Research on the Control Effects of Several Insecticides on Wheat Aphids

[Objective] The aim was to determine control effects of the 6 insecticides and recommended the optimal doses. [Method] In 2014, the control effects of sophocarpidine, pymetrozine, beta-cypermethrin, acetamiprid, imidacloprid, and chlor- pyrifos on wheat aphids were tested, and every pesticide was designed with three doses in Shou County, Anhui Province, to explore the significance of differences on control effects. [Result] The results showed that the control effects of the 6 insecti- cides were satisfied, and the insecticides were safe on wheat. [Conclusion] During initial diseasing stage of aphid, it is recommended to use sophocarpidine soluble concentrate （1.5%）, pymetrozine water dispersible granule （50%）, imidacloprid wet- table powder （25%）, and acetamiprid wettable powder （5%）, and chlorpyrifos missi- ble oil （40%）, cypermethrin missible oil （4.5%） and imidacloprid wettable powder （25%） can be applied in peak-diseasing stage.

Spatial Distribution Pattern and Sampling Technique of Spring Wheat Aphid

[ Objective] The aim was to study the spatial distribution pattern and field sampling method of aphid population in spring wheat. [ Method] The aphid quantity in tested wheat field was calculated, the field distribution pattern of wheat aphid was calculated by using aggregated index method, the aggregated reason was analyzed and the field theoretical sampling number was ascertained. [ Result] The wheat aphid population showed aggregation distribution and negative binomial distribution, and such aggregation distribution was induced by interaction of its behavior and environmental factors. The field theoretical sampling number of wheat aphid was related to sample variance and permissible error; the less the sam- ple variance [ S^2 ） was, the less the permissible error [ d＇） was, the bigger the theoretical sampling number without replacement was; when the initial population numbers were different, the theoretical sampling numbers were also different; after the permissible error being set, the bigger the sample variance （ S^2 ） was, the bigger the theoretical sampling number was. [ Conclusion] This study supplied scientific basis for prediction and field control of wheat aphid.

Toxicity and Antifeedant Activity of Extracts from Walnut Green Husk against Wheat Aphid

[Objective] The research aimed to study the toxicity and antifeedant activity of walnut green husk extract on wheat aphid. [Method] Using ultrasonic extraction, 5 kinds of different polarity solvents were used to prepare the extracts from walnut green husk. The toxicity and antifeedant activity on wheat aphid were determined, [ Result ] Walnut green husk extracts in the solvent of ethanol, acetone, ethyl acetate had higher toxicity and antifeedant activity on wheat aphid. When the concentration was 100 mg/ml, after 24 h, the toxicity and antifeedant activity of three kinds extracts on wheat aphid were greater than 84.35% and 66.98%, respectively. After 48 h, the toxicity and antifeedant activity were greater than 85.91% and 79.34%, respectively. Among 5 kinds extracts,ethanol extracts had the highest toxicity and antifeedant activity on wheat aphid. After 24 h, the corrected mortality rate was 93.64% and the antifeedant rate was 83.61%. After 48 h,the corrected mortality rate was 94.95% and antifeedant rate was 92.21%. Petroleum ether extract had the smallest toxicity and antifeedant activity on wheat aphid. After 24 h,the corrected mortality rate and antifeedant rate were 19.54% and 34.65%, respectively. After 48 h,the corrected mortality rate and antifeedant rate were 20.13% and 39. 03%, respectively. [ Conclsion] The extracts from walnut green husk with larger polarity solvent had better toxicity and higher antifeedant activity on wheat aphid.

