WorldWideScience

Sample records for corn borer resistance

  1. Sources of resistance to pink stem borer and european corn borer in maize

    OpenAIRE

    Malvar Pintos, Rosa Ana; Cartea González, María Elena; Revilla Temiño, Pedro; Ordás Pérez, Amando; Álvarez Rodríguez, Ángel; Mansilla, J.P.

    1993-01-01

    The European corn borer (Ostrinia nubilalis Hbn) is an important insect pest of maize (Zea mays L.) in Europe. However, the larvae of pink stem borer (Sesamia nonagrioides Lef.) produce important damage to the stems, especially in Southern Europe. The first step in an insect-resistance breeding program is to identify sources of resistance. The objective of this work was to study the resistance/tolerance of several populations of maize to attack by corn borers in general, and of Sesamia nonagr...

  2. Hydroxycinnamate Synthesis and Association with Mediterranean Corn Borer Resistance.

    Science.gov (United States)

    Santiago, Rogelio; Malvar, Rosa Ana; Barros-Rios, Jaime; Samayoa, Luis Fernando; Butrón, Ana

    2016-01-27

    Previous results suggest a relationship between maize hydroxycinnamate concentration in the pith tissues and resistance to stem tunneling by Mediterranean corn borer (MCB, Sesamia nonagrioides Lef.) larvae. This study performs a more precise experiment, mapping an F2 derived from the cross between two inbreds with contrasting levels for hydroxycinnamates EP125 × PB130. We aimed to co-localize genomic regions involved in hydroxycinnamate synthesis and resistance to MCB and to highlight the particular route for each hydroxycinnamate component in relation to the better known phenylpropanoid pathway. Seven quantitative trait loci (QTLs) for p-coumarate, two QTLs for ferulate, and seven QTLs for total diferulates explained 81.7, 26.9, and 57.8% of the genotypic variance, respectively. In relation to borer resistance, alleles for increased hydroxycinnamate content (affecting one or more hydroxycinnamate compounds) could be associated with favorable effects on stem resistance to MCB, particularly the putative role of p-coumarate in borer resistance.

  3. Resistance to Bacillus thuringiensis endotoxins in the European corn borer (Ostrinia nubilalis)

    Science.gov (United States)

    The European corn borer, Ostrinia nubilalis (Hübner), is the primary target of the widely adopted transgenic corn events MON810 and Bt11, expressing the Bacillus thuringiensis (Bt) insecticidal toxin, Cry1Ab. Resistant strains of O. nubilalis have been selected in the laboratory by exposure to Bt ...

  4. Understanding successful resistance management: The European corn borer and Bt corn in the United States

    Science.gov (United States)

    European corn borer, Ostrinia nubilalis Hubner (Lepidoptera: Crambidae) has been a major pest of corn and other crops in North America since its accidental introduction nearly a hundred years ago. Wide adoption of transgenic corn that expresses toxins from Bacillus thuringiensis, referred to as Bt c...

  5. Evaluation of Bt Corn with Pyramided Genes on Efficacy and Insect Resistance Management for the Asian Corn Borer in China

    Science.gov (United States)

    Bai, Shuxiong; Wang, Zhenying; He, Kanglai

    2016-01-01

    A Bt corn hybrid (AcIe) with two Bt genes (cry1Ie and cry1Ac) was derived by breeding stack from line expressing Cry1Ie and a line expressing Cry1Ac. Efficacy of this pyramided Bt corn hybrid against the Asian corn borer (ACB), Ostrinia furnacalis, was evaluated. We conducted laboratory bioassays using susceptible and resistant ACB strains fed on artificial diet or fresh plant tissues. We also conducted field trials with artificial infestations of ACB neonates at the V6 and silk stages. The toxin-diet bioassay data indicated that mixtures of Cry1Ac and Cry1Ie proteins had synergistic insecticidal efficacy. The plant tissue bioassay data indicated that Bt corn hybrids expressing either a single toxin (Cry1Ac or Cry1Ie) or two toxins had high efficacy against susceptible ACB. Damage ratings in the field trials indicated that the Bt corn hybrids could effectively protect against 1st and the 2nd generation ACB in China. The hybrid line with two Bt genes showed a higher efficacy against ACB larvae resistant to Cry1Ac or CryIe than the hybrid containing one Bt gene, and the two gene hybrid would have increased potential for managing or delaying the evolution of ACB resistance to Bt corn plants. PMID:28006032

  6. QTL mapping for Mediterranean corn borer resistance in European flint germplasm using recombinant inbred lines

    Directory of Open Access Journals (Sweden)

    Santiago Rogelio

    2010-03-01

    Full Text Available Abstract Background Ostrinia nubilalis (ECB and Sesamia nonagrioides (MCB are two maize stem borers which cause important losses in temperate maize production, but QTL analyses for corn borer resistance were mostly restricted to ECB resistance and maize materials genetically related (mapping populations derived from B73. Therefore, the objective of this work was to identify and characterize QTLs for MCB resistance and agronomic traits in a RILs population derived from European flint inbreds. Results Three QTLs were detected for stalk tunnel length at bins 1.02, 3.05 and 8.05 which explained 7.5% of the RILs genotypic variance. The QTL at bin 3.05 was co-located to a QTL related to plant height and grain humidity and the QTL at bin 8.05 was located near a QTL related to yield. Conclusions Our results, when compared with results from other authors, suggest the presence of genes involved in cell wall biosynthesis or fortification with effects on resistance to different corn borer species and digestibility for dairy cattle. Particularly, we proposed five candidate genes related to cell wall characteristics which could explain the QTL for stalk tunnelling in the region 3.05. However, the small proportion of genotypic variance explained by the QTLs suggest that there are also many other genes of small effect regulating MCB resistance and we conclude that MAS seems not promising for this trait. Two QTLs detected for stalk tunnelling overlap with QTLs for agronomic traits, indicating the presence of pleitropism or linkage between genes affecting resistance and agronomic traits.

  7. Covalent cross-linking of cell-wall polysaccharides through esterified diferulates as a maize resistance mechanism against corn borers.

    Science.gov (United States)

    Barros-Rios, Jaime; Santiago, Rogelio; Jung, Hans-Joachim G; Malvar, Rosa A

    2015-03-04

    There is strong evidence to suggest that cross-linking of cell-wall polymers through ester-linked diferulates has a key role in plant resistance to pests; however, direct experimentation to provide conclusive proof is lacking. This study presents an evaluation of the damage caused by two corn borer species on six maize populations particularly selected for divergent diferulate concentrations in pith stem tissues. Maize populations selected for high total diferulate concentration had 31% higher diferulates than those selected for low diferulates. Stem tunneling by corn borer species was 29% greater in the population with the lowest diferulates than in the population with the highest diferulates (31.7 versus 22.6 cm), whereas total diferulate concentration was negatively correlated with stem tunneling by corn borers. Moreover, orthogonal contrasts between groups of populations evaluated showed that larvae fed in laboratory bioassays on pith stem tissues from maize populations with higher diferulates had 30-40% lower weight than larvae fed on the same tissues from maize populations with lower diferulates. This is the first report that shows a direct relationship between diferulate deposition in maize cell walls and corn borer resistance. Current findings will help to develop adapted maize varieties with an acceptable level of resistance against borers and be useful in special kinds of agriculture, such as organic farming.

  8. Chemical Changes during Maize Tissue Aging and its Relationship with the Mediterranean Corn Borer Resistance.

    Science.gov (United States)

    Lopez-Malvar, Ana; Ordas, Bernardo; Souto, Carlos; Encina, Antonio; Malvar, Rosa Ana; Santiago, Rogelio

    2017-10-02

    Mediterranean Corn Borer (MCB), Sesamia nonagrioides Lef, is an important pest of maize in temperate areas causing significant stalk lodging and yield losses. The main focus of the current study were to determine possible changes in chemical traits (phenols, flavonoids, anthocyanins, sugars, fibers, and lignin) during plant development after the flowering stage, and to assess how those traits may differ in diverse genotypes of maize, MCB resistant and susceptible respectively. Higher values for some particular traits in more mature tissues seemed to increase their effectiveness against the MCB attack. A reduced amount of borer damage in the field was recorded in the resistant inbred line and in older tissues (7.90 cm vs. 31.70 cm as mean for stalk tunnel length). In accordance with these results, the resistant inbred line showed higher hemicellulose cross-linkage (due to ferulic and diferulic acids), soluble sugars content, and higher stalk strength. The use of resistant varieties and early sowings is highly recommended as an integrated approach in order to reduce the yield losses produced by this pest.

  9. Changes in phenolic concentrations during recurrent selection for resistance to the Mediterranean corn borer (Sesamia nonagrioides Lef.).

    Science.gov (United States)

    Santiago, Rogelio; Sandoya, German; Butrón, Ana; Barros, Jaime; Malvar, Rosa A

    2008-09-10

    Recurrent selection has been reported as successful for improving maize resistance against corn borers. This study was conducted to determine if phenolics concentration in maize changes during recurrent selection to improve stalk resistance to the Mediterranean corn borer. Three cycles of selection [EPS12(S)C0, ESP12(S)C2, and EPS12(S)C3] from the maize synthetic population EPS12 and test crosses to inbred lines A639, B93, and EP42 were field grown and artificially infested with Mediterranean corn borer larvae, and the pith tissues were sampled for biochemical analyses. Two major simple phenolic acids [p-coumaric (p-CA) and trans-ferulic (E-FA) acids] were identified in free and cell-wall fractions, whereas four isomers of diferulic acid (DFA) (8-5'l, 5-5', 8-o-4', and 8-5' benzofuran form) were present in the cell-wall bound fraction. The selection cycles EPS12(S)C0 and EPS12(S)C3 showed less damage and higher cell wall phenolics concentrations than the cycle EPS12(S)C2. In addition, higher concentrations of total DFAs were associated with shorter tunnel length and lower numbers of larvae per stem. The current study shows new and concrete evidence that the cell-wall bound phenolics could have a determinative role in the resistance to the Mediterranean corn borer, although future development of recurrent and divergent selection cycles will clarify this point.

  10. Research Prospects in Corn Resistance Mechanisms to Corn Borers%玉米对钻蛀性害虫的抗性机制研究进展

    Institute of Scientific and Technical Information of China (English)

    郭井菲; 何康来; 王振营

    2014-01-01

    Corn is a major food crop in the world. Corn borers are the most destructive insect pests, which can substantially reduce the yield and quality of corn. Chemical control and genetically modified insect resistant corn could effectively control corn borer damage to certain degree. However, as the environmental and food safety concerns caused by insecticide application and increasing public concern of genetically modified insect resistant corn in food and ecological safety, the research of corn resistance mechanisms to corn borers is of more important significance in reducing corn borer damage. Mechanisms of resistance to stem borers, including physiological and biochemical factors, such as secondary metabolites, cell wall structure component and physical structure, were summarized in this paper. Also, suggestions and prospects of further research were put forward on base of the summary.%玉米是重要的粮食作物,玉米钻蛀性害虫是玉米生产上为害最重的害虫,其为害严重影响玉米的产量和品质。农药的应用和 Bt 抗虫玉米的种植在一定程度上有效地控制了玉米钻蛀性害虫的为害,但随着化学防治带来的环境和食品安全问题以及人们对转 Bt 玉米的食用和环境安全的担心,利用玉米自身的抗虫性控制钻蛀性害虫为害显得尤为重要。玉米对钻蛀性害虫的抗虫机制主要涉及玉米次生代谢产物和细胞壁结构成分等生理生化特性以及茎秆外表皮穿刺强度等物理结构特性等。本文从生理生化特性和物理结构特性方面总结了玉米抗虫性机制,并针对玉米抗虫机制的研究现状提出建议和展望,以期为培育抗性品种以及钻蛀性害虫的综合治理提供参考。

  11. Resistance Identification of Maize Germplasms to Corn Borer%玉米种质资源抗螟性鉴定

    Institute of Scientific and Technical Information of China (English)

    李青青; 郭成; 郭满库; 魏宏玉; 郭建国

    2014-01-01

    为明确玉米不同品种(系)之间的抗螟性差异,采用田间自然感螟法,于2010~2011年在甘肃省天水市甘谷县对478份玉米种质资源进行田间抗性鉴定。结果表明:在216份农家种资源、216份自交系和46份杂交种中共筛选出高抗材料86份、抗螟材料85份、中抗材料167份,分别占供鉴材料的18.0%、17.8%和34.9%;其余140份为感螟和高感材料,占29.3%。%So as to confirm the borer-resistance differences among different corn varieties ( inbred lines ) , the study adopted the method of being naturally infected by Ostrinia furnacalis under field conditions , and identified the resistance of 478 maize germ-plasms to corn borer in Gan ’ gu county, Tianshui city, Gansu province from 2010 to 2012.The results showed that: among 478 maize germplasms (216 peasant variety resources , 216 inbred lines and 46 hybrids), 86 high-resistant materials (18.0% of all materials), 85 borer-resistant materials (17.8%), 167 middle-resistant materials (34.9%) were screened out;the other 140 materials were susceptible or highly susceptible to corn borer , accounting for 29.3%of all tested materials.

  12. Diferulate content of maize sheaths is associated with resistance to the Mediterranean corn borer Sesamia nonagrioides (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Santiago, Rogelio; Butrón, Ana; Reid, Lana M; Arnason, John T; Sandoya, German; Souto, Xose C; Malvar, Rosa A

    2006-11-29

    The leaf sheaths of selected inbred lines of maize (Zea mays L.) with variable levels of stem resistance to the Mediterranean corn borer Sesamia nonagrioides (Lefèvbre) were evaluated for antibiotic effect on insect development. Phytochemical analyses of leaf sheaths were conducted for cell wall phenylpropanoid content to gain a better understanding of maize-resistance mechanisms. Laboratory bioassays established that sheath tissues from different genotypes significantly affected the growth of neonate larvae. Three hydroxycinnamates, p-coumaric, trans-ferulic, and cis-ferulic acids, and three isomers of diferulic acid, 8-5', 8-O-4', and 8-5' b (benzofuran form), were identified. Significant negative correlations were found between larvae weight and diferulic acid content for six genotypes. These results are in agreement with previous studies concerning the role of cell wall structural components in stem borer resistance.

  13. Modeling evolution of resistance of sugarcane borer (Lepidoptera: Crambidae) to transgenic Bt corn.

    Science.gov (United States)

    Kang, J; Huang, F; Onstad, D W

    2014-08-01

    Diatraea saccharalis (F.) (Lepidoptera: Crambidae) is a target pest of transgenic corn expressing Bacillus thuringiensis (Bt) protein, and the first evidence of resistance by D. saccharalis to Cry1Ab corn was detected in a field population in northeast Louisiana in 2004. We used a model of population dynamics and genetics of D. saccharalis to 1) study the effect of interfield dispersal, the first date that larvae enter diapause for overwintering, toxin mortality, the proportion of non-Bt corn in the corn patch, and the area of a crop patch on Bt resistance evolution; and 2) to identify gaps in empirical knowledge for managing D. saccharalis resistance to Bt corn. Increasing, the proportion of corn refuge did not always improve the durability of Bt corn if the landscape also contained sugarcane, sorghum, or rice. In the landscape, which consisted of 90% corn area, 5% sorghum area, and 5% rice area, the durability of single-protein Bt corn was 40 yr when the proportion of corn refuge was 0.2 but 16 yr when the proportion of corn refuge was 0.5. The Bt resistance evolution was sensitive to a change (from Julian date 260 to 272) in the first date larvae enter diapause for overwintering and moth movement. In the landscapes with Bt corn, non-Bt corn, sugarcane, sorghum, and rice, the evolution of Bt resistance accelerated when larvae entered diapause for overwintering early. Intermediate rates of moth movement delayed evolution of resistance more than either extremely low or high rates. This study suggested that heterogeneity in the agrolandscapes may complicate the strategy for managing Bt resistance in D. saccharalis, and designing a Bt resistance management strategy for D. saccharalis is challenging because of a lack of empirical data about overwintering and moth movement.

  14. Modeling evolution of resistance of sugarcane borer (Lepidoptera: Crambidae) to transgenic Bt corn

    NARCIS (Netherlands)

    Kang, J.; Huang, F.; Onstad, D. W.

    2014-01-01

    Diatraea saccharalis (F.) (Lepidoptera: Crambidae) is a target pest of transgenic corn expressing Bacillus thuringiensis (Bt) protein, and the first evidence of resistance by D. saccharalis to Cry1Ab corn was detected in a field population in northeast Louisiana in 2004. We used a model of populatio

  15. Mapping of QTL for resistance to the Mediterranean corn borer attack using the intermated B73 x Mo17 (IBM) population of maize.

    Science.gov (United States)

    Ordas, Bernardo; Malvar, Rosa A; Santiago, Rogelio; Sandoya, German; Romay, Maria C; Butron, Ana

    2009-11-01

    The Mediterranean corn borer or pink stem borer (MCB, Sesamia nonagrioides Lefebvre) causes important yield losses as a consequence of stalk tunneling and direct kernel damage. B73 and Mo17 are the source of the most commercial valuable maize inbred lines in temperate zones, while the intermated B73 x Mo17 (IBM) population is an invaluable source for QTL identification. However, no or few experiments have been carried out to detect QTL for corn borer resistance in the B73 x Mo17 population. The objective of this work was to locate QTL for resistance to stem tunneling and kernel damage by MCB in the IBM population. We detected a QTL for kernel damage at bin 8.05, although the effect was small and two QTL for stalk tunneling at bins 1.06 and 9.04 in which the additive effects were 4 cm, approximately. The two QTL detected for MCB resistance were close to other QTL consistently found for European corn borer (ECB, Ostrinia nubilalis Hübner) resistance, indicating mechanisms of resistance common to both pests or gene clusters controlling resistance to different plagues. The precise mapping achieved with the IBM population will facilitate the QTL pyramiding and the positional cloning of the detected QTL.

  16. Effect of maize lines on larval fitness costs of Cry1F resistance in the European corn borer (Lepidoptera: Crambidae).

    Science.gov (United States)

    Petzold-Maxwell, Jennifer L; Siegfried, Blair D; Hellmich, Richard L; Abel, Craig A; Coates, Brad S; Spencer, Terrence A; Gassmann, Aaron J

    2014-04-01

    Crops producing insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) are widely planted and enable management of key insect pests while reducing the use of conventional insecticides. However, the evolution of Bt resistance could diminish these benefits. Fitness costs of Bt resistance occur in the absence of Bt toxin when individuals with resistance alleles show a reduction in fitness relative to susceptible individuals, and they can delay the evolution of resistance. Ecological factors including host-plant variety can affect the magnitude of fitness costs, and consequently, the degree to which fitness costs delay resistance. In this study, we measured fitness costs of resistance to Bt toxin Cry1F in the European corn borer Ostrinia nubilalis Hübner (Lepidoptera: Crambidae) using Cry1F-resistant and Cry1F-susceptible strains sharing a similar genetic background. Fitness costs were tested on three lines of maize, Zea mays L., by measuring larval survival and development in two greenhouse experiments with plants in either the vegetative or reproductive stage. Both experiments showed that maize line significantly affected larval survival and developmental rate. However, larval survival, mass, and developmental rate did not differ between the Cry1F-resistant and susceptible strains, indicating a lack of fitness costs of resistance to Cry1F for the larval fitness components measured in this experiment. Future experiments should test for fitness costs of Cry1F resistance affecting survival to adulthood and adult life-history parameters.

  17. Fitness costs associated with Cry1F resistance in the European corn borer

    Science.gov (United States)

    Crops producing insecticidal toxins derived from the soil bacterium Bacillus thuringiensis (Bt) are widely planted in order to manage key insect pests. Bt crops can provide an effective tool for pest management; however, the evolution of Bt resistance can diminish this benefit. The European corn b...

  18. Landscape refuges delay resistance of the European corn borer to Bt-maize: a demo-genetic dynamic model.

    Science.gov (United States)

    Tyutyunov, Yuri; Zhadanovskaya, Ekaterina; Bourguet, Denis; Arditi, Roger

    2008-08-01

    We constructed a reaction-diffusion model of the development of resistance to transgenic insecticidal Bt crops in pest populations. Kostitzin's demo-genetic model describes local interactions between three competing pest genotypes with alleles conferring resistance or susceptibility to transgenic plants, the spatial spread of insects being modelled by diffusion. This new approach makes it possible to combine a spatial demographic model of population dynamics with classical genetic theory. We used this model to examine the effects of pest dispersal and of the size and shape of the refuge on the efficiency of the "high-dose/refuge" strategy, which was designed to prevent the development of resistance in populations of insect pests, such as the European corn borer, Ostrinia nubilalis Hübner (Lepidoptera, Crambidae). We found that, with realistic combinations of refuge size and pest dispersal, the development of resistance could be considerably delayed. With a small to medium-sized farming area, contiguous refuge plots are more efficient than a larger number of smaller refuge patches. We also show that the formal coupling of classical Fisher-Haldane-Wright population genetics equations with diffusion terms inaccurately describes the development of resistance in a spatially heterogeneous pest population, notably overestimating the speed with which Bt resistance is selected in populations of pests targeted by Bt crops.

  19. High basal defense gene expression determines sorghum resistance to the whorl-feeding insect southwestern corn borer.

    Science.gov (United States)

    Cheng, Wei-Ning; Lei, Jia-Xin; Rooney, William L; Liu, Tong-Xian; Zhu-Salzman, Keyan

    2013-06-01

    Southwestern corn borer (SWCB, Diatraea grandiosella) and fall armyworm (FAW, Spodoptera frugiperda) are major pests of sorghum in the southern United States. Host plant resistance is a desirable means for reducing plant damage and yield losses from both insects. In this study, we evaluated 12 sorghum lines for whorl-stage resistance to leaf-feeding SWCB and FAW in greenhouse and laboratory bioassays. Differential plant responses were detected against the two insects. Among 12 lines tested, CM1821, Della and PI196583 were resistant to both insects, while BTx2752 was largely susceptible. Line R.09110 was resistant to SWCB, but susceptible to FAW, whereas Redbine-60 was susceptible to SWCB, but not to FAW. In addition, we quantified various chemical components in the plants and determined their association with insect resistance. Tannin and chlorophyll in leaves did not show any significant correlation with resistance to either insects, but contents of soluble protein in general were negatively correlated with resistance to both insects. Endogenous soluble sugar and dhurrin were only positively correlated with resistance to SWCB, but not with FAW resistance. To gain some molecular insight into resistance mechanism of sorghum to SWCB, we performed qPCR reactions for key genes encoding enzymes involved in dhurrin and jasmonic acid (JA) biosynthesis on selected resistant or susceptible lines. Although these genes were rapidly and strongly induced by insect feeding in all lines, the observed resistance is likely explained by higher constitutive dhurrin contents in some resistant lines and higher basal JA biosynthesis in others. Our results suggest that sorghum utilizes multiple strategies to defend itself against SWCB.

  20. High basal defense gene expression determines sorghum resistance to the whorl-feeding insect southwestern corn borer

    Institute of Scientific and Technical Information of China (English)

    Wei-Ning Cheng; Jia-Xin Lei; William L.Rooney; Tong-Xian Liu; Keyan Zhu-Salzman

    2013-01-01

    Southwestern corn borer (SWCB,Diatraea grandiosella) and fall armyworm (FAW,Spodoptera frugiperda) are major pests of sorghum in the southern United States.Host plant resistance is a desirable means for reducing plant damage and yield losses from both insects.In this study,we evaluated 12 sorghum lines for whorl-stage resistance to leaf-feeding SWCB and FAW in greenhouse and laboratory bioassays.Differential plant responses were detected against the two insects.Among 12 lines tested,CM1821,Della and PI196583 were resistant to both insects,while BTx2752 was largely susceptible.Line R.09110 was resistant to SWCB,but susceptible to FAW,whereas Redbine-60 was susceptible to SWCB,but not to FAW.In addition,we quantified various chemical components in the plants and determined their association with insect resistance.Tannin and chlorophyll in leaves did not show any significant correlation with resistance to either insects,but contents of soluble protein in general were negatively correlated with resistance to both insects.Endogenous soluble sugar and dhurrin were only positively correlated with resistance to SWCB,but not with FAW resistance.To gain some molecular insight into resistance mechanism of sorghum to SWCB,we performed qPCR reactions for key genes encoding enzymes involved in dhurrin and jasmonic acid (JA) biosynthesis on selected resistant or susceptible lines.Although these genes were rapidly and strongly induced by insect feeding in all lines,the observed resistance is likely explained by higher constitutive dhurrin contents in some resistant lines and higher basal JA biosynthesis in others.Our results suggest that sorghum utilizes multiple strategies to defend itself against SWCB.

  1. Expression of a Modified Crylle Gene in E.Coli and in Transgenic Tobacco Confers Resistance to Corn Borer

    Institute of Scientific and Technical Information of China (English)

    Yun-Jun LIU; Fu-Ping SONG; Kang-Lai HE; Yuan YUAN; Xiao-Xia ZHANG; Peng GAO; Jian-Hua WANG; Guo-Ying WANG

    2004-01-01

    The wild-type Crylle gene from Bacillus thuringiensis was modified for its efficient expression in transgenic plants. Modified Cry1 Ie gene (designated as Cry1 Iem) was cloned into prokaryotic expression vector pET28b and its expression in E. coli was confirmed by SDS-PAGE analysis. Bioassays using crude expression products in E. coli revealed that Cry1 Iem protein had a similar toxicity to corn borer as wild-type Cry1 Ie. Cry1 Iem gene was then inserted downstream of the maize ubiquitin-1 promoter in plant expression vector p3301. Transgenic tobacco plants carrying Cry1 Iem showed insecticidal activity against com borer.

  2. Bacillus thuringiensis toxin resistance mechanisms among Lepidoptera: progress on genomic approaches to uncover causal mutations in the European corn borer, Ostrinia nubilalis.

    Science.gov (United States)

    Coates, Brad S

    2016-06-01

    Transgenic plants that express Bacillus thuringiensis (Bt) crystal (Cry) protein toxins (Bt crops) effectively control feeding by the European corn borer, Ostrinia nubilalis, although documented resistance evolution among a number of species in both the laboratory and field has heightened concerns about the durability of this technology. Research has provided major insights into the mutations that alter Bt toxin binding receptor structure and function within the midgut of Lepidoptera that directly impacts the efficacy of Bt toxins, and potentially leads to the evolution of resistance to Bt crops in the field. In this manuscript we provide an overview of available data on the identification of genes involved in high levels of resistance to Cry toxins, with emphasis on resistance described for O. nubilalis as the main target of Bt corn.

  3. Resistance evolution to Bt crops: predispersal mating of European corn borers.

    Directory of Open Access Journals (Sweden)

    Ambroise Dalecky

    2006-06-01

    Full Text Available Over the past decade, the high-dose refuge (HDR strategy, aimed at delaying the evolution of pest resistance to Bacillus thuringiensis (Bt toxins produced by transgenic crops, became mandatory in the United States and is being discussed for Europe. However, precopulatory dispersal and the mating rate between resident and immigrant individuals, two features influencing the efficiency of this strategy, have seldom been quantified in pests targeted by these toxins. We combined mark-recapture and biogeochemical marking over three breeding seasons to quantify these features directly in natural populations of Ostrinia nubilalis, a major lepidopteran corn pest. At the local scale, resident females mated regardless of males having dispersed beforehand or not, as assumed in the HDR strategy. Accordingly, 0-67% of resident females mating before dispersal did so with resident males, this percentage depending on the local proportion of resident males (0% to 67.2%. However, resident males rarely mated with immigrant females (which mostly arrived mated, the fraction of females mating before dispersal was variable and sometimes substantial (4.8% to 56.8%, and there was no evidence for male premating dispersal being higher. Hence, O. nubilalis probably mates at a more restricted spatial scale than previously assumed, a feature that may decrease the efficiency of the HDR strategy under certain circumstances, depending for example on crop rotation practices.

  4. Detection of European corn borer infestation in rainfed and irrigated corn using airborne hyperspectral imaging: implications for resistance management

    Science.gov (United States)

    Recently, corn grown for grain in the United States has increased from 28 million ha in 2006 to more than 35 million ha in 2007 with a production value of over $52 billion dollars. Transgenic corn expressing the plant incorporated protectant Bacillus thuringiensis toxin represen...

  5. Genetic Basis of Cry1F-Resistance in a Laboratory Selected Asian Corn Borer Strain and Its Cross-Resistance to Other Bacillus thuringiensis Toxins.

    Science.gov (United States)

    Wang, Yueqin; Wang, Yidong; Wang, Zhenying; Bravo, Alejandra; Soberón, Mario; He, Kanglai

    2016-01-01

    The Asian corn borer (ACB), Ostrinia furnacalis (Guenée) (Lepidoptera: Crambidae), is the most destructive insect pest of corn in China. Susceptibility to the Cry1F toxin derived from Bacillus thuringiensis has been demonstrated for ACB, suggesting the potential for Cry1F inclusion as part of an insect pest management program. Insects can develop resistance to Cry toxins, which threatens the development and use of Bt formulations and Bt crops in the field. To determine possible resistance mechanisms to Cry1F, a Cry1F-resistant colony of ACB (ACB-FR) that exhibited more than 1700-fold resistance was established through selection experiments after 49 generations of selection under laboratory conditions. The ACB-FR strain showed moderate cross-resistance to Cry1Ab and Cry1Ac of 22.8- and 26.9-fold, respectively, marginally cross-resistance to Cry1Ah (3.7-fold), and no cross-resistance to Cry1Ie (0.6-fold). The bioassay responses of progeny from reciprocal F1 crosses to different Cry1 toxin concentrations indicated that the resistance trait to Cry1Ab, Cry1Ac and Cry1F has autosomal inheritance with no maternal effect or sex linked. The effective dominance (h) of F1 offspring was calculated at different concentrations of Cry1F, showing that h decreased as concentration of Cry1F increased. Finally, the analysis of actual and expected mortality of the progeny from a backcross (F1 × resistant strain) indicated that the inheritance of the resistance to Cry1F in ACB-FR was due to more than one locus. The present study provides an understanding of the genetic basis of Cry1F resistance in ACB-FR and also shows that pyramiding Cry1F with Cry1Ah or Cry1Ie could be used as a strategy to delay the development of ACB resistance to Bt proteins.

  6. Genetic Basis of Cry1F-Resistance in a Laboratory Selected Asian Corn Borer Strain and Its Cross-Resistance to Other Bacillus thuringiensis Toxins

    Science.gov (United States)

    Wang, Yueqin; Wang, Yidong; Wang, Zhenying; Bravo, Alejandra; Soberón, Mario; He, Kanglai

    2016-01-01

    The Asian corn borer (ACB), Ostrinia furnacalis (Guenée) (Lepidoptera: Crambidae), is the most destructive insect pest of corn in China. Susceptibility to the Cry1F toxin derived from Bacillus thuringiensis has been demonstrated for ACB, suggesting the potential for Cry1F inclusion as part of an insect pest management program. Insects can develop resistance to Cry toxins, which threatens the development and use of Bt formulations and Bt crops in the field. To determine possible resistance mechanisms to Cry1F, a Cry1F-resistant colony of ACB (ACB-FR) that exhibited more than 1700-fold resistance was established through selection experiments after 49 generations of selection under laboratory conditions. The ACB-FR strain showed moderate cross-resistance to Cry1Ab and Cry1Ac of 22.8- and 26.9-fold, respectively, marginally cross-resistance to Cry1Ah (3.7-fold), and no cross-resistance to Cry1Ie (0.6-fold). The bioassay responses of progeny from reciprocal F1 crosses to different Cry1 toxin concentrations indicated that the resistance trait to Cry1Ab, Cry1Ac and Cry1F has autosomal inheritance with no maternal effect or sex linked. The effective dominance (h) of F1 offspring was calculated at different concentrations of Cry1F, showing that h decreased as concentration of Cry1F increased. Finally, the analysis of actual and expected mortality of the progeny from a backcross (F1 × resistant strain) indicated that the inheritance of the resistance to Cry1F in ACB-FR was due to more than one locus. The present study provides an understanding of the genetic basis of Cry1F resistance in ACB-FR and also shows that pyramiding Cry1F with Cry1Ah or Cry1Ie could be used as a strategy to delay the development of ACB resistance to Bt proteins. PMID:27518813

  7. BT799玉米对亚洲玉米螟抗性研究%Resistance of transgenic Bt corn variety BT799 to the Asian corn borer

    Institute of Scientific and Technical Information of China (English)

    王月琴; 何康来; 江帆; 王依冬; 张天涛; 王振营; 白树雄

    2014-01-01

    Objectives] To review the resistance of transgenic Bt corn to target pests which is one of the primarily steps for research and development of insect-resistant, transgenic corn. This review mainly evaluates the resistance of transgenic Cry1Ac gene corn variety BT799 to the Asian corn borer (ACB), Ostrinia furnacalis (Guenée), and measured the quantity of Cry1Ac protein expressed in corn plant tissues. [Methods] Enzyme-linked immunosorbent assays, laboratory bioassay and field studies with artificial infestation were employed in this study. [Results] The expression levels of Cry1Ac protein were 768.0 ng/g (protein/fresh leaves), 1452.8-2978.5 ng/g (protein/dry mass of silk, husk and young kernels). Leaf-feeding rates in field trials indicated that BT799 and CC-2XBT799 were highly resistant to ACB. The survival of ACB larvae feeding on Zhengdan 958K, a single cross hybrid containing BT799, was significantly lower (0-37.5%) than that of larvae that fed on non-Bt Zhengdan 958 (89.9%-100.0%). In addition, larval survival of Cry1Ac-, Cry1Ie-, and Cry1F-selected ACB strains (ACB-AcR, ACB-IeR and ACB-FR) were significantly different when fed on Zhengdan 958K. ACB-IeR had the lowest survival followed by ACB-FR, both of them had significantly lower survival than those that fed on the control Zhengdan 958. However, the survival of ACB-AcR was not significantly different from larvae feeding on the control Zhengdan 958. [Conclusion] These results suggests that the transgenic Bt corn variety BT799 is highly toxic to the ACB and can provide effective control for ACB in the field.%【目的】抗螟性鉴定是转基因抗虫玉米研发的重要一环。本文主要就转基因玉米BT799对亚洲玉米螟的抗性展开评价,同时测定了BT799植株组织中Cry1Ac蛋白的表达量。【方法】采用了酶联免疫吸附测定法(ELISA)、室内生测和田间人工接虫鉴定3种方法。【结果】转基因抗虫玉米BT799组织中Cry1Ac蛋白含量分别为768

  8. Transgenic corn for control of the European corn borer and corn rootworms: a survey of Midwestern farmers' practices and perceptions.

    Science.gov (United States)

    Wilson, Ted A; Rice, Marlin E; Tollefson, Jon J; Pilcher, Clinton D

    2005-04-01

    In 2001, a self-administered questionnaire was sent to 1000 corn, Zea mays L., farmers in each of five states (Illinois, Indiana, Iowa, Minnesota, and Nebraska) to evaluate their perceptions of transgenic corn designed to control the European corn borer, Ostrinia nubilalis (Hübner), and corn rootworms, Diabrotica spp. Respondents returned 1,313 surveys (26.2%). Farmers with small acreages planted a greater portion of their corn (54.5%) with transgenic corn for control of European corn borer than farmers with large farms (39.2%). The majority (75.2%) of farmers use crop rotation to control the corn rootworm. Nine insecticides comprised 92.2% of the commercial soil insecticides used for control of corn rootworm larvae. More than one-third of the farmers in Illinois (33.5%) and Indiana (39.4%) treated first-year corn for corn rootworm, primarily due to western corn rootworm egg laying in soybean, Glycine max (L.). When asked whether they would plant transgenic corn protected against the corn rootworm, 35.0% of farmers responded they would, whereas 40.5% said they were unsure. The two greatest farmer concerns about transgenic corn were the ability to sell harvested grain (59.3%) and additional technology fees (54.8%). Respondents indicated that less farmer exposure to insecticide (69.9%) and less insecticide in the environment (68.5%) were the primary benefits of transgenic corn. Farmers who had no concerns about transgenic corn for rootworm control were more likely to purchase the product (46.8%). The most common refuge-planting options farmers favored were adjacent fields (30.9%) and split fields (29.9%). Farmers (21.1%) observed a yield increase (23.7 bu/ha [9.6 bu/acre]) when using transgenic corn for European corn borer control compared with non-transgenic corn. These data can help in understanding farmers' knowledge and concerns regarding transgenic corn. This information may be of value to guide researchers, extension specialists, and policy makers in designing

  9. Cell wall composition as a maize defense mechanism against corn borers.

    Science.gov (United States)

    Barros-Rios, Jaime; Malvar, Rosa A; Jung, Hans-Joachim G; Santiago, Rogelio

    2011-04-01

    European and Mediterranean corn borers are two of the most economically important insect pests of maize (Zea mays L.) in North America and southern Europe, respectively. Cell wall structure and composition were evaluated in pith and rind tissues of resistant and susceptible inbred lines as possible corn borer resistance traits. Composition of cell wall polysaccharides, lignin concentration and composition, and cell wall bound forms of hydroxycinnamic acids were measured. As expected, most of the cell wall components were found at higher concentrations in the rind than in the pith tissues, with the exception of galactose and total diferulate esters. Pith of resistant inbred lines had significantly higher concentrations of total cell wall material than susceptible inbred lines, indicating that the thickness of cell walls could be the initial barrier against corn borer larvae attack. Higher concentrations of cell wall xylose and 8-O-4-coupled diferulate were found in resistant inbreds. Stem tunneling by corn borers was negatively correlated with concentrations of total diferulates, 8-5-diferulate and p-coumarate esters. Higher total cell wall, xylose, and 8-coupled diferulates concentrations appear to be possible mechanisms of corn borer resistance. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Yield performance of the European Union Maize Landrace Core Collection under multiple corn borer infestations

    OpenAIRE

    Malvar Pintos, Rosa Ana; Butrón Gómez, Ana María; Álvarez Rodríguez, Ángel; Padilla Alonso, Guillermo; Cartea González, María Elena; Revilla Temiño, Pedro; Ordás Pérez, Amando

    2007-01-01

    In Europe, corn borer attack is the main biotic stressor for the maize (Zea mays L.) crop. European corn borer (Ostrinia nubilalis Hbn.) is the most important maize pest in central and north Europe, while pink stem borer (Sesamia nonagrioides Lef.) is predominant in warmer areas of southern Europe. The objective of this study was the evaluation of the European Maize Union Landrace Core Collection (EUMLCC) for yield under infestation with European corn borer (O. nubilalis) and pink stem borer ...

