鲁豫皖交界地区四个小麦禾谷孢囊线虫群体致病型鉴定

为了明确鲁豫皖交界地区小麦禾谷孢囊线虫的致病类型,利用23个国际鉴别寄主品种和1个当地小麦品种温麦19对采自山东菏泽、安徽颍上、河南商丘和淮阳的4个小麦禾谷孢囊线虫群体致病型进行了鉴定。4个群体的致病型不同于国际上已命名的16个小麦禾谷孢囊线虫致病型。13个A组鉴别寄主对山东菏泽与安徽颍上群体具有相同的抗性反应,这2个线虫群体属于同一致病型;河南商丘群体与上述2个群体的毒性相似,但大麦寄主KVL191对山东菏泽群体和安徽颍上群体表现为抗病,而对河南商丘群体表现感病;河南淮阳群体的致病谱较宽,明显不同于其它3个群体。对照小麦品种温麦19对4个小麦禾谷孢囊线虫群体均表现感病。     

河北省小麦孢囊线虫病的发生与分布

于2009-2011年对河北省10个地区55个县的小麦孢囊线虫发生情况进行系统调查,共采集土样719份.调查结果表明:孢囊总检出率为52.7％,其中冬麦区孢囊的检出率为61.2％,春麦区孢囊检出率为0.石家庄地区孢囊检出率最高,达90％,各地区孢囊检出率大小顺序依次为:石家庄、邢台、保定、邯郸、廊坊、衡水、唐山、沧州、张家口、承德.其中唐山滦南县与任丘市孢囊线虫发生最为严重,分别有11.8％和7.7％地块每100mL土中的孢囊数量在40个以上.沙壤土中孢囊线虫的检出率最高,达63.0％,壤土与黏土中小麦孢囊线虫的检出率分别为60％和50％,在沙土地块未发现小麦孢囊线虫.依据孢囊线虫的形态特征,河北危害小麦的孢囊线虫种类应为禾谷孢囊线虫(Heterodera avenae).     

水稻白叶枯病菌毒素的分离、生物测定及化学成份初步分析

 采自山西太谷及安徽固镇小麦上两禾谷胞囊线虫群体对禾谷胞囊线虫致病型国际鉴别寄主A组内11个品种具有相同的反应型——除对小麦品种Capa有毒性外,对大麦四个品种(Emir,Ortolan,Siri和Morocco)、燕麦四个品种(Sun Ⅱ,Pusa hybrid bsl,Silva和A.stezilis I.76)以及小麦其它两个品种(Loros和Iskamish-k-2-Light)等均无毒性,与目前世界上已正式命名的13个致病型不同,而与瑞典的Knislingc和Ringaascn两禾谷胞囊线虫群体的致病型相似,但也存在一定差异,瑞典的两群体对Morocco有毒性,而太谷和固镇两群体对Morocco无毒性。     

甘肃小麦禾谷孢囊线虫rDNA-ITS和28S rDNA-D2/D3区序列特征及HS-RFLP分析

禾谷孢囊线虫是危害禾谷类作物的重要病原,严重威胁我国小麦主产区的小麦产量和品质.利用通用引物对甘肃、河南、安徽禾谷孢囊线虫群体28S rDNA-D2/D3区和rDNA-ITS区进行PCR扩增和序列测定,利用UPG-MA方法分析了甘肃省7个种群、河南1个种群、安徽1个种群的禾谷孢囊线虫群体D2/D3区和ITS区的系统发育关系;用9种限制性内切酶对7个甘肃禾谷孢囊线虫群体的rDNA-ITS区进行了RFLP分析.结果表明:中国甘肃的禾谷孢囊线虫rDNA-D2/D3区片段长度约为780 bp,rDNA-ITS片段长度约为1 040 bp.7个甘肃禾谷孢囊线虫群体、1个河南安阳群体、1个安徽蚌埠群体的D2/D3区和新西兰的H.aucklandica群体亲缘关系很近;其ITS区同澳大利亚的H.australis、北京通州的H.avenae(AY148382)的亲缘关系很接近.RFLP分析表明,9种限制性内切酶酶切禾谷孢囊线虫群体的rDNA-ITS共产生了22个酶切片段,不同酶切的RFLP分布型在7个种群间没有差异.甘肃省禾谷孢囊线虫群体的rDNA-ITS区具有高度的保守性,与中国的C型群体相近,但不同于欧洲的A型群体和印度的B型群体.这是首次报道甘肃CCN种群分子特征.     