Transgenic Expression of a Functional Fragment of Harpin Protein Hpa1 in Wheat Represses English Grain Aphid Infestation

The harpin protein Hpa1 produced by the rice bacterial blight pathogen promotes plant growth and induces plant resistance to pathogens and insect pests. The region of 10-42 residues （Hpa110-42） in the Hpa1 sequence is critical as the isolated Hpa110-42 fragment is 1.3-7.5-fold more effective than the full length in inducing plant growth and resistance. Here we report that transgenic expression of Hpa110-42 in wheat induces resistance to English grain aphid, a dominant species of wheat aphids. Hpa110-42-induced resistance is effective to inhibit the aphid behavior in plant preference at the initial colonization stage and repress aphid performances in the reproduction, nymph growth, and instar development on transgenic plants. The resistance characters are correlated with enhanced expression of defense-regulatory genes （EIN2, PP2-A, and GSL10） and consistent with induced expression of defense response genes （Hel, PDF1.2, PR-1b, and PR-2b）. As a result, aphid infestations are alleviated in transgenic plants. The level of Hpa110-42-induced resistance in regard to repression of aphid infestations is equivalent to the effect of chemical control provided by an insecticide. These results suggested that the defensive role of Hpa110-42 can be integrated into breeding germplasm of the agriculturally signiifcant crop with a great potential of the agricultural application.

Development and Characterization of Wheat Germplasm with Combined Resistance to Russian Wheat Aphid and Stem Rust (Race “Ug99”) in Kenya

Wheat is the second most important cereal in Kenya. However, production is severely constrained by both abiotic and biotic stresses. Of the biotic stresses a devastating pest (Russian wheat aphid (RWA)) and a serious disease (stem rust race TTKS (“Ug99”)) are currently the biggest problem for wheat producers in Kenya. Severe infestations by RWA may result in yield losses of up to 90% while “Ug99” infected fields may suffer 100% crop loss. The two pests combined are seriously affecting wheat farmers’ incomes because of the heavy reliance on pesticides that increase the cost of production. This study attempted to develop and characterize wheat lines that are resistant to both RWA and “Ug99” by pyramiding two major resistance genes. Three wheat varieties: “Kwale”, a Kenyan high yielding variety but susceptible to both RWA and “Ug99”;“Cook”, an Australian variety carrying stem rust resistance gene Sr36 conferring immunity to “Ug99”;and “KRWA9”, a Kenyan line with resistance to RWA but of poor agronomic attributes were used. A double cross F1 (DC F1) was obtained by crossing the F1 of “Kwale × Cook” and the F1 of “Kwale × KRWA9”. The DC F1 population was subjected to sequential screening for both RWA and “Ug99” resistance. Surviving DC F1 progenies were left to self pollinate to obtain the F2 of the double cross (DC F2). The DC F2 progenies were sequentially screened against RWA and “Ug99” to yield a population that was resistant to both RWA and “Ug99”. Genotyping of the DC F2:3 families were conducted to select homozygous resistant plants. Data indicated that the RWA and “Ug99” resistance genes were successfully pyramided. Though races with virulence for Sr36 have been reported, the gene provides immunity to race “Ug99” and can still be effectively used as a component for “Ug99” resistance breeding together with other Sr genes.

Yield Evaluation of a Wheat Line with Combined Resistance to Russian Wheat Aphid and Stem Rust Race “Ug99” in Kenya

InKenya, Russian wheat aphid (RWA) and stem rust race TTKS (“Ug99”) are the most devastating pests of wheat. Severe infestations by RWA result in yield losses of up to 90% while epidemics of “Ug99”can cause up to 100% loss. The two pests combined have seriously affected farmer incomes forcing them to rely heavily on pesticides and increasing the cost of production. This study sought to evaluate a wheat line that has been developed to be resistant to both RWA and “Ug99”by pyramiding two major resistance genes. Three varieties were used in this study: “Kwale”, a Kenyan high yielding commercial variety but susceptible to both RWA and “Ug99”;“Cook”, an Australian variety carrying stem rust resistance gene Sr36 conferring immunity to “Ug99”;and “KRWA9”, a Kenyan line resistant to RWA but with poor agronomic attributes. The F1 of the double cross (DC F1) was obtained by crossing the F1 of “Kwale × Cook” and the F1 of “Kwale × KRWA9”. The DC F1 population was subjected to sequential screening for both RWA and “Ug99”resistance. The surviving DC F1 progenies were left to self pollinate in the field to obtain the DC F2. The DC F2 progenies were sequentially screened against RWA and “Ug99”to obtain a resistant population to both RWA and “Ug99”. The yield and yield components of the new resistant line were compared with the three parents. Results showed that the DC F2:3 had higher yields than the three parents based on 1000 kernel weight, weight of kernel per spike, and the actual yield in tons/ha, indicating that the genes were successfully introgressed. It is concluded that though races with virulence for Sr36 have been reported, the gene provides immunity to race “Ug99”and can be used as a component for “Ug99”resistance breeding together with other Sr genes.