  11. Downregulation and Mutation of a Cadherin Gene Associated with Cry1Ac Resistance in the Asian Corn Borer, Ostrinia furnacalis (Guenée

    Directory of Open Access Journals (Sweden)

    Tingting Jin

    2014-09-01

    Full Text Available Development of resistance in target pests is a major threat to long-term use of transgenic crops expressing Bacillus thuringiensis (Bt Cry toxins. To manage and/or delay the evolution of resistance in target insects through the implementation of effective strategies, it is essential to understand the basis of resistance. One of the most important mechanisms of insect resistance to Bt crops is the alteration of the interactions between Cry toxins and their receptors in the midgut. A Cry1Ac-selected strain of Asian corn borer (ACB, Ostrinia furnacalis, a key pest of maize in China, evolved three mutant alleles of a cadherin-like protein (OfCAD (MPR-r1, MPR-r2 and MPR-r3, which mapped within the toxin-binding region (TBR. Each of the three mutant alleles possessed two or three amino acid substitutions in this region, especially Thr1457→Ser. In highly resistant larvae (ACB-Ac200, MPR-r2 had a 26-amino acid residue deletion in the TBR, which resulted in reduced binding of Cry1Ac compared to the MPR from the susceptible strain, suggesting that the number of amino acid deletions influences the level of resistance. Furthermore, downregulation of OfCAD gene (ofcad transcription was observed in the Cry1Ac resistant strain, ACB-Ac24, suggesting that Cry1Ac resistance in ACB is associated with the downregulation of the transcript levels of the cadherin-like protein gene. The OfCAD identified from ACB exhibited a high degree of similarity to other members of the cadherin super-family in lepidopteran species.

  12. Tolerance of Bt corn (MON 810) to maize stem borer, Chilo partellus (Lepidoptera: Pyralidae).

    Science.gov (United States)

    Singh, Ramkumar; Channappa, Ravi K; Deeba, Farah; Nagaraj, Nandi J; Sukavaneaswaran, Mohan K; Manjunath, T M

    2005-11-01

    Transgenic corn (MON 810), expressing the Bacillus thuringiensis (Bt) protein, Cry1Ab, was evaluated under greenhouse conditions for its tolerance to the maize stem borer, Chilo partellus. Bt corn (MON 810) provided effective protection against the stem borer even under a high level of larval infestation in the greenhouse. The observed tolerance is examined and discussed in the light of the susceptibility of C. partellus to the Cry1Ab protein in laboratory bioassays. The implications of the tissue concentrations of Cry1Ab in MON 810, and baseline susceptibility recorded in the current study, for insect-resistance management are discussed.

  13. QTL mapping for European corn borer resistance ( Ostrinia nubilalis Hb.), agronomic and forage quality traits of testcross progenies in early-maturing European maize ( Zea mays L.) germplasm.

    Science.gov (United States)

    Papst, C; Bohn, M; Utz, H F; Melchinger, A E; Klein, D; Eder, J

    2004-05-01

    In hybrid breeding the performance of lines in hybrid combinations is more important than their performance per se. Little information is available on the correlation between individual line and testcross (TC) performances for the resistance to European corn borer (ECB, Ostrinia nubilalis Hb.) in maize ( Zea mays L.). Marker assisted selection (MAS) will be successful only if quantitative trait loci (QTL) found in F(2) derived lines for ECB resistance are still expressed in hybrid combinations. The objectives of our study were: (1) to identify and characterize QTL for ECB resistance as well as agronomic and forage quality traits in a population of testcrossed F(2:3) families; (2) to evaluate the consistency of QTL for per se and TC performances; and (3) to determine the association between per se and TC performances of F(2:3) lines for these traits. Two hundred and four F(2:3) lines were derived from the cross between maize lines D06 (resistant) and D408 (susceptible). These lines were crossed to D171 and the TC progenies were evaluated for ECB resistance and agronomic performance in two locations in 2000 and 2001. Using these TC progenies, six QTL for stalk damage rating (SDR) were found. These QTL explained 27.4% of the genotypic variance in a simultaneous fit. Three QTL for SDR were detected consistently for per se and TC performance. Phenotypic and genotypic correlations were low for per se and TC performance for SDR. Correlations between SDR and quality traits were not significant. Based on these results, we conclude that MAS will not be an efficient method for improving SDR. However, new molecular tools might provide the opportunity to use QTL data as a first step to identify genes involved in ECB resistance. Efficient MAS procedures might then be based on markers designed to trace and to combine specific genes and their alleles in elite maize breeding germplasm.

  14. Proteins induced in corn (Zea mays) in response to the European corn borer (Ostrinia nubilalis)

    Science.gov (United States)

    The European corn borer (ECB, Ostrinia nubilalis) is a major pest of corn. ECB begin by feeding in the whorl tissue and then eventually tunnel into the stalk of the corn where they cause most of the damage. Tunneling can disrupt the transport of water and nutrients in the plant and it provides sites...

  15. Expressed sequence tags from larval gut of the European corn borer (Ostrinia nubilalis: Exploring candidate genes potentially involved in Bacillus thuringiensis toxicity and resistance

    Directory of Open Access Journals (Sweden)

    Crespo Andre LB

    2009-06-01

    Full Text Available Abstract Background Lepidoptera represents more than 160,000 insect species which include some of the most devastating pests of crops, forests, and stored products. However, the genomic information on lepidopteran insects is very limited. Only a few studies have focused on developing expressed sequence tag (EST libraries from the guts of lepidopteran larvae. Knowledge of the genes that are expressed in the insect gut are crucial for understanding basic physiology of food digestion, their interactions with Bacillus thuringiensis (Bt toxins, and for discovering new targets for novel toxins for use in pest management. This study analyzed the ESTs generated from the larval gut of the European corn borer (ECB, Ostrinia nubilalis, one of the most destructive pests of corn in North America and the western world. Our goals were to establish an ECB larval gut-specific EST database as a genomic resource for future research and to explore candidate genes potentially involved in insect-Bt interactions and Bt resistance in ECB. Results We constructed two cDNA libraries from the guts of the fifth-instar larvae of ECB and sequenced a total of 15,000 ESTs from these libraries. A total of 12,519 ESTs (83.4% appeared to be high quality with an average length of 656 bp. These ESTs represented 2,895 unique sequences, including 1,738 singletons and 1,157 contigs. Among the unique sequences, 62.7% encoded putative proteins that shared significant sequence similarities (E-value ≤ 10-3with the sequences available in GenBank. Our EST analysis revealed 52 candidate genes that potentially have roles in Bt toxicity and resistance. These genes encode 18 trypsin-like proteases, 18 chymotrypsin-like proteases, 13 aminopeptidases, 2 alkaline phosphatases and 1 cadherin-like protein. Comparisons of expression profiles of 41 selected candidate genes between Cry1Ab-susceptible and resistant strains of ECB by RT-PCR showed apparently decreased expressions in 2 trypsin-like and 2

  16. 黑龙江不同积温带玉米品种抗螟性分析%Maize Resistance to Corn Borer in Different Temperature Zones of Heilongjiang Province

    Institute of Scientific and Technical Information of China (English)

    张海燕; 王丽艳; 程晓娟; 赵长江; 林志伟; 孙强; 吴金花; 金永玲

    2013-01-01

      通过对百株折茎率、折雄率、茎秆钻蛀率及越冬幼虫数量和体重等指标分析,分析7个黑龙江省不同积温带玉米品种的抗虫性。研究结果表明,供试的7个不同积温带品种表现高抗的品种为垦单5和高油4515,中抗品种郑单958和兴垦3;高感品种为哲单37和绥玉19,中感品种德美亚1号。%Based on the analysis of the stalk broken rate, the tassel broken rate, the bored stems rate, the number of over-wintering larvaes and the weight, maize resistance to corn borer was studied in 7 temperature zones of Hei-longjiang province. The results showed that there were 7 maize varieties having resistance to corn borer, including 2 high resistant varieties, Kendan5 and Gaoyou4515;2 middle-resistant varieties, Zhengdan958 and Xingken3;2 high sensitive varieties, Zhedan37 and Suiyu19;one middle-sensitive, Demeiya1.

  17. Is the basal area of maize internodes involved in borer resistance?

    OpenAIRE

    Malvar Rosa; Revilla Pedro; Butrón Ana; Santiago Rogelio

    2011-01-01

    Abstract Background To elucidate the role of the length of the internode basal ring (LIBR) in resistance to the Mediterranean corn borer (MCB), we carried out a divergent selection program to modify the LIBR using two maize synthetic varieties (EPS20 and EPS21), each with a different genetic background. We investigated the biochemical mechanisms underlying the relationship between the LIBR and borer resistance. Selection to lengthen or shorten the LIBR was achieved for each synthetic variety....

  18. Datasets for transcriptomic analyses of maize leaves in response to Asian corn borer feeding and/or jasmonic acid

    Directory of Open Access Journals (Sweden)

    Yuliang Zhang

    2016-06-01

    Full Text Available Corn is one of the most widely grown crops throughout the world. However, many corn fields develop pest problems such as corn borers every year that seriously affect its yield and quality. Corn′s response to initial insect damage involves a variety of changes to the levels of defensive enzymes, toxins, and communicative volatiles. Such a dramatic change secondary metabolism necessitates the regulation of gene expression at the transcript level. In this paper, we summarized the datasets of the transcriptome of corn plants in response to corn stalk borers (Ostrinia furnacalis and/or methyl jasmonate (MeJA. Altogether, 39, 636 genes were found to be differentially expressed. The sequencing data are available in the NCBI SRA database under accession number SRS965087. Our dataset will provide more scientific and valuable information for future work such as the study of the functions of important genes or proteins and develop new insect-resistant maize varieties.

  19. Field Evaluation of the Asian Corn Borer Control in Hybrid of Transgenic Maize Event MON 810

    Institute of Scientific and Technical Information of China (English)

    HE Kang-lai; WANG Zhen-ying; WEN Li-ping; BAI Shu-xiong; ZHOU Da-rong; ZHU Qing-hua

    2003-01-01

    In this study,a transgenic Bt maize hybrid(event MON 810 from Monsanto Company)expressing Cry1Ab protein derived from Bacillus thuringiensis(Bt)and its negative isoline hybrid were evaluatrial. Maize plants were artificially infested with neonate larvae of Asian corn borer at the mid-whorl(firstgeneration),pre-tassel(first-and/or second-generation),and silk(second-generation)growth stages.The transgenic Bt maize hybrid sustained significantly less leaf feeding damage(rating 1.0±0.0)than its negative isoline control(rating 7.3±0.1).With the Bt maize,1.3-6.8%of plants were damaged by corn borer tunneling with<0.5 cm tunneling per stalk under different levels of infestation,compared with 100%of plants damaged with 9.3-25.0 cm tunneling per stalk for the negative isoline control. On average,transgenic Bt maize hybrids had only 0.01-0.05 tunnels per stalk and no stems were broken.In contrast,the negative isoline control had 3.11-8.36 tunnels per stalk and 31.2-73.9% of stems broken.Yields were significantly higher in trahsgenic Bt maize than in the control. These results demonstrate that transgenic Bt maize can significantly minimize yield losses caused by the Asian corn borer through resistance to the first-and second-generation larvae.

  20. Searching for new sources of pink stem borer resistance in maize

    OpenAIRE

    Butrón Gómez, Ana María; Sandoya Miranda, Germán; Santiago Carabelos, Rogelio; Ordás Pérez, Amando; A. Rial; Malvar Pintos, Rosa Ana

    2006-01-01

    The pink stem borer (Sesamia nonagrioides Lef.) is the main corn (Zea mays L.) pest in the Mediterranean area. Although, screening for resistance to this pest has been successful, the level of resistance shown by the most resistant varieties is not high. The objectives of the present work were: (i) the evaluation for pink stem borer resistance of the nontested inbred lines, field and popcorn materials, from the collection maintained at the Misión Biológica de Galicia and (ii) the study of the...

  1. Induced defenses in maize following attack by the European corn borer (Ostrinia nubilalis)

    Science.gov (United States)

    Over the course of the past two decades, insect pests such as the European corn borer (Ostrinia nubilalis) annually resulted in losses to US maize production exceeding one billion dollars. Despite the global significance of O. nubilalis and other stem borers, relatively little is known about the nat...

  2. 玉米种质资源对六种重要病虫害的抗性鉴定与评价%Screening and Evaluation of Maize Germplasm for Resistance to Five Diseases and Asian Corn Borer

    Institute of Scientific and Technical Information of China (English)

    段灿星; 朱振东; 武小菲; 杨知还; 王晓鸣

    2012-01-01

    在2003-2005年间,对604份玉米种质进行了抗弯孢菌叶斑病和玉米螟鉴定,筛选出抗弯孢菌叶斑病的材料93份,抗玉米螟材料22份.2006-2009年间,对836份玉米种质进行了抗大斑病、茎腐病、穗腐病和瘤黑粉病的鉴定与评价,筛选出一批高抗和多抗的资源.在836份资源中,对大斑病1、2和N号3个生理小种具有抗性的材料均为50%左右;抗茎腐病材料为41.3%,高抗和抗性种质分别为264和81份;穗腐病高抗和抗性种质分别为5和171份,占比为21.1%;瘤黑粉病高抗和抗性种质各261和14份,占总鉴定材料的32.9%.上述结果表明抗大斑病、茎腐病和瘤黑粉病的种质资源较为丰富.通过对抗性结果进行对比分析,发现不同生态区玉米种质的抗性强弱以及抗性多样性存在明显差异,黑龙江和内蒙古的种质对病虫害的抗性强弱及多样性程度明显高于四川种质.此外,玉米自交系对病虫害的抗性强弱以及多抗性程度高于农家种.%Among 604maize accessions screened in 2003 -2005,93 were resistant to Curvularia leaf spot and 22 were resistant to Asian corn borer. From 2006 to 2009 ,836 maize accessions were identified and evaluated for resistance to northern corn leaf blight, Pythium stalk rot, Fusarium ear rot and common smut and some of them were highly resistant and multiplely resistant. Approximately 50% of maize accessions with resistance to northern corn leaf blight racel ,2 and N were screened,respectively. 41. 3% of accessions were resistant to Pythium stalk rot,including 264 highly resistant and 81 resistant. 5 and 171 accessions were highly resistant and resistant to Fusarium ear rot,respectively,accounting for 21. 1% of total accessions screened. 32. 9% of accessions with different resistance to common smut was screened,261 highly resistant and 14 resistant lines were discovered. Based on the above data, we thought there were relatively abundant maize germplasm with

  3. Relationship between time to flowering and stalk and ear damage by second generation corn borers.

    Science.gov (United States)

    Ordas, B; Alvarez, A; Revilla, P; Butron, A; Malvar, R A

    2013-06-01

    In the Mediterranean area, the main corn borer species are Sesamia nonagrioides Lefebvre (Mediterranean corn borer) and Ostrinia nubilalis Hübner (European corn borer). In the overall context of integrated pest control, it is possible to reduce the effect of a pest without having a negative effect on the environment by varying the sowing date. Benefits are possible if the most susceptible stages of the crop no longer coincide with the peak of the pest. We used different cycles of selection (0, 6, 8, 10, and 12) of two populations (Purdue A and Purdue B) of maize selected for early flowering to get a more precise estimation of the relationship between maturity of plant tissues and corn borer damage. We found a relationship between the damage produced by corn borers and the number of days from flowering to infestation. We conclude that, after flowering, a later stage of plant development at the moment of the infestation by corn borers reduces the damage caused by the larvae. Based on our results, we recommend to plant as early as possible so the tissues would be as mature as possible at the moment of insect attack.

  4. THE INFLUENCE OF ABIOTIC FACTORS ON THE PRESENCE OF EUROPEAN CORN BORER (Ostrinia nubilalis Hubner

    Directory of Open Access Journals (Sweden)

    Ankica Sarajlić

    2015-12-01

    Full Text Available Field experiments with natural population of European corn borer (ECB were conducted in three vegetation seasons (2012-2014 at Agricultural Institute in Osijek. The experiment was set up in a randomized block design as split-split plot method, with three repetitions. This plot has been constantly maize - soybean rotation for already 15 years. It was a 3x3x4 factorial experiment with three irrigation levels (A1- non-irrigated (only natural precipitation, A2-from 60% to 80% field water capacity - FWC and A3-from 80% to100% FWC, three nitrogen fertilizer levels (B1-0, B2-100 and B3-200 kg N/ha and four different genotypes (C1-0SSK 596; C2-0SSK 617; C3-0SSK 602 and C4-0SSK 552.The aim of this study was to determine the effect of different levels of irrigation, nitrogen fertilization and genotypes on occurrence and damage of maize plants by the European corn borer larvae and relation between leaf feeding larvae with nitrogen and silicon concentration as well as C/N ratio. At the end of each growing season, ten maize plants from each variant were cut. Ear weight for each specific plant (g, tunnel length (cm, number of larvae in stalk, number of larvae in the ear shank, ear shank damage (cm and total number of larvae in maize plantwere determined. In silking stage (middle of July ten leaves (below the ear, from 10 maize plants were sampled on each variant. Nitrogen, carbon and silicon concentrations were determined in maize leaf (% and C/N ratio calculated. In 2014, a significantly lower ECB attack was determined taking into account lower temperatures and higher amount of precipitate compared to the previous years. Dominance of Z-type European corn borer on pheromone traps in the area of eastern Slavonia was confirmed. Increasing the level of soil water content, damage from larvae was reduced and increasing the level of nitrogen fertilization feeding activity was increased. We have confirmed different hybrid resistance in regards to damage from larvae

  5. Implications of European corn borer, Ostrinia nubilalis, infestation in an Aspergillus flavus-biocontrolled corn agroecosystem.

    Science.gov (United States)

    Mencarelli, Mariangela; Accinelli, Cesare; Vicari, Alberto

    2013-09-01

    A novel biocontrol strategy consisting of field application of bioplastic-based granules inoculated with a non-toxigenic Aspergillus flavus L. strain has recently been shown to be effective for reducing aflatoxin contamination in corn. This study focused on other factors that may affect the feasibility of this biocontrol technique, and more specifically the role of the European corn borer (ECB), Ostrinia nubilalis H., in the dispersal and infestation of A. flavus in corn and its impact on crop yield. In spite of the high percentage of corn ears showing larval feeding damage, ECB-bored kernels accounted for only 3 and 4% in 2009 and 2010 respectively. Most of the damaged kernels were localised in the ear tip or immediately below. More precisely, the average incidence of ECB-bored kernels in the upper end of the ear was 32%. However, less than 5% of kernels from the central body of the ear, which includes the majority of kernels, were injured by ECB. Although ECB larvae showed a high tolerance to aflatoxin B1 and thus had the potential to serve as vectors of the mould, fungal infection of kernels was poorly associated with insect damage. ECB infestation resulted in grain yield losses not exceeding 2.5%. © 2012 Society of Chemical Industry.

  6. Datasets for transcriptomic analyses of maize leaves in response to Asian corn borer feeding and/or jasmonic acid

    Science.gov (United States)

    Corn is one of the most widely grown crops throughout the world. However, many corn fields develop pest problems such as corn borers every year that seriously affect its yield and quality. Corn's response to initial insect damage involves a variety of changes to the levels of defensive enzymes, toxi...

  7. Delaying corn rootworm resistance to Bt corn.

    Science.gov (United States)

    Tabashnik, Bruce E; Gould, Fred

    2012-06-01

    Transgenic crops producing Bacillus thuringiensis (Bt) toxins for insect control have been successful, but their efficacy is reduced when pests evolve resistance. To delay pest resistance to Bt crops, the U.S. Environmental Protection Agency (EPA) has required refuges of host plants that do not produce Bt toxins to promote survival of susceptible pests. Such refuges are expected to be most effective if the Bt plants deliver a dose of toxin high enough to kill nearly all hybrid progeny produced by matings between resistant and susceptible pests. In 2003, the EPA first registered corn, Zea mays L., producing a Bt toxin (Cry3Bb1) that kills western corn rootworm, Diabrotica virgifera virgifera LeConte, one of the most economically important crop pests in the United States. The EPA requires minimum refuges of 20% for Cry3Bb1 corn and 5% for corn producing two Bt toxins active against corn rootworms. We conclude that the current refuge requirements are not adequate, because Bt corn hybrids active against corn rootworms do not meet the high-dose standard, and western corn rootworm has rapidly evolved resistance to Cry3Bb1 corn in the laboratory, greenhouse, and field. Accordingly, we recommend increasing the minimum refuge for Bt corn targeting corn rootworms to 50% for plants producing one toxin active against these pests and to 20% for plants producing two toxins active against these pests. Increasing the minimum refuge percentage can help to delay pest resistance, encourage integrated pest management, and promote more sustainable crop protection.

  8. A potential and novel type transgenic corn plant for control of the Corn Borer

    Science.gov (United States)

    Yue, Zhen; Li, Xiangrui; Zhang, Enyan; Liu, Xiaoxia; Zhao, Zhangwu

    2017-01-01

    The corn borer is a world-wide agricultural pest. In this study, a full-length neuropeptide F (npf) gene in Ostrinia furnacalis was sequenced and cloned from a cDNA library, in which the npf gene produces two splicing mRNA variants - npf1 and npf2 (with a 120 bp segment inserted into the npf1 sequence to generate npf2). A spatio-temporal expression analysis showed that the highest expression level of npf was in the midgut of 5th instar larvae (the gluttony period), and their npf expression and food consumption were significantly promoted after food deprivation for 6 h. When npf was knocked down by double-stranded RNA for NPF, larval food intake, weight and body size were effectively inhibited through changes of a biosynthesis and metabolism pathway; i.e. gene silencing of NPF causes decreases of total lipid and glycogen and increases of trehalose production. Moreover, we produced transgenic corn plants with stably expressed dsNPF. Results showed that O. furnacalis larvae fed on these transgenic leaves had lower food consumption and smaller body size compared to controls. These results indicate that NPF is important in the feeding control of O. furnacalis and valuable for production of potential transgenic corn. PMID:28290513

  9. INFLUENCE OF EUROPEAN CORN BORER (Ostrinia nubilalis Hübner ON CORN HYBRIDS IN NORTH-WEST AND EASTERN CROATIA

    Directory of Open Access Journals (Sweden)

    Zvjezdana Augustinović

    2005-12-01

    Full Text Available European corn borer (Ostrinia nubilalis Hubner is one of the major corn pest in the world and in Croatia. Former investigations of corn borer in Croatia covered mostly its Eastern region. In trials conducted in 1998 and 1999 the research was extended to the North Western part of Croatia too. Macro trials were carried out with corn hybrids of FAO groups 200-600 at three localities: Križevci, Agricultural institute Osijek and at «Belje» PIK Karanac. In 1998 the intensity of the corn borer attack at the locality of «Belje» PIK Karanac was about 37.92% and in Agricultural institute Osijek 80.83%. In 1999 it varied between 37.08% at the locality of Agricultural Institute Osijek and 71.20% at the locality in Križevci. The estimated number of holes per plant in all three localities in both years was higher than the number of caterpillars. Length of damage per plant was between 0.38 and 18.80 cm. The data showed significant differences in the intensity of damaging effects on different localities while no significant differences concerning various hybrids were found. The statistical data concerning yield in both years showed significant differences among hybrids, localities and their interactions.

  10. Maize defense response against the european corn borer (Ostrinia nubilaslis): a losing battle?

    Science.gov (United States)

    The goal of this research is to understand how maize stems respond to European corn borer (ECB) damage and how these defense tactics affect the invading ECB. We measured the levels of the plant hormones, jasmonic acid (JA) and ethylene, as well as the transcript levels of their key biosynthetic en...

  11. Sex Pheromone Receptor Specificity in the European Corn Borer Moth, Ostrinia nubilalis.

    Science.gov (United States)

    The European corn borer (ECB), Ostrinia nubilalis, exists as two separate sex pheromone races. ECB(Z) females produce a 97:3 blend of Z11- and E11-14:OAc whereas ECB(E) females produce an opposite 1:99 ratio of the Z and E isomers. Males of each race respond specifically to their conspecific female...

  12. Diallel Analysis of Southwestern Corn Borer Leaf Feeding Damage in Maize

    Science.gov (United States)

    Southwestern corn borer [Diatraea grandiosella (Dyar)] is an important pest of maize in the southern United States. It feeds extensively within the leaf whorls of plants in the vegetative stages of growth. This reduces both the quantity and quality of harvestable grain. Germplasm lines with resistan...

  13. Breeding for stem borer resistance in sugarcane

    Science.gov (United States)

    Stem borers are arguably the most important group of insect pests of sugarcane. Stem borers primarily belong to the insect order Lepidoptera, although a few species belong to the order Coleoptera. The larvae of these insects bore into the sugarcane stalk and heavy infestations can cause severe losse...

  14. Enhanced Resistance of Snowdrop Lectin (Galanthus nivalis L. Agglutinin)-Expressing Maize to Asian Corn Borer (Ostrinia furnacalis Guenée)

    Institute of Scientific and Technical Information of China (English)

    Zhao-Yu WANG; Xiao-Fen SUN; Fei WANG; Ke-Xuan TANG; Ju-Ren ZHANG

    2005-01-01

    In order to enhance the resistance to pests, transgenic maize (Zea mays L.) plants from elite inbred lines containing the gene encoding snowdrop lectin (Galanthus nivalis L. agglutinin; GNA) under control of a phloem-specific promoter were generated through the Agrobacterium tumefaciens-mediated also studied. Thirty-six independently derived plants were subjected to molecular analyses. The level of GNA expression at 0.13%-0.28% of total soluble protein was observed in different transgenic plants. The progeny of three GNA-expressing independent transformants that were derived separately from the elite inbred lines DH4866, DH9942, and 8902, were selected for examination of resistance to ACB. These plants synthesized GNA at levels above 0.24% total soluble protein and enhanced resistance to ACB was demonstrated by exposing the plants to insects under greenhouse conditions. Semi-artificial diet bioassays also showed the toxic effect of GNA on ACB. Field evaluation of the transgenic plants supported the results from the artificial trial. In the present study, we have obtained new insect-resistant maize material for further breeding work and have found that GNA-expressing plants not only gained significant resistance to homopterans, but also showed toxicity to ACB, which is a type of Lepidoptera.

  15. Is the basal area of maize internodes involved in borer resistance?

    Directory of Open Access Journals (Sweden)

    Malvar Rosa

    2011-10-01

    Full Text Available Abstract Background To elucidate the role of the length of the internode basal ring (LIBR in resistance to the Mediterranean corn borer (MCB, we carried out a divergent selection program to modify the LIBR using two maize synthetic varieties (EPS20 and EPS21, each with a different genetic background. We investigated the biochemical mechanisms underlying the relationship between the LIBR and borer resistance. Selection to lengthen or shorten the LIBR was achieved for each synthetic variety. The resulting plants were analyzed to determine their LIBR response, growth, yield, and borer resistance. Results In the synthetic variety EPS20 (Reid germplasm, reduction of the LIBR improved resistance against the MCB. The LIBR selection was also effective in the synthetic variety EPS21 (non-Reid germplasm, although there was no relationship detected between the LIBR and MCB resistance. The LIBR did not show correlations with agronomic traits such as plant height and yield. Compared with upper sections, the internode basal ring area contained lower concentrations of cell wall components such as acid detergent fiber (ADF, acid detergent lignin (ADL, and diferulates. In addition, some residual 2,4-dihydroxy-7-methoxy-(2H-1,4-benzoxazin-3-(4H-one (DIMBOA, a natural antibiotic compound, was detected in the basal area at 30 days after silking. Conclusion We analyzed maize selections to determine whether the basal area of maize internodes is involved in borer resistance. The structural reinforcement of the cell walls was the most significant trait in the relationship between the LIBR and borer resistance. Lower contents of ADF and ADL in the rind of the basal section facilitated the entry of larvae in this area in both synthetic varieties, while lower concentrations of diferulates in the pith basal section of EPS20 facilitated larval feeding inside the stem. The higher concentrations of DIMBOA may have contributed to the lack of correlation between the LIBR and

  16. Down-regulation of aminopeptidase N and ABC transporter subfamily G transcripts in Cry1Ab and Cry1Ac resistant Asian corn borer, Ostrina furnacalis (Lepidoptera: Crambidae)

    Science.gov (United States)

    Bacillus thuringiensis (Bt) crystalline protein (Cry) toxins cause mortality by a mechanism involving pore formation or signal transduction following toxin binding to receptors along the midgut lumen of susceptible insects, but this mechanism and mutations therein that lead to resistance remain poor...

  17. Framework to Delay Corn Rootworm Resistance

    Science.gov (United States)

    This proposed framework is intended to delay the corn rootworm pest becoming resistant to corn genetically engineered to produce Bt proteins, which kill corn rootworms but do not affect people or wildlife. It includes requirements on Bt corn manufacturers.

  18. RELATIONSHIP BETWEEN EUROPEAN CORN BORER FEEDING ACTIVITY AND NITROGEN LEAF CONTENT UNDER DIFFERENT AGRICULTURAL PRACTICES

    Directory of Open Access Journals (Sweden)

    Ankica Sarajlić

    2015-06-01

    Full Text Available One of the most destructive maize pest in Croatia is European corn borer (Ostrinia nubilalis Hübner (ECB. The aim of this study was to determine the influence of irrigation, nitrogen fertilization, different maize genotypes and nitrogen leaf content on ECB feeding activity. The experiment was set up in Osijek, Croatia under field conditions during 2012-2013 vegetation season. Experiment treatments were as follows: three irrigation levels (A1 - control, A2 from 60% to 80% field water capacity - FWC and A3 from 80% to100% FWC, three nitrogen fertilizer levels (B1 - 0, B2 - 100 and B3 - 200 kg N/ha and four different genotypes (C1 - OSSK 596; C2 - OSSK 617; C3 - OSSK 602 and C4 - OSSK 552. Ear weight, number of larvae in stem and shank, tunnel length and nitrogen leaf content were evaluated. Genotype C1 was the most susceptible for following the tested variables of ECB feeding: tunnel length (TL, larvae in stalk (LS and total number of larvae (TNL at P<0.05 probability level. By raising the level of irrigation, European corn borer feeding activity was reduced while by raising the level of nitrogen fertilization feeding activity was increased. These results suggest that good production practices can significantly affect the susceptibility of maize to European corn borer.

  19. Dispersal and movement behavior of neonate European corn borer (Lepidoptera: Crambidae) on non-Bt and transgenic Bt corn.

    Science.gov (United States)

    Goldstein, Jessica A; Mason, Charles E; Pesek, John

    2010-04-01

    Neonate movement and dispersal behavior of the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), were investigated under controlled conditions on Bacillus thuringiensis (Bt) and non-Bt corn, Zea mays L., to assess plant abandonment, dispersal from their natal plant, and silking behavior after Bt and non-Bt preexposure. With continuous airflow, neonates on a Bt corn plant for 24 h abandoned that plant 1.78 times more frequently than neonates on a non-Bt corn plant. Indirect evidence indicated that at least one third of the neonates were capable of ballooning within 24 h. In the greenhouse, some neonates were recovered after 24 h from plants 76 and 152 cm away that likely ballooned from their natal plant. After 1 h of preexposure on a Bt corn leaf, neonates placed on a new corn leaf and observed for 10 min began silking off of a new Bt leaf significantly sooner than a new non-Bt leaf. Results suggest that neonates are unable to detect Bt in the corn within 10 min but that they can detect it within the first hour.

  20. Volatiles induced by the larvae of the Asian corn borer (Ostrinia furnacalis) in maize plants affect behavior of conspecific larvae and female adults

    Institute of Scientific and Technical Information of China (English)

    Cui-Hong Huang; Feng-Ming Yan; John A.Byers; Rong-Jiang Wang; Chong-Ren Xu

    2009-01-01

    Effects of maize (Zea mays L.) volatiles induced by larvae of the Asian corn borer, Ostrinia furnacalis (Guenee), on the orientation behaviors of Asian corn borer larvae and oviposition of the females were investigated. Nineteen volatile chemicals, with terpenes being the major components, were identified from maize plants attacked by third instar Asian corn borer larvae. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses revealed some electroantennographic differences between female and male Asian corn borer antennae in response to larvae-induced maize volatiles; female responded to (E)-2-hexenal, nonanal, (Z)-3-hexen-1-ol and three unknown compounds while the male only responded to (E)-2-hexenal, nonanal and one unknown compound. In laboratory orientation bioassays, Asian corn borer neonate larvae were attracted to extracts collected from Asian corn borer-damaged plants as well as to synthetic famesene, but were repelled by (Z)-3-hexen- 1-ol. In laboratory oviposition bioassays, gravid females laid fewer eggs on plants damaged by larvae than on mechanically damaged plants or undamaged plants. Adult Asian corn borer females deposited fewer eggs on wax paper treated with (E)-2-hexenal or (Z)-3-hexen-l-ol than on wax paper treated with hexane (control). The results suggest that Asian corn borer can affect the behaviors of conspecific larvae and adults by changing host plant volatiles.

  1. Down regulation of a gene for cadherin but not alkaline phosphatase associated with Cry1Ab resistance in the sugarcane borer Diatraea saccharalis

    Science.gov (United States)

    The sugarcane borer, Diatraea saccharalis, is a major target pest of transgenic corn expressing Bacillus thuringiensis (Bt) proteins in South America and the mid-southern region of the United States. Evolution of insecticide resistance in such target pests is a major threat to the durability of tran...

  2. Mexican rice borer (Lepidoptera: Crambidae) injury to corn greater than to sorghum and sugarcane under field conditions.

    Science.gov (United States)

    Showler, Allan T; Wilson, Blake E; Reagan, Thomas E

    2012-10-01

    The Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), is the key pest of sugarcane (Saccharum spp.) in Texas; it can attack several grassy crop and noncrop host plants and has spread into Louisiana. Through small-plot, commercial field, and pheromone trap experiments, this study demonstrates that the pest uses corn, Zea mays L., more than sugarcane and sorghum, Sorghum bicolor (L.) Moench, but when corn is harvested in late summer, injury to nearby sugarcane strongly increases during the next approximately equal to 2 mo to harvest. Corn was more infested than sugarcane and sorghum in commercial fields regardless of whether sampling occurred on field edges or farther into field interiors. Differences in numbers of infested stalks and in numbers of larval entry holes between field edges and interiors were not detected. We found that Mexican rice borer infestation of corn can cause loss of ears, and lodging, shattering, and complete destruction of maturing stalks. The larger quantities of adult Mexican rice borers captured in pheromone-based traps placed at corn field edges compared with sorghum and sugarcane field edges further indicates that corn is preferred to sugarcane and sorghum. The basis for the pest's attraction to corn and implications to potential range expansion to other U.S. sugarcane-growing regions are discussed.

  3. Current European corn borer, Ostrinia nubilalis, injury levels in the northeastern United States and the value of Bt field corn.

    Science.gov (United States)

    Bohnenblust, Eric W; Breining, James A; Shaffer, John A; Fleischer, Shelby J; Roth, Gregory W; Tooker, John F

    2014-11-01

    Recent evidence indicates that some populations of European corn borer (ECB), Ostrinia nubilalis (Hübner), have declined to historic lows owing to widespread adoption of Bt corn hybrids. To understand current ECB populations in Pennsylvania field corn, the authors assessed larval damage in Bt and non-Bt corn hybrids at 29 sites over 3 years. The influence of Bt adoption rates, land cover types and moth activity on levels of ECB damage was also considered. Bt hybrids reduced ECB damage when compared with non-Bt, but these differences inconsistently translated to higher yields and, because of higher seed costs, rarely improved profits. No relationships were detected between land use or Bt adoption and ECB damage rates, but positive relationships were found between plant damage and captures of Z-race ECB moths in pheromone traps in the PestWatch network. ECB damage levels were generally low and appear to be declining across Pennsylvania. In many locations, farmers may gain greater profits by planting competitive non-Bt hybrids; however, Bt hybrids remain valuable control options, particularly in the parts of Pennsylvania where ECB populations persist. Moth captures from PestWatch appear to provide insight into where Bt hybrids are most valuable. © 2013 Society of Chemical Industry.

  4. Plant responses to hidden herbivores: European corn borer (ECB; Ostrinia nubilalis) attack on maize induces both defense and susceptibility

    Science.gov (United States)

    Herbivore-induced plant defenses have been widely described following attack on leaves; however, less attention has been paid to analogous local processes that occur in stems or roots. Early attempts to characterize maize responses to stem boring by European corn borer (ECB; Ostrinia nubilalis) larv...