甘肃小麦禾谷孢囊线虫rDNA-ITS和28S rDNA-D2/D3区序列特征及ITS-RFLP分析

禾谷孢囊线虫是危害禾谷类作物的重要病原,严重威胁我国小麦主产区的小麦产量和品质。利用通用引物对甘肃、河南、安徽禾谷孢囊线虫群体28SrDNA-D2/D3区和rDNA-ITS区进行PCR扩增和序列测定,利用UPG-MA方法分析了甘肃省7个种群、河南1个种群、安徽1个种群的禾谷孢囊线虫群体D2/D3区和ITS区的系统发育关系;用9种限制性内切酶对7个甘肃禾谷孢囊线虫群体的rDNA-ITS区进行了RFLP分析。结果表明:中国甘肃的禾谷孢囊线虫rDNA-D2/D3区片段长度约为780bp,rDNA-ITS片段长度约为1040bp。7个甘肃禾谷孢囊线虫群体、1个河南安阳群体、1个安徽蚌埠群体的D2/D3区和新西兰的H.aucklandica群体亲缘关系很近;其ITS区同澳大利亚的H.australis、北京通州的H.avenae(AY148382)的亲缘关系很接近。RFLP分析表明,9种限制性内切酶酶切禾谷孢囊线虫群体的rDNA-ITS共产生了22个酶切片段,不同酶切的RFLP分布型在7个种群间没有差异。甘肃省禾谷孢囊线虫群体的rDNA-ITS区具有高度的保守性,与中国的C型群体相近,但不同于欧洲的A型群体和印度的B型群体。这是首次报道甘肃CCN种群分子特征。     

禾谷孢囊线虫与不同小麦根系的互作表型特征

为了明确高抗品种‘华麦1号’的抗禾谷孢囊线虫机制,以Pluronic F-127胶体为介质,比较了禾谷孢囊线虫2龄幼虫(J2)侵入根系前对抗病品种‘华麦1号’与感病品种‘豫麦34’和‘矮抗58’的根尖趋性差异,并采用室内人工接种法观察了线虫侵入3个品种后的发育进程。结果表明,J2对3个品种的根尖均表现明显的趋性,对‘矮抗58’的趋性最强,而对‘华麦1号’的最弱,接种4h和6h时‘华麦1号’与‘矮抗58’根尖吸引的线虫总量差异显著(P0.05);组织染色观察到J2对3个品种的根系均有一定数量的侵入,但高抗品种‘华麦1号’根系侵入的幼虫量和后期形成的白雌虫量均显著低于感病品种‘豫麦34’和‘矮抗58’。结果证实,‘华麦1号’的抗性机制主要表现为减少线虫的有效侵入量、抑制侵入后的线虫生长发育。     

陕西省小麦禾谷孢囊线虫rDNA-ITS区序列与RFLP分析

 采用线虫通用引物TW81和AB28对采自陕西的20个小麦禾谷孢囊线虫群体的rDNA-ITS区进行PCR扩增、克隆和测序。利用Mega软件的UPGMA方法分析了陕西省小麦禾谷孢囊线虫群体及其与GenBank公布的近缘种的系统发育关系,结果表明陕西省小麦孢囊线虫群体的rDNA-ITS区片段的长度为1 045 bp,且均为禾谷孢囊线虫（Heterodera avenae）,ITS区序列同源性为99.56%,只有3处碱基存在差异。其ITS区同中国河南（EU106175）、北京（AY148382）、山东（HM370427）的禾谷孢囊线虫H. avenae,澳大利亚的H. australis（AY148395）及俄罗斯的H. pratensis（AY148351）的亲缘关系最为接近。利用8种限制性内切酶Ava Ⅰ（Eco88 Ⅰ）、Alu Ⅰ、Hha Ⅰ（Cfo Ⅰ）、Hae Ⅲ（BsuR Ⅰ）、Hind Ⅲ、Hinf Ⅰ、Rsa Ⅰ和Mva Ⅰ（Bst N1）对20个陕西省CCN群体的ITS区PCR扩增产物进行限制性内切酶谱（RFLP）分析,结果表明8种限制性内切酶酶切ITS-PCR产物后共产生22个酶切片段,20个种群的PCR-RFLP谱型一致,表明陕西省小麦禾谷孢囊线虫是同一个群体且与已报道的中国CCN群体的“C”型一致,有别于欧洲的“A”型群体和印度的“B”型群体。这是首次报道陕西省小麦禾谷孢囊线虫种群的分子特征。     