Evaluation of Dryland Wheat Cultivars on the Market in South Africa for Resistance against Four Known Russian Wheat Aphid, <i>Diuraphis noxia</i>, Biotypes in South Africa

An increased wheat yield potential under changing environmental conditions is a challenge in agriculture. Resistant wheat lines can yield more than susceptible wheat lines in the presence of Russian wheat aphid infestation. There are currently four Russian wheat aphid (RWA) biotypes known in South Africa with different virulence against different wheat cultivars. To keep up with the ever-changing patterns it is necessary to screen the cultivars for resistance against these Russian wheat aphid (RWA) biotypes. All the dryland wheat cultivars on the market were evaluated for resistance against the four known Russian wheat aphid (RWA) biotypes in South Africa. Through this evaluation, the status of Russian wheat aphid (RWA) resistance in South African dryland wheat cultivars can be updated to adapt to environmental changes and the wheat industry can adapt to changes in virulence of Russian wheat aphid (RWA) biotypes that may cause damage to Russian wheat aphid (RWA) resistant cultivars, subsequently affecting yield. Evaluations were done in the glasshouse by screening wheat cultivars against four different South African Russian wheat aphid (RWA) biotypes, RWASA1-RWASA4, under controlled conditions. The glasshouse evaluations showed that out of the 19 dryland wheat cultivars currently on the market in South Africa 16 are resistant against RWASA1, 7 are resistant against RWASA2, 7 are resistant against RWASA3 and 5 are resistant against RWASA4. Dryland wheat cultivars were also evaluated under field conditions at four different field localities. In the field, 5 cultivars were resistant to RWASA3 at two localities, respectively, and 3 and 5 cultivars were resistant to RWASA4 at two localities, respectively. Since Russian wheat aphid (RWA) damage can influence the final yield of a wheat cultivar significantly, changing conditions can influence both resistant cultivars, and the virulence of Russian wheat aphid (RWA). It is advisable to evaluate wheat cultivars on the market under different conditions and with all known Russian wheat aphid (RWA) biotypes in an area.

Field Screening of Lesotho and South African Wheat Cultivars for Russian Wheat Aphid Resistance