  5. Susceptibility of Cry1Ab-resistant and -susceptible Sugarcane Borer (Lepidoptera: crambidae) to Four Bacillus thuringiensis Toxins

    Science.gov (United States)

    Sugarcane borer, Diatraea saccharalis (F.), is a primary corn stalk borer pest targeted by transgenic corn expressing Bacillus thuringiensis (Bt) proteins in many areas of the mid-southern region of the United States. Recently, genes encoding for Cry1A.105 and Cry2Ab2 Bt proteins were transferred in...

  6. European corn borer (Lepidoptera: Crambidae) infestation level and plant growth stage on whole-plant corn yield grown for silage in Virginia.

    Science.gov (United States)

    Tiwari, S; Youngman, R R; Laub, C A; Brewster, C C; Jordan, T A; Teutsch, C

    2009-12-01

    Field experiments were conducted in 2004 and 2005 to determine the effect of different levels of hand-infested third instar European corn borer, Ostrinia nubilalis (Hiibner) (Lepidoptera: Crambidae), on whole-plant yield and plant growth stage in corn, Zea mays L., grown for silage. In 2004 and 2005, European corn borer infestation level had a significant negative impact on whole-plant yield (grams of dry matter per plant) with increasing infestation; however, whole-plant yield was not significantly affected by plant growth stage in either year. In 2004, the six larvae per plant treatment caused the greatest percentage of reduction (23.4%) in mean (+/-SEM) whole-plant yield (258.5 +/- 21.0 g dry matter per plant) compared with the Bacillus thuringiensis (Bt) CrylAb control (337.3 +/- 11.1 g dry matter per plant). In 2005, the five larvae per plant treatment caused the greatest percentage of reduction (8.3%) in mean whole-plant yield (282.3 +/- 10.8 g dry matter per plant) compared with the Bt CrylAb control (307.8 +/- 8.3 g dry matter per plant). The relationship between mean whole-plant yield and European corn borer larvae infestation level from the pooled data of both years was described well by using an exponential decay model (r2 = 0.84, P = 0.0038). The economic injury level for silage corn was estimated to be approximately 73% higher than for corn grown for grain based on similar control costs and crop values. In addition, plant growth stage and European corn borer infestation level had no effect on percentage of acid detergent fiber, neutral detergent fiber, and crude protein values in either year of the study.

  7. Effect of sequential applications of foliar nutrients, biofertilizers and sowing dates on the incidence of corn stem borers in Egypt.

    Science.gov (United States)

    Mesbah, H A; Mourad, A K; el-Nimr, Hanyiat M; el-Kady, Magda B; Haroun, Nagah S

    2002-01-01

    In this study either early sown (May 1st) or lately sown (June 2nd) corn plants were treated with Phosphorin & Rhizobactrin as biofertilizers and sprayed with six selected foliar nutrients, i.e. Polymex; Greenzit SP100, Greenzit NPK, Potasin-F, Copper sulphate and Ascorbic acid; in mono-, bi-, and/or tri-sequential applications. Such practices were conducted to show their beneficial effects compared with the chemical treatment in checking the incidence of the stem borers and hence increasing the corn yield. The obtained results could be summarized in the following chief points: (a) the lately sown biofertilized plants showed somewhat higher levels of infestation than the early planted ones., (b) in general, spraying the biofertilized corn plants in both sowing dates with the tested foliar nutrients, significantly decreased the rate of the stem borers infestation than the untreated plants of control., (c) the foliar sprays of Greenzit NPK alone, bi- or tri-sequential applications of Potasin-F, Polymex, Ascorbic acid and Copper sulphate achieved considerable success in reducing larval numbers of the borers species. For example, in case of using the bi-sequential nutrients (Polymex/Ascorbic acid) the numbers were 1.2, 1.5 and 1.2 larvae/5 plants, whereas the numbers were 1.3, 1.0 and 0.7 larvae/5 plants as a result, of the tri-sequential applications (Potasin-F/Ascorbic acid/Polymex) for the pink stem borer, Sesamia cretica, (Led.), the purple lined borer, Chilo agamemnon, (Bels.), and the European corn borer Ostrinia nubilalis (Hb.), in respect, vs. 4.8, 4.5 and 2.9 larvae/5 plants for the same stem borers, respectively, in case of the untreated corn plants. In addition, the other trisequential applications (Polymex/ascorbic acid/Copper sulphate), (Potasin-F/Copper sulphate/ascorbic acid) and (Potasin-F/Copper sulphate/Polymex) reduced the stem borers infestation; (d) from the view point of the interaction effects of sowing dates and the tested foliar nutrients, it

  8. Use of Spectral Vegetation Indices for Detection of European Corn Borer Infestation in Iowa Corn Plots

    Science.gov (United States)

    Recently, corn grown for grain in the United States has increased from 28 million ha in 2006 to more than 35 million ha in 2007 with a production value of over $52 billion dollars. Transgenic corn expressing the plant incorporated protectant Bacillus thuringiensis toxin represen...

  9. Breeding Resistant Sugarcane for Managing the Stem Borer Diatraea saccharalis: Progress and Prospects for Louisiana

    Science.gov (United States)

    The stem borer, Diatraea saccharalis (F.), is an important insect pest of sugarcane in Louisiana. Growing resistant varieties is a component of the Integrated Pest Management Program as practiced in Louisiana for managing this insect; however, the release of stem borer resistant varieties is intermi...

  10. Feeding regulation by neuropeptide Y on Asian corn borer Ostrinia furnacalis.

    Science.gov (United States)

    Yue, Zhen; Zhao, Zhangwu

    2017-06-01

    The Asian Corn Borer Ostrinia furnacalis is a major agricultural pest. In this study, a full-length neuropeptide Y (npy) gene in O. furnacalis was sequenced and cloned from cDNA library, which contains an ORF of 273 bp by encoding 90 amino acid residues. The mature OfurNPY is composed of 29 amino acids with amidation in C-terminal. The spatiotemporal expression analysis showed that npy highest expression level was in the midgut of the fifth instar larvae (the gluttony period). When the expression of npy was knocked down by feeding or injecting dsNPY, larval food consumption, body size, and body weight were significantly inhibited compared to controls. These results indicate that NPY is an important regulator in the control of feeding of O. furnacalis. © 2017 Wiley Periodicals, Inc.

  11. THE EUROPEAN CORN BORER (OSTRINIA NUBILALIS HÜBNER REVIEW OF RESULTS FROM CROATIA

    Directory of Open Access Journals (Sweden)

    Marija Ivezić

    2001-06-01

    Full Text Available European Corn Borer (ECB - (Ostrinia nubilalis Hübner is one of the most important pest on corn in Croatia. In the last decade corn production was on over 400 000 ha, in Eastern Croatia. Although ECB is present every year, with no such a low intensity, their control is not implemented. Corn is grown in monoculture, at 40% of cornfields, which also has influence on spreading of ECB. In the last ten years average attack of ECB was 51.5%; been done three different kinds of trials for controlling ECB. First trials were carried out in DeKalb hybrids, and ECB was controlled by Biobit XL, on the base of Bacillus thuringiensis Berliner. Intensity of attack was decreased for 46%. Second trial was carried out in ten hybrids, in order to determine the tolerance of hybrids against ECB. It was identified that several domestic hybrids (OSSK 382, OSSK 664 and BC 462 are tolerant to ECB. The third trial was carried out with GM hybrids. Experiments included Pioneer hybrids Evelina Bt, and Landia Bt. Intensity of attack at Evelina standard was 52%, while in Evelina Bt, ECB wasn't present at all. At Landia standard ECB was present on 98%, while in Landia Bt, intensity of attack was 21%. At both Bt hybrids, number of larvae and tunnels was lower comparing to standard hybrids. Length of damage in Landia check was 20.66 cm, while in Landia Bt it was 0.45 cm. The yield was increased for 10.27% at Evelina Bt, and for 26.67% in Landia Bt comparing to their standards. This kind of experiments will be continued in the future, not only because of its agronomic importance, but also because of its ecological relevance.

  12. Comparisons of Transcriptional Profiles of Gut Genes between Cry1Ab-Resistant and Susceptible Strains of Ostrinia nubilalis Revealed Genes Possibly Related to the Adaptation of Resistant Larvae to Transgenic Cry1Ab Corn

    Science.gov (United States)

    European corn borer (Ostrinia nubilalis) gut 2,895 unique genes expressions were quantified and compared between a laboratory-selected Cry1Ab-resistant (R) strain and a susceptible (S) strain after fed transgenic corn (MON810) leaves expressing Cry1Ab by microarray. A total of 398 gut genes were di...

  13. The insecticide resistance in stripped stem borer, Chilo suppressalis (Walker)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ The stripped stem borer (SSB), Chilo suppressalis (Walker) is one of the major insect pests of rice in China. Chemical control has been a common practice in SSB management since 1950s. Insecticides used included BHC before 1983;organophosphorus insecticides (methyl-parathion, trichophon, methamidophos, and monocrotophos), and chlordimeform in mid-1970s-1980s; Shachongshuang (dimehypo) and Shachongdan (monousltap) since early 1980s. In recent years, SSB population and its damage to rice increased rapidly and failures on control has been reported. To find out the cause of failure and to put forward the suitable control methods, we studied the resistance of SSB to major insecticides used in China.

  14. 应用白僵菌防治玉米螟的研究进展%Research Progress of Prevention and Controlling Corn Borer by Beauveria bassiana

    Institute of Scientific and Technical Information of China (English)

    陆晴; 佘花娣; 佟文悦

    2013-01-01

    The damage characteristics of corn borer, biological characteristics and pathogenic mechanism of Beauveria bassiana were introduced briefly.The present situation, problems and corresponding measures of prevention and controlling corn borer using Beauveria bassiana were summarized, and the new direction was discussed so as to promote the corn safety production and improve the control efficiency of corn borer.%简要介绍了玉米螟的为害特点以及白僵菌的生物学特性、致病机理,对利用白僵菌防治玉米螟的现状、存在问题及相应措施进行了阐述,并对防治玉米螟的新方向进行了展望,以促进玉米安全生产和提高玉米螟的防治效率。

  15. Modeling the impact of cross-pollination and low toxin expression in corn kernels on adaptation of European corn borer (Lepidoptera: Crambidae) to transgenic insecticidal corn.

    Science.gov (United States)

    Kang, J; Onstad, D W; Hellmich, R L; Moser, S E; Hutchison, W D; Prasifka, J R

    2012-02-01

    We used a mathematical model with processes reflecting larval mortality resulting from feeding on cross-pollinated ears or Bt ears of corn to analyze the risk of evolution of Cry-toxin resistance in Ostrinia nubilalis (Hübner). In the simulations, evolution of resistance was delayed equally well by both seed mixtures and blocks with the same proportion of refuge. Our results showed that Bt-pollen drift has little impact on the evolution of Bt resistance in O. nubilalis. However, low-toxin expression in ears of transgenic corn can reduce the durability of transgenic corn expressing single toxin, whereas durability of pyramided corn hybrids is not significantly reduced. The toxin-survival rate of heterozygous larvae in Bt-corn ears expressing one or two proteins has more impact on evolution of Bt resistance in O. nubilalis than the parameters related to larval movement to Bt ears or the toxin-survival rate of the homozygous susceptible larvae in Bt ears. Bt resistance evolves slower when toxin mortality is distributed across the first two larval stadia than when only the first instars are susceptible to Bt toxins. We suggest that stakeholders examine toxin-survival rates for insect pests and take into account that instars may feed on different parts of Bt corn.

  16. The role of some agricultural practices and fertilizer type on both the incidence of stem borers infestation and corn yield in Egypt.

    Science.gov (United States)

    Mesbah, H A; Mourad, A K; el-Nimr, Hanyiat M; Massoud, M A; Abd el-Aziz, A A

    2002-01-01

    Maize, Zea mays, L. is one of the most important field crops in Egypt. It is used mainly for human, animal and poultry feeding. Corn plants are usually attacked by several injourious insect pests at different stages of development. Out of them, the pink stem borer, Sesamia cretica (Led.), the purple lined borer, Chilo agamemnon (Bles.), and the European corn borer Ostrinia nubilalis (Hb.); which cause great damage and yield losses. It is profitable to adopt an effective and sustainable strategy for controlling these insect-pests. In this concern, sowing dates, planting spaces, foliar fertilizers (macro and micro-nutrients), mineral and/or biofertilization, were investigated to evaluate their role as tools in the so-called Integrated Pest Management (IPM) program of corn pests. In general, the used planting spaces of 60 and 70 cm apart between furrows insignificantly affected the level of stem borers infestation. It was clearly observed that the sowing dates have a role in the incidence of stem borers infestation throughout the corn growing seasons of 1994 and 1995. Moreover, The biofertilized corn plants were more tolerant to the infestation by the stem borers than the minerally fertilized ones. Application of Polytrin significantly decreased the mean numbers of larvae. The tested nutrients preparations affected to less extent, the infestation levels. Concerning the interaction effect of applied nutrients preparations, used sowing dates and/or fertilizer type on the deduced means of larval numbers, it was revealed that: (i) the application of the nutrients preparations decreased to a great extent the effect of the studied sowing dates on the stem borers infestation; particularly in case of spraying ascorbic acid alone or in sequence with Polymex, coppersulphate & Potasin-F, (ii) the dressing of corn grains with the biofertilizers Phosphorin & Rhizobacterin before sowing, lowered to some extent the levels of infestation by Ch. agamemnon and O. nubilalis, in

  17. EFFICIENCY OF THE CHEMICAL TREATMENT AGAINST THE EUROPEAN CORN BORER IN SEED MAIZE PRODUCTION

    Directory of Open Access Journals (Sweden)

    Emilija Raspudić

    2013-06-01

    Full Text Available The aim of this study was to determine the effectiveness of a chemical treatment against larvae of the European corn borer (Ostrinia nubilalis Hubner. The experiment was set up in 2010 and 2011 in Čepin (eastern Croatia in two treatments: control treatment and insecticide treatment. The trial involved two hybrids of FAO group 400: PR37N01 and PR37F73. Biology of pests was monitored in order to determine population size and larvae development stage as well as the optimal time of insecticide application. After determination of thresholds, maize was treated with chemical formulations of active substance dimethoate. Towards the end of vegetation, length of stem damage, number of larvae in maize stalk and ear as well as grain yield were recorded by dissection of maize stalks. Statistical analysis shows that year, hybrid and chemical treatment significantly influenced the incidence of this pest and justified the use of chemical preparations with mandatory monitoring biology of this pest.

  18. EFFICASY OF NATURAL POPULATION OF Trichogramma WASPS AGAINST EUROPEAN CORN BORER IN FIELD MAIZE

    Directory of Open Access Journals (Sweden)

    Ankica Sarajlić

    2014-12-01

    Full Text Available The aim of this study was to determine the natural infestation of European corn borer (ECB eggs by Trichogramma wasps (Hymenoptera: Trichogrammatidae under field conditions. The experiment was set up in Osijek, Croatia in 2013. The experiment included two levels of irrigations, two nitrogen rates and two maize genotypes. Parameters of ECB feeding activity and maize tolerance (cob mass, tunnel length, number of ECB larvae per plant, as well as number of parasitized ECB eggs by Trihogramma wasps were evaluated. Genotypes were significantly different in terms of tolerance to ECB injury. In treatments with nitrogen fertilization, ECB feeding activity was increased at both nitrogen rates. Agricultural practices did not significantly affect parasitism of ECB eggs by Trichogramma. Correlation between parameters of ECB feeding activity and parasitism by Trichogramma was slight to moderate and not significant. Natural occurrence of Trichogramma wasps were not significantly affected by agricultural practices in maize, and population of these parasitoids was low significantly affect ECB feeding activity.

  19. Salivary signals of European corn borer induce indirect defenses in tomato.

    Science.gov (United States)

    Louis, Joe; Luthe, Dawn S; Felton, Gary W

    2013-11-01

    Plants can recognize the insect elicitors and activate its defense mechanisms. European Corn Borer (ECB; Ostrinia nubilalis) saliva, produced from the labial salivary glands and released through the spinneret, is responsible for inducing direct defenses in host plants. Glucose oxidase (GOX) present in the ECB saliva induced direct defenses in tomato. By contrast, GOX activity in ECB saliva was insufficient to trigger defenses in maize, suggesting that host-specific salivary elicitors are responsible for inducing direct defenses in host plants. Our current study further examined whether ECB saliva can trigger indirect defenses in tomato. Relative expression levels of TERPENE SYNTHASE5 (TPS5) and HYDROPEROXIDE LYASE (HPL), marker for indirect defenses in host plants, were monitored. Quantitative real-time PCR analysis revealed that ECB saliva can induce the expression of TPS5 and HPL, suggesting that salivary signals can induce indirect defenses in addition to the direct defenses. Further experiments are required to identify different ECB elicitors that are responsible for inducing direct and indirect defenses in host plants.

  20. Cloning, Expression, and Characterization of Prophenoloxidases from Asian Corn Borer, Ostrinia furnacalis (Gunée

    Directory of Open Access Journals (Sweden)

    Shasha Zhang

    2016-01-01

    Full Text Available Insect phenoloxidase (PO belongs to the type 3 copper protein family and possesses oxidoreductase activities. PO is typically synthesized as a zymogen called prophenoloxidase (PPO and requires the proteolytic activation to function. We here cloned full-length cDNA for 3 previously unidentified PPOs, which we named OfPPO1a, OfPPO1b, and OfPPO3, from Asian corn borer, Ostrinia furnacalis (Gunée, in addition to the previously known OfPPO2. These conceptual PPOs and OfPPO2 all contain two common copper-binding regions, two potential proteolytic activation sites, a plausible thiol-ester site, and a conserved C-terminal region but lack a secretion signal peptide sequence at the N-terminus. O. furnacalis PPOs were highly similar to other insect PPOs (42% to 79% identity and clustered well with other lepidopteran PPOs. RT-PCR assay showed the transcripts of the 4 OfPPOs were all detected at the highest level in hemocytes and at the increased amounts after exposure to infection by bacteria and fungi. Additionally, we established an Escherichia coli (E. coli expression system to produce recombinant O. furnacalis PPO proteins for future use in investigating their functions. These insights could provide valuable information for better understanding the activation and functioning mechanisms of O. furnacalis PPOs.

  1. Mechanism of rice variety resistance to the yellow stem borer, Scirpophaga incertulas (Walker)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ Yellow stem borer (YSB), Scirpophaga incertulas (Walker) has become the main rice insect pest once again along the Changjiang River sinee 1990s. Unfortunately, no rice variety with resistance to YSB has been reported so far.

  2. Preliminary Study on Resistance of the Rice Stem Borer (Chilo Suppressalis) to Fipronil

    Institute of Scientific and Technical Information of China (English)

    JIANG Wei-hua; HAN Zhao-jun; HAO Ming-li

    2005-01-01

    By means of topical application, fipronil resistance was surveyed in the rice stem borer, Chilo suppressalis, from 12 diferent areas in east China from 2001 to 2004. The rice stem borers in most regions of Jiangsu and Anhui were still susceptible to fipronil. But in Wuxi, Jiangsu Province and Cixi, Zhejiang Province, their sensitivity became decreased (resistance ratios were 3.1 and 3.6,respectively), and the medium level of resistance (resistance ratio was 21.2) was found in Cangnan, Zhejiang Province. So, it was still at the early stage for fipronil resistance development in this pest. Synergism experiments showed that piperonyl butoxide(PBO) had a little effect on both susceptible and resistant borers (synergism ratios were 1.1-1.2). Tho ugh triphenyl phosphate (TPP) and diethyl meleate (DEM) had no effect on the susceptible borers, they had significant synergism on fipronil in the resistant population to fipronil (synergism ratios were 1,8 and 1.6, respectively), indicating esterase and glutathion S-transferase may be involved in the resistance mechanism. Bioassay with currently used insecticides indicated that triazophos (because of high resistance), trichlorphon and acephate had very low toxicity to resistant borers. But diazinon, pyridaphenthion, decamethrin and avermeotin showed high toxicity and had no cross resistance to fipronil, which could be considered as substitute insecticides in the resistance managment.

  3. Resistance Evaluation of Btcry1Ah-transgenic Maize to Asian Corn Borer,Cotton Bollworm and Oriental Armyworm%转Bt cry1Ah基因抗虫玉米对亚洲玉米螟、棉铃虫和黏虫的抗性评价

    Institute of Scientific and Technical Information of China (English)

    宋苗; 汪海; 张杰; 何康来; 梁革梅; 朱莉; 黄大昉; 郎志宏

    2016-01-01

    Bt cry1Ah gene was transferred into inbred line maize Zong31 via Agrobacterium-mediated method,and transgenic maize HGK60 with significant resistance to corn borer was acquired. In order to investigate its insecticidal activity to Lepidoptera pests,we evaluated the insecticidal effects of HGK60 to Asian corn boner(Ostrinia furnacalis),cotton bollworm(Mythimna separate(Walker))and oriental armyworm(Helicoverpa armigeraHubne)through laboratory and field bioassay. The results of laboratory bioassay indicated that no Asian corn boner feeding on HGK60 leaves survived. HGK60 presented the toxic effect on neonate of cotton bollworm,and different tissues of it had different insecticidal effects. Compared to the non-transgenic maize,the body-weight of armyworm neonate was significantly inhibited after a week of feeding HGK 60 leaves. The results of field bioassay showed that HGK60 had solid insecticidal effects to O. furnacalis and H. armigera in high resistance level,while the efficacy to M. separate was in resistance level.%利用农杆菌介导法将Btcry1Ah基因转入玉米自交系综31,获得对玉米螟有显著抗性的转基因玉米HGK60,为了研究其对鳞翅目害虫的杀虫活性,在室内和田间分别用亚洲玉米螟、棉铃虫和黏虫幼虫对HGK60玉米的杀虫效果进行检测。室内生物活性检测结果表明,取食HGK60玉米心叶的亚洲玉米螟幼虫在3d后死亡率达100%;HGK60玉米对棉铃虫幼虫有毒杀作用,玉米不同部位对棉铃虫幼虫的杀虫效果存在差异;与非转基因玉米对照相比,取食HGK60玉米叶片一周后的黏虫幼虫体重增长明显受到抑制。田间生物活性检测结果表明,HGK60玉米对于亚洲玉米螟和棉铃虫有很强的杀虫活性,达到高抗级别,对于黏虫有一定的杀虫活性,为抗性级别。

  4. Genetic mapping of male pheromone response in the European corn borer identifies candidate genes regulating neurogenesis

    Science.gov (United States)

    Dekker, Teun; Heckel, David G.

    2016-01-01

    The sexual pheromone communication system of moths is a model system for studies of the evolution of reproductive isolation. Females emit a blend of volatile components that males detect at a distance. Species differences in female pheromone composition and male response directly reinforce reproductive isolation in nature, because even slight variations in the species-specific pheromone blend are usually rejected by the male. The mechanisms by which a new pheromone signal–response system could evolve are enigmatic, because any deviation from the optimally attractive blend should be selected against. Here we investigate the genetic mechanisms enabling a switch in male response. We used a quantitative trait locus-mapping approach to identify the genetic basis of male response in the two pheromone races of the European corn borer, Ostrinia nubilalis. Male response to a 99:1 vs. a 3:97 ratio of the E and Z isomers of the female pheromone is governed by a single, sex-linked locus. We found that the chromosomal region most tightly linked to this locus contains genes involved in neurogenesis but, in accordance with an earlier study, does not contain the odorant receptors expressed in the male antenna that detect the pheromone. This finding implies that differences in the development of neuronal pathways conveying information from the antenna, not differences in pheromone detection by the odorant receptors, are primarily responsible for the behavioral response differences among the males in this system. Comparison with other moth species reveals a previously unexplored mechanism by which male pheromone response can change in evolution. PMID:27698145

  5. European corn borer (Ostrinia nubilalis) induced responses enhance susceptibility in maize.

    Science.gov (United States)

    Dafoe, Nicole J; Thomas, James D; Shirk, Paul D; Legaspi, Michelle E; Vaughan, Martha M; Huffaker, Alisa; Teal, Peter E; Schmelz, Eric A

    2013-01-01

    Herbivore-induced plant responses have been widely described following attack on leaves; however, less attention has been paid to analogous local processes that occur in stems. Early studies of maize (Zea mays) responses to stem boring by European corn borer (ECB, Ostrinianubilalis) larvae revealed the presence of inducible acidic diterpenoid phytoalexins, termed kauralexins, and increases in the benzoxazinoid 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one-glucose (HDMBOA-Glc) after 24 h of herbivory. Despite these rapidly activated defenses, larval growth was not altered in short-term feeding assays. Unexpectedly, ECB growth significantly improved in assays using stem tissue preconditioned by 48 h of larval tunneling. Correspondingly, measures of total soluble protein increased over 2.6-fold in these challenged tissues and were accompanied by elevated levels of sucrose and free linoleic acid. While microarray analyses revealed up-regulation of over 1100 transcripts, fewer individual protein increases were demonstrable. Consistent with induced endoreduplication, both wounding and ECB stem attack resulted in similar significant expansion of the nucleus, nucleolus and levels of extractable DNA from challenged tissues. While many of these responses are triggered by wounding alone, biochemical changes further enhanced in response to ECB may be due to larval secreted effectors. Unlike other Lepidoptera examined, ECB excrete exceedingly high levels of the auxin indole-3-acetic acid (IAA) in their frass which is likely to contact and contaminate the surrounding feeding tunnel. Stem exposure to a metabolically stable auxin, such as 2,4-dichlorophenoxyacetic acid (2,4-D), promoted significant protein accumulation above wounding alone. As a future testable hypothesis, we propose that ECB-associated IAA may function as a candidate herbivore effector promoting the increased nutritional content of maize stems.

  6. European corn borer (Ostrinia nubilalis induced responses enhance susceptibility in maize.

    Directory of Open Access Journals (Sweden)

    Nicole J Dafoe

    Full Text Available Herbivore-induced plant responses have been widely described following attack on leaves; however, less attention has been paid to analogous local processes that occur in stems. Early studies of maize (Zea mays responses to stem boring by European corn borer (ECB, Ostrinianubilalis larvae revealed the presence of inducible acidic diterpenoid phytoalexins, termed kauralexins, and increases in the benzoxazinoid 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one-glucose (HDMBOA-Glc after 24 h of herbivory. Despite these rapidly activated defenses, larval growth was not altered in short-term feeding assays. Unexpectedly, ECB growth significantly improved in assays using stem tissue preconditioned by 48 h of larval tunneling. Correspondingly, measures of total soluble protein increased over 2.6-fold in these challenged tissues and were accompanied by elevated levels of sucrose and free linoleic acid. While microarray analyses revealed up-regulation of over 1100 transcripts, fewer individual protein increases were demonstrable. Consistent with induced endoreduplication, both wounding and ECB stem attack resulted in similar significant expansion of the nucleus, nucleolus and levels of extractable DNA from challenged tissues. While many of these responses are triggered by wounding alone, biochemical changes further enhanced in response to ECB may be due to larval secreted effectors. Unlike other Lepidoptera examined, ECB excrete exceedingly high levels of the auxin indole-3-acetic acid (IAA in their frass which is likely to contact and contaminate the surrounding feeding tunnel. Stem exposure to a metabolically stable auxin, such as 2,4-dichlorophenoxyacetic acid (2,4-D, promoted significant protein accumulation above wounding alone. As a future testable hypothesis, we propose that ECB-associated IAA may function as a candidate herbivore effector promoting the increased nutritional content of maize stems.

  7. Ostrinia revisited: Evidence for sex linkage in European Corn Borer Ostrinia nubilalis (Hubner pheromone reception

    Directory of Open Access Journals (Sweden)

    Heckel David G

    2010-09-01

    Full Text Available Abstract Background The European Corn Borer, Ostrinia nubilalis (Hubner, is a keystone model for studies on the evolution of sex pheromone diversity and its role in establishing reproductive isolation. This species consists of two sympatric races, each utilizing opposite isomers of the same compound as their major pheromone component. Female production and male response are congruent in each race, and males from each strain exhibit phenotypic differences in peripheral physiology. Both strains possess co-localized pheromone-sensitive olfactory sensory neurons characterized by a larger amplitude action potential (spike responding to the major pheromone component, and a smaller spike amplitude cell responding to the minor component, i.e. the opposite isomer. These differences in amplitude correspond to differences in dendritic diameter between the two neurons. Previous studies showed that behavioral response to the pheromone blend was sex-linked, but spike amplitude response to pheromone components matched autosomal, not sex-linked inheritance. Results As part of a larger study to finely map the loci responsible for pheromone communication in this species, we have reanalyzed peripheral physiology among parental, and first and second generation hybrids between the two pheromone strains using tungsten electrode electrophysiology. Our results reveal that differences in spike amplitude ratio between male pheromone-sensitive sensory neurons in O. nubilalis races are controlled, at least partially, by sex-linked genes that exhibit E-strain dominance. Conclusions We propose that peripheral olfactory response in O. nubilalis may be affected both by autosomal and sex-linked genes exhibiting a cross-locus dominance effect, and suggest that the genetic basis for pheromone reception and response in the species is more closely linked than previously thought.

  8. Role of the European corn borer (Ostrinia nubilalis) on contamination of maize with 13 Fusarium mycotoxins.

    Science.gov (United States)

    Blandino, Massimo; Scarpino, Valentina; Vanara, Francesca; Sulyok, Michael; Krska, Rudolf; Reyneri, Amedeo

    2015-01-01

    The European corn borer (ECB) plays an important role in promoting Fusarium verticillioides infections and in the consequent fumonisin contamination in maize grain in temperate areas. The objective of this study was to evaluate whether the ECB feeding activity could also affect the occurrence of emerging mycotoxins in maize kernels. During the 2008-10 period, natural infestation of the insect was compared, in field research, with the protection of infestation, which was obtained by using an entomological net. The ears collected in the protected plots were free from ECB attack, while those subject to natural insect attacks showed a damage severity that varied from 10% to 25%. The maize samples were analysed by means of an LC-MS/MS-based multi-mycotoxin method, which led to the detection of various metabolites: fumonisins (FUMs), fusaproliferin (FUS), moniliformin (MON), bikaverin (BIK), beauvericin (BEA), fusaric acid (FA), equisetin (EQU), deoxynivalenol (DON), deoxynivalenol-3-glucoside (DON-3-G), zearalenone (ZEA), culmorin (CULM), aurofusarin (AUR) and butenolide (BUT). The occurrence of mycotoxins produced by Fusarium spp. of Liseola section was affected significantly by the ECB feeding activity. The presence of ECB injuries increased the FUMs from 995 to 4694 µg kg(-1), FUS from 17 to 1089 µg kg(-1), MON from 22 to 673 µg kg(-1), BIK from 58 to 377 µg kg(-1), BEA from 6 to 177 µg kg(-1), and FA from 21 to 379 µg kg(-1). EQU, produced by F. equiseti section Gibbosum, was also increased by the ECB activity, by 1-30 µg kg(-1) on average. Instead, the content of mycotoxins produced by Fusarium spp. of Discolor and Roseum sections was not significantly affected by ECB activity. As for FUMs, the application of a strategy that can reduce ECB damage could also be the most effective solution to minimise the other mycotoxins produced by Fusarium spp. of Liseola section.

  9. Concerted evolution of male and female display traits in the European corn borer, Ostrinia nubilalis

    Directory of Open Access Journals (Sweden)

    Löfstedt Christer

    2009-03-01

    Full Text Available Abstract Background Sexual reproduction entails the encounter of the sexes and the multiplicity of rituals is parallel to the diversity of mating systems. Evolutionary mechanisms such as sexual selection and sexual conflict have led to the elaboration of traits to gain attention and favours from potential partners. A paradox exists about how coordinated systems can evolve and diverge when there would seem to be a stabilising selection acting. Moth display traits – pheromones – constitute an advantageous model with which to address questions about the evolution of mating systems in animals. Both males and females can possess pheromones that are involved either in close- or long-range communication. Female and male pheromones appear to have different origins and to be under different evolutionary constraints, thus they might be envisioned as independently evolving traits. We conducted laboratory experiments to explore the role of scents released during courtship by males of the European corn borer, Ostrinia nubilalis. Results Information provided by the male pheromone appears critical for female acceptance. The composition of this male pheromone varies in an age-dependent manner and females show mating preference towards older males in choice experiments. Furthermore, male signals may allow species discrimination and reinforce reproductive isolation. Finally, we found evidence for a genetic correlation between male and female signals, the evolution of which is best explained by the constraints and opportunities resulting from the sharing of gene products. Conclusion In this study we used an integrative approach to characterise the male sex pheromone in a moth. Interestingly, the male chemical signal is analogous to the female signal in that structurally similar compounds are being used by both sexes. Hence, in systems where both sexes possess display traits, the pleiotropy of genes generating the traits could influence the evolutionary

  10. Screening for corn rootworm (Coleoptera: Chrysomelidae) resistance to transgenic Bt corn in North Dakota

    Science.gov (United States)

    Western (WCR), Diabrotica virgifera virgifera LeConte, and northern corn rootworms (NCR), D. barberi Smith & Lawrence, are major economic pests of corn in much of the U.S. Corn Belt. Western corn rootworm resistance to transgenic corn expressing Bt (Bacillus thuringiensis) endotoxins has been confi...

  11. Homology of olfactory receptor neuron response characteristics inferred from hybrids between Asian and European corn borer moths (Lepidoptera: Crambidae).

    Science.gov (United States)

    Domingue, Michael J; Musto, Callie J; Linn, Charles E; Roelofs, Wendell L; Baker, Thomas C

    2010-01-01

    First generation hybrid males from crosses between the Asian corn borer (ACB), Ostrinia furnacalis, and the "univoltine Z-strain" European corn borer (ECB), Ostrinia nubilalis, were examined with respect to behavioral and physiological responses to ACB and ECB pheromones. The hybrid males often flew to the pheromone of ECB Z-strain, but very rarely to the ACB pheromone. We mapped the tuning profiles of each ORN of the F(1) hybrids with respect to the relevant pheromone components and a common behavioral antagonist by employing differential cross-adaptation and varying doses of the ligands. In the trichoid sensilla of F(1) hybrid males, the three co-compartmentalized ORNs produced spikes that were very difficult to distinguish by size, unlike the parental populations. Comparing the responses to ACB and ECB components at different doses reveals overlapping profiles similar to males of both parental types, but more responsiveness to the ECB pheromone components. We were unable to detect any differences in the ORN tuning profiles when comparing males with different behavioral phenotypes. While the two ECB pheromone races have similar ORN tuning properties that are different from those in ACB, the spike-amplitude patterns of ECB E-strain and ACB have greater homology when compared to ECB Z-strain.

  12. Comparison of fumonisin contamination using HPLC and ELISA methods in Bt and near-isogenic maize hybrids infested with European corn borer or Western bean cutworm

    Science.gov (United States)

    Field trials were conducted (2007 to 2010) to compare grain fumonisin levels among non-Bt maize hybrids and Bt hybrids with transgenic protection against European corn borer and Western bean cutworm (WBC). High-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA) w...

  13. Spatial and temporal genetic analyses reveal high gene flow among European corn borer (Lepidoptera: Crambidae) populations across the central U.S. cornbelt

    Science.gov (United States)

    European corn borer, Ostrinia nubilalis (Hubner), adults were sampled at 13 sites along two perpendicular 720-km transects intersecting in central Iowa, and for the following two generations at four of the same sites separated by 240-km in the cardinal directions. More than 50 mo...

  14. Research on Corn Borer Prevention by Using Beauveria Bassiana Sealing Method%白僵菌封垛防治玉米螟研究

    Institute of Scientific and Technical Information of China (English)

    陈佳广

    2014-01-01

    Corn borer is one of the main pests of maize crops. Using beauveria bassiana sealing method can decrease the quantity of corn borer larva. The article introduces the features and growing condition of corn borer, expounds the theory, methods, effects, considerations and advantages of using beauveria bassiana sealing method for corn borer prevention, provides a reference for the application and extension for the technique.%玉米螟是危害玉米作物的主要害虫之一,利用白僵菌可以有效减少玉米螟幼虫数量。介绍玉米螟的危害特点与发生条件,阐述白僵菌封垛防治玉米螟技术的原理、方法、效果、注意事项及优点,为该技术的推广应用提供参考。

  15. Interspecific variation in resistance to emerald ash borer (Coleoptera: Buprestidae) among North American and Asian ash (Fraxinus spp.).

    Science.gov (United States)

    Rebek, Eric J; Herms, Daniel A; Smitley, David R

    2008-02-01

    We conducted a 3-yr study to compare the susceptibility of selected North American ash and an Asian ash species to emerald ash borer, Agrilus planipennis Fairmaire, an invasive wood-boring beetle introduced to North America from Asia. Because of a coevolutionary relationship between Asian ashes and emerald ash borer, we hypothesized an Asian ash species, Manchurian ash, is more resistant to the beetle than its North American congeners. Consistent with our hypothesis, Manchurian ash experienced far less mortality and yielded far fewer adult beetles than several cultivars of North American green and white ash. Surprisingly, a black ash (North American) x Manchurian ash hybrid was highly susceptible to emerald ash borer, indicating this cultivar did not inherit emerald ash borer resistance from its Asian parent. A corollary study investigated the efficacy of soil-applied imidacloprid, a systemic, neonicotinoid insecticide, for controlling emerald ash borer in each of the five cultivars. Imidacloprid had no effect on emerald ash borer colonization of Manchurian ash, which was low in untreated and treated trees. In contrast, imidacloprid did enhance survival of the North American and hybrid cultivars and significantly reduced the number of emerald ash borer adults emerging from green and white ash cultivars. We identify a possible mechanism of resistance of Manchurian ash to emerald ash borer, which may prove useful for screening, selecting, and breeding emerald ash borer-resistant ash trees.