河北省大豆孢囊线虫分子鉴定及其分布

2003年,在河北省邯郸、邢台、石家庄、保定、秦皇岛、唐山、张家口等地采集大豆根际土壤样品65份,应用大豆孢囊线虫特异性引物对采集的孢囊线虫进行了分子鉴定,结果表明从邯郸的永年、磁县、峰峰,邢台的南和、广宗、清河,保定的南大园、西马池、望都、定州,石家庄的栾城、鹿泉、平山及石家庄市郊,秦皇岛的抚宁、昌黎,唐山的迁西、迁安、丰润的大豆和张家口的红云豆上采集的孢囊线虫的孢囊及其二龄幼虫均为大豆孢囊线虫;卢龙和滦县的样品中没有发现大豆孢囊线虫的孢囊及其二龄幼虫,且孢囊的检出率与二龄幼虫的检出率的趋势一致。     

小麦对小麦孢囊线虫抗病性研究进展

由小麦孢囊线虫引起的小麦孢囊线虫病发生分布范围广,防治困难,严重危害我国小麦生产.在我国危害小麦的孢囊线虫主要包括禾谷孢囊线虫(Heterodera avenae)和菲利普孢囊线虫(H.filipjevi).种植抗病小麦品种是防治小麦孢囊线虫病最经济有效的措施,近10年来,我国科学家制定了小麦孢囊线虫抗性评价标准,测试...     

豫北及冀南地区4个小麦禾谷孢囊线虫群体的种类鉴定

禾谷孢囊线虫病(Cereal Cyst Nematode,CCN)是世界上为害小麦等禾谷类作物的重要根部线虫病害,许多国家受害严重[1].该病的病原禾谷孢囊线虫(Heterodera avenae group)是一个复合种群组,包括12个有效种和几个未命名的种,其中发生普遍、危害严重的有燕麦孢囊线虫(H.avenae)、菲利普孢囊线虫(H.filipjevi)、大麦孢囊线虫(H.hordecalis)和麦类孢囊线虫(H.latipons)[1].我国1987年在湖北省天门县首次在小麦上发现禾谷孢囊线虫病,Wang等[2]鉴定病原为燕麦孢囊线虫(H.avenae);后陆续在河南、安徽、山东等多个省份发现该病,病原均为该种线虫.2010年Li等[3]在河南许昌报道发现了菲利普孢囊线虫(H.filipjevi).     

Sublethal effects of a synthetic pyrethroid,deltamethrin, on the glycemia,the lipemia,and the gut alkaline phosphatases of honeybees

A sublethal dose (0.1 pmol per honeybee, i.e., approx. 0.9 pmol/g body wt) of the synthetic pyrethroid, deltamethrin, was injected intrathoracically into the hemocoel of emerging bees and the biochemical effects were determined over a period of 3 hr. The variations in hemolymph concentrations of trehalose, glucose, phospholipid, steroid, and diacylglycerol were limited, but large variations were observed for other lipids. Mono- and triacylglycerols increased dramatically 1.5 hr after injections; then a peak of free fatty acid appeared at the same time (3 hr) as the monoacylglycerols reached their maximum and the triacylglycerols started to decrease. Atypical forms of triacylglycerols accumulated from 1.5 hr to a maximum level 2 hr after injection. Then, after 3 hr, the concentrations of regular fatty acids, monoacylglycerols, and atypical triacylglycerols returned to normal while longer-chain fatty acids and different forms of ceride simultaneously appeared. The gut alkaline phosphatase parameters (V_M, K, and Hill coefficient) also showed large variations 1.5 and 2 hr after injection, indicating an initial inhibition phase followed by superimposed induction and inhibition mechanisms. These data are discussed according to the hemolymph-lipid transport scheme from the biosynthetic to the utilization sites. Hormone release associated to mitochondrial alteration could be responsible for the observed effects.     