Russian wheat aphid (Diuraphis noxia) is an international wheat pest and was first recorded in South Africa in 1978 in the Bethlehem area in the Eastern Free State. Le-sotho lies adjacent to one of the largest wheat producing areas in South Africa, the Eastern Free State, where winter wheat and facultative types are cultivated under dry land conditions. Wheat (Triticum aestivum L.) is an important crop adapted to all agro-ecological zones of Lesotho. Russian wheat aphid may have a significant impact on wheat yield. No monitoring or pest control is being done in Lesotho and at this stage there is very little information on the Russian wheat aphid resistance of wheat culti-vars cultivated in Lesotho. In view of this it is important to monitor the distribution of Russian wheat aphid biotypes in Lesotho and determine the level of Russian wheat aphid resistance in local Lesotho wheat cultivars. Two local Lesotho wheat cultivars, Bolane and Makalaote were screened together with South African cultivars Elands, Matlabas, Senqu, PAN3379, PAN3118 and SST387, in the glasshouse against all four known biotypes that occur in South Africa. All these cultivars were also planted in 5 m plots in the field at two localities Leribe and Roma in the lowlands of Lesotho. These cultivars were screened in the field for Russian wheat aphid resistance. The predomi-nant Russian wheat aphid biotypes in these areas were also determined. The Lesotho cultivar, Bolane had resistance against RWASA2 in the glasshouse, while Makalaote did not have any Russian wheat aphid resistance in either the glasshouse or field screenings. To contribute to food security an increasing wheat yield potential is a high priority. Russian wheat aphid has been included in the list of important international cereal pests. Russian wheat aphid adapts to changing environments and taking their ecology, distribution, virulence patterns, and variability into account is important in minimizing the gap between actual and attainable yields. Current management prac-tices for winter wheat in South Africa include the use of resistant cultivars, which is the most economical management strategy for Russian wheat aphid. Introducing Russian wheat aphid resistant cultivars in Lesotho will improve overall yield and as a result food security. This will also result in lower Russian wheat aphid pest pressure in the adjacent wheat production areas in the Eastern Free State, South Africa.

Responses of Wheat (Triticum aestivum) to Grain Aphid (Sitobion avenae) Infestation and Mechanical Wounding Using a cDNA Subtractitve Library Approach

Aphids are major insect pests of cereal crops, acting as virus vectors as well as causing direct damage. The responses of commercial wheat (cv. Claire) to grain aphid (Sitobion avenae) infestation and mechanical wounding were investigated in this study, with the aim to eventually identify a source of molecular markers to breed wheat for enhanced insect resistance, and in particular for enhanced resistance to phloem-feeding insects. Mechanical wounding was included in this study as a comparison with aphid feeding to distinguish between insect-specific responses in wheat plants to those involved in a general wounding response. Wheat (Triticum spp.) is known to have partial resistance toward aphids [1]. The plant response and defence against insect feeding are complicated, but always follow the same principle: insect detection, signal transmission to initiate defence, changes in plant gene expression and subsequent production of defensive compounds, which may be targeted to the wound site to deter or kill insects. Defensive gene products/proteins reach the target area and deter or kill insects. Whether the last step is successful or not depends on the resistance and susceptibility of the plant towards that particular pest. In the light of this principle, it is important to detect changes in gene expression, first at the transcriptional level, which is useful for detection of early-stage responses, and then once sufficient time is allowed for the plant to produce defensive gene products, responses at the proteome level can be identified. Work presented in this study focuses on the changes at the transcriptional level;differential responses at the proteome level were investigated and presented in Ferry et al. 2011 [2] and Guan et al. 2015 [3]. Two cDNA subtractive hybridization libraries were constructed, one to identify transcripts involved in the responses to aphid infestation, and the second to identify transcripts involved in responses to mechanical wounding. Following subtractive hybridization, 520 and 800 clones were obtained from the subtractive hybridization between aphid-infested and un-infested wheat cDNAs and between mechanically wounded and un-wounded wheat cDNAs, respectively. Over 70% of the total clones were sequenced and 44% and 55% of sequenced clones were successfully identified by homology to known sequences held at NCBI with Blastx search engine in aphid-infested vs un-infested and mechanically wounded vs un-wounded cDNA subtractive libraries, respectively. These results reveal that the differences in the response of commercial wheat (cv. Claire) plants towards aphid infestation and mechanical wounding are subtle. Although the majority of differentially expressed putative genes after aphid infestation or mechanical wounding were involved in metabolic processes and photosynthesis, the majority of the genes expressed were different. Genes encoding glutathione transferase (GST), apoptosis and proteolysis were up-regulated after aphid feeding, suggesting their importance towards plant defence/tolerance against aphid attack. These results suggest that commercial wheat does have a certain degree of tolerance to aphids, but appears to lack a specific response to aphids;these findings are supported by those presented in Ferry et al. 2011 [2].