  16. Relationship between maize stem structural characteristics and resistance to pink stem borer (Lepidoptera: Noctuidae) attack.

    Science.gov (United States)

    Santiago, R; Souto, X C; Sotelo, J; Butrón, A; Malvar, R A

    2003-10-01

    The pink stem borer, Sesamia nonagrioides (Lefebvre), is one of the most important insect pests of maize (Zea mays L.) in northwestern Spain. The objectives of this work were to evaluate, at different times during the growth of maize, structural traits related to the entry point and tissues on which larvae feed and to determine the relationship between these structural traits and the stem borer resistance. Six inbred lines with different levels of stem resistance to S. nonagrioides were evaluated in several trials. Potential structural resistance factors included rind and pith puncture resistance (RPR and PPR), rind thickness, length of the meristematic area (LMA), and pith parenchyma interlumen thickness (PPIT). Surprisingly, the inbred lines that showed the strongest stalks, EP42 and EP47, were not stem resistant to pink stem borer attack, while the stem resistant inbreds A509, CM151, and PB130 were among the least resistant to rind puncture. There were no significant differences among resistant and susceptible inbreds for the rind thickness. However, the susceptible inbred EP42 had the softest internode pith, and the resistant inbred PB130 showed the hardest, as was expected. Susceptible inbred lines in general showed higher values for the LMA, while the PPIT was important for individual inbreds. The results suggest that the usefulness of these characters as estimators of pink stem borer resistance is limited to some genotypes. Besides, even among those genotypes, other mechanisms of resistance that do not involve stalk strength could be present. Among the traits considered, the LMA was the most promising as an indicator of resistance to pink stem borer, although further experimentation is necessary.

  17. A relative resistance Ratio for Evaluation of Stem Borer Susceptibility Among Sugarcane Cultivars

    Science.gov (United States)

    The Mexican rice borer, Eoreuma loftini (Dyar), is a major pest of sugarcane in Louisiana and Texas. Cultivar resistance to E. loftini was evaluated in commercial and experimental sugarcane cultivars in four replicated field studies between 2009 and 2012. A relative resistance ratio was developed t...

  18. Estimating E-Race European Corn Borer (Lepidoptera: Crambidae) Adult Activity in Snap Bean Fields Based on Corn Planting Intensity and Their Activity in Corn in New York Agroecosystems.

    Science.gov (United States)

    Schmidt-Jeffris, Rebecca A; Huseth, Anders S; Nault, Brian A

    2016-07-24

    European corn borer, Ostrinia nubilalis (Hübner), is a major pest of processing snap bean because larvae are contaminants in pods. The incidence of O. nubilalis-contaminated beans has become uncommon in New York, possibly because widespread adoption of Bt field corn has suppressed populations. Snap bean fields located where Bt corn has been intensively grown in space and time may be at lower risk for O. nubilalis than fields located where Bt corn is not common. To manage O. nubilalis infestation risk, growers determine insecticide application frequency in snap bean based on pheromone-trapping information in nearby sweet corn fields; adult activity is presumed equivalent in both crops. Our goal was to determine if corn planting intensity and adult activity in sweet corn could be used to estimate O. nubilalis populations in snap bean in New York in 2014-2015. Numbers of O nubilalis adults captured in pheromone-baited traps located in snap bean fields where corn was and was not intensively grown were similar, suggesting that O. nubilalis does not respond to local levels of Bt corn in the landscape. Numbers of Ostrinia nubilalis captured in pheromone-baited traps placed by snap bean fields and proximal sweet corn fields were not related, indicating that snap bean growers should no longer make control decisions based on adult activity in sweet corn. Our results also suggest that the risk of O. nubilalis infestations in snap bean is low (∼80% of the traps caught zero moths) and insecticide applications targeting this pest should be reduced or eliminated. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Flight Tunnel Response of Male European Corn Borer Moths to Cross-Specific Mixtures of European and Asian Corn Borer Sex Pheromones: Evidence Supporting a Critical Stage in Evolution of a New Communication System.

    Science.gov (United States)

    Martin, Nathan; Moore, Kevin; Musto, Callie J; Linn, Charles E

    2016-01-01

    Previous flight tunnel studies showed that 3-5 % of male European corn borer (ECB) moths, Ostrinia nubilalis, could fly upwind and make contact with sources releasing the sex pheromone of the closely related Asian corn borer (ACB), Ostrina furnacalis, [2:1 (Z)-12-tetradecenyl acetate (Z12-14:OAc) : (E)-12-teradecenyl acetate (E12-14:OAc)] and that 2-4 % of ACB males could similarly fly upwind to the sex pheromone blends of the ECB Z- [97:3 (Z)-tetradecenyl acetate (Z11-14:OAc) : (E)-tetradecenyl acetate (E11-14:Ac)] and E-strains (1:99 Z/E11-14:OAc) pheromones. The results supported the hypothesis that the evolution of the ACB pheromone system from an ECB-like ancestor included a stage in which males could be attracted to the unusual females emitting Z12- and E12-14:OAc while retaining their responsiveness to the ancestral pheromone blend of Z11- and E11-14:OAc. Here, we showed further that ECB E-strain males exhibited upwind oriented flight and source contacts to sources containing all combinations of ECB and ACB components. Maximal response levels were observed with the E-strain 99:1 E11/Z11-14:OAc blend, and high response levels also were observed with two other blends containing E11-14:OAc as the major component (E11:E12 and E11:Z12). Upwind flight and source contact also occurred at lower levels with the remaining blend combinations in which Z11-, E12-, or Z12-14:OAc was the major component. Our current results support the hypothesis concerning the evolution of ACB from an ECB-like ancester by showing that males were able to respond to females producing either the 12-14:Ac isomers, 11-14:Ac isomers, or even mixtures of all four components.

  20. Overview on current status of biotechnological interventions on yellow stem borer Scirpophaga incertulas (Lepidoptera: Crambidae) resistance in rice.

    Science.gov (United States)

    Deka, Sikha; Barthakur, Sharmistha

    2010-01-01

    Yellow stem borer (YSB), Scirpophaga incertulas (Lepidoptera: Crambidae), a monophagous pest of paddy is considered as most important pest of rain fed low land and flood prone rice eco-systems. Breeding of yellow stem borer resistance in rice is difficult owing to the complex genetics of the trait, inherent difficulties in screening and poor understanding of the genetics of resistance. On the other hand, a good level of resistance against the widespread yellow stem borer has been rare in the rice germplasm. Resistance to insects has been demonstrated in transgenic plants expressing genes for delta-endotoxins from Bacillus thuringiensis (Bt), protease inhibitors, enzymes and plant lectins. The performance of insect resistant GM rice in trials in China has been quite impressive. The present review is an attempt to assess the current state of development in biotechnological intervention for yellow stem borer resistance in rice.

  1. Cross-pollination of nontransgenic corn ears with transgenic Bt corn: efficacy against lepidopteran pests and implications for resistance management.

    Science.gov (United States)

    Burkness, E C; O'Rourke, P K; Hutchison, W D

    2011-10-01

    The efficacy of nontransgenic sweet corn, Zea mays L., hybrids cross-pollinated by Bacillus thuringiensis (Bt) sweet corn hybrids expressing Cry1Ab toxin was evaluated in both field and laboratory studies in Minnesota in 2000. Non-Bt and Bt hybrids (maternal plants) were cross-pollinated with pollen from both non-Bt and Bt hybrids (paternal plants) to create four crosses. Subsequent crosses were evaluated for efficacy in the field against European corn borer, Ostrinia nubilalis (Hübner), and corn earworm, Helicoverpa zea (Boddie), and in laboratory bioassays against O. nubilalis. Field studies indicated that crosses with maternal Bt plants led to low levels of survival for both O. nubilalis and H. zea compared with the non-Bt x non-Bt cross. However, the cross between non-Bt ears and Bt pollen led to survival rates of 43 and 63% for O. nubilalis and H. zea larvae, respectively. This intermediate level of survival also was reflected in the number of kernels damaged. Laboratory bioassays for O. nubilalis, further confirmed field results with larval survival on kernels from the cross between non-Bt ears and Bt pollen reaching 60% compared with non-Bt crossed with non-Bt. These results suggest that non-Bt refuge plants, when planted in proximity to Bt plants, and cross-pollinated, can result in sublethal exposure of O. nubilalis and H. zea larvae to Bt and may undermine the high-dose/refuge resistance management strategy for corn hybrids expressing Cry1Ab.

  2. Impact on bacterial community in midguts of the Asian corn borer larvae by transgenic Trichoderma strain overexpressing a heterologous chit42 gene with chitin-binding domain.

    Science.gov (United States)

    Li, Yingying; Fu, Kehe; Gao, Shigang; Wu, Qiong; Fan, Lili; Li, Yaqian; Chen, Jie

    2013-01-01

    This paper is the first report of the impact on the bacterial community in the midgut of the Asian corn borer (Ostrinia furnacalis) by the chitinase from the transgenic Trichoderma strain. In this study, we detected a change of the bacterial community in the midgut of the fourth instar larvae by using a culture-independent method. Results suggested that Proteobacteria and Firmicutes were the most highly represented phyla, being present in all the midgut bacterial communities. The observed species richness was simple, ranging from four to five of all the 16S rRNA clone libraries. When using Trichoderma fermentation liquids as additives, the percentages of the dominant flora in the total bacterial community in larval midgut changed significantly. The community of the genus Ochrobactrum in the midgut decreased significantly when the larvae were fed with the fermentation liquids of the transgenic Trichoderma strain Mc4. However, the Enterococcus community increased and then occupied the vacated niche of the Ochrobactrum members. Furthermore, the Shannon-Wiener (H) and the Simpson (1-D) indexes of the larval midgut bacterial library treated by feeding fermentation liquids of the transgenic Trichoderma strain Mc4 was the lowest compared with the culture medium, fermentation liquids of the wild type strain T30, and the sterile artificial diet. The Enterococcus sp. strain was isolated and characterized from the healthy larvae midgut of the Asian corn borer. An infection study of the Asian corn borer larvae using Enterococcus sp. ACB-1 revealed that a correlation existed between the increased Enterococcus community in the larval midgut and larval mortality. These results demonstrated that the transgenic Trichoderma strain could affect the composition of the midgut bacterial community. The change of the midgut bacterial community might be viewed as one of the factors resulting in the increased mortality of the Asian corn borer larvae.

  3. Impact on bacterial community in midguts of the Asian corn borer larvae by transgenic Trichoderma strain overexpressing a heterologous chit42 gene with chitin-binding domain.

    Directory of Open Access Journals (Sweden)

    Yingying Li

    Full Text Available This paper is the first report of the impact on the bacterial community in the midgut of the Asian corn borer (Ostrinia furnacalis by the chitinase from the transgenic Trichoderma strain. In this study, we detected a change of the bacterial community in the midgut of the fourth instar larvae by using a culture-independent method. Results suggested that Proteobacteria and Firmicutes were the most highly represented phyla, being present in all the midgut bacterial communities. The observed species richness was simple, ranging from four to five of all the 16S rRNA clone libraries. When using Trichoderma fermentation liquids as additives, the percentages of the dominant flora in the total bacterial community in larval midgut changed significantly. The community of the genus Ochrobactrum in the midgut decreased significantly when the larvae were fed with the fermentation liquids of the transgenic Trichoderma strain Mc4. However, the Enterococcus community increased and then occupied the vacated niche of the Ochrobactrum members. Furthermore, the Shannon-Wiener (H and the Simpson (1-D indexes of the larval midgut bacterial library treated by feeding fermentation liquids of the transgenic Trichoderma strain Mc4 was the lowest compared with the culture medium, fermentation liquids of the wild type strain T30, and the sterile artificial diet. The Enterococcus sp. strain was isolated and characterized from the healthy larvae midgut of the Asian corn borer. An infection study of the Asian corn borer larvae using Enterococcus sp. ACB-1 revealed that a correlation existed between the increased Enterococcus community in the larval midgut and larval mortality. These results demonstrated that the transgenic Trichoderma strain could affect the composition of the midgut bacterial community. The change of the midgut bacterial community might be viewed as one of the factors resulting in the increased mortality of the Asian corn borer larvae.

  4. Construction of transgenic Trichoderma koningi with chit42 of Metarhizium anisopliae and analysis of its activity against the Asian corn borer.

    Science.gov (United States)

    Li, Ying Y; Tang, Jun; Fu, Ke H; Gao, Shi G; Wu, Qiong; Chen, Jie

    2012-01-01

    The chit42 gene was cloned from Metarhizium anisopliae CY1 and was inserted into Trichoderma koningii T30 genome by protoplast transformation. Sixteen transgenic isolates were identified by polymerase chain reaction analysis. The chit42 gene was 1275 bp in length and its coded protein was approximately 42 kDa in size. Semi-quantitative RT-PCR analysis and the measurement of the chitinase activity under induced conditions were conducted. Mortality of the Asian corn borer (Ostrinia furnacalis) was used for assessing efficacy of culture filtrates and conidial suspensions of transgenic Trichoderma strains against the insect. The results indicated that the transgenic Trichoderma strain harboring chit42 gene from Metarhizium anisopliae CY1 showed significant lethal effect on the Asian corn borer larvae. Study on growth inhibition of silkworm (Bombyx mori) larvae was carried out. The transgenic Trichoderma could better hinder the growth and development of the silkworm larvae than the wild-type Trichoderma did. The inhibition to the expression of three genes associated with development and anti-stress response in the mid-gut of the Asian corn borer larvae was more significant in the transcriptional level after larvae were fed with transgenic biomass than with the wild type. Evaluation of inhibition on the growth of maize ear rot pathogens was carried out in vitro test and the transgenic strains kept antagonistic activity against Fusarium verticilloides.

  5. Resistance of corn genotypes to fall armyworm Spodoptera ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-08-31

    Aug 31, 2016 ... The objective of this study was to evaluate resistance mechanisms in 12 corn genotypes (transgenic hybrids: ..... FAW that fed on GM corn genotypes exhibited lower ... preference for other food types, particularly given the.

  6. Differential resistance reaction of maize genotypes to maize stem borer (Chilo partellus Swinhoe at Chitwan, Nepal

    Directory of Open Access Journals (Sweden)

    Ghanashyam Bhandari

    2016-12-01

    Full Text Available Maize stem borer (MSB, Chilo partellus Swinhoe, Lepidoptera: Pyralidae is one of the most important insect pest of maize in Nepal. Host plant resistance is the cost-effective, ecologically sound and stable approach to reduce damage by stem borers. Forty four maize genotypes were screened for resistance to maize stem borer at the research field of National Maize Research Program, Rampur during spring seasons (March to June of two consecutive years 2013 and 2014. The maize genotypes were evaluated in randomized complete block design with three replications and data were collected on foliar damage rating, tunnel length and number of exit holes made by the borer. The foliar damage and tunnel length damage were significant for genotypes for both the years. The exit holes were not significant in 2013 but significant in 2014 ranging from 2-6 scale. The foliar rating ranged from 2 to 5.5 in 2013 and 1.1 to 4.5 in 2014 on a 1-9 rating scale. The highly resistant genotypes (10 cm scale. The least susceptible genotypes (<5 cm were RampurSO3F8, RampurSO3FQ02 and RampurS10F18. The genotypes having least exit holes (2.0 in 2014 were RampurSO3F8, RampurSO3FQ02, RampurS10F18. Thus less damage parameters were observed in R-POP-2, RML-5/RML-8, RampurSO3F8, RampurSO3FQ02 and RampurS10F18 and therefore they can be used as parents or as sources of resistance in breeding program.

  7. Microbial diversity in the midguts of field and lab-reared populations of the European corn borer Ostrinia nubilalis.

    Directory of Open Access Journals (Sweden)

    Eugeni Belda

    Full Text Available BACKGROUND: Insects are associated with microorganisms that contribute to the digestion and processing of nutrients. The European Corn Borer (ECB is a moth present world-wide, causing severe economical damage as a pest on corn and other crops. In the present work, we give a detailed view of the complexity of the microorganisms forming the ECB midgut microbiota with the objective of comparing the biodiversity of the midgut-associated microbiota and explore their potential as a source of genes and enzymes with biotechnological applications. METHODOLOGICAL/PRINCIPAL FINDINGS: A high-throughput sequencing approach has been used to identify bacterial species, genes and metabolic pathways, particularly those involved in plant-matter degradation, in two different ECB populations (field-collected vs. lab-reared population with artificial diet. Analysis of the resulting sequences revealed the massive presence of Staphylococcus warneri and Weissella paramesenteroides in the lab-reared sample. This enabled us to reconstruct both genomes almost completely. Despite the apparently low diversity, 208 different genera were detected in the sample, although most of them at very low frequency. By contrast, the natural population exhibited an even higher taxonomic diversity along with a wider array of cellulolytic enzyme families. However, in spite of the differences in relative abundance of major taxonomic groups, not only did both metagenomes share a similar functional profile but also a similar distribution of non-redundant genes in different functional categories. CONCLUSIONS/SIGNIFICANCE: Our results reveal a highly diverse pool of bacterial species in both O. nubilalis populations, with major differences: The lab-reared sample is rich in gram-positive species (two of which have almost fully sequenced genomes while the field sample harbors mainly gram-negative species and has a larger set of cellulolytic enzymes. We have found a clear relationship between the

  8. Effects of Droplet Distribution on Insecticide Toxicity to Asian Corn Borers (Ostrinia furnaealis) and Spiders (Xysticus ephippiatus)

    Institute of Scientific and Technical Information of China (English)

    YANG Dai-bin; ZHANG Lin-na; YAN Xiao-jing; WANG Zhen-ying; YUAN Hui-zhu

    2014-01-01

    Distribution of horizontal boom produced droplets downwards into maize canopies at lfowering period and its effects on the efifcacies of emamectin benzoate, lambda-cyhalothrin and chlorantraniliprole against the second generation of Asian corn borer (ACB) larvae and their toxicity to spiders were studied. When insecticides were sprayed downwards into the maize canopies, randomly ifltering out droplets by upper leaves led to great variations of droplet coverage and density within the canopies. Consequently, the efifcacies of lambda-cyhalothrin and emamectin benzoate against ACB larvae were decreased because of randomly filtering out droplets by upper leaves. But field investigation showed that lambda-cyhalothrin was extremely toxic to hunting spiders, Xysticus ephippiatus, and not suitable to IPM programs in regulation of the second generation of ACB. Therefore,randomly ifltering out droplets by upper leaves decreased lambda-cyhalothrin’s efifcacy against ACB larvae, but did little to decrease its toxicity to X. ephippiatus. Amamectin benzoate can reduce the populations of X. ephippiatus by 58.1-61.4%, but the populations can recover at the end of the experiment. Chlorantraniliprole was relatively safe to X. ephippiatus. It only reduced the populations of X. ephippiatus by 22.3-33.0%, and the populations can totally recover 9 d after application.

  9. Host-specific salivary elicitor(s) of European corn borer induce defenses in tomato and maize.

    Science.gov (United States)

    Louis, Joe; Peiffer, Michelle; Ray, Swayamjit; Luthe, Dawn S; Felton, Gary W

    2013-07-01

    Plants turn on induced defenses upon insect herbivory. In the current study, we evaluated the role of European corn borer (ECB) elicitors (molecules secreted by herbivores) that either induce/suppress defenses in Solanum lycopersicum (tomato) and Zea mays (maize), two very important crop plants that are grown for food and/or fuel throughout the world. We used a combination of molecular, biochemical, confocal and scanning electron microscopy, caterpillar spinneret ablation/cauterization, and conventional insect bioassay methods to determine the role of ECB elicitors in modulating defenses in both tomato and maize crop plants. Our results clearly demonstrate that the components present in the ECB saliva induce defense-related proteinase inhibitors in both tomato (PIN2) and maize (MPI). Presence of glucose oxidase in the ECB saliva induced defenses in tomato, but not in maize. However, ECB saliva induced genes present in the jasmonic acid biosynthesis pathway in both tomato and maize. Although ECB saliva can induce defenses in both tomato and maize, our results suggest that host-specific salivary components are responsible for inducing host plant defenses. Proteomic analysis of ECB salivary elicitors and plant receptors/signaling mechanisms involved in recognizing different ECB elicitors remains to be determined. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  10. Development of transgenic sorghum for insect resistance against the spotted stem borer (Chilo partellus).

    Science.gov (United States)

    Girijashankar, V; Sharma, H C; Sharma, Kiran K; Swathisree, V; Prasad, L Sivarama; Bhat, B V; Royer, Monique; Secundo, Blanca San; Narasu, M Lakshmi; Altosaar, I; Seetharama, N

    2005-11-01

    Transgenic sorghum plants expressing a synthetic cry1Ac gene from Bacillus thuringiensis (Bt) under the control of a wound-inducible promoter from the maize protease inhibitor gene (mpiC1) were produced via particle bombardment of shoot apices. Plants were regenerated from the transformed shoot apices via direct somatic embryogenesis with an intermittent three-step selection strategy using the herbicide Basta. Molecular characterisation based on polymerase chain reaction and Southern blot analysis revealed multiple insertions of the cry1Ac gene in five plants from three independent transformation events. Inheritance and expression of the Bt gene was confirmed in T(1) plants. Enzyme-linked immunosorbant assay indicated that Cry1Ac protein accumulated at levels of 1-8 ng per gram of fresh tissue in leaves that were mechanically wounded. Transgenic sorghum plants were evaluated for resistance against the spotted stem borer (Chilo partellus Swinhoe) in insect bioassays, which indicated partial resistance to damage by the neonate larvae of the spotted stem borer. Reduction in leaf damage 5 days after infestation was up to 60%; larval mortality was 40%, with the surviving larvae showing a 36% reduction in weight over those fed on control plants. Despite the low levels of expression of Bt delta-endotoxin under the control of the wound-inducible promoter, the transgenic plants showed partial tolerance against first instar larvae of the spotted stem borer.

  11. Transgenic rice plants expressing cry1Ia5 gene are resistant to stem borer (Chilo agamemnon).

    Science.gov (United States)

    Moghaieb, Reda E A

    2010-01-01

    The stem borer, Chilo agamemnon Bles., is the most serious insect pest in rice fields of the Egyptian Nile Delta. To induce rice plant resistance to Chilo agamemnon, the cry1Ia5 gene was introduced to rice plants (Oryza sativa L.). The integration of the cry1Ia5 gene into the plant genome was confirmed using PCR and Southern blot analyses. The obtained plantlets were transferred to the greenhouse until seeds were collected. Northern blot analysis of the T1 plants confirmed the expression of the cry1Ia5 gene. The insecticidal activity of the transgenic plants against the rice stem borer Chilo agamemnon were tested. The third larval instars were fed on stem cuts from three transgenic lines (L1, L2 and L3) as well as cuts from the control (gfp-transgenic) plants for one week and the mortality percentage was daily recorded. Transgenic line-3 showed the highest mortality percentage after one day (50%) followed by L2 (25%) then L1 (0%). Two days post treatment the mortality percentage increased to 70, 45 and 25% for transgenic lines 1, 2 and 3 respectively. Mortality of 100% was recorded four days post treatment, while those fed on the gfp-transgenic rice (control) showed 0% mortality. Thus, transgenic plants showed high resistance to stem borers and can serve as a novel genetic resource in breeding programs. Transgenic plants expressing BT protein were normal in phenotype with as good seed setting as the nontransgenic control plants.

  12. Erianthus: A sugarcane relative with potential as a source of resistance to the stem borer Diatraea saccharalis (Lepidoptera: Crambidae)

    Science.gov (United States)

    Plant resistance can play an important role in IPM strategies to reduce damage from infestations of stem borers. However, resistance, when it is present, is often negatively associated with yield potential. There exists then, a need to identify sources of resistance that have no adverse effect on su...

  13. FLIGHT OF THE EUROPEAN CORN BORER (OSTRINIA NUBILALIS HBN. AS FOLLOWED BY LIGHT- AND PHEROMONE TRAPS IN VÁRDA AND BALATONMAGYARÓD 2002

    Directory of Open Access Journals (Sweden)

    S KESZTHELYI

    2003-07-01

    Full Text Available The investigations were made in 2002 in the outskirts of two settlements: Balatonmagyaród (Zala county and Várda (Somogy county. In the corn fields Jermy’s light- and Arco-Pheron MZ pheromone traps were placed in order to follow up the course of flight. From the material collected the corn borer specimens were isolated, then separated by sex. The generation number of the populations appearing on the respective areas, and the characteristics of the flight were determined. The meteorological data of the areas obtained from Keszthely and Kaposvár for the period concerned were compared woth the data of flight. In that way the effect of the different meteorological elements on the flight and on the trend of the female ratio could be established. The results showed the presence of two-generation corn borer populations in both places. In Balatonmagyaród the first- while in Várda the second generation proved larger. The meteorological elements significally influenced the possibility of trapping in the case of both sexes. As for the female sex ratio close correlations were found with the minimum (P=100%; r=0.297-, maximum (P=99.9%; r=0.267-, average (P=100%; r=0.308 temperature and precipitation (P=98.2%; r=0.187 data. Considerable asynchrony was observed between the data obtained with the two prognostic means that we ascribed to the unreliability of the pheromone trap.

  14. Evaluation of the European Union Maize Landrace Core Collection for resistance to Sesamia nonagrioides (Lepidoptera: Noctuidae) and Ostrinia nubilalis (Lepidoptera: Crambidae).

    Science.gov (United States)

    Malvar, R A; Butrón, A; Alvarez, A; Ordás, B; Soengas, P; Revilla, L P; Ordás, A

    2004-04-01

    Two corn borer species are the principal maize insect pests in Europe, the European corn borer, Ostrinia nubilalis (Hübner), and the pink stem borer, Sesamia nonagrioides (Lefebvre). Hence, it would be advisable to evaluate the European maize germplasm for corn borer resistance to generate European varieties resistant to corn borer attack. The creation of the European Union Maize Landrace Core Collection (EUMLCC) allowed the screening of most of the variability for European corn borer resistance present among European maize local populations from France, Germany, Greece, Italy, Portugal, and Spain, testing a representative sample. The objective of this study was the evaluation of stem and ear resistance of the EUMLCC to European corn borer and pink stem borer attack. Trials were made at two Spanish locations that represent two very different maize-growing areas. Populations that performed relatively well under corn borer infestation for stem and ear damage were 'PRT0010008' and'GRC0010085', among very early landraces; 'PRT00100120' and 'PRT00100186', among early landraces; 'GRC0010174', among midseason landraces; and 'ESP0070441', among late landraces. Either the selection that could have happen under high insect pressure or the singular origin of determined maize populations would be possible explanations for the higher corn borer resistance of some landraces. Landraces 'PRT0010008', 'FRA0410090', 'PRT00100186', and 'ESP0090214' would be selected to constitute a composite population resistant to corn borers and adapted to short season, whereas populations 'ESP0090033', 'PRT00100530', 'GRC0010174', and 'ITA0370005' would be used to make a resistant composite adapted to longer season.

  15. Interspecific proteomic comparisons reveal ash phloem genes potentially involved in constitutive resistance to the emerald ash borer.

    Directory of Open Access Journals (Sweden)

    Justin G A Whitehill

    Full Text Available The emerald ash borer (Agrilus planipennis is an invasive wood-boring beetle that has killed millions of ash trees since its accidental introduction to North America. All North American ash species (Fraxinus spp. that emerald ash borer has encountered so far are susceptible, while an Asian species, Manchurian ash (F. mandshurica, which shares an evolutionary history with emerald ash borer, is resistant. Phylogenetic evidence places North American black ash (F. nigra and Manchurian ash in the same clade and section, yet black ash is highly susceptible to the emerald ash borer. This contrast provides an opportunity to compare the genetic traits of the two species and identify those with a potential role in defense/resistance. We used Difference Gel Electrophoresis (DIGE to compare the phloem proteomes of resistant Manchurian to susceptible black, green, and white ash. Differentially expressed proteins associated with the resistant Manchurian ash when compared to the susceptible ash species were identified using nano-LC-MS/MS and putative identities assigned. Proteomic differences were strongly associated with the phylogenetic relationships among the four species. Proteins identified in Manchurian ash potentially associated with its resistance to emerald ash borer include a PR-10 protein, an aspartic protease, a phenylcoumaran benzylic ether reductase (PCBER, and a thylakoid-bound ascorbate peroxidase. Discovery of resistance-related proteins in Asian species will inform approaches in which resistance genes can be introgressed into North American ash species. The generation of resistant North American ash genotypes can be used in forest ecosystem restoration and urban plantings following the wake of the emerald ash borer invasion.

  16. Interspecific proteomic comparisons reveal ash phloem genes potentially involved in constitutive resistance to the emerald ash borer.

    Science.gov (United States)

    Whitehill, Justin G A; Popova-Butler, Alexandra; Green-Church, Kari B; Koch, Jennifer L; Herms, Daniel A; Bonello, Pierluigi

    2011-01-01

    The emerald ash borer (Agrilus planipennis) is an invasive wood-boring beetle that has killed millions of ash trees since its accidental introduction to North America. All North American ash species (Fraxinus spp.) that emerald ash borer has encountered so far are susceptible, while an Asian species, Manchurian ash (F. mandshurica), which shares an evolutionary history with emerald ash borer, is resistant. Phylogenetic evidence places North American black ash (F. nigra) and Manchurian ash in the same clade and section, yet black ash is highly susceptible to the emerald ash borer. This contrast provides an opportunity to compare the genetic traits of the two species and identify those with a potential role in defense/resistance. We used Difference Gel Electrophoresis (DIGE) to compare the phloem proteomes of resistant Manchurian to susceptible black, green, and white ash. Differentially expressed proteins associated with the resistant Manchurian ash when compared to the susceptible ash species were identified using nano-LC-MS/MS and putative identities assigned. Proteomic differences were strongly associated with the phylogenetic relationships among the four species. Proteins identified in Manchurian ash potentially associated with its resistance to emerald ash borer include a PR-10 protein, an aspartic protease, a phenylcoumaran benzylic ether reductase (PCBER), and a thylakoid-bound ascorbate peroxidase. Discovery of resistance-related proteins in Asian species will inform approaches in which resistance genes can be introgressed into North American ash species. The generation of resistant North American ash genotypes can be used in forest ecosystem restoration and urban plantings following the wake of the emerald ash borer invasion.

  17. Parasitoid inventarisation of European corn borer (Ostrinia nubilalis Hübner, 1796 and options for its biological control in Slovenia

    Directory of Open Access Journals (Sweden)

    Jaka RAZINGER

    2016-04-01

    Full Text Available European corn borer (Ostrinia nubilalis (ECB is an important maize pest in central and northern Europe. Presently it is controlled by insecticides or biological agents such as Trichogramma brassicae in several European countries, excluding Slovenia, where the pest’s pressure is highly variable and no appropriate mechanization is available. Lessening the dependence on chemical pesticides is an integral part of the European Union’s agenda for agriculture. Mass release of Trichogramma spp. could be seen as a promising alternative for ECB control in countries with a highly fluctuating ECB pressure and no mechanization for insecticide applications. However, no records of naturally occurring hymenopteran parasitoids of ECB exist in Slovenia. To address this important under-researched topic and provide the expert basis for potential introduction of ECB egg parasitoids in Slovene maize production, a systematic inventarisation programme of ECB parasitoids was launched in 2010. Additionally, ECB flight was monitored in 2011 and 2012 at two locations in Slovenia: Jablje and Rakičan. In both locations two ECB generations  were observed. ECB was fist observed at the end of May in Rakičan. During the five years of the systematic survey we discovered two ECB parasitoid species. ECB egg masses were parasitized by Trichogramma brassicae, whereas ECB pupae were parasitized by Tycherus nigridens, with 6 or 7 % parasitation rate, respectively. T. nigridens represents a new taxon report for Slovenia. We conclude that there is a strong need for undertaking systematic surveys of natural enemies of agricultural pests.

  18. Development of stem borer resistant transgenic parental lines involved in the production of hybrid rice.

    Science.gov (United States)

    Ramesh, S; Nagadhara, D; Pasalu, I C; Kumari, A Padma; Sarma, N P; Reddy, V D; Rao, K V

    2004-07-15

    Stem borer resistant transgenic parental lines, involved in hybrid rice, were produced by Agrobacterium-mediated gene transfer method. Two pSB111 super-binary vectors containing modified cry1Ab/cry1Ac genes driven by maize ubiquitin promoter, and herbicide resistance gene bar driven by cauliflower mosaic virus 35S promoter were, used in this study. Embryogenic calli after co-cultivation with Agrobacterium were selected on the medium containing phosphinothricin. Southern blot analyses of primary transformants revealed the stable integration of bar, cry1Ab and cry1Ac coding sequences into the genomes of three parental lines with a predominant single copy integration and without any rearrangement of T-DNA. T1 progeny plants disclosed a monogenic pattern (3:1) of transgene segregation as confirmed by molecular analyses. Furthermore, the co-segregation of bar and cry genes in T1 progenies suggested that the transgenes are integrated at a single site in the rice genome. In different primary transformants with alien inbuilt resistance, the levels of cry proteins varied between 0.03 and 0.13% of total soluble proteins. These transgenic lines expressing insecticidal proteins afforded substantial resistance against stem borers. This is the first report of its kind dealing with the introduction of Bacillus thuringiensis (Bt) cry genes into the elite parental lines involved in the development of hybrid rice.

  19. Molecular changes in the maize composite EPS12 during selection for resistance to pink stem borer.

    Science.gov (United States)

    Butrón, A; Tarrío, R; Revilla, P; Ordás, A; Malvar, R A

    2005-04-01

    The pink stem borer (Sesamia nonagrioides Lefèvbre) is the most important pest of maize (Zea mays L.) throughout the Mediterranean area. The maize composite EPS12 has been chosen as the base population for a breeding program based on its resistance to pink stem borer, with the main selection criterion being resistance to stem tunneling. Yield was taken as a secondary selection criterion to avoid any unwanted negatively correlated response on this character. The aims of investigation were: (1) to monitor the effects of selection for resistance to pink stem borer on allele frequency at 70 simple sequence repeat (SSR) markers and their impact on the genetic structure of EPS12 and (2) to identify loci at which allelic frequencies changed significantly due to directional selection. Genetic diversity was reduced during the selection process (as expected since random genetic drift as well as selection could reduce genetic variability), but not significantly so. Although the loss of genetic variation was generally consistent with that expected in a model in which random genetic drift acts alone on neutral alleles, the changes observed in the frequency of five alleles were significantly greater than expected. Further, the linear trend of the departure from the random genetic drift model was significant for some allelic versions of two SSR markers, umc1329 and phi076; directional selection was therefore acting on these loci. The significant effect of directional selection on those markers suggests the presence of quantitative trait loci (QTLs) for tunnel length and/or for yield under artificial infestation with Sesamia nonagrioides on the long arm of chromosome 4.

  20. Silent genes and rare males: A fresh look at pheromone blend response specificity in the European corn borer moth, Ostrinia nubilalis

    Directory of Open Access Journals (Sweden)

    Charles Linn Jr.

    2003-05-01

    Full Text Available The response of male moths from two pheromone races of the European corn borer, Ostrinia nubilalis, was measured in a flight tunnel assay to different ratios of structurally different compounds that comprise the sex pheromone of the Asian corn borer, Ostrinia furnacalis. For both O. nubilalis races, between 1 and 5% of the males completed upwind flights to two different blends of the O. furnacalis pheromone components (the 2:1 Z/E12-14:OAc female-produced blend, and a 97:3 Z/E mix, confirming that rare males exist in the O. nubilalis populations that can detect and respond to mixtures of the O. furnacalis pheromone components. Rare males that responded to the O. furnacalis blends also responded to their own O. nubilalis blends (97:3 or 1:99 Z/E11-14:OAc, indicating that rare O. nubilalis males are not preferentially sensitive to mixtures of the O. furnacalis compounds, but rather that they have a broad range of response specificity, which includes recognition of a wide range of conspecific female-produced ratios, and also recognition of heterospecific mixtures. The results support the hypothesis that saltational shifts in pheromone blend composition (Roelofs et al., 2002 can lead to the evolution of a new species-specific communication system, in part because the broad response specificity of some males includes the ability to respond in an agonistic manner to novel mixtures of compounds.

  1. Repetitive Genomic Elements in a European Corn Borer, Ostrinia nubilalis, BAC Library were Indicated by BAC End Sequencing and Development of Sequence Tag Site Markers: Implications for Lepidopteran Genomic Research

    Science.gov (United States)

    The European corn borer, Ostrinia nubilalis, is a serious pest of food, fiber, and biofuel crops in Europe, North America, and Asia, and a model system for insect olfaction and speciation. A bacterial artificial chromosome (BAC) library constructed for O. nubilalis contains 36,864 clones with estim...