Establishment of, and preliminary impact studies on, the rust, Maravalia cryptostegiae, of the invasive alien weed, Cryptostegia grandiflora in Queensland, Australia

The rust fungus Maravalia cryptostegiae , from south-west Madagascar, was introduced into Australia in 1995 as a classical biological control agent against the highly invasive rubber-vine weed Cryptostegia grandiflora , a woody climber endemic to Madagascar. The rust was released at 69 sites between 1995 and 1997 and is now established throughout the plant's exotic range in Queensland, estimated at over 40 000 km². Dispersal was low in the first 3–4 months but was virtually linear thereafter, and the rust spread over 100 km within the first year; after 3 years it was recorded 550 km away from the nearest release site. Spraying both dry and aqueous inoculum of uredinioid teliospores from the ground using mist-blowers, as well as from the air by atomizing spore suspensions, resulted in rust-induced defoliation, producing an overall reduction in fecundity and biomass of the weed. In sites with low water tables, weed growth decreased markedly, with a reduction in plant volume from 9 m⁻³ to 1 m⁻³ over a 4-year period. Both rust- and drought-induced stress combined to cause up to 75% plant mortality at some sites, and at all monitored sites, seedling recruitment was virtually nil. Improved growth of indigenous grasses amongst rubber-vine thickets has increased fuel loads and created opportunities to use fire as a component of an integrated approach to the management of this economically and ecologically damaging weed.     

Effects of the host, the pathogen, the environment and their interactions, on fusarium wilt in carnation

Fusarium oxysporum f.sp.dianthi causes severe wilting in carnation (Dianthus caryophyllus L.) worldwide. The pathogen is present in the soil profile in which carnation roots are distributed and may infect the plants at any time during the growing season. To minimize the losses induced by Fusarium wilt, growers use carnation cuttings free ofFusarium spp. and fumigate the soil with methyl bromide prior to planting. The severity of epidemics and the resulting losses are governed by the main and interacting effects of the three components of the disease syndrome: the host, the pathogen and the environment. Host variables include the type and the degree of cultivar resistance (i.e., complete, partial or tolerance); pathogen variables include the race, its virulence and infectivity, and the amount of initial inoculum; environmental variables include solar radiation intensity, photoperiod, temperature and the growth substrate. In the present review the information available on the effect of the host, the pathogen and the environment, and their interactions, on Fusarium wilt in carnation is summarized.     

草地螟幼虫取食量、头宽、体长及体重的测定

研究了草地螟(Loxostege sticticalis L.)幼虫的取食量、头宽、体长及体重增长的变化。草地螟的幼虫历期约为13 d,取食量635 mg,其中前3龄的取食量仅为幼虫总取食量的30%,而4、5龄的取食量分别占24%和46%。幼虫头宽增加的数值从1龄的0.31 mm增加到5龄的1.51 mm,增加的数值随幼虫龄期的增加而增大,增加倍数则随龄期的增加而缩小。幼虫体长从1龄的2.3 mm增加到5龄的18.9 mm,增加了约7倍。体重则由1龄期的0.2 mg增加到5龄时的43.6 mg,增加了约240倍。3龄前幼虫体重增长缓慢,4龄后增长量达到10 mg以上,到5龄第2天达到最大值68.94mg后下降。幼虫的总取食量约为本身体重的15倍。本文还讨论了以上结果在了解草地螟幼虫危害特征和规律及监测、防治中的作用。     

Modeling the Risk of Entry, Establishment, Spread, Containment, and Economic Impact of Tilletia indica, the Cause of Karnal Bunt of Wheat, Using an Australian Context

ABSTRACT Modeling techniques were developed to quantify the probability of Tilletia indica entering and establishing in Western Australia (WA), and to simulate spread, containment, and the economic impact of the pathogen. Entry of T. indica is most likely to occur through imports of bulk grain or fertilizer (0.023 +/- 0.017 entries per year and approximately 0.009 +/- 0.009 establishments per year). Entry may also occur through straw goods, new or second-hand agricultural machinery, and on personal effects of travelers who have visited regions with infected plants. The combined probability of entry and establishment of T. indica, for all pathways of entry, is about one entry every 25 years and one establishment every 67 years. Alternatively, sensitivity analysis does show that increases in quarantine funding can reduce the probability of entry to about one entry every 50 years and less than one establishment every 100 years. T. indica is spread efficiently through contaminated farm machinery, seed and soil, rain, air currents, and animals. Depending on the rate of spread of the pathogen and the amount of resources allocated for detection, the time until first detection could range from 4 to 11 years and the economic impact could range from 8 to 24% of the total value of wheat production in WA.     