基于结构方程模型分析天敌因子对麦蚜种群动态的影响

在麦蚜生态系统中,天敌因子是蚜虫种群数量增长的重要抑制因子,不同天敌种群对麦蚜种群动态的影响不同且综合作用关系复杂.通过构建结构方程模型,刻画了多个天敌种群综合作用下麦蚜种群状态的变化规律;再通过验证性因子分析,检验和拟合所构建的模型,分析多个天敌种群对麦蚜种群的综合影响并给出优势天敌种群,为科学防治虫害提供了理论依据.

种衣剂减量下增施菌剂和肥料对小麦光合、产量、蚜虫及白粉病防控的影响

为探究拌种药剂减量下增施不同类型肥料对麦田蚜虫和白粉病防控及光合和产量的影响,以小麦蚜虫低感品种川麦104和高感品种内麦836为试验材料,采用大田试验,对种衣剂减量20%下,配合施用光合菌剂、微生物菌剂、硅肥或磷酸二氢钾后麦田土壤酶活性、小麦植株光合特性、病虫防治情况和产量性状的变化进行了比较分析。结果表明,拌种药剂减量20%条件下增施微生物菌剂较种衣剂常规用量处理能显著提高孕穗期川麦104的根际土壤的脲酶活性,以及内麦836的根际土壤过氧化氢酶和纤维素酶活性。在孕穗期和抽穗期,低感品种川麦104的麦蚜数量均显著低于内麦836;增施微生物菌剂和硅肥均能显著降低麦蚜和白粉病发生,对蚜虫防效和白粉病防效较常规药剂拌种用量处理分别提高8.0和10.2个百分点。拌种药剂减量20%配合施用光合菌剂、微生物菌剂、硅肥和磷酸二氢钾均能有效提高小麦旗叶氮素含量和SPAD值,改善叶片光合效率。增施硅肥下川麦104和内麦836的产量最高,较常规种衣剂用量处理分别增加16.0%和18.2%,差异均显著。以上结果说明,小麦种子种衣剂减量配合施用硅肥或微生物菌剂可有效提高麦田土壤酶活性,减少蚜虫和白粉病发生,改善小麦叶片光合特性,提高产量。

河北廊坊小麦穗期蚜虫优势度和生态位分析

为明确华北小麦穗期主要蚜虫种类及其生态位,为京津冀地区小麦蚜虫预测预报和科学防控提供技术支持,采用五点式和棋盘式取样法系统调查了河北廊坊小麦穗期不同蚜虫种类的种群动态及其在植株上的分布,利用生态位理论,计算荻草谷网蚜Sitobion miscanthi(Takahashi)、禾谷缢管蚜Rhopalosiphum padi(Linnaeus)和麦无网长管蚜Metopolophium dirhodum(Walker) 3种优势蚜虫的生态位宽度和重叠度。禾谷缢管蚜的时空生态位最宽,其次为荻草谷网蚜和麦无网长管蚜,其中禾谷缢管蚜的生态位宽度随时间推移呈上升趋势,其他两种蚜虫呈下降趋势。不同蚜虫种类之间存在生态位重叠,其中荻草谷网蚜与禾谷缢管蚜的重叠度最大,为2.073 0,荻草谷网蚜与麦无网长管蚜的重叠度最低,为1.656 4;随时间推移,荻草谷网蚜与禾谷缢管蚜之间的竞争趋于增强,禾谷缢管蚜与麦无网长管蚜之间的竞争趋于减弱,而荻草谷网蚜与麦无网长管蚜的竞争关系相对稳定。荻草谷网蚜是当地小麦蚜虫主要优势种群,禾谷缢管蚜时空生态位宽度最大,与荻草谷网蚜竞争激烈,麦无网长管蚜时空生态位相对稳定。