  2. Identification and Evaluation on the Resistance to Insect Pest and Disease of Sweet and Waxy Corn Varieties%甜糯玉米新品种抗病虫性的鉴定与评价

    Institute of Scientific and Technical Information of China (English)

    王桂跃; 俞琦英; 谭禾平; 韩海亮; 苏婷

    2012-01-01

    From 2002 to 2010, two hundred and fifty new varieties of sweet and waxy com were chosen to identify on resistance to northern corn leaf blight(NCLB), southern corn leaf blight(SCLB), corn stalk rot(CSR) and corn borer (CB), respectively. The results showed that the average disease levels were significantly different between years, while the borer level was not significantly different. Among all varieties, 80.0% were moderately resistant or better to NCLB, 76.4% were moderately resistant or better to SCLB, 77.2% were moderately resistant or better to stalk rot, while there was only 5.8% moderately resistant or better to corn borer. According to different types of corn, sweet corn showed the better comprehensive resistance than waxy corn. What's more, twelve varieties of sweet corn such as "Micui 678", "Huazhen", "Lvsechaoren" , etc., and ten varieties of waxy corn such as "Zhenuoyu 4", "Jintianzihuanuo" and so on, those showed the stronger resistance to diseases and borer.%2002~2010年对250个甜、糯玉米新品种进行玉米大斑病、小斑病、茎腐病和亚洲玉米螟的抗性鉴定.结果表明,不同年份间的平均病害级别差异显著,玉米螟的食叶级别无显著差异.所有鉴定品种中,对大斑病表现中抗以上的占80.0%,对小斑病表现中抗以上的占76.4%,对茎腐病表现中抗以上的占77.2%,对玉米螟表现中抗及以上的仅占5.8%.根据玉米类型分析,甜玉米的综合抗性高于糯玉米,甜玉米品种“蜜脆678”、“华珍”和“绿色超人”等12个品种以及糯玉米“浙糯玉4号”和“京甜紫花糯”等10个品种的综合抗性较佳,表现出较强的抗病虫性.

  3. Regeneration of sugarcane elite breeding lines and engineering of stem borer resistance.

    Science.gov (United States)

    Weng, Li-Xing; Deng, Haihua; Xu, Jin-Ling; Li, Qi; Wang, Lian-Hui; Jiang, Zide; Zhang, Hai Bao; Li, Qiwei; Zhang, Lian-Hui

    2006-02-01

    Five elite sugarcane breeding lines were tested for efficiency in embryogenesis and plant regeneration. All of them produced regenerative embryogenic calli but with varied efficiencies. To engineer strongly insect-resistant sugarcanes, the GC content of a truncated cry1Ac gene, which encodes the active region of Cry1Ac insecticidal delta-endotoxin, was increased from the original 37.4 to 47.5% following the sugarcane codon usage pattern. The synthetic cry1Ac gene (s-cry1Ac) was placed under the control of maize ubiquitin promoter and introduced by microprojectile bombardment into the embryogenic calli of sugarcane lines YT79-177 and ROC16. Southern blotting analysis showed that multicopies of s-cry1Ac were integrated into the genomes of transgenic sugarcane lines. Immunoblotting analysis identified 18 transgenic lines expressing detectable levels of s-Cry1Ac, which were estimated in the range of 1.8-10.0 ng mg(-1) total soluble proteins. Four transgenic and two parental lines were assayed for sugarcane stem borer resistance in leaf tissue feeding trials and greenhouse plant assays. The results showed that, while the untransformed control lines were severely damaged in both leaves and stems, the transgenic sugarcane lines expressing high levels of s-Cry1Ac proteins were highly resistant to sugarcane stem borer attack, resulting in complete mortality of the inoculated insects within 1 week after inoculation.

  4. Using RNA sequencing to characterize female reproductive genes between Z and E Strains of European Corn Borer moth (Ostrinia nubilalis).

    Science.gov (United States)

    Al-Wathiqui, Nooria; Lewis, Sara M; Dopman, Erik B

    2014-03-12

    Reproductive proteins often evolve rapidly and are thought to be subject to strong sexual selection, and thus may play a key role in reproductive isolation and species divergence. However, our knowledge of reproductive proteins has been largely limited to males and model organisms with sequenced genomes. With advances in sequencing technology, Lepidoptera are emerging models for studies of sexual selection and speciation. By profiling the transcriptomes of the bursa copulatrix and bursal gland from females of two incipient species of moth, we characterize reproductive genes expressed in the primary reproductive tissues of female Lepidoptera and identify candidate genes contributing to a one-way gametic incompatibility between Z and E strains of the European corn borer (Ostrinia nubilalis). Using RNA sequencing we identified transcripts from ~37,000 and ~36,000 loci that were expressed in the bursa copulatrix or the bursal gland respectively. Of bursa copulatrix genes, 8% were significantly differentially expressed compared to the female thorax, and those that were up-regulated or specific to the bursa copulatrix showed functional biases toward muscle activity and/or organization. In the bursal gland, 9% of genes were differentially expressed compared to the thorax, with many showing reproduction or gamete production functions. Of up-regulated bursal gland genes, 46% contained a transmembrane region and 16% possessed secretion signal peptides. Divergently expressed genes in the bursa copulatrix were exclusively biased toward protease-like functions and 51 proteases or protease inhibitors were divergently expressed overall. This is the first comprehensive characterization of female reproductive genes in any lepidopteran system. The transcriptome of the bursa copulatrix supports its role as a muscular sac that is the primary site for disruption of the male ejaculate. We find that the bursal gland acts as a reproductive secretory body that might also interact with male

  5. Spinosad and the Tomato Borer Tuta absoluta: A Bioinsecticide, an Invasive Pest Threat, and High Insecticide Resistance

    Science.gov (United States)

    Campos, Mateus R.; Rodrigues, Agna Rita S.; Silva, Wellington M.; Silva, Tadeu Barbosa M.; Silva, Vitória Regina F.; Guedes, Raul Narciso C.; Siqueira, Herbert Alvaro A.

    2014-01-01

    The introduction of an agricultural pest species into a new environment is a potential threat to agroecosystems of the invaded area. The phytosanitary concern is even greater if the introduced pest’s phenotype expresses traits that will impair the management of that species. The invasive tomato borer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is one such species and the characterization of the insecticide resistance prevailing in the area of origin is important to guide management efforts in new areas of introduction. The spinosad is one the main insecticides currently used in Brazil for control of the tomato borer; Brazil is the likely source of the introduction of the tomato borer into Europe. For this reason, spinosad resistance in Brazilian populations of this species was characterized. Spinosad resistance has been reported in Brazilian field populations of this pest species, and one resistant population that was used in this study was subjected to an additional seven generations of selection for spinosad resistance reaching levels over 180,000-fold. Inheritance studies indicated that spinosad resistance is monogenic, incompletely recessive and autosomal with high heritability (h2 = 0.71). Spinosad resistance was unstable without selection pressure with a negative rate of change in the resistance level ( = −0.51) indicating an associated adaptive cost. Esterases and cytochrome P450-dependent monooxygenases titration decreased with spinosad selection, indicating that these detoxification enzymes are not the underlying resistance mechanism. Furthermore, the cross-resistance spectrum was restricted to the insecticide spinetoram, another spinosyn, suggesting that altered target site may be the mechanism involved. Therefore, the suspension of spinosyn use against the tomato borer would be a useful component in spinosad resistance management for this species. Spinosad use against this species in introduced areas should be carefully monitored to

  6. Spinosad and the tomato borer Tuta absoluta: a bioinsecticide, an invasive pest threat, and high insecticide resistance.

    Directory of Open Access Journals (Sweden)

    Mateus R Campos

    Full Text Available The introduction of an agricultural pest species into a new environment is a potential threat to agroecosystems of the invaded area. The phytosanitary concern is even greater if the introduced pest's phenotype expresses traits that will impair the management of that species. The invasive tomato borer, Tuta absoluta (Meyrick (Lepidoptera: Gelechiidae, is one such species and the characterization of the insecticide resistance prevailing in the area of origin is important to guide management efforts in new areas of introduction. The spinosad is one the main insecticides currently used in Brazil for control of the tomato borer; Brazil is the likely source of the introduction of the tomato borer into Europe. For this reason, spinosad resistance in Brazilian populations of this species was characterized. Spinosad resistance has been reported in Brazilian field populations of this pest species, and one resistant population that was used in this study was subjected to an additional seven generations of selection for spinosad resistance reaching levels over 180,000-fold. Inheritance studies indicated that spinosad resistance is monogenic, incompletely recessive and autosomal with high heritability (h(2 = 0.71. Spinosad resistance was unstable without selection pressure with a negative rate of change in the resistance level ( = -0.51 indicating an associated adaptive cost. Esterases and cytochrome P450-dependent monooxygenases titration decreased with spinosad selection, indicating that these detoxification enzymes are not the underlying resistance mechanism. Furthermore, the cross-resistance spectrum was restricted to the insecticide spinetoram, another spinosyn, suggesting that altered target site may be the mechanism involved. Therefore, the suspension of spinosyn use against the tomato borer would be a useful component in spinosad resistance management for this species. Spinosad use against this species in introduced areas should be carefully

  7. Spinosad and the tomato borer Tuta absoluta: a bioinsecticide, an invasive pest threat, and high insecticide resistance.

    Science.gov (United States)

    Campos, Mateus R; Rodrigues, Agna Rita S; Silva, Wellington M; Silva, Tadeu Barbosa M; Silva, Vitória Regina F; Guedes, Raul Narciso C; Siqueira, Herbert Alvaro A

    2014-01-01

    The introduction of an agricultural pest species into a new environment is a potential threat to agroecosystems of the invaded area. The phytosanitary concern is even greater if the introduced pest's phenotype expresses traits that will impair the management of that species. The invasive tomato borer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is one such species and the characterization of the insecticide resistance prevailing in the area of origin is important to guide management efforts in new areas of introduction. The spinosad is one the main insecticides currently used in Brazil for control of the tomato borer; Brazil is the likely source of the introduction of the tomato borer into Europe. For this reason, spinosad resistance in Brazilian populations of this species was characterized. Spinosad resistance has been reported in Brazilian field populations of this pest species, and one resistant population that was used in this study was subjected to an additional seven generations of selection for spinosad resistance reaching levels over 180,000-fold. Inheritance studies indicated that spinosad resistance is monogenic, incompletely recessive and autosomal with high heritability (h(2) = 0.71). Spinosad resistance was unstable without selection pressure with a negative rate of change in the resistance level ( = -0.51) indicating an associated adaptive cost. Esterases and cytochrome P450-dependent monooxygenases titration decreased with spinosad selection, indicating that these detoxification enzymes are not the underlying resistance mechanism. Furthermore, the cross-resistance spectrum was restricted to the insecticide spinetoram, another spinosyn, suggesting that altered target site may be the mechanism involved. Therefore, the suspension of spinosyn use against the tomato borer would be a useful component in spinosad resistance management for this species. Spinosad use against this species in introduced areas should be carefully monitored to

  8. Water stress augments silicon-mediated resistance of susceptible sugarcane cultivars to the stalk borer Eldana saccharina (Lepidoptera: Pyralidae).

    Science.gov (United States)

    Kvedaras, O L; Keeping, M G; Goebel, F-R; Byrne, M J

    2007-04-01

    Silicon (Si) can improve resistance of plants to insect attack and may also enhance tolerance of water stress. This study tested if Si-mediated host plant resistance to insect attack was augmented by water stress. Four sugarcane cultivars, two resistant (N21, N33) and two susceptible (N26, N11) to Eldana saccharina Walker were grown in a pot trial in Si-deficient river sand, with (Si+) and without (Si-) calcium silicate. To induce water stress, irrigation to half the trial was reduced after 8.5 months. The trial was artificially infested with E. saccharina eggs after water reduction and harvested 66 days later. Silicon treated, stressed and non-stressed plants of the same cultivar did not differ appreciably in Si content. Decreases in numbers of borers recovered and stalk damage were not associated with comparable increases in rind hardness in Si+ cane, particularly in water-stressed susceptible cultivars. Overall, Si+ plants displayed increased resistance to E. saccharina attack compared with Si- plants. Borer recoveries were significantly lower in stressed Si+ cane compared with either stressed Si- or non-stressed Si- and Si+ cane. Generally, fewer borers were recovered from resistant cultivars than susceptible cultivars. Stalk damage was significantly lower in Si+ cane than in Si- cane, for N21, N11 and N26. Stalk damage was significantly less in Si+ combined susceptible cultivars than in Si- combined susceptible cultivars under non-stressed and especially stressed conditions. In general, the reduction in borer numbers and stalk damage in Si+ plants was greater for water-stressed cane than non-stressed cane, particularly for susceptible sugarcane cultivars. The hypothesis that Si affords greater protection against E. saccharina borer attack in water-stressed sugarcane than in non-stressed cane and that this benefit is greatly enhanced in susceptible cultivars is supported. A possible active role for soluble Si in defence against E. saccharina is proposed.

  9. Insect Resistance Management in Bt Maize: Wild Host Plants of Stem Borers Do Not Serve as Refuges in Africa.

    Science.gov (United States)

    Van den Berg, J

    2017-02-01

    Resistance evolution by target pests threatens the sustainability of Bt maize in Africa where insect resistance management (IRM) strategies are faced by unique challenges. The assumptions, on which current IRM strategies for stem borers are based, are not all valid for African maize stem borer species. The high dose-refuge strategy which is used to delay resistance evolution relies heavily on the presence of appropriate refuges (non-Bt plants) where pests are not under selection pressure and where sufficient numbers of Bt-susceptible individuals are produced to mate with possible survivors on the Bt maize crop. Misidentification of stem borer species and inaccurate reporting on wild host plant diversity over the past six decades created the perception that grasses will contribute to IRM strategies for these pests in Africa. Desired characteristics of refuge plants are that they should be good pest hosts, implying that larval survival is high and that it produces sufficient numbers of high-quality moths. Refuge plants should also have large cover abundance in areas where Bt maize is planted. While wild host plants may suffice in IRM strategies for polyphagous pests, this is not the case with stenophagous pests. This review discusses data of ecological studies and stem borer surveys conducted over the past decade and shows that wild host plants are unsuitable for development and survival of sufficient numbers of stem borer individuals. These grasses rather act as dead-end-trap plants and do not comply with refuge requirements of producing 500 susceptible individuals for every one resistant individual that survives on Bt maize.

  10. Interspecific variation in resistance of Asian, European, and North American birches (Betula spp.) to bronze birch borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Nielsen, David G; Muilenburg, Vanessa L; Herms, Daniel A

    2011-06-01

    Bronze birch borer (Agrilus anxius Gory) is the key pest of birches (Betula spp.) in North America, several of which have been recommended for ornamental landscapes based on anecdotal reports of borer resistance that had not been confirmed experimentally. In a 20-yr common garden experiment initiated in 1979 in Ohio, North American birch species, including paper birch (Betula papyrifera Marshall), 'Whitespire' gray birch (Betula populifolia Marshall), and river birch (Betula nigra L.), were much more resistant to bronze birch borer than species indigenous to Europe and Asia, including European white birch (Betula pendula Roth), downy birch (Betula pubescens Ehrh.), monarch birch (Betula maximowicziana Regel), and Szechuan white birch (Betula szechuanica Jansson). Within 8 yr of planting, every European white, downy, and Szechuan birch had been colonized and killed, although 100% of monarch birch had been colonized and 88% of these plants were killed after nine years. Conversely, 97% of river birch, 76% of paper birch, and 73% Whitespire gray birch were alive 20 yr after planting, and river birch showed no evidence of colonization. This pattern is consistent with biogeographic theory of plant defense: North American birch species that share a coevolutionary history with bronze birch borer were much more resistant than naïve hosts endemic to Europe and Asia, possibly by virtue of evolution of targeted defenses. This information suggests that if bronze birch borer were introduced to Europe or Asia, it could threaten its hosts there on a continental scale. This study also exposed limitations of anecdotal observation as evidence of host plant resistance.

  11. Distribution and variations of three 1,4-benzoxazin-3-ones in maize induced by the Asian corn borer, Ostrinia furnacalis (Guenée).

    Science.gov (United States)

    Huang, Cuihong; Wang, Xiaoying; Wang, Rongjiang; Xue, Kun; Yan, Fengming; Xu, Chongren

    2006-01-01

    Contents of three 1,4-benzoxazin-3-ones in tissue samples from different parts (young leaf, second leaf, old leaf, stem and root) of young maize plants of 4-leaves stage, fed by the third instar larvae of the Asian corn borer, Ostrinia furnacalis (Guenée), were analyzed by high-performance liquid chromatography-mass spectroscopy (HPLC-MS). Samples were taken immediately (set A) or 48 h (set B) after larvae had fed on the second leaf for 48 h. The three 1,4-benzoxazin-3-ones investigated in our experiments were 2,4-dihydroxy-7-methoxy-1,4(2H)-benzoxazin-3-one (DIMBOA), 2,4-dihydroxy-1,4(2H)-benzoxazin-3-one (DIBOA) and 2-hydroxy-7-methoxy-1,4(2H)-benzoxazin-3-one (HMBOA). In samples of set A, the levels of DIMBOA and HMBOA were significantly lifted in the old leaf (L3) and young leaf (L1), respectively, while amounts of these two chemicals in other plant parts were not significantly different between larvae-fed plants and intact plants. Concentrations of DIBOA in each plant part remained unchanged. In samples of set B, no concentration differences for any of these three 1,4-benzoxazin-3-ones between larvae-fed plants and controls were observed in any plant part. The feeding of the Asian corn borer seems to have limited effects on induction of these three 1,4-benzoxazin-3-ones in young maize plants of the variety investigated.

  12. Efficiency of insecticide and bioinsecticide treatments against infestation of European corn borer and their effect on maize yield

    Directory of Open Access Journals (Sweden)

    Gošić-Dondo Snežana

    2016-01-01

    Full Text Available During 2008 and 2009, efficacy of insecticidal products, based on thiamethoxam and imidacloprid, were tested. Furthermore, effects of entomophatogenic fungus Beauveria bassiana on the infestation intensity of European corn borer (Ostrinia nubilalis, were established over effects of both, 10 different treatments of maize seed (8 treatments and 2 controls and the application of the fungal inoculum. Trials were carried out on maize crop under field conditions in accordance with the EPPO method. Results obtained in the studies with the product Cruiser 350 FS (350g l-1 thiamethoxam applied in the amount of 0.9 l per 100 kg of seed and the products Imidor 600 FS and Gaucho 600FS (600g l-1 imidacloprid applied in the amount of 0.7 l per 100 kg of seed, point out to satisfactory efficacy in controlling ECB and satisfactory effects on maize yields. The intensity of ECB infestation, expressed in percentages, ranged from 50.1% to 74.1%. The interrelation between average percentages of infested plants and obtained yields in both investigation years (2008-2009 in Zemun Polje was established. Results over treatments indicate that the highest percentages (62.2% of infested plants were observed in the control variant (K1- Captan. Moreover, as expected, the lowest yield was also recorded in this variant. The treatment with the fungicide Maxim combined with the insecticide Criuser proved to be the most efficient. At the same time, the percentage of infested plants was the lowest in this treatment (53.32% and the yield was the highest (8.610 t ha-1. The infestation level of maize plants in this treatment was significantly reduced over years of investigation in comparison with remaining treatments. Meteorological factors during the years of investigation, especially unfavourable agroecological conditions in 2009, affected the average yield of maize per hectare. The yield (8.314 t ha-1 recorded in the treatment with the inoculum of B. basssiana was almost equal to

  13. Pod Characteristics of Cocoa (Theobroma cacao L. Related to Cocoa Pod Borer Resistance (Conopomorpha cramerella Snell.

    Directory of Open Access Journals (Sweden)

    Agung Wahyu Soesilo

    2015-03-01

    Full Text Available AbstractThe characteristics of pod related to cocoa pod borer resistance (CPB, Conopomorpha cramerella Snell. had been identified in a series study. This research has objective to evaluate performance of the characteristics using more diverse of genetic background to select criteria for selection. Genetic materials for this study were 25 cocoa clones which be planted in Central Sulawesi for resistant evaluation. Field evaluation of the resistance were assessed using the variable of the percentage of unextractable bean, number of entry and exit hole larvae by which the clones were grouped into 5 groups of resistance. A laboratory works were carried out to assess pod characteristics based on the number of trichome, granule of tannin and thickness the lignified-tissue of sclerotic layer using micro-technique method at the different level of pod maturity (3.0; 3.5; 4.0 months. Correlation between groups of those variables was analyzed using Canonical Correlation. The analysis performed a positive association between the thickness of sclerotic layer at the secondary furrow with the number of entry holes and the number of entry holes through sclerotic layer. The thickness performed a higher value of the coefficient in association with the variables of canonical for pod characteristics (0.59; 0.55; 0.43 and the variables of canonical for CPB resistance (0.54; 0.51; 0.39 that would presenting the characteristics of pod related to CPB resistance. Lignification at sclerotic layer was considered as genotypic expressions due to the thickness at the secondary furrow at 3.0, 3.5 and 4.0 months of pod maturity performed high value of broad-sense heritability i.e. 0.75, 0.89 and 0.92 respectively. A qualitative assessment of the lignification clearly differentiate the resistant clones (ARDACIAR 10 with the susceptible clones (ICCRI 04, KW 516 and KW 564.Key words : cocoa pod borer, Theobroma cacao L., pod characteristics, resistance

  14. Greenhouse-selected resistance to Cry3Bb1-producing corn in three western corn rootworm populations.

    Directory of Open Access Journals (Sweden)

    Lisa N Meihls

    Full Text Available Transgenic corn producing the Bacillus thuringiensis (Bt toxin Cry3Bb1 has been useful for controlling western corn rootworm, Diabrotica virgifera virgifera LeConte, one of the most economically important crop pests in the United States. However, rapid evolution of resistance by this beetle to Bt corn producing Cry3Bb1 has been reported previously from the laboratory, greenhouse, and field. Here we selected in the greenhouse for resistance to Cry3Bb1 corn in three colonies of WCR derived from Kansas, Minnesota, and Wisconsin, respectively. Three generations of rearing on Cry3Bb1 corn significantly increased larval survival on Cry3Bb1 corn, resulting in similar survival in the greenhouse for selected colonies on Cry3Bb1 corn and isoline corn that does not produce Bt toxin. After four to seven generations of rearing on Cry3Bb1 corn, survival in the field on Cry3Bb1 corn relative to isoline corn more than doubled for selected colonies (72% compared with control colonies (33%. For both selected and control colonies, survival in the field was significantly lower on Cry3Bb1 corn than on isoline corn. On isoline corn, most fitness components were similar for selected colonies and control colonies. However, fecundity was significantly lower for selected colonies than control colonies, indicating a fitness cost associated with resistance. The rapid evolution of resistance by western corn rootworm to Bt corn reported here and previously underlines the importance of effective resistance management for this pest.

  15. A Survey: Potential Impact of Genetically Modified Maize Tolerant to Drought or Resistant to Stem Borers in Uganda

    Directory of Open Access Journals (Sweden)

    Isaac M. Wamatsembe

    2017-03-01

    Full Text Available Maize production in Uganda is constrained by various factors, but especially drought and stem borers contribute to significant yield losses. Genetically modified (GM maize with increased drought tolerance and/or Bt insect resistance (producing the Bacillus thuringiensis Cry protein is considered as an option. For an ex ante impact analysis of these technologies, a farmer survey was carried out in nine districts of Uganda, representing the major farming systems. The results showed that farmers did rate stem borer and drought as the main constraints for maize farming. Most farmers indicated a positive attitude towards GM maize, and 86% of all farmers said they would grow GM maize. Farmer estimated yield losses to drought and stem borer damage were on average 54.7% and 23.5%, respectively, if stress occurred. Taking the stress frequency into consideration (67% for both, estimated yield losses were 36.5% and 15.6% for drought and stem borer, respectively. According to the ex-ante partial budget analysis, Bt hybrid maize could be profitable, with an average value/cost ratio of 2.1. Drought tolerant hybrid maize had lower returns and a value/cost ratio of 1.5. Negative returns occurred mainly for farmers with non-stressed grain yields below 2 t·ha−1. The regulatory framework in Uganda needs to be finalized with consideration of strengthening key institutions in the maize sector for sustainable introduction of GM maize.

  16. Down regulation of a gene for cadherin, but not alkaline phosphatase, associated with Cry1Ab resistance in the sugarcane borer Diatraea saccharalis.

    Directory of Open Access Journals (Sweden)

    Yunlong Yang

    Full Text Available The sugarcane borer, Diatraea saccharalis, is a major target pest of transgenic corn expressing Bacillus thuringiensis (Bt proteins (i.e., Cry1Ab in South America and the mid-southern region of the United States. Evolution of insecticide resistance in such target pests is a major threat to the durability of transgenic Bt crops. Understanding the pests' resistance mechanisms will facilitate development of effective strategies for delaying or countering resistance. Alterations in expression of cadherin- and alkaline phosphatase (ALP have been associated with Bt resistance in several species of pest insects. In this study, neither the activity nor gene regulation of ALP was associated with Cry1Ab resistance in D. saccharalis. Total ALP enzymatic activity was similar between Cry1Ab-susceptible (Cry1Ab-SS and -resistant (Cry1Ab-RR strains of D. saccharalis. In addition, expression levels of three ALP genes were also similar between Cry1Ab-SS and -RR, and cDNA sequences did not differ between susceptible and resistant larvae. In contrast, altered expression of a midgut cadherin (DsCAD1 was associated with the Cry1Ab resistance. Whereas cDNA sequences of DsCAD1 were identical between the two strains, the transcript abundance of DsCAD1 was significantly lower in Cry1Ab-RR. To verify the involvement of DsCAD1 in susceptibility to Cry1Ab, RNA interference (RNAi was employed to knock-down DsCAD1 expression in the susceptible larvae. Down-regulation of DsCAD1 expression by RNAi was functionally correlated with a decrease in Cry1Ab susceptibility. These results suggest that down-regulation of DsCAD1 is associated with resistance to Cry1Ab in D. saccharalis.

  17. Repetitive genome elements in a European corn borer, Ostrinia nubilalis, bacterial artificial chromosome library were indicated by bacterial artificial chromosome end sequencing and development of sequence tag site markers: implications for lepidopteran genomic research.

    Science.gov (United States)

    Coates, Brad S; Sumerford, Douglas V; Hellmich, Richard L; Lewis, Leslie C

    2009-01-01

    The European corn borer, Ostrinia nubilalis, is a serious pest of food, fiber, and biofuel crops in Europe, North America, and Asia and a model system for insect olfaction and speciation. A bacterial artificial chromosome library constructed for O. nubilalis contains 36 864 clones with an estimated average insert size of >or=120 kb and genome coverage of 8.8-fold. Screening OnB1 clones comprising approximately 2.76 genome equivalents determined the physical position of 24 sequence tag site markers, including markers linked to ecologically important and Bacillus thuringiensis toxin resistance traits. OnB1 bacterial artificial chromosome end sequence reads (GenBank dbGSS accessions ET217010 to ET217273) showed homology to annotated genes or expressed sequence tags and identified repetitive genome elements, O. nubilalis miniature subterminal inverted repeat transposable elements (OnMITE01 and OnMITE02), and ezi-like long interspersed nuclear elements. Mobility of OnMITE01 was demonstrated by the presence or absence in O. nubilalis of introns at two different loci. A (GTCT)n tetranucleotide repeat at the 5' ends of OnMITE01 and OnMITE02 are evidence for transposon-mediated movement of lepidopteran microsatellite loci. The number of repetitive elements in lepidopteran genomes will affect genome assembly and marker development. Single-locus sequence tag site markers described here have downstream application for integration within linkage maps and comparative genomic studies.

  18. Selection for resistance to mCry3A-expressing transgenic corn in western corn rootworm.

    Science.gov (United States)

    Meihls, Lisa N; Higdon, Matthew L; Ellersieck, Mark; Hibbard, Bruce E

    2011-06-01

    To investigate the development of resistance to mCry3A, a laboratory colony of the western corn rootworm, Diabrotica virgifera virgifera LeConte, was established from field survivors of mCry3A-expressing (MIR604) corn, Zea mays L. Feral adults emerging from MIR604 (selected) and isoline (control) field plots were collected and returned to the laboratory. Progeny of each colony was reared one generation on isoline corn and then crossed reciprocally with a nondiapausing colony. The resulting nondiapausing progeny were then reared on greenhouse corn in accordance with the wild type parent's origin (on MIR604 or isoline corn). After four, seven, and 10 total generations of selection, the resistance ratio of the selected colony was 0.5, 4.3, and 15.4 in terms of lethal concentration (LC)50 values in toxicity assays, with the latter two LC50 values being significant. After seven generations of selection in total, selected and control colonies were screened on MIR604 and isoline corn under field conditions. There was a significant colony x corn pedigree interaction in terms of plant damage. There was no significant difference in damage between MIR604 and isoline corn, whereas this difference was significant for the control colony. After 14 generations of selection, a seedling bioassay was performed. Again, there was a significant colony x corn pedigree interaction, this time in terms of the number of larvae recovered. There was no significant difference in the number of larvae recovered from MIR604 and isoline corn for the selected colony, whereas this difference was significant for the control colony, although larval size was greater on isoline corn for both colonies. Resistance has developed in western corn rootworm laboratory colonies to all Bt proteins currently registered for corn rootworm management, which emphasizes the importance of adhering to resistance management plans for maintaining product efficacy.

  19. Field-Evolved Resistance in Corn Earworm to Cry Proteins Expressed by Transgenic Sweet Corn

    Science.gov (United States)

    Dively, Galen P.; Finkenbinder, Chad

    2016-01-01

    Background Transgenic corn engineered with genes expressing insecticidal toxins from the bacterium Bacillus thuringiensis (Berliner) (Bt) are now a major tool in insect pest management. With its widespread use, insect resistance is a major threat to the sustainability of the Bt transgenic technology. For all Bt corn expressing Cry toxins, the high dose requirement for resistance management is not achieved for corn earworm, Helicoverpa zea (Boddie), which is more tolerant to the Bt toxins. Methodology/Major Findings We present field monitoring data using Cry1Ab (1996–2016) and Cry1A.105+Cry2Ab2 (2010–2016) expressing sweet corn hybrids as in-field screens to measure changes in field efficacy and Cry toxin susceptibility to H. zea. Larvae successfully damaged an increasing proportion of ears, consumed more kernel area, and reached later developmental stages (4th - 6th instars) in both types of Bt hybrids (Cry1Ab—event Bt11, and Cry1A.105+Cry2Ab2—event MON89034) since their commercial introduction. Yearly patterns of H. zea population abundance were unrelated to reductions in control efficacy. There was no evidence of field efficacy or tissue toxicity differences among different Cry1Ab hybrids that could contribute to the decline in control efficacy. Supportive data from laboratory bioassays demonstrate significant differences in weight gain and fitness characteristics between the Maryland H. zea strain and a susceptible strain. In bioassays with Cry1Ab expressing green leaf tissue, Maryland H. zea strain gained more weight than the susceptible strain at all concentrations tested. Fitness of the Maryland H. zea strain was significantly lower than that of the susceptible strain as indicated by lower hatch rate, longer time to adult eclosion, lower pupal weight, and reduced survival to adulthood. Conclusions/Significance After ruling out possible contributing factors, the rapid change in field efficacy in recent years and decreased susceptibility of H. zea to Bt

  20. Field-Evolved Resistance in Corn Earworm to Cry Proteins Expressed by Transgenic Sweet Corn.

    Science.gov (United States)

    Dively, Galen P; Venugopal, P Dilip; Finkenbinder, Chad

    2016-01-01

    Transgenic corn engineered with genes expressing insecticidal toxins from the bacterium Bacillus thuringiensis (Berliner) (Bt) are now a major tool in insect pest management. With its widespread use, insect resistance is a major threat to the sustainability of the Bt transgenic technology. For all Bt corn expressing Cry toxins, the high dose requirement for resistance management is not achieved for corn earworm, Helicoverpa zea (Boddie), which is more tolerant to the Bt toxins. We present field monitoring data using Cry1Ab (1996-2016) and Cry1A.105+Cry2Ab2 (2010-2016) expressing sweet corn hybrids as in-field screens to measure changes in field efficacy and Cry toxin susceptibility to H. zea. Larvae successfully damaged an increasing proportion of ears, consumed more kernel area, and reached later developmental stages (4th - 6th instars) in both types of Bt hybrids (Cry1Ab-event Bt11, and Cry1A.105+Cry2Ab2-event MON89034) since their commercial introduction. Yearly patterns of H. zea population abundance were unrelated to reductions in control efficacy. There was no evidence of field efficacy or tissue toxicity differences among different Cry1Ab hybrids that could contribute to the decline in control efficacy. Supportive data from laboratory bioassays demonstrate significant differences in weight gain and fitness characteristics between the Maryland H. zea strain and a susceptible strain. In bioassays with Cry1Ab expressing green leaf tissue, Maryland H. zea strain gained more weight than the susceptible strain at all concentrations tested. Fitness of the Maryland H. zea strain was significantly lower than that of the susceptible strain as indicated by lower hatch rate, longer time to adult eclosion, lower pupal weight, and reduced survival to adulthood. After ruling out possible contributing factors, the rapid change in field efficacy in recent years and decreased susceptibility of H. zea to Bt sweet corn provide strong evidence of field-evolved resistance in H

  1. Distinguishing defensive characteristics in the phloem of ash species resistant and susceptible to emerald ash borer.

    Science.gov (United States)

    Cipollini, Don; Wang, Qin; Whitehill, Justin G A; Powell, Jeff R; Bonello, Pierluigi; Herms, Daniel A

    2011-05-01

    We examined the extent to which three Fraxinus cultivars and a wild population that vary in their resistance to Emerald Ash Borer (EAB) could be differentiated on the basis of a suite of constitutive chemical defense traits in phloem extracts. The EAB-resistant Manchurian ash (F. mandshurica, cv. Mancana) was characterized by having a rapid rate of wound browning, a high soluble protein concentration, low trypsin inhibitor activities, and intermediate levels of peroxidase activity and total soluble phenolic concentration. The EAB-susceptible white ash (F. americana, cv. Autumn Purple) was characterized by a slow wound browning rate and low levels of peroxidase activity and total soluble phenolic concentrations. An EAB-susceptible green ash cultivar (F. pennsylvanica, cv. Patmore) and a wild accession were similar to each other on the basis of several chemical defense traits, and were characterized by high activities of peroxidase and trypsin inhibitor, a high total soluble phenolic concentration, and an intermediate rate of wound browning. Lignin concentration and polyphenol oxidase activities did not differentiate resistant and susceptible species. Of 33 phenolic compounds separated by HPLC and meeting a minimum criterion for analysis, nine were unique to Manchurian ash, five were shared among all species, and four were found in North American ashes and not in the Manchurian ash. Principal components analysis revealed clear separations between Manchurian, white, and green ashes on the basis of all phenolics, as well as clear separations on the basis of quantities of phenolics that all species shared. Variation in some of these constitutive chemical defense traits may contribute to variation in resistance to EAB in these species.

  2. Systematics and biology of Cotesia typhae sp. n. (Hymenoptera, Braconidae, Microgastrinae), a potential biological control agent against the noctuid Mediterranean corn borer, Sesamia nonagrioides

    Science.gov (United States)

    Kaiser, Laure; Fernandez-Triana, Jose; Capdevielle-Dulac, Claire; Chantre, Célina; Bodet, Matthieu; Kaoula, Ferial; Benoist, Romain; Calatayud, Paul-André; Dupas, Stéphane; Herniou, Elisabeth A.; Jeannette, Rémi; Obonyo, Julius; Silvain, Jean-François; Ru, Bruno Le

    2017-01-01

    Abstract Many parasitoid species are subjected to strong selective pressures from their host, and their adaptive response may result in the formation of genetically differentiated populations, called host races. When environmental factors and reproduction traits prevent gene flow, host races become distinct species. Such a process has recently been documented within the Cotesia flavipes species complex, all of which are larval parasitoids of moth species whose larvae are stem borers of Poales. A previous study on the African species C. sesamiae, incorporating molecular, ecological and biological data on various samples, showed that a particular population could be considered as a distinct species, because it was specialized at both host (Sesamia nonagrioides) and plant (Typha domingensis) levels, and reproductively isolated from other C. sesamiae. Due to its potential for the biological control of S. nonagrioides, a serious corn pest in Mediterranean countries and even in Iran, we describe here Cotesia typhae Fernandez-Triana sp. n. The new species is characterized on the basis of morphological, molecular, ecological and geographical data, which proved to be useful for future collection and rapid identification of the species within the species complex. Fecundity traits and parasitism success on African and European S. nonagrioides populations, estimated by laboratory studies, are also included. PMID:28769725

  3. Management of fumonisin contamination in maize kernels through the timing of insecticide application against the European corn borer Ostrinia nubilalis Hübner.

    Science.gov (United States)

    Blandino, Massimo; Reyneri, Amedeo; Vanara, Francesca; Pascale, Michelangelo; Haidukowski, Miriam; Campagna, Claudio

    2009-11-01

    The European corn borer (ECB), Ostrinia nubilalis, is the principal pest of maize in Central and South Europe. It is known to promote Fusarium verticillioides infection in maize grain, a recognized producer of fumonisins. Field experiments were performed in 2006 and 2007 in two sites in NW Italy to determine the effects of the timing of insecticide application on ECB damage, fungal ear rot and fumonisin contamination under natural conditions. Different insecticide application timings were compared, from maize flowering to approximately 15 days after the flight peak of adult ECB. At harvest, the ears were rated for incidence and severity of ECB damage, fungal ear rot symptoms and fumonisin (FB(1) + FB(2)) contamination. In all years/sites, treatments applied at the beginning of consistent ECB flight activity were most effective in controlling insect damage on ears. Fungal ear rot and fumonisin contamination were significantly affected by ECB control. The efficacy of the best timing of insecticide application in controlling fumonisin contamination was, on average, 93% compared to the untreated control. Contamination levels of these mycotoxins increased with either an earlier or later treatment. Furthermore, an earlier insecticide application showed lower fumonisin contamination than a treatment applied after the adult flight peak. Production of maize kernels and maize-based foods that do not exceed the maximum international and EU permitted levels for fumonisins could be enhanced by appropriate insecticide treatment against second generation ECB. The optimum time for insecticide application is between the beginning of consistent adult flight activity and the flight peak.

