBCMV across three European countries. Possible sources of SBCMV resistance are discussed.     

Parietaria mottle virus, a possible new ilarvirus from Parietaria officinalis (Urticaceae)

A previously undescribed virus, probably a new member of the ilarvirus group, was isolated from Parietaria officinalis showing symptoms of yellow mosaic or mottling. This virus, for which the name parietaria mottle virus (ParMV) is proposed, differs in host range from other ilarviruses. ParMV was purified from Chenopodium quinoa by sap clarification with chloroform, and differential and sucrose density gradient centrifugation.
Purified particles were quasi-isometric to ovoid with diameters of about 24, 29 and 36 nm; no bacilliform particles were detected. Buoyant density in caesium chloride, determined on glutaraldehyde-fixed virus, was 1.35 g/cm³.
An antiserum to ParMV was obtained with a titre of 1:32 in agar gel double-diffusion tests. ParMV did not react with eight other viruses or virus strains belonging to the ilarvirus group or to pelargonium zonate spot virus.
Polyacrylamide gel electrophoresis indicated that ParMV contains a single major protein species of estimated molecular weight 24300 Da and four RNA species of estimated molecular weight 1 37, 1.19, 0.86 and 0.36 × 10⁶ Da.     

Characterization of a synergistic interaction between two cucurbit-infecting begomoviruses: Squash leaf curl virus and Watermelon chlorotic stunt virus

Squash leaf curl virus (SLCV) and Watermelon chlorotic stunt virus (WmCSV) are cucurbit-infecting bipartite begomoviruses. Both viruses are found in the eastern Mediterranean basin but the effects of dual infection of both viruses on melon (Cucumis melo L.) have not been described. 'Arava' melon plants were inoculated in the greenhouse, using whiteflies, with either SLCV, WmCSV, or both. Control plants were exposed to nonviruliferous whiteflies or not exposed at all. Following inoculation, plants were transplanted to a 50-mesh insect-proof nethouse and grown until fruit maturity. The experiment was performed in two melon-growing seasons: spring, transplant in May and harvest in July; and summer, transplant in August and harvest in October. Following inoculation, SLCV-infected melon plants showed mild symptoms that disappeared with time, and there was no effect on plant height. WmCSV-infected plants developed disease symptoms that became more obvious with time, and plants were somewhat shorter than control plants in the spring but not in the summer. SLCV had no effect on yield, regardless of season. WmCSV had no statistically significant effect on yield in the spring but, in the summer, reduced yield by 22%, on average. Dual-inoculated plants showed a synergistic interaction between the two viruses. They developed disease symptoms that were more pronounced than WmCSV alone, with plants being shorter than control plants by 20 to 25% regardless of season. Moreover, the yield of dual-inoculated plants was reduced on average by 21% in the spring and 54% in the summer, and fruit appearance was adversely affected. Dual inoculation did not affect WmCSV DNA level but SLCV DNA level was increased several-fold by the presence of WmCSV.     

The partial characterization of melon vein-banding mosaic virus, a newly recognized virus infecting cucurbits in Taiwan

A potyvirus (designated as no. 656) causing mosaic or vein-banding symptoms on melons was isolated and characterized. The virus was mechanically transmitted to 14 herbaceous plant species, and induced mosaic symptoms in most cucurbitaceous plants. Aphis gossypii transmitted the virus non-persistently, and flexuous filamentous virus particles c. 755 nm in length were consistently observed in extracts of the infected pumpkin leaf tissues. Pinwheel and tubular inclusions were observed in the cytoplasm of infected zucchini leaf tissues. The virus was purified from infected pumpkin leaves by isopycnic centrifugation (Cs₂SO₄). The molecular weights of purified capsid and cylindrical inclusion proteins as estimated by SDS-PAGE were 32·5 and 73 KD_a, respectively. In SDS-immunodiffusion tests, antiserum to virus particles from isolate 656 was serologically unrelated to ZYMV, WMV-2, PRV-W and a type W variant of PRV, but antiserum to its cylindrical inclusion protein did produce spur precipitin bands between homologous and WMV-2 antigen wells. However, neither WMV-2 virus particle nor cylindrical inclusion antisera reacted with this virus. Furthermore, this virus was not serologically related to BCMV, BYMV, CYVV, SMV, WMV-M or ZYFV. Based on test results and symptomatology, this virus appears to be a new potyvirus, for which the name melon vein-banding mosaic virus (MVbMV) is proposed.     

小麦丛矮病研究之二关于小麦丛矮病的病原病毒问题

在田间的小麦丛矮病非典型病株申常常分离到北方禾谷花叶病毒(NCMV)及玉米粗缩病毒(MRDV)两种病原物。单独用前者接种,仅表现小麦丛矮症,单独用后者接种,仅表现小麦蓝矮症,即植株矮化、暗绿、分蘖减少,叶坚挺。两者混合侵染时,往往表现两者的混合症状,但以何种病毒占优势而倾向于优势病毒的症状。典型丛矮症植株中电镜检出弹状病毒粒体,40—70×270—400nm尺度与日本报导的稍异。典型丛矮病株中不存在玉米粗缩病毒的粒体。小麦丛矮病毒很可能是北方禾谷花叶病毒的一种地方性株系。     

Insect juvenile hormones: Chemistry and action: Edited by Julius J. Menn and Morton Beroza. Academic Press,New York, 1972, $11.00

Heptachlor metabolism was determined in young male rats fed for 10 days diets containing 18% protein supplied either by gluten or casein. Rats on the casein diet were either pair-fed on an individual basis to the gluten-fed animals or they were fed ad lib. Saline, sodium phenobarbital (80 mg/kg) or diethylaminoethyl 2,2-diphenylvalerate HCl (SKF 525-A, 50 mg/kg) was administered ip to the animals before sacrifice. Weight gain, liver microsomal protein, and heptachlor metabolism (nmole of product/g liver/10 min), assayed in 9000g rat liver supernatants, were found to be significantly reduced in the gluten-fed animals. Animals pair-fed the casein diet had higher heptachlor epoxidase activity than those fed ad lib. Phenobarbital pretreatment significantly enhanced the metabolism of heptachlor in animals in all groups to varying magnitudes. Heptachlor epoxidase activity (units/g liver) was increased 11-fold in the gluten-fed animals, 6-fold in the pair-fed animals on casein diet, and 7-fold in the animals fed casein ad lib. Heptachlor metabolism was less inhibited by SKF 525-A in the rats fed gluten compared to the rats on casein diet, either pair-fed or ad lib. The degree of induction or inhibition of enzyme activity was not influenced by restriction of food intake (pair-fed vs ad lib). The results of these studies suggest an interaction of protein inadequacy with drug metabolism and its induction or inhibition.