苯醚甲环唑拌种对小麦根际微生物群落的影响

小麦茎基腐病是我国北方小麦主产区的重大病害,对小麦安全生产造成严重威胁。化学农药的使用是最直接有效的防治方法,在植物病害防治中发挥重要作用。苯醚甲环唑是一种具有较高安全性的三唑类杀菌剂。本课题前期明确了苯醚甲环唑拌种对小麦茎基腐病有一定的防治效果,且促生增产,但其对小麦根际微生物的影响尚不清楚。本文研究了苯醚甲环唑拌种对茎基腐病田中小麦根际土壤微生物的影响,结果表明,苯醚甲环唑拌种处理对小麦分蘖期,拔节期和灌浆期根际微生物的alpha和beta多样性均无显著影响,但使分蘖期镰孢属的相对丰度显著降低。微生物共现网络分析表明,苯醚甲环唑拌种处理提高了细菌网络的复杂性,降低了真菌网络复杂性,使植株根际微生物网络更接近健康植株根际的特征。该研究从根际微生物的角度为苯醚甲环唑防治小麦茎基腐病的机制研究及对土壤微生物的安全性评价提供理论依据。

温度升高通过小麦根际微生物加快禾谷缢管蚜和麦长管蚜的种群增长

【目的】气候变暖可影响小麦(Triticum aestivum)蚜虫发生和危害,禾谷缢管蚜(Rhopalosiphum padi)和麦长管蚜(Sitobion avenae)作为我国黄淮海小麦的主要害虫,其种群发育与繁殖受气候变暖的影响。本文旨在探究气候变暖是否会改变小麦根际微生物,从而间接影响禾谷缢管蚜和麦长管蚜的发育和繁殖。【方法】在河南原阳试验基地悬挂红外辐射加热器模拟温度升高2℃,待小麦返青后调查小麦蚜虫发生数量。在小麦拔节期收集根际微生物,并带回室内获得小麦根际微生物混合菌液。用混合菌液浇灌小麦开展两种蚜虫种群动态、年龄-龄期两性生命表试验。浇灌根际微生物混合菌液,后接种蚜虫,连续观察5次,记录蚜虫的数量。将两种麦蚜用生态盒单头固定于小麦第2片叶片上开展生命表试验,每天观察记录若蚜蜕皮、龄期、死亡等情况;同时,记录成蚜产蚜量及死亡数。【结果】不同处理下,禾谷缢管蚜和麦长管蚜的种群动态均呈持续增加趋势。随着调查次数的增加,浇灌增温田根际微生物相比常温田根际微生物,蚜虫的增加量逐渐增大。增温田根际微生物显著增加禾谷缢管蚜和麦长管蚜总平均发生量,相较于麦长管蚜,禾谷缢管蚜增加量更大,为麦长管蚜的4.49倍。种群生命表结果表明,增温田根际微生物显著缩短了禾谷缢管蚜的平均世代周期、种群加倍时间、若蚜发育历期及产蚜历期,同时显著增加了其内禀增长率、周限增长率和产蚜量。此外,增温田根际微生物显著提高了麦长管蚜各阶段种群存活率。【结论】温度升高分别通过影响根际微生物而促进禾谷缢管蚜的生长发育和繁殖,提高麦长管蚜的存活率,加速禾谷缢管蚜和麦长管蚜的种群增长,这些影响可导致蚜虫迁飞行为的变化。研究结果初步解析了气候变暖条件下麦蚜暴发机制,可为预测和评估未来气候变暖下的麦蚜发生提供重要参考。