  4. THE INFLUENCE OF ULTRAVIOLET LIGHT ON PATHOGENICITY OF ENTOMOPATHOGENIC FUNGUS BEAUVERIA BASSIANA (BALSAMO VUILLEMIN TO THE EUROPEAN CORN BORER, OSTRINIA NUBILALIS HBN. (LEPIDOPTERA: CRAMBIDAE

    Directory of Open Access Journals (Sweden)

    L Cagán

    2002-05-01

    Full Text Available The influence of different doses of ultraviolet (UV light on the pathogenicity of entomopathogenic fungus Beauveria bassiana (Balsamo Vuillemin to the European corn borer, Ostrinia nubilalis Hbn., and radial growth of fungus was studied in laboratory conditions. The suspensions of B. bassiana isolate SK99 were exposed to UV light. Four different doses of UV light were used in the experiment. The distance between exposed suspensions and UV light source was 0.3 m. Exposure duration was 15, 30, 45 and 60 minutes (as A, B, C and D variants. Control variant SK99 and obtained variants SK99A, SK99B, SK99C and SK99D were cultivated 21 days on Sabourard-dextrose agar. The larvae of O. nubilalis were infected with dry powder consisted of mycelia and spores from fungus cultures. During 10 days, the mortality of infected larvae was evaluated. It was ascertained that UV light exposition significantly influenced the mortality effect of B. bassiana isolates to O. nubilalis larvae. Variant SK99C showed the highest level of infectivity. Radial growth of UV variants was slower with rising time of exposure. The best ability to grow possessed non-irradiated isolate SK99 and the worse variant SK99D. The difference between these two variants was significant.

  5. Pod Characteristics of cocoa (Theobroma cacao L. related to rocoa pod borer resistance.

    Directory of Open Access Journals (Sweden)

    Agung Wahyu Susilo

    2015-04-01

    Full Text Available The characteristics of cocoa (Theobroma cacao L. pod related to cocoa pod borer resistance (CPB had been identified in a series of study. The objective of this research is to evaluate the characteristics of cocoa pod using more diverse of genetic background to obtain selection criteria. Genetic materials for this studywere 25 cocoa clones planted in Central Sulawesi for resistance evaluation. Field evaluation of the resistance were assessed by using variable of the percentage of unextractable beans, number of larvae entry and exit holes by which the clones were grouped into 5 groups of resistance. A laboratory works were carried out to assess pod characteristics based on the number of trichomes, granules of tannin and thickness the lignified-tissue of sclerotic layer using micro-technique method at the different level of pod maturity (3.0; 3.5; 4.0 months. Correlation between groups of those variables was analyzed using canonical correlation. The result performed a positive association between the thickness of sclerotic layer at the secondary furrow with the number of entry holes and the number of entry holes through sclerotic layer. The thickness performed a higher value of the coefficient in association with the variables of canonical for pod characteristics 0.59; 0.55; 0.43 and the variables of canonical correlation for CPB resistance 0.54; 0.51; 0.39 that would presenting the characteristics of pod related to CPB resistance in 3.0, 3.5 and 4.0 months of pod maturity. Lignification at sclerotic layer was considered as genotypic expressions due to the thickness at the secondary furrow at 3.0, 3.5 and 4.0 months of pod maturity performed high value of broad-sense heritability i.e. 0.75, 0.89 and 0.92 respectively. A qualitative assessment of the lignification clearly differentiated the resistant clones of ARDACIAR 10 with the susceptible clones of ICCRI 04, KW 516, and KW 564.

  6. Greenhouse-selected resistance to Cry3Bb1-producing corn in three western corn rootworm populations

    Science.gov (United States)

    Transgenic corn producing the Bacillus thuringiensis (Bt) toxin Cry3Bb1 has been useful for controlling western corn rootworm, Diabrotica virgifera virgifera LeConte, one of the most economically important crop pests in the United States. However, rapid evolution of resistance by this beetle to Bt c...

  7. Climate change, transgenic corn adoption and field-evolved resistance in corn earworm.

    Science.gov (United States)

    Venugopal, P Dilip; Dively, Galen P

    2017-06-01

    Increased temperature anomaly during the twenty-first century coincides with the proliferation of transgenic crops containing the bacterium Bacillus thuringiensis (Berliner) (Bt) to express insecticidal Cry proteins. Increasing temperatures profoundly affect insect life histories and agricultural pest management. However, the implications of climate change on Bt crop-pest interactions and insect resistance to Bt crops remains unexamined. We analysed the relationship of temperature anomaly and Bt adoption with field-evolved resistance to Cry1Ab Bt sweet corn in a major pest, Helicoverpa zea (Boddie). Increased Bt adoption during 1996-2016 suppressed H. zea populations, but increased temperature anomaly buffers population reduction. Temperature anomaly and its interaction with elevated selection pressure from high Bt acreage probably accelerated the Bt-resistance development. Helicoverpa zea damage to corn ears, kernel area consumed, mean instars and proportion of late instars in Bt varieties increased with Bt adoption and temperature anomaly, through additive or interactive effects. Risk of Bt-resistant H. zea spreading is high given extensive Bt adoption, and the expected increase in overwintering and migration. Our study highlights the challenges posed by climate change for Bt biotechnology-based agricultural pest management, and the need to incorporate evolutionary processes affected by climate change into Bt-resistance management programmes.

  8. Polymerization of the CrylAb and CrylF Transgenic Corn on the Impact of the Asian Corn Borer Survival and Average Weight%聚合CrylAb和CrylF基因抗虫玉米对亚洲玉米螟存活率及平均体重的影响

    Institute of Scientific and Technical Information of China (English)

    张琦; 丛斌; 钱海涛

    2012-01-01

    In this experiment, the Asian com borer larvae were fed on the polymerization of Cry1Ab and Cry1F transgenic corn 335YH,696YH artificial diet. We study the impaction on survival and average weight of the Asian corn borer larvae. The results showed that 25% of the amount of processing, the corn borer larvae survival rate was less than 38%, the average weight was less than 45 mg. This indicates polymerization of the CrylAb and CrylF transgenic corn seed can inhibit the growth and survival of the Asian corn borer larvae. 335YH,on the 25% and 50% usage,the survival of the Asian corn borer are no significant difference,but 50% compared with 25% usage, larval on the latter grows better. Dose effects 696YH on larval lethality and inhibiting the growth.%实验用聚合crylAb和CrylF基因抗虫玉米335YH、696YH的人工饲料饲养亚洲玉米螟幼虫,研究人工饲料中聚合基因玉米对其存活率和平均体重的影响.结果表明:在25%用量处理下,玉米螟幼虫的存活率均低于38%,平均体重均低于45mg,说明聚合CrylAb和cryIF基因抗虫玉米种子能抑制供试亚洲玉米螟幼虫的生长和存活.335YH25%用量和50%用量的致死性差异不大,但50%用量比25%用量抑制幼虫生长的效果更好.696YH品种对幼虫的致死性和抑制生长效果受剂量影响较大.

  9. Genetic markers for western corn rootworm resistance to Bt toxin.

    Science.gov (United States)

    Flagel, Lex E; Swarup, Shilpa; Chen, Mao; Bauer, Christopher; Wanjugi, Humphrey; Carroll, Matthew; Hill, Patrick; Tuscan, Meghan; Bansal, Raman; Flannagan, Ronald; Clark, Thomas L; Michel, Andrew P; Head, Graham P; Goldman, Barry S

    2015-01-07

    Western corn rootworm (WCR) is a major maize (Zea mays L.) pest leading to annual economic losses of more than 1 billion dollars in the United States. Transgenic maize expressing insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) are widely used for the management of WCR. However, cultivation of Bt-expressing maize places intense selection pressure on pest populations to evolve resistance. Instances of resistance to Bt toxins have been reported in WCR. Developing genetic markers for resistance will help in characterizing the extent of existing issues, predicting where future field failures may occur, improving insect resistance management strategies, and in designing and sustainably implementing forthcoming WCR control products. Here, we discover and validate genetic markers in WCR that are associated with resistance to the Cry3Bb1 Bt toxin. A field-derived WCR population known to be resistant to the Cry3Bb1 Bt toxin was used to generate a genetic map and to identify a genomic region associated with Cry3Bb1 resistance. Our results indicate that resistance is inherited in a nearly recessive manner and associated with a single autosomal linkage group. Markers tightly linked with resistance were validated using WCR populations collected from Cry3Bb1 maize fields showing significant WCR damage from across the US Corn Belt. Two markers were found to be correlated with both diet (R2 = 0.14) and plant (R2 = 0.23) bioassays for resistance. These results will assist in assessing resistance risk for different WCR populations, and can be used to improve insect resistance management strategies.

  10. Feeding behavior of neonate Ostrinia nubilalis (Lepidoptera: Crambidae) on Cry1Ab Bt corn: implications for resistance management.

    Science.gov (United States)

    Razze, J M; Mason, C E; Pizzolato, T D

    2011-06-01

    The European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), is an economically important insect pest of corn, Zea mays L., in the United States and Canada. The development of genetically modified corn expressing genes derived from Bacillus thuringiensis (Bt) that encodes insecticidal crystalline (Cry) proteins has proven to be effective in controlling this insect. To assess the feeding behavior of neonate O. nubilalis on Bt corn, we examined differences in feeding behavior, based on presence of plant material in the gut, between Cry1Ab Bt corn and non-Bt near isoline corn for four intervals over a 48-h period. Feeding experiments revealed that there was significantly less feeding on Bt corn compared with non-Bt near isoline corn. The behavior of neonates on the plant corresponded with the differences in feeding on the two corn lines. The findings also showed that > 50% of the larvae initially left the plant before there was evidence in the gut of feeding regardless of whether the source was Bt or non-Bt corn. A higher quantity of plant material was found in the gut of larvae recovered from leaves of non-Bt compared with Bt corn. At the end of 48 h among the larvae that had left the plant, a greater proportion from Bt corn had plant material in the gut than did those from non-Bt corn.

  11. Domain III of Bacillus thuringiensis Cry1Ie Toxin Plays an Important Role in Binding to Peritrophic Membrane of Asian Corn Borer

    Science.gov (United States)

    Feng, Dongmei; Chen, Zhen; Wang, Zhiwen; Zhang, Chunlu; He, Kanglai; Guo, Shuyuan

    2015-01-01

    The insecticidal IE648 toxin is a truncated Cry1Ie protein with increased toxicity against Asian corn borer (ACB). Cry toxins are pore-forming toxins that disrupt insect midgut cells to kill the larvae. However, the peritrophic membrane (PM) is an important barrier that Cry toxins must cross before binding to midgut cells. Previously, it was shown that Cry toxins are able to bind and accumulate in the PM of several lepidopteran insects. Binding of IE648 toxin to PM of ACB was previously reported and the goal of the current work was the identification of the binding region between Cry1Ie and the PM of ACB. Homologous competition binding assays showed that this interaction was specific. Heterologous competition binding assays performed with different fragments corresponding to domain I, domain II and domain III allowed us to identify that domain III participates in the interaction of IE648 with the PM. Specifically, peptide D3-L8 (corresponding to Cry1Ie toxin residues 607 to 616), located in an exposed loop region of domain III is probably involved in this interaction. Ligand blot assays show that IE648 interact with chitin and PM proteins with sizes of 30, 32 and 80 kDa. The fact that domain III interacts with proteins of similar molecular masses supports that this region of the toxin might be involved in PM interaction. These data provide for the first time the identification of domain III as a putative binding region between PM and 3D-Cry toxin. PMID:26295704

  12. Domain III of Bacillus thuringiensis Cry1Ie Toxin Plays an Important Role in Binding to Peritrophic Membrane of Asian Corn Borer.

    Directory of Open Access Journals (Sweden)

    Dongmei Feng

    Full Text Available The insecticidal IE648 toxin is a truncated Cry1Ie protein with increased toxicity against Asian corn borer (ACB. Cry toxins are pore-forming toxins that disrupt insect midgut cells to kill the larvae. However, the peritrophic membrane (PM is an important barrier that Cry toxins must cross before binding to midgut cells. Previously, it was shown that Cry toxins are able to bind and accumulate in the PM of several lepidopteran insects. Binding of IE648 toxin to PM of ACB was previously reported and the goal of the current work was the identification of the binding region between Cry1Ie and the PM of ACB. Homologous competition binding assays showed that this interaction was specific. Heterologous competition binding assays performed with different fragments corresponding to domain I, domain II and domain III allowed us to identify that domain III participates in the interaction of IE648 with the PM. Specifically, peptide D3-L8 (corresponding to Cry1Ie toxin residues 607 to 616, located in an exposed loop region of domain III is probably involved in this interaction. Ligand blot assays show that IE648 interact with chitin and PM proteins with sizes of 30, 32 and 80 kDa. The fact that domain III interacts with proteins of similar molecular masses supports that this region of the toxin might be involved in PM interaction. These data provide for the first time the identification of domain III as a putative binding region between PM and 3D-Cry toxin.

  13. Generation of marker-free Bt transgenic indica rice and evaluation of its yellow stem borer resistance.

    Science.gov (United States)

    Kumar, S; Arul, L; Talwar, D

    2010-01-01

    We report on generation of marker-free (‘clean DNA’) transgenic rice (Oryza sativa), carrying minimal gene-expression-cassettes of the genes of interest, and evaluation of its resistance to yellow stem borer Scirpophaga incertulas (Lepidoptera: Pyralidae). The transgenic indica rice harbours a translational fusion of 2 different Bacillus thuringiensis (Bt) genes, namely cry1B-1Aa, driven by the green-tissue-specific phosphoenol pyruvate carboxylase (PEPC) promoter. Mature seed-derived calli of an elite indica rice cultivar Pusa Basmati-1 were co-bombarded with gene-expression-cassettes (clean DNA fragments) of the Bt gene and the marker hpt gene, to generate marker-free transgenic rice plants. The clean DNA fragments for bombardment were obtained by restriction digestion and gel extraction. Through biolistic transformation, 67 independent transformants were generated. Transformation frequency reached 3.3%, and 81% of the transgenic plants were co-transformants. Stable integration of the Bt gene was confirmed, and the insert copy number was determined by Southern analysis. Western analysis and ELISA revealed a high level of Bt protein expression in transgenic plants. Progeny analysis confirmed stable inheritance of the Bt gene according to the Mendelian (3:1) ratio. Insect bioassays revealed complete protection of transgenic plants from yellow stem borer infestation. PCR analysis of T2 progeny plants resulted in the recovery of up to 4% marker-free transgenic rice plants.

  14. Native Resistance of Maize to Western Corn Rootworm Larval Feeding

    Science.gov (United States)

    The western corn rootworm (WCR) is a major insect pest in continuous corn production. By feeding on corn roots, WCR causes economic losses due to plant lodging and decreased nutrient uptake. Currently, insecticides and transgenic corn are only available options for its control under continuous cor...

  15. Oviposition Behaviors in Relation to Rotation Resistance in the Western Corn Rootworm

    NARCIS (Netherlands)

    Knolhoff, L.M.; Glas, J.J.; Spencer, J.L.; Berenbaum, M.R.

    2010-01-01

    Across a large area of the midwestern United States Corn Belt, the western corn rootworm beetle (Diabrotica virgifera virgifera LeConte, Coleoptera: Chrysomelidae) exhibits behavioral resistance to annual crop rotation. Resistant females exhibit increased locomotor activity and frequently lay eggs i

  16. Searching for Natural Resistance to the Northern Corn Rootworm at the USDA/ARS Lab in Brookings

    Science.gov (United States)

    Corn rootworms and their management costs US farmers over 1 billion dollars annually. In recent years companies have developed corn hybrids with resistance to corn rootworms by inserting bacterial genes into the corn genome. These hybrids are often called GMOs (genetically modified organisms) and a...

  17. 基于高光谱成像的玉米螟无损检测最优波段的选取%Optimal Wavelengths Determination for Non-destructive Detection of Corn Borer on Corn Stem Based on Hyperspectral Imaging

    Institute of Scientific and Technical Information of China (English)

    田有文; 邢晓琪; 王小奇; 崔博

    2015-01-01

    In order to solve the problem of nondestructive detection early pest of corn stalk and to provide theoretical basis of forecast early warning and precision spraying for corn pest, using hyperspectral imaging technology, a subsection hybrid distance method was proposed. The optimal wavelengths of corn borer on the corn stalks were determined for non-destructive detection. A signal band feature image was extracted. The wormhole was segmented to realize the detection of corn borer fast, accurately and non-destructively.First of all, through analysis of maize stalk hyperspectral images, according to the difference of spectral reflectance of corn stalk hyperspectral images of corn stalk region and background region of each band, the 450 nm band image was selected.The mask image was got by using the method of threshold segmentation. Then according to the characteristics of band spectrum correlation small between wavelengths visible range 530nm to 600nm and infrared range 750nm to 900nm, hybrid distance was used as measurement parameters to screen the best single band and dual bands combination. Finally, the 754.8nm band was determined the optimal band. This band image was features image. The corn borer hole was segmented by threshold segmentation and mathematical morphology method to detect the corn borer hole region to determine corn stalk the existence of pest. The results showed that the detection accuracy of corn borer was 100% through detection analysis of 60 corn borer samples on corn stem and 40 normal corn stem samples in the test set and validation set. The detection accuracy of normal corn stem is 90% and the overall detection accuracy is 96%. It is result that the optimal wavelengths obtained in this paper would provide the reference for the development of maize stem pests multi-spectral imaging detector.%为解决玉米茎秆虫害早期无损检测问题,以提供玉米虫害预测预警与精确喷药理论依据,利用高光谱成像技术,提出了

  18. Dominant inheritance of field-evolved resistance to Bt corn in Busseolafusca.

    Directory of Open Access Journals (Sweden)

    Pascal Campagne

    Full Text Available Transgenic crops expressing Bacillus thuringiensis (Bt toxins have been adopted worldwide, notably in developing countries. In spite of their success in controlling target pests while allowing a substantial reduction of insecticide use, the sustainable control of these pest populations is threatened by the evolution of resistance. The implementation of the "high dose/refuge" strategy for managing insect resistance in transgenic crops aims at delaying the evolution of resistance to Bt crops in pest populations by promoting survival of susceptible insects. However, a crucial condition for the "high dose/refuge" strategy to be efficient is that the inheritance of resistance should be functionally recessive. Busseolafusca developed high levels of resistance to the Bt toxin Cry 1Ab expressed in Bt corn in South Africa. To test whether the inheritance of B. fusca resistance to the Bt toxin could be considered recessive we performed controlled crosses with this pest and evaluated its survival on Bt and non-Bt corn. Results show that resistance of B. fusca to Bt corn is dominant, which refutes the hypothesis of recessive inheritance. Survival on Bt corn was not lower than on non-Bt corn for both resistant larvae and the F1 progeny from resistant × susceptible parents. Hence, resistance management strategies of B. fusca to Bt corn must address non-recessive resistance.

  19. Dominant inheritance of field-evolved resistance to Bt corn in Busseolafusca.

    Science.gov (United States)

    Campagne, Pascal; Kruger, Marlene; Pasquet, Rémy; Le Ru, Bruno; Van den Berg, Johnnie

    2013-01-01

    Transgenic crops expressing Bacillus thuringiensis (Bt) toxins have been adopted worldwide, notably in developing countries. In spite of their success in controlling target pests while allowing a substantial reduction of insecticide use, the sustainable control of these pest populations is threatened by the evolution of resistance. The implementation of the "high dose/refuge" strategy for managing insect resistance in transgenic crops aims at delaying the evolution of resistance to Bt crops in pest populations by promoting survival of susceptible insects. However, a crucial condition for the "high dose/refuge" strategy to be efficient is that the inheritance of resistance should be functionally recessive. Busseolafusca developed high levels of resistance to the Bt toxin Cry 1Ab expressed in Bt corn in South Africa. To test whether the inheritance of B. fusca resistance to the Bt toxin could be considered recessive we performed controlled crosses with this pest and evaluated its survival on Bt and non-Bt corn. Results show that resistance of B. fusca to Bt corn is dominant, which refutes the hypothesis of recessive inheritance. Survival on Bt corn was not lower than on non-Bt corn for both resistant larvae and the F1 progeny from resistant × susceptible parents. Hence, resistance management strategies of B. fusca to Bt corn must address non-recessive resistance.

  20. Compatibility of Intercropping Stem Borer Resistant Sorghum Sorghum bicolor Moench Genotypes with Cowpea Vigna unguiculata (L Walp and its Effect on Flower Thrips

    Directory of Open Access Journals (Sweden)

    Ampong-Nyarko, K.

    1994-01-01

    Full Text Available The compatibility of sorghum Sorghum bicolor Moench genotypes with varying levels of resistance to stem borers for intercropping was studied in field experiments for two cropping seasons at the ICIPE in Kenya. Sorghum genotypes IS-18520, IS-1044, IS-2269, ICS 3, ICS 4, LRB6, 2Kx17and Gaddam El Hamam were grown both as monocrops and as intercrops with cowpea. Intercropping reduced the Chilo partellus population density but there was no significant genotype x intercropping interaction. Intercropping significantly reduced the number of flower thrips Megalurothrips sjostedti in cowpea Vigna unguiculata (L Walp. The stem borer resistance level of sorghum genotypes tested was not affected by intercropping. There were, however, differences in agronomic productivity. Grain yield of intercropped sorghum was positively correlated with the number of tillers per harvestable head. Sorghum genotypes with high tillering capacity, of intermediate plant height and intermediate leaf area were considered compatible for intercropping with cowpea.

  1. Agrobacterium tumefaciens-mediated transformation of rice with the spider insecticidal gene conferring resistance to leaffolder and striped stem borer

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Immature embryos of rice varieties “Xiushui11” and “Chunjiang 11” precultured for 4d were infected and transformed by Agrobacterium tumefaciens strain EHA101/pExT7(containing the spider insecticidal gene).The resistant calli were transferred onto the differentiation medium and plants were regenerated.The transformation frequency reached 56%~72% measured as numbers of Geneticin(G418)-resistant calli produced and 36%~60% measured as numbers of transgenic plants regenerated,respectively.PCR and Southern blot analysis of transgenic plants confirmed that the T-DNA had been integrated into the rice genome.Insect bioassays using T1 transgenic plants indicated that the mortality of the leaffolder(Cnaphalocrasis medinalis)after 7d of leaf feeding reached 38%~61% and the corrected mortality of the striped stem borer(Chilo suppressalis)after 7d of leaf feeding reached 16%~75%.The insect bioassay results demonstrated that the transgenic plants expressing the spider insecticidal protein conferred enhanced resistance to these pests.

  2. Transgenic maize plants expressing the Totivirus antifungal protein, KP4, are highly resistant to corn smut

    Science.gov (United States)

    The corn smut fungus, Ustilago maydis, is a global pathogen responsible for extensive agricultural losses. Control of corn smut using traditional breeding has met with limited success because natural resistance to U. maydis is organ specific and involves numerous maize genes. Here, we present a tran...

  3. Resistant Starch and Starch Thermal Characteristics in Exotic Corn Lines Grown in Temperate and Tropical Environments

    Science.gov (United States)

    Corn as a food that is heated and cooled to allow starch retrogradation has higher levels of resistant starch (RS). Increasing the amount of RS can make corn an even healthier food and may be accomplished by breeding and selection, especially by using exotic germplasm. Sixty breeding lines of introg...

  4. Limited divergence among populations of rice striped stem borer in southeast China caused by gene flow: Implications for resistance management

    Institute of Scientific and Technical Information of China (English)

    Chao YANG; Xiao YANG; Qiang FU; Kai XU; Bao-Rong LU

    2012-01-01

    Rice striped stem borer (RSSB,Chilo suppressalis) is a serious lepidopteron pest occurring in rice ecosystems of Asia and Europe.Genetically modified (GM) insect-resistant Bt rice has been developed to deter lepidopteron pests including RSSB.The concern of resistance evolution to the Bt toxin by the pests under commercial cultivation of GM Bt rice and the need of effective management of the resistance encourage the studies of genetic variation and divergence,as well as gene flow of RSSB populations.We analyzed 13 RSSB populations fed on water-oats or rice plants,respectively,from southeast China applying the fluorescent amplified fragment length polymorphism fingerprints.A generally moderate level of genetic variation was detected in the populations,as estimated by Nei's genetic diversity (0.27) and Shannon's index (0.42).The FsT- and AMOVA values indicated a low level (~ 12%) of genetic divergence among the RSSB populations.A relatively frequent gene flow (an average Nm =2.62) was detected among the 12 RSSB populations,which may explain the limited genetic divergence among the rice-feeding populations.This explanation gains support by the assignment test of the corresponding populations,suggesting that a considerable proportion of individuals was contributed from non-native populations.Our results revealed that the moderate level of genetic diversity combined with relatively frequent gene flow among RSSB populations across a large geographical range may slow down the resistance evolution of the RSSB populations,given that a proper measure of resistance management is taken.

  5. Report: EPA Needs Better Data, Plans and Tools to Manage Insect Resistance to Genetically Engineered Corn

    Science.gov (United States)

    Report #16-P-0194, June 1, 2016. Bt crops have reduced insecticide applications by 123 million pounds. The EPA can preserve this significant public benefit through enhanced monitoring and preparation to address insect resistance in Bt corn.

  6. Advances in the Mechanism Study of Borer Resistance in Sugarcane%甘蔗对螟虫的抗性及其机制研究进展

    Institute of Scientific and Technical Information of China (English)

    甘仪梅; 曾凡云; 张树珍; 杨本鹏

    2012-01-01

    Sugarcane is the main sugar crop and energy crop. Borer is a major pest to sugarcane, which can significantly reduce the yield and quality of sugarcane. Although cchemicalontrol and integrated pests management are common for control of borer, success is often limited due to practical difficulties. Breeding sugarcane cultivars with insect resistance allows the most effective and low—cost control of strip borer populations. The main resistance mechanisms are larvae antixenosis and antibiosis in resistant way. This article reviews the research advances concerning the methods of resistant identification based on field and laboratory trials, respectively, and the relationship of resistance with physical structure (including stem hardness, fiber content, silicon content) and physiological and biochemical factors (including flavonoid, nitrogen and essential amino acids). The function of physical structure and physiological and biochemical factors in borer resistance were elucidated. Also, this article discussed the resistance mechanisms based on the sources of resistance.%甘蔗是主要的糖料作物和能源作物,螟虫是甘蔗生产中为害最严重的钻蛀性害虫,使甘蔗的产量和品质显著降低.尽管目前普遍采用化学药剂和生物防治方法,但因甘蔗的特殊性使防治效果甚微.利用品种的抗虫性是最为经济有效的防治方法.从抗性方式来看,甘蔗抗螟虫性机制主要是幼虫的排趋性和抗生性.本文从甘蔗对螟虫的田间抗性鉴定、室内抗性鉴定讨论了抗性鉴定方法,以及茎表皮硬度、纤维素含量、硅含量等物理结构特性和类黄酮、氮素和必需氨基酸等化学因子与抗性的关系,阐述了物理结构和化学因子在甘蔗对螟虫抗性机制中的作用,最后从抗性来源等方面探讨抗性机制的研究,并对今后的研究方向提出展望.

  7. Nutritional attributes of ash (Fraxinus spp.) outer bark and phloem and their relationships to resistance against the emerald ash borer.

    Science.gov (United States)

    Hill, Amy L; Whitehill, Justin G A; Opiyo, Stephen O; Phelan, P Larry; Bonello, Pierluigi

    2012-12-01

    The emerald ash borer (Agrilus planipennis Fairmaire, EAB) is an alien, invasive wood-boring insect that is responsible for killing millions of ash trees since its discovery in North America in 2002. All North American ash species (Fraxinus spp.) that EAB has encountered have shown various degrees of susceptibility, while Manchurian ash (Fraxinus mandshurica Ruprecht), which shares a co-evolutionary history with this insect, is resistant. Recent studies have looked into constitutive resistance mechanisms in Manchurian ash, concentrating on the secondary phloem, which is the feeding substrate for the insect. In addition to specialized metabolism and defense-related components, primary metabolites and nutritional summaries can also be important to understand the feeding behavior of insect herbivores. Here, we have compared the nutritional characteristics (water content, total protein, free amino acids, total soluble sugars and starch, percent carbon and nitrogen, and macro- and micronutrients) of outer bark and phloem from black, green, white and Manchurian ash to determine their relevance to resistance or susceptibility to EAB. Water content and concentrations of Al, Ba, Cu, Fe, K, Li, tryptophan and an unknown compound were found to separate black and Manchurian ash from green and white ash in a principal component analysis (PCA), confirming their phylogenetic placements into two distinct clades. The traits that distinguished Manchurian ash from black ash in the PCA were water content and concentrations of total soluble sugars, histidine, lysine, methionine, ornithine, proline, sarcosine, tyramine, tyrosol, Al, Fe, K, Na, V and an unknown compound. However, only proline, tyramine and tyrosol were significantly different, and higher, in Manchurian ash than in black ash.

  8. Changes in insecticide resistance of the rice striped stem borer (Lepidoptera: Crambidae).

    Science.gov (United States)

    Su, Jianya; Zhang, Zhenzhen; Wu, Min; Gao, Congfen

    2014-02-01

    Application of insecticides is the most important method to control Chilo suppressalis (Walker) (Lepidoptera: Crambidae), and continuous use of individual insecticides has driven the rapid development of insecticide resistance in C. suppressalis during the past 30 yr. Monitoring insecticide resistance provides information essential for integrated pest management. Insecticide resistance of field populations to monosultap, triazophos, chlorpyrifos, and abamectin in China was examined in 2010 and 2011. The results indicated that the resistance levels of 14 field populations to four insecticides were significantly different. Four populations showed moderate resistance, and other populations possessed low-level resistance or were susceptible to monosultap. Nine populations displayed an extremely high or a high level of resistance to triazophos, whereas four populations were sensitive to this agent. Five populations exhibited a low level of resistance to abamectin, while the others remained sensitive. When compared with historical data, resistance to monosultap and triazophos decreased significantly, and the percentage of populations with high-level or extremely high-level resistance was obviously reduced. By contrast, the resistance to abamectin increased slightly. The increasing and decreasing resistance levels reported in this study highlight the different evolutionary patterns of insecticide resistance in C. suppressalis. An overreliance on one or two insecticides may promote rapid development of resistance. Slow development of resistance to abamectin, which was used mainly in mixtures with other insecticides, implies that the use of insecticide mixtures may be an effective method to delay the evolution of resistance to insecticides.

  9. Field-evolved resistance by western corn rootworm to multiple Bacillus thuringiensis toxins in transgenic maize.

    Science.gov (United States)

    Gassmann, Aaron J; Petzold-Maxwell, Jennifer L; Clifton, Eric H; Dunbar, Mike W; Hoffmann, Amanda M; Ingber, David A; Keweshan, Ryan S

    2014-04-01

    The widespread planting of crops genetically engineered to produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) places intense selective pressure on pest populations to evolve resistance. Western corn rootworm is a key pest of maize, and in continuous maize fields it is often managed through planting of Bt maize. During 2009 and 2010, fields were identified in Iowa in which western corn rootworm imposed severe injury to maize producing Bt toxin Cry3Bb1. Subsequent bioassays revealed Cry3Bb1 resistance in these populations. Here, we report that, during 2011, injury to Bt maize in the field expanded to include mCry3A maize in addition to Cry3Bb1 maize and that laboratory analysis of western corn rootworm from these fields found resistance to Cry3Bb1 and mCry3A and cross-resistance between these toxins. Resistance to Bt maize has persisted in Iowa, with both the number of Bt fields identified with severe root injury and the ability western corn rootworm populations to survive on Cry3Bb1 maize increasing between 2009 and 2011. Additionally, Bt maize targeting western corn rootworm does not produce a high dose of Bt toxin, and the magnitude of resistance associated with feeding injury was less than that seen in a high-dose Bt crop. These first cases of resistance by western corn rootworm highlight the vulnerability of Bt maize to further evolution of resistance from this pest and, more broadly, point to the potential of insects to develop resistance rapidly when Bt crops do not achieve a high dose of Bt toxin.

  10. Interspecific comparison of constitutive ash phloem phenolic chemistry reveals compounds unique to manchurian ash, a species resistant to emerald ash borer.

    Science.gov (United States)

    Whitehill, Justin G A; Opiyo, Stephen O; Koch, Jennifer L; Herms, Daniel A; Cipollini, Donald F; Bonello, Pierluigi

    2012-05-01

    The emerald ash borer (Agrilus planipennis, EAB) is an invasive wood-borer indigenous to Asia and is responsible for widespread ash (Fraxinus spp.) mortality in the U.S. and Canada. Resistance and susceptibility to EAB varies among Fraxinus spp., which is a result of their co-evolutionary history with the pest. We characterized constitutive phenolic profiles and lignin levels in the phloem of green, white, black, blue, European, and Manchurian ash. Phloem was sampled twice during the growing season, coinciding with phenology of early and late instar EAB. We identified 66 metabolites that displayed a pattern of variation, which corresponded strongly with phylogeny. Previously identified lignans and lignan derivatives were confirmed to be unique to Manchurian ash, and may contribute to its high level of resistance to EAB. Other compounds that had been considered unique to Manchurian ash, including hydroxycoumarins and the phenylethanoids calceolarioside A and B, were detected in closely related, but susceptible species, and thus are unlikely to contribute to EAB resistance of Manchurian ash. The distinct phenolic profile of blue ash may contribute to its relatively high resistance to EAB.

  11. Early Detection and Mitigation of Resistance to Bt Maize by Western Corn Rootworm (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Andow, David A; Pueppke, Steven G; Schaafsma, Arthur W; Gassmann, Aaron J; Sappington, Thomas W; Meinke, Lance J; Mitchell, Paul D; Hurley, Terrance M; Hellmich, Richard L; Porter, R Pat

    2016-02-01

    Transgenic Bt maize that produces less than a high-dose has been widely adopted and presents considerable insect resistance management (IRM) challenges. Western corn rootworm, Diabrotica virgifera virgifera LeConte, has rapidly evolved resistance to Bt maize in the field, leading to local loss of efficacy for some corn rootworm Bt maize events. Documenting and responding to this resistance has been complicated by a lack of rapid diagnostic bioassays and by regulatory triggers that hinder timely and effective management responses. These failures are of great concern to the scientific and agricultural community. Specific challenges posed by western corn rootworm resistance to Bt maize, and more general concerns around Bt crops that produce less than a high-dose of Bt toxin, have caused uncertainty around current IRM protocols. More than 15 years of experience with IRM has shown that high-dose and refuge-based IRM is not applicable to Bt crops that produce less than a high-dose. Adaptive IRM approaches and pro-active, integrated IRM-pest management strategies are needed and should be in place before release of new technologies that produce less than a high-dose. We suggest changes in IRM strategies to preserve the utility of corn rootworm Bt maize by 1) targeting local resistance management earlier in the sequence of responses to resistance and 2) developing area-wide criteria to address widespread economic losses. We also favor consideration of policies and programs to counteract economic forces that are contributing to rapid resistance evolution.

  12. 海南自然诱发条件下籼稻A232抗螟性鉴定%Identification of Resistant to Stem-borer of Indica Rice A232 Under Natural Conditions in Hainan Province

    Institute of Scientific and Technical Information of China (English)

    李永洪; 谢戎; 刘成元; 向箭宇

    2011-01-01

    筛选、发掘抗螟虫种质资源是培育抗虫品种的基础.本试验利用海南螟虫选择压大的自然条件,采用枯心指数法鉴定A232抗螟性.结果表明:A232枯心率为10.82%,极显著低于对照F77.A232枯心指数为36.31%,抗螟性达中抗水平.对该材料的利用进行了讨论.%Screening and exploring the germplasm resources of resistant to stem-borer were a foundation to breed the resistant varieties. Characteristics of resistance to stem-borer of A232 were identified by using the index of dead heart under natural rice fields condition with high selection pressure to stem-borer in Hainan province. The results showed that the dead heart rate of A232 was 10.82 % , significantly less than that of the contrast variety F77. The index of dead heart of A232 was 36.31 % , indicating that A232 reached the medium level of stem-borer resistance. At the same time,the use of tested material were discussed in this paper.