Metabolic aspects of the toxicology of diazinon. I. Hepatic metabolism in the sheep,cow, pig,guinea-pig,rat, turkey,chicken and duck

The phosphorothionate insecticide diazinon was incubated with liver microsomes from the sheep, cow, pig, guinea-pig, rat, turkey, chicken and duck. Metabolism by liver slices of most of these species was also examined. Hydroxydiazinon, isohydroxydiazinon, dehydrodiazinon, their oxons and diazoxon were identified and determined quantitatively or semi-quantitatively. An eighth metabolite was tentatively identified as the 6-aldehyde analogue of diazinon. Yields and rates of production of these metabolites varied greatly between species. Production of oxons was not generally correlated with susceptibility to diazinon poisoning, although it was lowest in the least susceptible animal, the sheep. The degradation of oxons by liver slices was too slow to explain the low toxicity of diazinon to the mammals. The relative importance of hepatic and extrahepatic metabolism in determining toxicity to vertebrates is discussed.     

Optimisation of the pheromone blend of the swede midge,Contarinia nasturtii,for monitoring

BACKGROUND: The swede midge, Contarinia nasturtii Kieffer, is a serious pest in crucifers. Its pheromone is a blend of (2S,9S)‐diacetoxyundecane, (2S,10S)‐diacetoxyundecane and (2S)‐acetoxyundecane. The pheromone is used in monitoring traps, and this study examines possible ways to optimise the traps. RESULTS: Two dispenser types were compared: polyethylene dispensers and cotton dispensers. Polyethylene dispensers attracted male C. nasturtii for more than 6 weeks, whereas cotton dispensers were attractive for only 2 weeks. All three pheromone components were important for attraction of male midges in the field. The importance of the stereoisomeric compositions of the pheromone compounds was also tested—both in the wind tunnel and in the field. In the case of 2,9‐diacetoxyundecane and 2‐acetoxyundecane, the non‐natural stereoisomers did not inhibit male C. nasturtii attraction, whereas one or both of the stereoisomers of 2,10‐diacetoxyundecane did. CONCLUSION: Pheromone traps with the synthetic pheromone in a 1:2:0.02 ratio emitted from PE dispensers were highly effective and long lasting. As the mixture of stereoisomers of 2,10‐diacetoxyundecane strongly inhibited attraction of male C. nasturtii while those of 2,9‐diacetoxyundecane and 2‐acetoxyundecane did not have any inhibitory effect, it is possible to produce traps that are effective and long lasting but cheaper to produce and maintain. Copyright © 2009 Society of Chemical Industry     

Evidence for different mechanisms of action of the three pyrethroids,deltamethrin, cypermethrin,and fenvalerate,on the excitation threshold of myelinated nerve

The effects of three α-cyano pyrethroids (deltamethrin, fenvalerate, and cypermethrin) on the electrophysiological function of single myelinated nerve fibers from Rana esculenta were investigated. The time course of pyrethroid-induced changes on the threshold interval, V_s − V_m (V_s: threshold voltage; V_m: membrane potential), as well as stationary membrane parameters determining this interval was measured on the same nerve preparation (membrane potential V_m, stationary transition voltage V_Tr, stationary sodium conductance). The results suggest that the mechanisms of changing the threshold interval are different for the three pyrethroids. Deltamethrin and cypermethrin increase this interval until inexcitability, deltamethrin by increasing the stationary sodium conductance and cypermethrin by blocking the sodium conductance. Fenvalerate, however, insignificantly affects the threshold interval because both V_m and V_s are shifted parallel by about the same amount in the same direction (depolarization). These qualitatively different effects of chemically related substances differentiate the pyrethroids from other classes of substances which are effective on the nerve function and suggests that the molecular mechanisms underlying the pyrethroid effects might have a unique quality.     

International Symposium on the Evaluation of Biological Activity,Wageningen, April, 1975

Abstract

A method was devised for estimating large populations of cowpea aphid Aphis craccivora Koch (Hemiptera: Aphididae) on cowpea. The densities of the aphid on stem, leaves and pod were first estimated in the laboratory for use in the field later. The densities were estimated in three arbitrary classes of infestation, viz. heavy, medium and low, determined visually based on the intensity of colonization. The densities of the aphid per cm² on stems were 108.50, 49.77 and 2503, while on pods they were 80.68, 44.46 and 23.20, in the three classes of infestation respectively. The aphid did not show any preference for the thickness of stems whereas young pods were preferred to old pods for colonization. The mean aphid densities on leaflets of topmost leaves were 62.10, 36–35 and 18–50, while on leaflets of top 2nd and 3rd leaves they were 124–60, 69–35 and 38.20, in the three infestation classes respectively. Comparisons made between the aphid densities on different parts of cowpea plant showed that the aphid colonized them in descending order of preference as stem > pod > top most leaf > top 2nd and 3rd leaves.