高效氯氟氰菊酯与烯啶虫胺增效混配剂的筛选及其对小麦蚜虫的田间防治效果

为了延缓麦蚜抗药性和降低杀虫剂使用量,本研究筛选了具有增效作用的高效氯氟氰菊酯和烯啶虫胺的复配比例,并研究了增效复配剂对麦蚜的田间防治效果。浸叶法测定结果表明,高效氯氟氰菊酯对麦蚜的LC_(50)为25.01 mg/L,烯啶虫胺对麦蚜的LC_(50)为28.21 mg/L。通过最佳增效配比的筛选,发现高效氯氟氰菊酯和烯啶虫胺的有效成分比为1.3∶1、1∶1.1、1∶1.7、1∶10.2时,对麦蚜的毒效比分别为1.28、1.49、1.64、1.50,表现为增效作用。深入研究发现高效氯氟氰菊酯和烯啶虫胺的有效成分为1∶4.5、1∶7.5和1∶10.2的混配组合的共毒系数均显示了显著增效作用,其中,当高效氯氟氰菊酯与烯啶虫胺有效成分比为1∶7.5时,混配剂的LC_(50)为5.22 mg/L,共毒系数达到532.61。按有效成分比1∶7.5,将10%高效氯氟氰菊酯水乳剂与20%烯啶虫胺可溶液剂混用后,进行田间试验,结果表明,在药后1、3 d和7 d,混配剂的防效与高效氯氟氰菊酯单剂的防效无显著性差异,在药后1 d,混配剂的防效高于烯啶虫胺单剂的防效,在药后3 d及7 d,混剂与烯啶虫胺单剂的防效没有显著差异。混配剂的防效在药后7 d内不断上升,其中药后7 d防效达到92.98%。混配剂的使用可以达到对高效氯氟氰菊酯减量的目的,同时保证了对麦蚜的防效。

黄色粘板对小麦田蚜虫及天敌的诱集作用

为明确黄色粘板(黄板)对小麦田蚜虫及天敌的诱集作用,2021~2022年度在河南省漯河市农业科学院五里岗试验基地,通过小麦田间悬挂黄板,对其诱集小麦蚜虫效果及对天敌的影响进行了监测分析。结果表明,两年诱集到的节肢动物分属6目13科21种,其中害虫隶属于3目7科,优势种为禾谷缢管蚜;天敌隶属于5目5科,优势种为烟蚜茧蜂。两年所诱集的节肢动物种类和数量占比保持相对稳定。不同年份黄板所诱集蚜虫和主要天敌数量有差异,但发生动态和峰期基本保持一致。两年所诱总个体数量随温度变化趋势明显,呈多峰波动型变化。所诱蚜虫发生动态可分为迁入期、定居期、越冬期、恢复期、快速上升期、盛发期、下降期共七个阶段,可以将黄板放在有翅蚜虫恢复期使用,对其进行监测,为麦田蚜虫的预测预报提供参考。

Resistance in Barley (<i>Hordeum vulgare</i>L.) to New Invasive Aphid, Hedgehog Grain Aphid (<i>Sipha maydis</i>, Passerini) (Hemiptera: Aphididae)

Sipha maydis Passerini (Hemiptera: Aphididae) is a pest of cereals in many regions of the world and was identified as an invasive pest of the US in 2007. Regional surveys from 2015-2017 revealed this pest was broadly distributed throughout many of the western Great Plains states where it is a potential threat to cereal production. The common name hedgehog grain aphid, HGA, has been associated with Sipha maydis in the US. Cross-resistance where a plant is resistant to one aphid species and is also resistant to another species that is known to occur. Six barleys were evaluated for cross-resistance to HGA: Russian wheat aphid, RWA, resistant germplasms STARS 9301B and STARS 9577B and cultivar “Mesa”;greenbug, GB, resistant germplasm STARS 1501B and cultivar “Post 90”;and RWA and GB resistant experimental line 00BX 11-115. Cultivars “Morex” and “Schuyler” were susceptible controls. Antixenosis was measured 5 days after infestation by HGA. Seedling damage ratings and reductions in seedling growth were recorded after 17 days of infestation. Intrinsic rate of increase, rm, of HGA was determined by following the development of newborn aphids to adulthood and reproduction. 00BX 11-115 and Post 90 had significantly greater antixenosis (fewer aphids/seedling), significantly lower plant damage ratings, and significantly lower intrinsic rates of increase than other entries. Differences in seedling growth were not significant. 00BX 11-115 and Post 90 were the only entries with the Rsg1 greenbug resistance gene. Rsg1 greenbug resistance confers cross-resistance to HGA in the seedling stage.