  13. Risk assessment for Helicoverpa zea (Lepidoptera: Noctuidae) resistance on dual-gene versus single-gene corn.

    Science.gov (United States)

    Edwards, Kristine T; Caprio, Michael A; Allen, K Clint; Musser, Fred R

    2013-02-01

    Recent Environmental Protection Agency (EPA) decisions regarding resistance management in Bt-cropping systems have prompted concern in some experts that dual-gene Bt-corn (CrylA.105 and Cry2Ab2 toxins) may result in more rapid selection for resistance in Helicoverpa zea (Boddie) than single-gene Bacillus thuringiensis (Bt)-corn (CrylAb toxin). The concern is that Bt-toxin longevity could be significantly reduced with recent adoption of a natural refuge for dual-gene Bt-cotton (CrylAc and Cry2Ab2 toxins) and concurrent reduction in dual-gene corn refuge from 50 to 20%. A population genetics framework that simulates complex landscapes was applied to risk assessment. Expert opinions on effectiveness of several transgenic corn and cotton varieties were captured and used to assign probabilities to different scenarios in the assessment. At least 350 replicate simulations with randomly drawn parameters were completed for each of four risk assessments. Resistance evolved within 30 yr in 22.5% of simulations with single-gene corn and cotton with no volunteer corn. When volunteer corn was added to this assessment, risk of resistance evolving within 30 yr declined to 13.8%. When dual-gene Bt-cotton planted with a natural refuge and single-gene corn planted with a 50% structured refuge was simulated, simultaneous resistance to both toxins never occurred within 30 yr, but in 38.5% of simulations, resistance evolved to toxin present in single-gene Bt-corn (CrylAb). When both corn and cotton were simulated as dual-gene products, cotton with a natural refuge and corn with a 20% refuge, 3% of simulations evolved resistance to both toxins simultaneously within 30 yr, while 10.4% of simulations evolved resistance to CrylAb/c toxin.

  14. Toward elucidation of genetic and functional genetic mechanisms in corn host resistance to Aspergillus flavus infection and aflatoxin contamination

    Directory of Open Access Journals (Sweden)

    Xueyan eShan

    2014-07-01

    Full Text Available Aflatoxins are carcinogenic mycotoxins produced by some species in the Aspergillus genus, such as A. flavus and A. parasiticus. Contamination of aflatoxins in corn profusely happens at pre-harvest stage when heat and drought field conditions favor A. flavus colonization. Commercial corn hybrids are generally susceptible to A. flavus infection. An ideal strategy for preventing aflatoxin contamination is through the enhancement of corn host resistance to Aspergillus infection and aflatoxin production. Constant efforts have been made by corn breeders to develop resistant corn genotypes. Significantly low levels of aflatoxin accumulation have been determined in certain resistant corn inbred lines. A number of reports of quantitative trait loci (QTLs have provided compelling evidence supporting the quantitative trait genetic basis of corn host resistance to aflatoxin accumulation. Important findings have also been obtained from the investigation on candidate resistance genes through transcriptomics approach. Elucidation of molecular mechanisms will provide in-depth understanding of the host-pathogen interactions and hence facilitate the breeding of corn with resistance to A. falvus infection and aflatoxin accumulation.

  15. Identification of Bt-transgenic Rice Plants for Resistance to Stripe Stem Borer (Chilo suppressalis) and Genetic Analysis of the Transgenes

    Institute of Scientific and Technical Information of China (English)

    ZHU Chang-xiang; YAO Fang-yin; LI Guang-xian; WEN Fu-jiang

    2002-01-01

    Resistance to herbicide Basta was used to identify Bt-transgenic rice plants and the progenies of crosses between the Bt-transgenic rice and the rice varieties cultivated in the Huang Huai area of China. The results demonstrated that the Basta-positive rice plants were highly resistant to stripe stem borer (Chilo suppressalis ) both in the laboratory and field tests. Both cryIA (b) and bar genes were expressed and co-inherited in both selfing and crossing progenies. Mendelian segregation of the marker gene bar was observed in F2 and BC1 progenies. The results implicates that it is possible to transfer cryIA (b) gene into other cultivated varieties through crosses and back crosses.

  16. Expression of the maize proteinase inhibitor (mpi) gene in rice plants enhances resistance against the striped stem borer (Chilo suppressalis): effects on larval growth and insect gut proteinases.

    Science.gov (United States)

    Vila, Laura; Quilis, Jordi; Meynard, Donaldo; Breitler, Jean Christophe; Marfà, Victoria; Murillo, Isabel; Vassal, Jean Michel; Messeguer, Joaquima; Guiderdoni, Emmanuel; San Segundo, Blanca

    2005-03-01

    The maize proteinase inhibitor (mpi) gene was introduced into two elite japonica rice varieties. Both constitutive expression of the mpi gene driven by the maize ubiquitin 1 promoter and wound-inducible expression of the mpi gene driven by its own promoter resulted in the accumulation of MPI protein in the transgenic plants. No effect on plant phenotype was observed in mpi-expressing lines. The stability of transgene expression through successive generations of mpi rice lines (up to the T(4) generation) and the production of functional MPI protein were confirmed. Expression of the mpi gene in rice enhanced resistance to the striped stem borer (Chilo suppressalis), one of the most important pests of rice. In addition, transgenic mpi plants were evaluated in terms of their effects on the growth of C. suppressalis larvae and the insect digestive proteolytic system. An important dose-dependent reduction of larval weight of C. suppressalis larvae fed on mpi rice, compared with larvae fed on untransformed rice plants, was observed. Analysis of the digestive proteolytic activity from the gut of C. suppressalis demonstrated that larvae adapted to mpi transgene expression by increasing the complement of digestive proteolytic activity: the serine and cysteine endoproteinases as well as the exopeptidases leucine aminopeptidase and carboxypeptidases A and B. However, the induction of such proteolytic activity did not prevent the deleterious effects of MPI on larval growth. The introduction of the mpi gene into rice plants can thus be considered as a promising strategy to protect rice plants against striped stem borer.

  17. Effect of plant age, larval age, and fertilizer treatment on resistance of a cry1Ab-transformed aromatic rice to lepidopterous stem borers and foliage feeders.

    Science.gov (United States)

    Alinia, F; Ghareyazie, B; Rubia, L; Bennett, J; Cohen, M B

    2000-04-01

    The resistance of vegetative, booting, and flowering stage plants of a variety of an aromatic rice, Oryza sativa L., transformed with a Bacillus thuringiensis Berliner cry1Ab gene under control of the maize phosphoenolpyruvate carboxylase (PEPC) promoter was evaluated against four lepidopterous rice pests--the stem borers Chilo suppressalis (Walker) (Lepidoptera: Crambidae) and Scirpophaga incertulas (Walker) (Lepidoptera: Pyralidae), and the foliage feeders Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae) and Naranga aenescens Moore (Lepidoptera: Noctuidae). Plants of the cry1Ab-transformed line (no. 827) were more resistant to young larvae of S. incertulas, C. suppressalis, and C. medinalis than control plants at the vegetative stage but not at the flowering stage. Survival of 10-d-old stem borer larvae did not differ on cry1Ab plants and control plants at either the vegetative or flowering stage, but the development of 10-d-old C. suppressalis larvae was retarded on the vegetative stage cry1Ab plants. Immunological analysis also showed an apparent decline in Cry1Ab titer in leaf blades and leaf sheaths at the reproductive stage. In experiments comparing three fertilizer treatments (NPK, PK, and none), there was a significant interaction between fertilizer treatment and variety on larval survival only in whole-plant assays at booting stage with C. suppressalis. On cry1Ab plants, larval survival did not differ significantly among the three fertilizer levels, whereas on control plants survival was highest with the NPK treatment. cry1Ab plants tested at the sixth and seventh generations after transformation were more resistant than control plants to N. aenescens and C. suppressalis, respectively, suggesting that gene silencing will not occur in line 827. The results of the experiments are discussed in terms of resistance management for B. thuringiensis toxins in rice.

  18. Correlations between the contents of phytic acid and inorganic phosphorous and downy mildew resistance of corn inbred lines

    OpenAIRE

    Pantipa Na Chiangmai*; Phrutiya Nilprapruck; Warapon Bunkoed; Phakatip Yodmingkhwan; Chokechai Aekatasanawan; Mana Kanjanamaneesathian

    2015-01-01

    Seeds of corn inbred lines collected at the National Corn and Sorghum Research Center (NCSRC), Kasetsart University, were analyzed to determine the contents of phytic acid (PA) and inorganic phosphorous (InP). These 28 and 29 inbred lines were cultivated at the NCSRC (in the 2008 late rainy season and 2009 early rainy season) to evaluate their resistance to corn downy mildew caused by Peronosclerospora sorghi. Results showed that the values of the PA, InP contents and downy mildew...

  19. THE STATUS OF PESTCIDE RESISTANCE OF RICE STALK BORER IN ZHEJIANG PROVICE AND THEIR MANAGEMENT TACTICS%浙江省水稻二化螟抗药性现状与治理对策

    Institute of Scientific and Technical Information of China (English)

    蒋学辉; 章强华; 胡仕孟; 谢士杰; 徐喜刚

    2001-01-01

    The strip stem borer, Chilo suppressalis, is the one of most serious rice pests in the rice ecosystems of Zhejiang province. The pest resistance to two insecticides, bisultap and triazophos, were caused in a large rice area, mainly due to the continuously injudicious use of above two insecticides for 20 and 10 years respectively.The field monitoring shown that resistance ratio of stem borer populations collected from different rice areas of Zhejiang was among 67 ~ 587, and all tested populations were of high resistance to bisultap. The resistance ratio of stem borer populations collected from rice areas of Wenzhou and Taizhou was among 68 ~ 162, and tested population were high resistance to triazophos. To efficiently manager the insecticide resistance, the following measures should be taken, 1 )to frequently monitor the insecticide resistance in stem borer in all rice ecosystems, 2) to prohibit the use of above insecticides in rice ecosystems with high insecticide resistance, and 3) to minimize the injudicious use of above insecticides in rice ecosystems with low or susceptible insecticide resistance. The rational use of insecticides for suppressing strip stem borer could reduce the selective pressure of insecticides to stem borer populations.%二化螟是浙江省水稻的主要害虫。由于连续使用杀虫双超过20 a,三唑磷10 a防治二化螟,致使二化螟对杀虫单(杀虫双)普遍产生抗药性。1999年测定抗性增加67~587倍,达到高抗和极高抗水平;二化螟对三唑磷在温州和台州等局部地区也达到了68~162倍的高抗水平。为治理二化螟抗药性,必须加强对害虫抗药性的监测,在高抗药性地区停止使用杀虫单(杀虫双)和三唑磷防治二化螟;在低抗药性和敏感地区也应减少使用次数和用量,达到延缓抗药性产生的目的。

  20. Broad-spectrum resistance to Bacillus thuringiensis toxins by western corn rootworm (Diabrotica virgifera virgifera).

    Science.gov (United States)

    Jakka, Siva R K; Shrestha, Ram B; Gassmann, Aaron J

    2016-06-14

    The evolution of resistance and cross-resistance threaten the sustainability of genetically engineered crops that produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt). Western corn rootworm, Diabrotica virgifera virgifera LeConte, is a serious pest of maize and has been managed with Bt maize since 2003. We conducted laboratory bioassays with maize hybrids producing Bt toxins Cry3Bb1, mCry3A, eCry3.1Ab, and Cry34/35Ab1, which represent all commercialized Bt toxins for management of western corn rootworm. We tested populations from fields where severe injury to Cry3Bb1 maize was observed, and populations that had never been exposed to Bt maize. Consistent with past studies, bioassays indicated that field populations were resistant to Cry3Bb1 maize and mCry3A maize, and that cross-resistance was present between these two types of Bt maize. Additionally, bioassays revealed resistance to eCry3.1Ab maize and cross-resistance among Cry3Bb1, mCry3A and eCry3.1Ab. However, no resistance or cross-resistance was detected for Cry34/35Ab1 maize. This broad-spectrum resistance illustrates the potential for insect pests to develop resistance rapidly to multiple Bt toxins when structural similarities are present among toxins, and raises concerns about the long-term durability of Bt crops for management of some insect pests.

  1. Maize silk antibiotic polyphenol compounds and molecular genetic improvement of resistance to corn earworm (Helicoverpa zea Boddie in sh2 sweet corn

    Directory of Open Access Journals (Sweden)

    Baozhu Guo

    2010-01-01

    Full Text Available The flavor of sh2 super-sweet corn is preferred by consumers. Unfortunately, sh2 sweet corn has little genetic variation for insect resistance. In this paper we review the functions of two loci, p1 and a1. The P1 allele has a major role in sh2 sweet corn resistance to corn earworm, an allele that was lost in historical selection because of its pleiotropic effect on undesirable cob color and silk browning. The P1 allele has significant effects on biosyntheses of silk antibiotic compounds, maysin, apimaysin, methoxymaysin, and chlorogenic acid. The effect of a1 shows gene action for lowered maysin and significant epistatic action with p1. The dominant functional allele A1 causes anthocyanin pigments in aleurone, plant, and pericarp tissues; the recessive a1 allele causes absence of pigment in these tissues. If silk browning and cob color are critical factors for maysin production but lack the customer’s preference, then separating red cob and browning silk, which are controlled by the P1 allele, may be difficult if not impossible. One high silk maysin sh2 sweet corn germ­plasm, shrunken Zapalote Chico, has been released. There is some field corn germplasm with p1-wwr alleles, but the amount of antibiotic flavones and their potential as a donor need further investigation.

  2. Western corn rootworm and Bt maize: challenges of pest resistance in the field.

    Science.gov (United States)

    Gassmann, Aaron J; Petzold-Maxwell, Jennifer L; Keweshan, Ryan S; Dunbar, Mike W

    2012-01-01

    Crops genetically engineered to produce insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) manage many key insect pests while reducing the use of conventional insecticides. One of the primary pests targeted by Bt maize in the United States is the western corn rootworm, Diabrotica virgifera virgifera LeConte. Beginning in 2009, populations of western corn rootworm were identified in Iowa, USA that imposed severe root injury to Cry3Bb1 maize. Subsequent laboratory bioassays revealed that these populations were resistant to Cry3Bb1 maize, with survival on Cry3Bb1 maize that was three times higher than populations not associated with such injury. Here we report the results of research that began in 2010 when western corn rootworm were sampled from 14 fields in Iowa, half of which had root injury to Cry3Bb1 maize of greater than 1 node. Of these samples, sufficient eggs were collected to conduct bioassays on seven populations. Laboratory bioassays revealed that these 2010 populations had survival on Cry3Bb1 maize that was 11 times higher and significantly greater than that of control populations, which were brought into the laboratory prior to the commercialization of Bt maize for control of corn rootworm. Additionally, the developmental delays observed for control populations on Cry3Bb1 maize were greatly diminished for 2010 populations. All 2010 populations evaluated in bioassays came from fields with a history of continuous maize production and between 3 and 7 y of Cry3Bb1 maize cultivation. Resistance to Cry34/35Ab1 maize was not detected and there was no correlation between survival on Cry3Bb1 maize and Cry34/35Ab1 maize, suggesting a lack of cross resistance between these Bt toxins. Effectively dealing with the challenge of field-evolved resistance to Bt maize by western corn rootworm will require better adherence to the principles of integrated pest management.

  3. Evaluation of corn germplasm lines for multiple ear-colonizing insect and disease resistance.

    Science.gov (United States)

    Ni, Xinzhi; Xu, Wenwei; Blanco, Michael H; Wilson, Jeffrey P

    2012-08-01

    Ear-colonizing insects and diseases that reduce yield and impose health threats by mycotoxin contaminations in the grain, are critical impediments for corn (Zea mays L.) production in the southern United States. Ten germplasm lines from the Germplasm Enhancement of Maize (GEM) Program in Ames, IA, and Raleigh, NC, and 10 lines (derived from GEM germplasm) from the Texas Agricultural Experiment Station in Lubbock, TX, were examined in 2007 and 2008 with local resistant and susceptible controls. Four types of insect damage and smut disease (Ustilago maydis) infection, as well as gene X environment (G X E) interaction, was assessed on corn ears under field conditions. Insect damage on corn ears was further separated as cob and kernel damage. Cob penetration rating was used to assess corn earworm [Helicoverpa zea (Boddie)] and fall armyworm [Spodoptera frugiperda (J.E. Smith)] feeding on corn cobs, whereas kernel damage was assessed using three parameters: 1) percentage of kernels discolored by stink bugs (i.e., brown stink bug [Euschistus serous (Say)], southern green stink bug [Nezara viridula (L.)], and green stink bug [Chinavia (Acrosternum) hilare (Say)]; 2) percentage of maize weevil (Sitophilus zeamais Motschulsky)-damaged kernels; and 3) percentage of kernels damaged by sap beetle (Carpophilus spp.), "chocolate milkworm" (Moodna spp.), and pink scavenger caterpillar [Pyroderces (Anatrachyntis) rileyi (Walsingham)]. The smut infection rates on ears, tassels, and nodes also were assessed. Ear protection traits (i.e., husk tightness and extension) in relation to insect damage and smut infection also were examined. Significant differences in insect damage, smut infection, and husk protection traits were detected among the germplasm lines. Three of the 20 germplasm lines were identified as being multiple insect and smut resistant. Of the three lines, entries 5 and 7 were derived from DKXL370, which was developed using corn germplasm from Brazil, whereas entry 14 was

  4. Transgenic maize plants expressing the Totivirus antifungal protein, KP4, are highly resistant to corn smut.

    Science.gov (United States)

    Allen, Aron; Islamovic, Emir; Kaur, Jagdeep; Gold, Scott; Shah, Dilip; Smith, Thomas J

    2011-10-01

    The corn smut fungus, Ustilago maydis, is a global pathogen responsible for extensive agricultural losses. Control of corn smut using traditional breeding has met with limited success because natural resistance to U. maydis is organ specific and involves numerous maize genes. Here, we present a transgenic approach by constitutively expressing the Totivirus antifungal protein KP4, in maize. Transgenic maize plants expressed high levels of KP4 with no apparent negative impact on plant development and displayed robust resistance to U. maydis challenges to both the stem and ear tissues in the greenhouse. More broadly, these results demonstrate that a high level of organ independent fungal resistance can be afforded by transgenic expression of this family of antifungal proteins.

  5. Selection for Cry3Bb1 resistance in a genetically diverse population of nondiapausing Western Corn Rootworm (Coleoptera: Chrysomelidae)

    Science.gov (United States)

    Five short-diapause laboratory lines of western corn rootworm (Diabrotica virgifera virgifera) were selected for resistance to MON863, a variety of corn genetically modified with the Bacillus thuringiensis (Bt) transgene that expresses the Cry3Bb1 endotoxin. Three of the selecte...

  6. Relationship between Resistance of Rice Stem Borer and Insecticide Use Intensity in South China%中国华南水稻螟虫抗药性与用药的关系

    Institute of Scientific and Technical Information of China (English)

    周克; 闫苗苗

    2013-01-01

    [Objective] This study aimed to survey the effect of insecticide use intensity on the resistance of rice stem borer in South China.[Method] The data includes 19 counties from Guangdong Province and Guangxi Province from 1991 to 2010.A fixed effect model was established to evaluate the effect of insecticide use intensity on the resistance of rice stem borer.[Result] The regression results suggest that one-period lagged total number of insecticide sprays has significant effect on the infestation level of rice stem borer.[Conclusion] Although rice stem borer is a migratory rice pest,insecticide use intensity has significant effect on the resistance level of rice stem borer in South China.%[目标]研究中国华南稻田用药强度对水稻螟虫的抗药性的影响.[方法]采用来自广东和广西的19个水稻种植县从1991年到2010年的面板数据,建立个体固定效应模型.[结果]滞后一期针对水稻螟虫的总用药次数对当期水稻螟虫的发生级别有显著的正的影响.[结论]虽然水稻螟虫是一种迁飞性害虫,但是不同地区的农民的用药行为都受到了水稻螟虫发生级别的影响,因此,长期来看滞后一期用药对当期水稻螟虫的抗药性有显著的正的影响.

  7. Field-evolved resistance to Bt maize by western corn rootworm.

    Directory of Open Access Journals (Sweden)

    Aaron J Gassmann

    Full Text Available BACKGROUND: Crops engineered to produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt are planted on millions of hectares annually, reducing the use of conventional insecticides and suppressing pests. However, the evolution of resistance could cut short these benefits. A primary pest targeted by Bt maize in the United States is the western corn rootworm Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae. METHODOLOGY/PRINCIPAL FINDINGS: We report that fields identified by farmers as having severe rootworm feeding injury to Bt maize contained populations of western corn rootworm that displayed significantly higher survival on Cry3Bb1 maize in laboratory bioassays than did western corn rootworm from fields not associated with such feeding injury. In all cases, fields experiencing severe rootworm feeding contained Cry3Bb1 maize. Interviews with farmers indicated that Cry3Bb1 maize had been grown in those fields for at least three consecutive years. There was a significant positive correlation between the number of years Cry3Bb1 maize had been grown in a field and the survival of rootworm populations on Cry3Bb1 maize in bioassays. However, there was no significant correlation among populations for survival on Cry34/35Ab1 maize and Cry3Bb1 maize, suggesting a lack of cross resistance between these Bt toxins. CONCLUSIONS/SIGNIFICANCE: This is the first report of field-evolved resistance to a Bt toxin by the western corn rootworm and by any species of Coleoptera. Insufficient planting of refuges and non-recessive inheritance of resistance may have contributed to resistance. These results suggest that improvements in resistance management and a more integrated approach to the use of Bt crops may be necessary.

  8. Field-evolved resistance to Bt maize by western corn rootworm: predictions from the laboratory and effects in the field.

    Science.gov (United States)

    Gassmann, Aaron J

    2012-07-01

    Crops engineered to produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) provide an effective management tool for many key insect pests. However, pest species have repeatedly demonstrated their ability to adapt to management practices. Results from laboratory selection experiments illustrate the capacity of pest species to evolve Bt resistance. Furthermore, resistance has been documented to Bt sprays in the field and greenhouse, and more recently, by some pests to Bt crops in the field. In 2009, fields were discovered in Iowa (USA) with populations of western corn rootworm, Diabrotica virgifera virgifera LeConte, that had evolved resistance to maize that produces the Bt toxin Cry3Bb1. Fields with resistant insects in 2009 had been planted to Cry3Bb1 maize for at least three consecutive years and as many as 6years. Computer simulation models predicted that the western corn rootworm might evolve resistance to Bt maize in as few as 3years. Laboratory and field data for interactions between western corn rootworm and Bt maize indicate that currently commercialized products are not high-dose events, which increases the risk of resistance evolution because non-recessive resistance traits may enhance survival on Bt maize. Furthermore, genetic analysis of laboratory strains of western corn rootworm has found non-recessive inheritance of resistance. Field studies conducted in two fields identified as harboring Cry3Bb1-resistant western corn rootworm found that survival of western corn rootworm did not differ between Cry3Bb1 maize and non-Bt maize and that root injury to Cry3Bb1 maize was higher than injury to other types of Bt maize or to maize roots protected with a soil insecticide. These first cases of field-evolved resistance to Bt maize by western corn rootworm provide an early warning and point to the need to apply better integrated pest management practices when using Bt maize to manage western corn rootworm.

  9. Elite Indica transgenic rice plants expressing modified Cry1Ac endotoxin of Bacillus thuringiensis show enhanced resistance to yellow stem borer (Scirpophaga incertulas).

    Science.gov (United States)

    Khanna, H K; Raina, S K

    2002-08-01

    Bt-transgenics of elite indica rice breeding lines (IR-64, Pusa Basmati-1 and Karnal Local) were generated through biolistic or Agrobacterium-mediated approaches. A synthetic cry1Ac gene, codon optimised for rice and driven by the maize ubiquitin-1 promoter, was used. Over 200 putative transformants of IR-64 and Pusa Basmati-1 and 26 of the Karnal Local were regenerated following use of the hpt (hygromycin phosphotransferase) selection system. Initial transformation frequency was in the range of 1 to 2% for particle bombardment while it was comparatively higher (approximately 9%) for Agrobacterium. An improved selection procedure, involving longer selection on the antibiotic-supplemented medium, enhanced the frequency of Bt-transformants and reduced the number of escapes. Molecular evaluation revealed multiple transgene insertions in transformants, whether generated through biolistic or Agrobacterium. In the latter case, it was also observed that all genes on the T-DNA do not necessarily get transferred as an intact insert. Selected Bt-lines of IR-64 and Pusa Basmati-1, having Bt-titers of 0.1% (of total soluble protein) and above were evaluated for resistance against manual infestation of freshly hatched neonate larvae of yellow stem borers collected from a hot spot stem borer infested area in northern India. Several Bt-lines were identified showing 100% mortality of larvae, within 4-days of infestation, in cut-stem as well as vegetative stage whole plant assays. However, there was an occasional white head even among such plants when assayed at the reproductive stage. Results are discussed in the light of resistance management strategies for deployment of Bt-rice.

  10. Progress and gaps in understanding mechanisms of ash tree resistance to emerald ash borer, a model for wood-boring insects that kill angiosperms.

    Science.gov (United States)

    Villari, Caterina; Herms, Daniel A; Whitehill, Justin G A; Cipollini, Don; Bonello, Pierluigi

    2016-01-01

    We review the literature on host resistance of ash to emerald ash borer (EAB, Agrilus planipennis), an invasive species that causes widespread mortality of ash. Manchurian ash (Fraxinus mandshurica), which coevolved with EAB, is more resistant than evolutionarily naïve North American and European congeners. Manchurian ash was less preferred for adult feeding and oviposition than susceptible hosts, more resistant to larval feeding, had higher constitutive concentrations of bark lignans, coumarins, proline, tyramine and defensive proteins, and was characterized by faster oxidation of phenolics. Consistent with EAB being a secondary colonizer of coevolved hosts, drought stress decreased the resistance of Manchurian ash, but had no effect on constitutive bark phenolics, suggesting that they do not contribute to increased susceptibility in response to drought stress. The induced resistance of North American species to EAB in response to the exogenous application of methyl jasmonate was associated with increased bark concentrations of verbascoside, lignin and/or trypsin inhibitors, which decreased larval survival and/or growth in bioassays. This finding suggests that these inherently susceptible species possess latent defenses that are not induced naturally by larval colonization, perhaps because they fail to recognize larval cues or respond quickly enough. Finally, we propose future research directions that would address some critical knowledge gaps.

  11. Susceptibility of Ostrinia furnacalis to Bacillus thuringiensis and Bt Corn Under Long-Term Laboratory Selection

    Institute of Scientific and Technical Information of China (English)

    WEN Li-ping; HE Kang-lai; WANG Zhen-ying; ZHOU Da-rong; BAI Shu-xiong

    2005-01-01

    The susceptibility of the Asian corn borer, Ostrinia furnacalis to Bacillus thuringiensis (Bt) formulation and Bt corn was evaluated using insect bioassays for 6 years. Four strains of O. furnacalis were developed by laboratory selection from the laboratory strain reared on a non-agar semi-artificial diet. The RR-1 strain was exposed to a commercial formulation of B. thuringiensis subsp. kurstaki (Btk) incorporated into the artificial diet, the RR-2 strain was exposed to Bt corn (MON810)tissue incorporated into the diet, and the SS-1 and SS-2 strains were reared on the standard diet with or without non-Bt corn tissues material. Decreasing susceptibility of O. furnacalis to Bt and to Bt corn were found in each selected strain although the ED50 and larval weight fluctuated from generation to generation. The resistance of Bt-exposed strain (RR-1)to Btk increased 48-fold by generation 39; the Bt corn-exposed strain (RR-2) increased its resistance 37-fold to Btk by generation 24. No larvae of SS-1 survived when they were exposed to the leaves of Bt corn, Bt1 1 and MON810. However,2-54% of the RR-1 (generation 46) and RR-2 (generation 20) larvae survived a 3 day-exposure to the leaves of Bt1 1 and MON810. The survival of both selected strains on Bt corn silk increased by 10-69%, and the larval weights after many generations selection were increased by 15-22% compared with the unselected susceptible strain. The young larvae were much more susceptible to Bt than older larvae. The highest mortality occurred when the larvae were exposed to Bt at the neonate stage. All of the results suggested that ACB could not only develop resistance to Bt preparation but also to Bt corn. Bt had significant effects on the growth and development of Asian corn borer than on the larval mortality. In order to maintain the long-term effectiveness of Bt pesticide and Bt corn, the resistance management should pay much attention to the larvae that may have opportunities to grow and developed on non

  12. Identification of a novel aminopeptidase P-like gene (OnAPP possibly involved in Bt toxicity and resistance in a major corn pest (Ostrinia nubilalis.

    Directory of Open Access Journals (Sweden)

    Chitvan Khajuria

    Full Text Available Studies to understand the Bacillus thuringiensis (Bt resistance mechanism in European corn borer (ECB, Ostrinia nubilalis suggest that resistance may be due to changes in the midgut-specific Bt toxin receptor. In this study, we identified 10 aminopeptidase-like genes, which have previously been identified as putative Bt toxin receptors in other insects and examined their expression in relation to Cry1Ab toxicity and resistance. Expression analysis for the 10 aminopeptidase-like genes revealed that most of these genes were expressed predominantly in the larval midgut, but there was no difference in the expression of these genes in Cry1Ab resistant and susceptible strains. This suggested that altered expression of these genes was unlikely to be responsible for resistance in these ECB strains. However, we found that there were changes in two amino acid residues of the aminopeptidase-P like gene (OnAPP involving Glu(305 to Lys(305 and Arg(307 to Leu(307 in the two Cry1Ab-resistant strains as compared with three Cry1Ab-susceptible strains. The mature OnAPP contains 682 amino acid residues and has a putative signal peptide at the N-terminus, a predicted glycosylphosphatidyl-inositol (GPI-anchor signal at the C-terminal, three predicted N-glycosylation sites at residues N178, N278 and N417, and an O-glycosylation site at residue T653. We used a feeding based-RNA interference assay to examine the role of the OnAPP gene in Cry1Ab toxicity and resistance. Bioassays of Cry1Ab in larvae fed diet containing OnAPP dsRNA resulted in a 38% reduction in the transcript level of OnAPP and a 25% reduction in the susceptibility to Cry1Ab as compared with larvae fed GFP dsRNA or water. These results strongly suggest that the OnAPP gene could be involved in binding the Cry1Ab toxin in the ECB larval midgut and that mutations in this gene may be associated with Bt resistance in these two ECB strains.

  13. Identification of a novel aminopeptidase P-like gene (OnAPP) possibly involved in Bt toxicity and resistance in a major corn pest (Ostrinia nubilalis).

    Science.gov (United States)

    Khajuria, Chitvan; Buschman, Lawrent L; Chen, Ming-Shun; Siegfried, Blair D; Zhu, Kun Yan

    2011-01-01

    Studies to understand the Bacillus thuringiensis (Bt) resistance mechanism in European corn borer (ECB, Ostrinia nubilalis) suggest that resistance may be due to changes in the midgut-specific Bt toxin receptor. In this study, we identified 10 aminopeptidase-like genes, which have previously been identified as putative Bt toxin receptors in other insects and examined their expression in relation to Cry1Ab toxicity and resistance. Expression analysis for the 10 aminopeptidase-like genes revealed that most of these genes were expressed predominantly in the larval midgut, but there was no difference in the expression of these genes in Cry1Ab resistant and susceptible strains. This suggested that altered expression of these genes was unlikely to be responsible for resistance in these ECB strains. However, we found that there were changes in two amino acid residues of the aminopeptidase-P like gene (OnAPP) involving Glu(305) to Lys(305) and Arg(307) to Leu(307) in the two Cry1Ab-resistant strains as compared with three Cry1Ab-susceptible strains. The mature OnAPP contains 682 amino acid residues and has a putative signal peptide at the N-terminus, a predicted glycosylphosphatidyl-inositol (GPI)-anchor signal at the C-terminal, three predicted N-glycosylation sites at residues N178, N278 and N417, and an O-glycosylation site at residue T653. We used a feeding based-RNA interference assay to examine the role of the OnAPP gene in Cry1Ab toxicity and resistance. Bioassays of Cry1Ab in larvae fed diet containing OnAPP dsRNA resulted in a 38% reduction in the transcript level of OnAPP and a 25% reduction in the susceptibility to Cry1Ab as compared with larvae fed GFP dsRNA or water. These results strongly suggest that the OnAPP gene could be involved in binding the Cry1Ab toxin in the ECB larval midgut and that mutations in this gene may be associated with Bt resistance in these two ECB strains.

  14. Methods of insecticides resistance monitoring of the striped stem borer, Chilo suppressalis%水稻二化螟抗药性监测方法

    Institute of Scientific and Technical Information of China (English)

    吴敏; 张真真; 高聪芬

    2013-01-01

    Methods of insecticide resistance monitoring, including micro-topical and rice seedling dipping methods, adapted for resistance monitoring in the striped stem borer, are introduced. The topical method is used to bioassay contact insecticides. However, this method does not accurately reflect the activity of insecticides which act after being ingested. The rice seedling dipping technique was therefore established to detect resistance to insecticides that require ingestion, such as diamides and Bt microbial insecticides.%本文首先介绍了二化螟Chilo suppressalis(Walker)抗药性监测的方法:点滴法和稻苗浸渍法.其中点滴法已有标准化的生测规程,其适用于以触杀作用为主的杀虫剂抗性监测,但无法准确反映以胃毒作用为主的杀虫剂的毒力效果,因此,本文新建了以胃毒作用为主的双酰胺类或微生物杀虫剂Bt等的抗性监测方法——稻苗浸渍法.

  15. Seeds of change: corn seed mixtures for resistance management and integrated pest management.

    Science.gov (United States)

    Onstad, David W; Mitchell, Paul D; Hurley, Terrance M; Lundgren, Jonathan G; Porter, R Patrick; Krupke, Christian H; Spencer, Joseph L; DiFonzo, Christine D; Baute, Tracey S; Hellmich, Richard L; Buschman, Lawrent L; Hutchison, William D; Tooker, John F

    2011-04-01

    The use of mixtures of transgenic insecticidal seed and nontransgenic seed to provide an in-field refuge for susceptible insects in insect-resistance-management (IRM) plans has been considered for at least two decades. However, the U.S. Environmental Protection Agency has only recently authorized the practice. This commentary explores issues that regulators, industry, and other stakeholders should consider as the use of biotechnology increases and seed mixtures are implemented as a major tactic for IRM. We discuss how block refuges and seed mixtures in transgenic insecticidal corn, Zea mays L., production will influence integrated pest management (IPM) and the evolution of pest resistance. We conclude that seed mixtures will make pest monitoring more difficult and that seed mixtures may make IRM riskier because of larval behavior and greater adoption of insecticidal corn. Conversely, block refuges present a different suite of risks because of adult pest behavior and the lower compliance with IRM rules expected from farmers. It is likely that secondary pests not targeted by the insecticidal corn as well as natural enemies will respond differently to block refuges and seed mixtures.

  16. Physiological responses of emerald ash borer larvae to feeding on different ash species reveal putative resistance mechanisms and insect counter-adaptations.

    Science.gov (United States)

    Rigsby, C M; Showalter, D N; Herms, D A; Koch, J L; Bonello, P; Cipollini, D

    2015-07-01

    Emerald ash borer, Agrilus planipennis Fairmaire, an Asian wood-boring beetle, has devastated ash (Fraxinus spp.) trees in North American forests and landscapes since its discovery there in 2002. In this study, we collected living larvae from EAB-resistant Manchurian ash (Fraxinus mandschurica), and susceptible white (Fraxinus americana) and green (Fraxinus pennsylvanica) ash hosts, and quantified the activity and production of selected detoxification, digestive, and antioxidant enzymes. We hypothesized that differences in larval physiology could be used to infer resistance mechanisms of ash. We found no differences in cytochrome P450, glutathione-S-transferase, carboxylesterase, sulfotransferase, and tryptic BApNAase activities between larvae feeding on different hosts. Despite this, Manchurian ash-fed larvae produced a single isozyme of low electrophoretic mobility that was not produced in white or green ash-fed larvae. Additionally, larvae feeding on white and green ash produced two serine protease isozymes of high electrophoretic mobility that were not observed in Manchurian ash-fed larvae. We also found lower activity of β-glucosidase and higher activities of monoamine oxidase, ortho-quinone reductase, catalase, superoxide dismutase, and glutathione reductase in Manchurian ash-fed larvae compared to larvae that had fed on susceptible ash. A single isozyme was detected for both catalase and superoxide dismutase in all larval groups. The activities of the quinone-protective and antioxidant enzymes are consistent with the resistance phenotype of the host species, with the highest activities measured in larvae feeding on resistant Manchurian ash. We conclude that larvae feeding on Manchurian ash could be under quinone and oxidative stress, suggesting these may be potential mechanisms of resistance of Manchurian ash to EAB larvae, and that quinone-protective and antioxidant enzymes are important counter-adaptations of larvae for dealing with these resistance

  17. Different binding sites for Bacillus thuringiensis Cry1Ba and Cry9Ca proteins in the European corn borer, Ostrinia nubilalis (Hübner).

