阿维菌素对苹果园主要害虫的控制作用

为明确阿维菌素对苹果主要害虫的控制作用,为其在生产中的合理使用提供理论依据,以1.8%阿维菌素乳油为代表品种,针对苹果园桃小食心虫、绣线菊蚜、金纹细蛾、二斑叶螨、苹果全爪螨等5种主要害虫开展了田间药效试验。结果表明：阿维菌素可作为防治苹果树桃小食心虫和绣线菊蚜的兼治药剂,宜在二者发生较轻、结合防治其它害虫时使用;阿维菌素防治苹果树金纹细蛾与生产上常用药剂灭幼脲防效相当,可在生产上推广使用;阿维菌素对苹果树活动态螨有较好防效,但杀卵效果较差,适于在叶螨发生初期,卵量较小时使用。只要正确的掌握其使用技术,阿维菌素对苹果多种害虫均具有较好的防效。     

不同立体种植对棉花主要害虫及其天敌种群消长的影响

通过种植麦套春棉、麦套春棉播种玉米诱集带、麦套春棉邻近种植玉米三种类型的棉田，以平作春棉为对照。明确了不同类型生态区的主要害虫及天敌种群消长动态。立体种植棉田与平作春棉相比：盛期平均百株黄地老虎为害降低８７．５％；棉叶螨发生早为害重；苗蚜降低９７．８％，差异极显著；伏蚜发生量上升２０２％，差异显著；第二代棉铃虫落卵士降低３３．８％；三、四代棉铃虫落卵量差异不显著。第二代棉铃虫发生期，玉米诱集带百株累计诱集棉铃虫落卵量达１４８４粒，天敌数量最高达８４０头，明显看出种植玉米诱集带对棉铃虫有较好的诱集作用，对天敌有很好的保护和增殖作用。     

大豆菟丝子生物学特性及化学防治技术的研究

通过对菟丝子生物学特性的系统观察和药剂防治试验,发现在大豆播后芽前和苗期的3—5片复叶期,单用或混用25%胺草磷、48%地乐胺进行防治,对菟丝子的防效可达90—95%,还可兼治豆地其它杂草.经生产实践证明有显著的增产效果.     

华棉101的抗虫性鉴定机制及育种技术研究

华棉１０１是采用杂交育种和抗虫鉴定技术相结合选育而成。该品种高抗棉铃虫，其蕾铃受害率比ＣＫ“ＨＧ—８”减退２６．１７％；抗红铃虫，其子害率比对照品种相对下降３０％；高抗苗蚜，苗期蚜指比非洲棉Ｅ４０减退１２．９％，７叶恢复期蚜指减退３４．６％。华棉１０１在完全治虫的湖北省区试中产量与ＣＫ鄂荆１号相当，在减少２～４次化学治虫的生产试验中比ＣＫ增产１～２成。其纤维品质优于鄂荆１号，现已在湖北、河南等省推广种植。     

缓释长效多功能新药剂对甘蔗螟虫和绵蚜防控效果评价

为筛选防控甘蔗螟虫和绵蚜的缓释长效低毒低风险多功能配方新药剂及精准高效施药技术,选用10%杀虫单.噻虫嗪颗粒剂和1%Bt.噻虫胺颗粒剂根施进行田间药效试验。田间试验结果表明,10%杀虫单.噻虫嗪颗粒剂和1%Bt.噻虫胺颗粒剂对甘蔗螟虫和绵蚜均具有良好的防控效果,是防控甘蔗螟虫和绵蚜理想的缓释长效低毒低风险多功能配方新药剂,与其他药剂交替使用,可延缓害虫抗药性产生和发展。两种药剂田间使用最适宜用量均为45 kg/hm2,可在1-7月结合新植蔗下种、宿根蔗管理或大培土,按每公顷用药量45kg与每公顷施肥量1200-1800 kg混合均匀一次性撒施于蔗沟、蔗桩或蔗株基部覆土或全膜盖膜,对螟害枯心苗的防效可达79.2%以上,对甘蔗绵蚜的防效可达98.8%以上;甘蔗实测产量和糖分分别较对照增加41555 kg/hm2和6.5%以上。缓释长效强内吸性多功能新药剂与底肥追肥混匀一次性根施,施用方便,精准高效,省工省时,环境友好,值得在蔗区大面积推广应用。     