郭予元院士在小麦害虫预测和治理上的学术贡献——纪念郭予元院士诞辰90周年

本文回顾了郭予元院士在小麦害虫预测和治理上的重要贡献,主要包括:在20世纪70-90年代,创新了害虫生物学与生态学有机结合方法,显著提升小麦害虫预测技术水平。从宏观到机理,突破了多项小麦害虫治理关键技术,包括小麦品种抗吸浆虫鉴定技术与抗吸浆虫机制,创新性提出吸浆虫成虫期防治及穗期保护策略;利用田间开放式控制虫量的办法建立小麦蚜虫防治阈值及复合防治指标;麦田天敌资源的保护及利用。面向小麦生产实际,创建小麦吸浆虫综合治理技术体系。吸浆虫穗期保护策略和技术、蚜虫防治指标与防治适期等研究成果一直传承至今,列入我国农业行业标准和国家标准。本文还介绍了在后续小麦吸浆虫、蚜虫预测与防控研究与实践中,传承与发展郭予元院士的学术思想,以及未来研究展望。

麦类作物对蚜虫抗性机制及抗性遗传研究进展

小麦蚜虫是小麦上的重大害虫,严重威胁小麦产量和粮食安全。种植抗虫品种为最经济有效的麦蚜防控措施之一,充分了解小麦品种对蚜虫的抗性及其机制是培育与利用抗性品种的基础。本文对近10年来小麦抗蚜品种的鉴定筛选、抗蚜机理、抗蚜基因与抗性遗传,以及转基因抗蚜小麦创制等研究进展进行了系统综述,并对今后研究进行展望,以期为深入研究小麦对蚜虫抗性机制,促进抗虫小麦改良,并为抗虫品种在麦蚜绿色防控中应用提供参考。

多元复配拌种剂对小麦病虫害防治效果及幼苗生长的影响

为了响应黄淮南片小麦播种期极端气候变化,促进小麦幼苗生长及病虫害有效防治,本试验以商麦188和商优1号为材料,根据不同种类化学药剂之间的作用机理和理化性质对不同药剂进行复配组合,比较不同处理对小麦病虫害防治效果及幼苗生长的影响。结果表明,在防治蚜虫方面:商优1号的F_(7)防治效果最佳,商麦188的F_(7)处理和壤动FT+F4对蚜虫防治效果明显,2个品种中,F_(7)和F_(9)处理的小麦苗期蚜虫数量均明显少于其他处理;在小麦红蜘蛛防治方面:2品种F_(7)、F8、F_(9)与其他处理之间的差异均具有统计学意义(P<0.05),说明阿维菌素的添加有利于防除红蜘蛛;在防治纹枯病方面:2个品种F_(1)、F_(2)、F_(3)处理与其他处理的数据相比差异具有统计学意义(P<0.05),说明苯醚甲环唑与咯菌腈复配处理对纹枯病防治效果较好,能够控制住小麦纹枯病在苗期的传播和蔓延,且F_(9)表现最佳,说明壤动FT在其中起到一定作用;在小麦根系生长方面:未加入吲哚乙酸+壳寡糖或者壤动FT的处理(F_(1)、F4、F_(7))尽管品种与药剂处理不同,但其根长均显著降低,且壤动FT处理对根长生长的积极影响高于吲哚乙酸+壳寡糖处理;在小麦株高差异方面:壤动FT处理的株高比对应吲哚乙酸+壳寡糖处理的稍高;在促进小麦叶龄方面:2个品种F_(9)叶龄数值高于其他处理,说明F_(9)可以有效加快幼苗发育,促进叶龄增长。可见,F_(9)拌种处理防治蚜虫、红蜘蛛和纹枯病效果最佳,并对幼苗株高、根长和叶龄有显著促进作用。