转双价基因棉田主要害虫及其天敌的种群动态

2002—2003年在田间小区研究了转双价基因(Cry1Ac+CpTI)棉田主要害虫及其天敌的种群动态。结果表明,2、3、4代棉铃虫平均百株幼虫数量分别比常规棉减少81.4%、87.1%和87.0%,比Bt棉田减少11.1%、33.3%和57.1%,比常规棉用药田减少20.0%、66.7%和40.0%;百株棉苗蚜数量比Bt棉田减少4.0%,但分别比常规棉田和常规棉用药田增加21.6%和153.9%;百株伏蚜、棉粉虱数量分别比Bt棉田和常规棉田减少5.5%和23.3%、16.7%和13.0%,但比常规棉用药田增加61.7%和33.3%;百株棉叶螨、棉盲蝽和棉蓟马的数量比Bt棉减少34.0%、39.6%和5.9%,但分别比常规棉田和常规棉用药田增加158.3%和287.5%、20.8%和52.6%、23.1%和60.0%。百株草间小黑蛛、龟纹瓢虫和小花蝽的数量均明显高于常规棉用药田,与Bt棉和常规棉田差异不显著;百株棉蚜茧蜂和中红侧沟茧蜂数量均明显低于常规棉田,与Bt棉和常规棉用药田差异不显著。     

15种氨基甲酸酯类杀虫剂在我国的登记作物范围

<正>氨基甲酸酯类杀虫剂是20世纪50年代,继有机氯和有机磷之后发展起来的一类农药,因化学结构归属于氨基甲酸酯而得名。其多数品种持效期较短,选择性强,以防治蚜虫、飞虱等刺吸类害虫和蚊、蝇、蚂蚁、蜚蠊等卫生害虫为主,对螨类、蚧类无效。灭多威、茚虫威等部分品种可防治棉铃虫、烟青虫、甜菜夜蛾、小菜蛾、潜叶蛾等鳞翅目害虫。涕灭威、克百威等少数品种持效期较长,对地下害虫、线虫防效较好。甲奈威等少数品种可防治蜗牛等软体动物。     

乙基多杀霉素治茄子蓟马效果好

<正>据了解,今年江苏等地茄子上蓟马发生和危害严重,生产上应及时采取药剂防治等措施控制其发生和危害。吡虫啉、噻虫嗪、烯啶虫胺等烟碱类杀虫剂,丁硫克百威、杀虫单、杀虫双等沙蚕毒素类杀虫剂以及马拉硫磷、阿维菌素等药,对蓟马均有不同程度的防效,可以用于茄子、番茄、辣椒等茄科作物防治蓟马。其中有多种药对烟粉虱等害虫也有良好的兼治效果,可以根据情况选用。     

两种氟虫双酰胺复配制剂拌种对直播晚稻蓟马的控制效果及水稻生长的影响

为筛选直播晚稻蓟马的防治药剂,采用拌种法在大田试验了两种氟虫双酰胺复配制剂对直播水稻蓟马的控制效果,并考查了其对二化螟、稻纵卷叶螟的兼治效应及对水稻生长的影响。结果表明,48%氟虫双酰胺?噻虫啉SC 4~8 g a.i./kg种子处理拌种,可有效控制水稻苗期稻蓟马危害,药后14天杀虫和保叶效果分别为88.89%~95.03%和85.63%~91.67%,药后21天分别为87.64%~94.49%和78.86%~89.69%;2 g a.i./kg种子处理防效明显下降。同时,对二化螟具有兼治效果,并可刺激稻苗生长,提高水稻生长后期结实率和产量,而对稻纵卷叶螟防效较低。10%氟虫双酰胺?阿维菌素SC 1.5~3 g a.i./kg种子拌种对二化螟具有较好的控制效果,对稻蓟马和稻纵卷叶螟防效较低。因此,48%氟虫双酰胺?噻虫啉SC 4~8 g a.i./kg种子处理拌种可推荐用于水稻苗期稻蓟马和二化螟防治,而10%氟虫双酰胺?阿维菌素SC拌种处理不宜用于水稻苗期稻蓟马治理。     

90%盖萨林防除春玉米田杂草效果评价

1999~2000年进行了90%盖萨林水分散颗粒剂（WG）防除春玉米田杂草的效果及对春玉米的安全性田间小区试验。结果表明,90%盖萨林WG对春玉米田的藜、本氏蓼、反枝苋、龙葵等阔叶杂草有良好的防除效果,而对苍耳、苘麻及禾本科杂草防效较差。春玉米播后苗前土壤处理,适宜的用药量为90%盖萨林1620~1890(g·ai)/hm2(有效成份用量),对阔叶杂草总的株数和鲜重防效均在90%以上,在上述推荐剂量范围内对春玉米安全。     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.