    Science.gov (United States)

    Hernández-Martínez, Patricia; Hernández-Rodríguez, Carmen Sara; Van Rie, Jeroen; Escriche, Baltasar; Ferré, Juan

    2014-07-01

    Binding studies using (125)I-Cry9Ca and biotinylated-Cry1Ba proteins showed the occurrence of independent binding sites for these proteins in Ostrinia nubilalis. Our results, along with previously available binding data, indicate that combinations of Cry1A or Cry1Fa proteins with Cry1Ba and/or Cry9Ca could be a good strategy for the resistance management of O. nubilalis. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Herança da resistência ao enfezamento em milho Inheritance of the resistance to corn stunt

    Directory of Open Access Journals (Sweden)

    Flávio Trevizoli Silveira

    2008-12-01

    Full Text Available Os objetivos deste trabalho foram determinar a herança da resistência ao complexo de enfezamento em milho e determinar as melhores fontes de resistência entre as linhagens estudadas. Foram realizadas as análises dialélica e médias de gerações em linhagens de milho. Para a análise dialélica, foram cruzadas 12 linhagens de milho, em dialélico parcial. Para análises de médias de gerações, foram cruzadas três linhagens resistentes e quatro suscetíveis, para a obtenção das gerações F1, F2, RCP R e RCP S. Os trabalhos foram conduzidos em Jaboticabal, SP. A incidência de enfezamento foi avaliada no estádio fenológico R3. Efeitos significativos quanto à capacidade geral de combinação e capacidade específica de combinação foram obtidos, o que indicou que, no controle do caráter enfezamentos, estão envolvidos tanto os efeitos aditivos quanto os de dominância. Análises de médias de gerações mostraram a presença de poucos genes envolvidos com o controle da resistência, com predominância de efeitos aditivos, o que permite a seleção de genótipos resistentes. As linhagens L02, L03 e L05 poderão ser utilizadas como fontes de resistência, em futuras combinações híbridas.The objectives of this work were to determine the inheritance of resistance to corn stunt and determine the best resistance sources among the studied inbred lines. Diallel analysis and generation means were made for corn inbred lines. For the diallel analysis, twelve corn-inbred lines were crossed, in a partial diallel scheme. For the analyses of generation means, three resistant inbred lines and four susceptible ones were crossed, to obtain the F1, F2, RCP R and RCP S generations. The experiments were carried out in Jaboticabal, SP, Brazil. Corn sfunt incidence was evaluated at the phenological phase R3. Significant effects for CGC and CEC were obtained, which indicated that both additive and dominance effects were involved in corn expression of

  19. 转Bt毒蛋白基因玉米及其抗虫性研究进展%Transgenic Corn with Bt Toxin Protein Gene and Insect-resistance

    Institute of Scientific and Technical Information of China (English)

    杨春英; 宋建成

    2001-01-01

    本文从转Bt毒蛋白基因玉米的培育及商品化,Bt毒蛋白基因在转基因玉米中的遗传分离与整合、对玉米螟及其它害虫的杀虫效果、对天敌种群数量和玉米病害发生程度的影响、玉米螟对转Bt毒蛋白基因玉米产生抗性及解决措施、应用转Bt毒蛋白基因玉米潜在的生态风险性等方面对国内外最新研究进展进行了综述。%This review briefly focused on the progress at home and overseas in the study of transgenic corn transformed with Bt toxic protein gene,including the breeding and commercial production of transgenic corn transformed with Bt toxic protein gene,genetic segregation and combination of Bt toxin protein in transgenic corn,insecticidal effect on corn borer and other pests,influence on natural enemy population amount and corn disease,corn borer tolerance to Bt toxic protein gene and countermeasures,and the potential ecological risk of transgenic corn transformed with Bt toxic protein gene.

  20. Analysis on transgentic corn hybrids' resistance to corn borer%转Bt基因玉米的应用效果分析

    Institute of Scientific and Technical Information of China (English)

    金益; 王振华; 马文荣; 李伟玲; 周广旭

    2000-01-01

    分析了对美国Monsanto公司提供的转Bt基因玉米及其近等基因品系进行的接种亚洲玉米螟试验。结果表明,在黑龙江省转Bt基因玉米品系在心叶期和穗期对亚洲玉米螟的抗性明显高于其近等基因品系,但在籽粒产量上无明显优势。

  1. Genetically Engineered Corn Rootworm Resistance: Potential for Reduction of Human Health Effects From Pesticides

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Objective and Methods Insecticide use, grower preferences regarding genetically engineered (GE) corn resistant to corn rootworm (CRW), and the health effects of using various CRW insecticides (organophosphates, pyrethroids, fipronil and carbamates) are reviewed for current and future farm practices. Results Pest damage to corn has been reduced only one-third by insecticide applications. Health costs from insecticide use appear significant, but costs attributable to CRW control are not quantifiable from available data. Methods reducing health-related costs of insecticide-based CRW control should be evaluated. As a first step, organophosphate insecticide use has been reduced as they have high acute toxicity and risk of long-term neurological consequences. A second step is to use agents which more specifically target the CRW. Conclusion Whereas current insecticides may be poisonous to many species of insects, birds, mammals and humans, a protein derived from Bacillus thurigiensis and produced in plants via genetic modification can target the specific insect of CRW (Coleoptra), sparing other insect and non-insect species from injury.

  2. In vitro analyses of resistant starch in retrograded waxy and normal corn starches.

    Science.gov (United States)

    Zhou, Xing; Chung, Hyun-Jung; Kim, Jong-Yea; Lim, Seung-Taik

    2013-04-01

    Gelatinized waxy and normal corn starches (40% starch) were subjected to temperature cycling between 4 and 30°C (1 day at each temperature) or isothermal storage (4°C) to induce retrogradation. The in vitro analysis methods that are currently used for the measurement of resistant starch (RS), i.e. Englyst, AACC 32-40 and Goni methods, were compared with homogenized retrograded starch gels and freeze-dried powders of the gels. RS contents obtained by the three analysis methods were in the following order: Goni>Englyst>AACC. Although different RS values were obtained among the analysis methods, similar trends in regards to the starch type and storage conditions could be observed. Little or no RS was found in freeze-dried powders of the retrograded starch gels and storage conditions had no effect, indicating that the physical state for RS analysis is important. More RS was found in normal corn starch gels than in waxy corn starch gels under identical storage conditions and in the gels stored under temperature cycling than those under isothermal storage (4°C), indicating that the presence of amylose inhibits starch digestion and the level of crystalline structure of re-crystallized amylopectin also affects the RS formation during retrogradation.

  3. Postharvest resistance in hard spring and winter wheat varieties of the northern Great Plains to the lesser grain borer (Coleoptera: Bostrichidae).

    Science.gov (United States)

    Watts, Vanessa M; Dunkel, Florence V

    2003-02-01

    Wheat (Triticum aestivum L.) varietal resistance to the lesser grain borer, Rhyzopertha dominica (F), was evaluated in hard spring and winter wheat produced 1997, 1998 (Bozeman, Montana). We tested the hypothesis that six Montana-grown spring wheat varieties, 'Ernest', 'Scholar', 'Hi-Line', 'McNeal', 'Newana', and 'Amidon', were equally and strongly resistant to R. dominica at low moisture contents (9-10%). Mortality/Feeding damage occurred in all varieties. In most assays, Ernest had significantly greater feeding damage from R. dominica than other varieties, usually not significantly different from the susceptible control. Mean adult mortality was significantly greater in McNeal (93%) and Hi-Line (92%) than in Ernest (34%) and Montana-grown, soft white spring wheat (Penawawa), the susceptible control (36%). In 9 wk, twice as many adult progeny were produced on Ernest than on McNeal, Hi-Line, or Scholar. We also compared three Montana-grown winter wheat varieties for resistance to R. dominica attack at low moisture contents (9-10%). Significantly more mortality after 6 wk was associated with all winter wheat varieties than the susceptible control. In 'Nuwest', 'Rocky', and 'Vanguard', significantly fewer progeny were produced than in the susceptible control; these varieties appeared more resistant. 'Tiber' and 'Neeley', in contrast, appeared more susceptible than other winter wheat varieties evaluated. Susceptibility decreased significantly with a 1.2% decrease in moisture content. Percentage of total protein was positively correlated with percentage of sound kernels and negatively with total progeny (r2 = -0.69). Kernel hardness was positively correlated with percentage of sound kernels, but negatively correlated with total progeny (r2 = -0.87) and dry weight loss.

  4. PCR-based Synthesis of Codon Optimized cry2Aa Gene for Production of Shoot and Fruit Borer (Leucinodes orbonalis) Resistant Eggplant (Solanum melongena L.) Cultivars

    OpenAIRE

    2005-01-01

    Brinjal shoot and fruit borer (Leucinodes orbonalis Guenee) is a major limiting factor in commercial cultivation of eggplant in southeast Asia. Extensive use of pesticides as well as the conventional breeding methods have been ineffective in controlling the borer so there is a need for Integrated Pest Management (IPM) strategies for its control. Bacillus thuringiensis (Bt) is known to produce a variety of insecticidal crystal proteins toxic to lepidopteran, dipteran and coleopteran pests. The...

  5. Herança da resistência de milho a Pratylenchus spp. Inheritance of corn resistance to Pratylenchus spp.

    Directory of Open Access Journals (Sweden)

    Eduardo Sawazaki

    1987-01-01

    Full Text Available As espécies de nematóides que mais causam problemas na cultura do milho no Brasil são Pratylenchus zeae e P. brachyurus. O uso de variedades resistentes é o método ideal de controle, sendo que já foram identificadas fontes de resistência em alguns genótipos de milho. Utilizou-se a linhagem Col 2(22, considerada como resistente, e a Ip 48-5-3, como suscetível, mais as gerações F1, F2 e retrocruzamentos com o objetivo de obter informações sobre a herança da resistência. Avaliaram-se esses genótipos em campo, em área infestada por P. zeae (76% e P. brachyurus (24%, em Pindorama. Plantou-se o experimento em janeiro de 1986 e, após oitenta dias, coletaram-se amostras de raízes dos tratamentos para avaliação do número de nematóides por grama de raiz. Os resultados mostraram que a diferença observada quanto à resistência entre as linhagens Col 2(22 e Ip 48-5-3 é, provavelmente, devida a dois pares de genes dominantes de efeitos genéticos aditivos. As herdabilidades no sentido amplo e restrito foram altas, respectivamente 82,0 e 80,8%.The species Pratylenchus zeae and P. brachyurus are the most important nematodes in Brazilian corn fields. Their control with systemic nematicides is efficient but frequently not economic. Previous work indicated that resistance to these nematodes could be found in some corn genotypes. The inheritance of corn resistance to the nematodes was studied using lines of Col 2(22 (resistant and Ip 48-5-3 (susceptible, the generations F1, F2 and backcrosses. The genotypes were sowed in a field infested with P. zeae (76% and P. brachyurus (24%. The experiment was carried out at the Pindorama Experimental Station, State of São Paulo, Brazil, in January of 1986. Eighty days after planting the number of nematodes per gram of roots was determined. The results indicated that the resistance to this pest for the line Col 2(22 was due to two dominant genes with additive effect. The heritability was high in broad

  6. What do farmers' weed control decisions imply about glyphosate resistance? Evidence from surveys of US corn fields.

    Science.gov (United States)

    Wechsler, Seth J; McFadden, Jonathan R; Smith, David J

    2017-04-26

    The first case of glyphosate-resistant weeds in the United States was documented in 1998, 2 years after the commercialization of genetically engineered herbicide-resistant (HR) corn and soybeans. Currently, over 15 glyphosate-resistant weed species affect US crop production areas. These weeds have the potential to reduce yields, increase costs, and lower farm profitability. The objective of our study is to develop a behavioral model of farmers' weed management decisions and use it to analyze weed resistance to glyphosate in US corn farms. On average, we find that weed control increased US corn yields by 3700 kg ha(-1) (worth approximately $US 255 ha(-1) ) in 2005 and 3500 kg ha(-1) (worth approximately $US 575 ha(-1) ) in 2010. If glyphosate resistant weeds were absent, glyphosate killed approximately 99% of weeds, on average, when applied at the label rate in HR production systems. Average control was dramatically lower in states where glyphosate resistance was widespread. We find that glyphosate resistance had a significant impact on weed control costs and corn yields of US farmers in 2005 and 2010. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  7. Transgenic elite indica rice plants expressing CryIAc delta-endotoxin of Bacillus thuringiensis are resistant against yellow stem borer (Scirpophaga incertulas).

    Science.gov (United States)

    Nayak, P; Basu, D; Das, S; Basu, A; Ghosh, D; Ramakrishnan, N A; Ghosh, M; Sen, S K

    1997-03-18

    Generation of insect-resistant, transgenic crop plants by expression of the insecticidal crystal protein (ICP) gene of Bacillus thuringiensis (Bt) is a standard crop improvement approach. In such cases, adequate expression of the most appropriate ICP against the target insect pest of the crop species is desirable. It is also considered advantageous to generate Bt-transgenics with multiple toxin systems to control rapid development of pest resistance to the ICP. Larvae of yellow stem borer (YSB), Scirpophaga incertulas, a major lepidopteran insect pest of rice, cause massive losses of rice yield. Studies on insect feeding and on the binding properties of ICP to brush border membrane receptors in the midgut of YSB larvae revealed that cryIAb and cryIAc are two individually suitable candidate genes for developing YSB-resistant rice. Programs were undertaken to develop Bt-transgenic rice with these ICP genes independently in a single cultivar. A cryIAc gene was reconstructed and placed under control of the maize ubiquitin 1 promoter, along with the first intron of the maize ubiquitin 1 gene, and the nos terminator. The gene construct was delivered to embryogenic calli of IR64, an elite indica rice cultivar, using the particle bombardment method. Six highly expressive independent transgenic ICP lines were identified. Molecular analyses and insect-feeding assays of two such lines revealed that the transferred synthetic cryIAc gene was expressed stably in the T2 generation of these lines and that the transgenic rice plants were highly toxic to YSB larvae and lessened the damage caused by their feeding.

  8. Lack of detection of ampicillin resistance gene transfer from Bt176 transgenic corn to culturable bacteria under field conditions.

    Science.gov (United States)

    Badosa, Esther; Moreno, Carmen; Montesinos, Emilio

    2004-05-01

    Population levels of total and ampicillin-resistant culturable bacteria and the putative horizontal bla gene acquirement from Bt-corn were studied in commercial fields of transgenic corn in Spain during the years 2000-2003. Commercial fields consisting of conventional corn (Dracma) and Bt176 transgenic corn (Compa CB) were located in three climatic regions. The effect of corn type, plant material, field location, stage of sampling and year of study were studied on total and ampicillin resistant bacterial population levels, on median effective dose and on the slope of the dose-response curve to ampicillin. None of the parameters measured were significantly different (Ptransgenic and non-transgenic cornfields under the diverse conditions studied. However, in population levels of ampicillin resistant bacteria, the minimum difference between sample means to be significant with a likelihood of 80% was 8.9%. Specific detection of putative bacteria harbouring bla TEM-1 ampicillin resistance genes acquired from Bt176 corn was performed with a method based on the extraction of DNA from the culturable bacterial fraction and with PCR. Primers for PCR were targeted to the bla gene and the corresponding flanking regions present in the pUC18 cloning vector or the Bt176 construct. The culturable bacterial fraction of 144 field samples (up to 864 analysis, including ampicillin enrichments) was analysed by PCR. The estimated total number of bacteria analysed was 10(8). The level of detection of a transfer event according to the sensitivity of the methods used was 10(-6). Four samples of transgenic and five of non-transgenic corn gave positive signals. However, the amplification products did not correspond to the ones expected from Bt176 or pUC18. The limitations of the sampling design and of the methods used are discussed.

  9. Comparative methodologies for measuring metabolizable energy of various types of resistant high amylose corn starch.

    Science.gov (United States)

    Tulley, Richard T; Appel, Marko J; Enos, Tanya G; Hegsted, Maren; McCutcheon, Kathleen L; Zhou, Jun; Raggio, Anne M; Jeffcoat, Roger; Birkett, Anne; Martin, Roy J; Keenan, Michael J

    2009-09-23

    Energy values of high amylose corn starches high in resistant starch (RS) were determined in vivo by two different methodologies. In one study, energy values were determined according to growth relative to glucose-based diets in rats fed diets containing RS(2), heat-treated RS(2) (RS(2)-HT), RS(3), and amylase predigested versions to isolate the RS component. Net metabolizable energy values ranged from 2.68 to 3.06 kcal/g for the RS starches, and 1.91-2.53 kcal/g for the amylase predigested versions. In a second study, rats were fed a diet containing RS(2)-HT and the metabolizable energy value was determined by bomb calorimetry. The metabolizable energy value was 2.80 kcal/g, consistent with Study 1. Thus, high amylose corn based RS ingredients and their amylase predigested equivalents have energy values approximately 65-78% and 47-62% of available starch (Atwater factor), respectively, according to the RS type (Garcia, T. A.; McCutcheon, K. L.; Francis, A. R.; Keenan, M. J.; O'Neil, C. E.; Martin, R. J.; Hegsted, M. The effects of resistant starch on gastrointestinal organs and fecal output in rats. FASEB J. 2003, 17, A335).

  10. nhancement of Drought Resistance in Wheat and Corn by Nanoparticles of Natural Mineral Analcite

    Directory of Open Access Journals (Sweden)

    Nataliya V. Zaimenko

    2014-06-01

    Full Text Available The effect of the application of nanoparticles of analcite to soil (at 0, 500, 1000 and 1500 mg L-1 on drought resistance of wheat and corn seedlings was studied in pot experiments. The dependence of the analcite effect on soil moisture level and type was also evaluated. For this, three levels of soil moisture were modeled: 20%, 40% and 60% field capacity. The following types of soils were studied: greenhouse soil mixtures, gray podzolic and sandy soils. The positive effect has been established for all doses of analcite tested: seed germination, seedlings growth criteria as well as content of photosynthetic pigments increased, while characteristics of water balance less deviated from the norm under water deficit. Application of analcite caused sharp accumulation of protective antioxidants (flavonoids, carotenoids and activation of catalase (in corn under soil drought. While proline content decreased. The dependence of analcite effect on its dose, soil moisture level and type as well as species of tested plants was discussed.

  11. Impact of glyphosate resistant corn, glyphosate applications, and tillage on soil nutrient ratios, exoenzyme activities, and nutrient acquisition ratios

    Science.gov (United States)

    We report results of the last two years of a 7-year (2008-2014) field experiment designed to test the null hypothesis that applications of glyphosate on glyphosate resistant corn (Zea mays L.) as a routine weed control practice under both conventional and reduced tillage practices would have no effe...

  12. Stacked -gene hybrids were not found to be superior to glyphosate resistant or Non-GMO corn hybrids

    Science.gov (United States)

    Seed costs of modern corn hybrids genetically modified with multiple traits for insect and herbicide resistance “stacked-gene” are in excess of $100.00 US per acre. Yields and net returns per acre along with yield component data were determined for ten hybrids, four stacked-gene, four glyphosate re...

  13. Gene interactions constrain the course of evolution of phosphine resistance in the lesser grain borer, Rhyzopertha dominica.

    Science.gov (United States)

    Schlipalius, D I; Chen, W; Collins, P J; Nguyen, T; Reilly, P E B; Ebert, P R

    2008-05-01

    Phosphine, a widely used fumigant for the protection of stored grain from insect pests, kills organisms indirectly by inducing oxidative stress. High levels of heritable resistance to phosphine in the insect pest of stored grain, Rhyzopertha dominica have been detected in Asia, Australia and South America. In order to understand the evolution of phosphine resistance and to isolate the responsible genes, we have undertaken genetic linkage analysis of fully sensitive (QRD14), moderately resistant (QRD369) and highly resistant (QRD569) strains of R. dominica collected in Australia. We previously determined that two loci, rph1 and rph2, confer high-level resistance on strain QRD569, which was collected in 1997. We have now confirmed that rph1 is responsible for the moderate resistance of strain QRD369, which was collected in 1990, and is shared with a highly resistant strain from the same geographical region, QRD569. In contrast, rph2 by itself confers only very weak resistance, either as a heterozygote or as a homozygote and was not discovered in the field until weak resistance (probably due to rph1) had become ubiquitous. Thus, high-level resistance against phosphine has evolved via stepwise acquisition of resistance alleles, first at rph1 and thereafter at rph2. The semi-dominance of rph2 together with the synergistic interaction between rph1 and rph2 would have led to rapid selection for homozygosity. A lack of visible fitness cost associated with alleles at either locus suggests that the resistance phenotype will persist in the field.

  14. Resistance of rice stem borer(Chilo suppressalis Walker) to insecticides in Cixi, Zhejiang Province%浙江慈溪水稻二化螟抗药性研究初报

    Institute of Scientific and Technical Information of China (English)

    胡仕孟; 谢士杰; 徐善刚; 毛国孟

    2001-01-01

    采用毛细管点滴法,测定了浙江慈溪水稻二化螟对4类9种杀虫剂的抗性和敏感性水平。结果表明,该地的二化螟对杀虫双、杀虫单、杀虫安、甲胺磷4种杀虫剂均已产生高水平抗性,对杀螟硫磷已产生中抗,对甲基对硫磷、三唑磷、氰戊菊酯则仍保持敏感水平,同时发现二化螟对氟虫腈极为敏感,对6龄幼虫的LD50仅0.3833μg/g。%Resistance level of rice stem borer (Chilo suppressalis Walker) to aeveral conventional insecticides was tested with topical application in Cixi, Zhejiang Province. Results showed high level of resistance appeared to dimhypo and other two derivatives,methamidophos; moderate level of resistance to fenitrothion; but parathionmethyl, triazophos, fenvalerate remained susceptible. The borer was discovered to be extremely susceptible to fipronil with LD50 to 6-instar larvae being 0.3833 μg/g.

  15. Identification and analysis of host plant resistance in leading maize genotypes against spotted stem borer, Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae).

    Science.gov (United States)

    Arabjafari, K H; Jalali, S K

    2007-06-01

    Twenty six popular varieties of maize in Karnataka state (India) were screened for resistance to Chilo partellus (Swinhoe). In field trial, varieties CM132, CM137 and PMZ103 showed the highest level of resistance, respectively. While the varieties GK3014, HY4642 and DK984 had the lowest level of resistance, respectively. In glasshouse trial, the varieties CM137 and HY4642 had the highest and lowest level of resistance. A positive correlation equal to +0.111 (in field) and +0.521 (in glasshouse) was found between the Leaf Injury Score (LIS) and Stem Diameter (SD). Meanwhile, negative correlation equal to -0.432 (in field) and -0.896 (in glasshouse) was found between Leaf Injury Score (LIS) and Internodal Distance (InD). Results of the studies on major nutritional elements on resistant variety CM137 and susceptible variety HY4642 indicated higher percentage of P, K, Fe and Si in stem tissues of the variety CM137, while the variety HY4642 had higher percentage of N and Sugar, highlighting the role of these elements in conferring resistance and susceptibility to C. partellus. Studies on the impact of resistance factors on biological events of C. partellus revealed significant differences between percentage survival of larvae, percentage of pupation, pupal weight and pupal period (females only) on two varieties CM137 and HY4642. But there was no significant difference in the percentage of moth emergence on two varieties.

  16. Correlations between the contents of phytic acid and inorganic phosphorous and downy mildew resistance of corn inbred lines

    Directory of Open Access Journals (Sweden)

    Pantipa Na Chiangmai

    2015-10-01

    Full Text Available Seeds of corn inbred lines collected at the National Corn and Sorghum Research Center (NCSRC, Kasetsart University, were analyzed to determine the contents of phytic acid (PA and inorganic phosphorous (InP. These 28 and 29 inbred lines were cultivated at the NCSRC (in the 2008 late rainy season and 2009 early rainy season to evaluate their resistance to corn downy mildew caused by Peronosclerospora sorghi. Results showed that the values of the PA, InP contents and downy mildew infection were statistically different among these inbred lines in both seasons. However, there were no correlations between the contents of either PA or InP and downy mildew infection.

  17. Enzyme resistant feruloylated xylooligomer analogues from thermochemically treated corn fiber contain large side chains, ethyl glycosides and novel sites of acetylation

    NARCIS (Netherlands)

    Appeldoorn, M.M.; Waard, de P.; Kabel, M.A.; Gruppen, H.; Schols, H.A.

    2013-01-01

    In order to use corn fiber as a source for bioethanol production the enzymatic hydrolysis of the complex glucuronoarabinoxylans present has to be improved. Several oligosaccharides present in the supernatant of mild acid pretreated and enzymatically saccharified corn fiber that resist the current av

  18. RESOURCE ALLOCATION IN A MAIZE BREEDING PROGRAM FOR NATIVE RESISTANCE TO WESTERN CORN ROOTWORM

    Directory of Open Access Journals (Sweden)

    Ivan Brkić

    2012-06-01

    Full Text Available The objective of this study was to determine the optimum allocation of the number of plants sampled per plot and number of locations and years required for screening maize genotypes for reduced root damage caused by western corn rootworm (WCR larvae, major pest of maize in Croatia, Europe and in the USA. Field trials were conducted on two locations Eastern Croatia, a major maize production area with natural WCR occurrence under continuous maize growing conditions. The trials were set as an incomplete lattice block design in two replications in 2007, 2008 and 2009 including 128 genotypes from various maize gene-pools. Our results suggest that the effect of year and respective interactions including year were the most important factors in maize breeding programs for native resistance to WCR. Thus, screening germplasm for WCR resistance should be made in a multi-year experiment, but not necessarily as a multi-location experiment. Resource optimization should be done by reducing number of roots per plot to minimum 4 sampled plants due to small within-plot environmental variance.

  19. Impact of seven years of glyphosate resistant corn and glyphosate applications under conventional and reduced tillage on bulk and rhizosphere soil exoenzyme activities and corn root endophytic microbial community structure

    Science.gov (United States)

    Background: Conservation tillage practices across the country have been implementing genetically engineered glyphosate resistant corn crops along with applications of the herbicide glyphosate. We tested the hypothesis that seven years of glyphosate applications to both glyphosate resistant and non-r...

  20. Characterization of Oligomeric Xylan Structures from Corn Fiber Resistant to Pretreatment and Simultaneous Saccharification and Fermentation

    NARCIS (Netherlands)

    Appeldoorn, M.M.; Kabel, M.A.; Eylen, van D.; Gruppen, H.; Schols, H.A.

    2010-01-01

    Corn fiber, a byproduct from the corn industry, would be a good source for bioethanol production if the hemicellulose, consisting of polymeric glucoronoarabinoxylans, can be degraded into fermentable sugars. Structural knowledge of the hemicellulose is needed to improve the enzymatic hydrolyses of c

  1. Solutions Network Formulation Report. Using NASA Sensors to Perform Crop Type Assessment for Monitoring Insect Resistance in Corn

    Science.gov (United States)

    Lewis, David; Copenhaver, Ken; Anderson, Daniel; Hilbert, Kent

    2007-01-01

    The EPA (U.S. Environmental Protection Agency) is tasked to monitor for insect pest resistance to transgenic crops. Several models have been developed to understand the resistance properties of insects. The Population Genetics Simulator model is used in the EPA PIRDSS (Pest Infestation and Resistance Decision Support System). The EPA Office of Pesticide Programs uses the DSS to help understand the potential for insect pest resistance development and the likelihood that insect pest resistance will negatively affect transgenic corn. Once the DSS identifies areas of concern, crews are deployed to collect insect pest samples, which are tested to identify whether they have developed resistance to the toxins in transgenic corn pesticides. In this candidate solution, VIIRS (Visible/Infrared Imager/Radiometer Suite) vegetation index products will be used to build hypertemporal layerstacks for crop type and phenology assessment. The current phenology attribute is determined by using the current time of year to index the expected growth stage of the crop. VIIRS might provide more accurate crop type assessment and also might give a better estimate on the crop growth stage.

  2. A review of bronze birch borer (Coleoptera: Buprestidae) life history, ecology, and management.

    Science.gov (United States)

    Muilenburg, Vanessa L; Herms, Daniel A

    2012-12-01

    Bronze birch borer (Agrilus anxius Gory) (Coleoptera: Buprestidae), a specialist wood-borer endemic to North America, is prone to periodic outbreaks that have caused widespread mortality of birch (Betula spp.) in boreal and north temperate forests. It is also the key pest of birch in ornamental landscapes. Amenity plantings have extended the distribution of birch in North America, for which we report an updated map. Life history and phenology also are summarized. Larvae feed primarily on phloem tissue of stems and branches, which can girdle and kill trees. Stressors such as drought, elevated temperature, and defoliation predispose trees to bronze birch borer colonization and trigger outbreaks, which implicates the availability of suitable host material in the bottom-up regulation of populations. Stress imposed by climate change may increase the frequency of outbreaks and alter the distribution of birch. Bronze birch borer has a diverse array of natural enemies, but their role in top-down population regulation has not been studied. There is substantial interspecific variation in resistance to this insect. North American species share a coevolutionary history with bronze birch borer and are much more resistant than Eurasian species, which are evolutionarily naïve. Potential resistance mechanisms are reviewed. The high susceptibility of Eurasian birch species and climatic similarities of North America and Eurasia create high risk of widespread birch mortality in Eurasia if the borer was inadvertently introduced. Bronze birch borer can be managed in amenity plantings through selection of resistant birch species, plant health care practices, and insecticides.

  3. New insights into an RNAi approach for plant defence against piercing-sucking and stem-borer insect pests.

    Science.gov (United States)

    Li, Haichao; Guan, Ruobing; Guo, Huimin; Miao, Xuexia

    2015-11-01

    Insect double-stranded (ds)RNA expression in transgenic crops can increase plant resistance to biotic stress; however, creating transgenic crops to defend against every insect pest is impractical. Arabidopsis Mob1A is required for organ growth and reproduction. When Arabidopsis roots were soaked in dsMob1A, the root lengths and numbers were significantly suppressed and plants could not bolt or flower. Twenty-four hours after rice roots were immersed in fluorescent-labelled dsEYFP (enhanced yellow fluorescent protein), fluorescence was observed in the rice sheath and stem and in planthoppers feeding on the rice. The expression levels of Ago and Dicer in rice and planthoppers were induced by dsEYFP. When rice roots were soaked in dsActin, their growth was also significantly suppressed. When planthoppers or Asian corn borers fed on rice or maize that had been irrigated with a solution containing the dsRNA of an insect target gene, the insect's mortality rate increased significantly. Our results demonstrate that dsRNAs can be absorbed by crop roots, trigger plant and insect RNAi and enhance piercing-sucking and stem-borer insect mortality rates. We also confirmed that dsRNA was stable under outdoor conditions. These results indicate that the root dsRNA soaking can be used as a bioinsecticide strategy during crop irrigation. © 2015 John Wiley & Sons Ltd.

  4. Evidence of field-evolved resistance of Spodoptera frugiperda to Bt corn expressing Cry1F in Brazil that is still sensitive to modified Bt toxins.

    Science.gov (United States)

    Monnerat, Rose; Martins, Erica; Macedo, Cristina; Queiroz, Paulo; Praça, Lilian; Soares, Carlos Marcelo; Moreira, Helio; Grisi, Isabella; Silva, Joseane; Soberon, Mario; Bravo, Alejandra

    2015-01-01

    Brazil ranked second only to the United States in hectares planted to genetically modified crops in 2013. Recently corn producers in the Cerrado region reported that the control of Spodoptera frugiperda with Bt corn expressing Cry1Fa has decreased, forcing them to use chemicals to reduce the damage caused by this insect pest. A colony of S. frugiperda was established from individuals collected in 2013 from Cry1Fa corn plants (SfBt) in Brazil and shown to have at least more than ten-fold higher resistance levels compared with a susceptible colony (Sflab). Laboratory assays on corn leaves showed that in contrast to SfLab population, the SfBt larvae were able to survive by feeding on Cry1Fa corn leaves. The SfBt population was maintained without selection for eight generations and shown to maintain high levels of resistance to Cry1Fa toxin. SfBt showed higher cross-resistance to Cry1Aa than to Cry1Ab or Cry1Ac toxins. As previously reported, Cry1A toxins competed the binding of Cry1Fa to brush border membrane vesicles (BBMV) from SfLab insects, explaining cross-resistance to Cry1A toxins. In contrast Cry2A toxins did not compete Cry1Fa binding to SfLab-BBMV and no cross-resistance to Cry2A was observed, although Cry2A toxins show low toxicity to S. frugiperda. Bioassays with Cry1AbMod and Cry1AcMod show that they are highly active against both the SfLab and the SfBt populations. The bioassay data reported here show that insects collected from Cry1Fa corn in the Cerrado region were resistant to Cry1Fa suggesting that resistance contributed to field failures of Cry1Fa corn to control S. frugiperda.

  5. Evidence of field-evolved resistance of Spodoptera frugiperda to Bt corn expressing Cry1F in Brazil that is still sensitive to modified Bt toxins.

    Directory of Open Access Journals (Sweden)

    Rose Monnerat

    Full Text Available Brazil ranked second only to the United States in hectares planted to genetically modified crops in 2013. Recently corn producers in the Cerrado region reported that the control of Spodoptera frugiperda with Bt corn expressing Cry1Fa has decreased, forcing them to use chemicals to reduce the damage caused by this insect pest. A colony of S. frugiperda was established from individuals collected in 2013 from Cry1Fa corn plants (SfBt in Brazil and shown to have at least more than ten-fold higher resistance levels compared with a susceptible colony (Sflab. Laboratory assays on corn leaves showed that in contrast to SfLab population, the SfBt larvae were able to survive by feeding on Cry1Fa corn leaves. The SfBt population was maintained without selection for eight generations and shown to maintain high levels of resistance to Cry1Fa toxin. SfBt showed higher cross-resistance to Cry1Aa than to Cry1Ab or Cry1Ac toxins. As previously reported, Cry1A toxins competed the binding of Cry1Fa to brush border membrane vesicles (BBMV from SfLab insects, explaining cross-resistance to Cry1A toxins. In contrast Cry2A toxins did not compete Cry1Fa binding to SfLab-BBMV and no cross-resistance to Cry2A was observed, although Cry2A toxins show low toxicity to S. frugiperda. Bioassays with Cry1AbMod and Cry1AcMod show that they are highly active against both the SfLab and the SfBt populations. The bioassay data reported here show that insects collected from Cry1Fa corn in the Cerrado region were resistant to Cry1Fa suggesting that resistance contributed to field failures of Cry1Fa corn to control S. frugiperda.

  6. Resveratrol prevents high-fructose corn syrup-induced vascular insulin resistance and dysfunction in rats.

    Science.gov (United States)

    Babacanoglu, C; Yildirim, N; Sadi, G; Pektas, M B; Akar, F

    2013-10-01

    Dietary intake of fructose and sucrose can cause development of metabolic and cardiovascular disorders. The consequences of high-fructose corn syrup (HFCS), a commonly consumed form of fructose and glucose, have poorly been examined. Therefore, in this study, we investigated whether HFCS intake (10% and 20% beverages for 12 weeks) impacts vascular reactivity to insulin and endothelin-1 in conjunction with insulin receptor substrate-1(IRS-1), endothelial nitric oxide synthase (eNOS) and inducible NOS (iNOS) mRNA/proteins levels in aorta of rats. At challenge, we tested the effectiveness of resveratrol (28-30 mg/kg body weight/day) on outcomes of HFCS feeding. HFCS (20%) diet feeding increased plasma triglyceride, VLDL, cholesterol, insulin and glucose levels, but not body weights of rats. Impaired nitric oxide-mediated relaxation to insulin (10⁻⁹ to 3×10⁻⁶ M), and enhanced contraction to endothelin-1 (10⁻¹¹ to 10⁻⁸ M) were associated with decreased expression of IRS-1 and eNOS mRNA and protein, but increased expression of iNOS, in aortas of rats fed with HFCS. Resveratrol supplementation restored many features of HFCS-induced disturbances, probably by regulating eNOS and iNOS production. In conclusion, dietary HFCS causes vascular insulin resistance and endothelial dysfunction through attenuating IRS-1 and eNOS expressions as well as increasing iNOS in rats. Resveratrol has capability to recover HFCS-induced disturbances.

  7. Resistance of Bt-maize (MON810) against the stem borers Busseola fusca (Fuller) and Chilo partellus (Swinhoe) and its yield performance in Kenya.

    Science.gov (United States)

    Tefera, Tadele; Mugo, Stephen; Mwimali, Murenga; Anani, Bruce; Tende, Regina; Beyene, Yoseph; Gichuki, Simon; Oikeh, Sylvester O; Nang'ayo, Francis; Okeno, James; Njeru, Evans; Pillay, Kiru; Meisel, Barbara; Prasanna, B M

    2016-11-01

    A study was conducted to assess the performance of maize hybrids with Bt event MON810 (Bt-hybrids) against the maize stem borer Busseola fusca (Fuller) in a biosafety greenhouse (BGH) and against the spotted stem borer Chilo partellus (Swinhoe) under confined field trials (CFT) in Kenya for three seasons during 2013-2014. The study comprised 14 non-commercialized hybrids (seven pairs of near-isogenic Bt and non-Bt hybrids) and four non-Bt commercial hybrids. Each plant was artificially infested twice with 10 first instar larvae. In CFT, plants were infested with C. partellus 14 and 24 days after planting; in BGH, plants were infested with B. fusca 21 and 31 days after planting. In CFT, the seven Bt hybrids significantly differed from their non-Bt counterparts for leaf damage, number of exit holes, percent tunnel length, and grain yield. When averaged over three seasons, Bt-hybrids gave the highest grain yield (9.7 t ha(-1)), followed by non-Bt hybrids (6.9 t ha(-1)) and commercial checks (6 t ha(-1)). Bt-hybrids had the least number of exit holes and percent tunnel length in all the seasons as compared to the non-Bt hybrids and commercial checks. In BGH trials, Bt-hybrids consistently suffered less leaf damage than their non-Bt near isolines. The study demonstrated that MON810 was effective in controlling B. fusca and C. partellus. Bt-maize, therefore, has great potential to reduce the risk of maize grain losses in Africa due to stem borers, and will enable the smallholder farmers to produce high-quality grain with increased yield, reduced insecticide inputs, and improved food security.

  8. Assessment of Inheritance and Fitness Costs Associated with Field-Evolved Resistance to Cry3Bb1 Maize by Western Corn Rootworm

    Directory of Open Access Journals (Sweden)

    Aubrey R. Paolino

    2017-05-01

    Full Text Available The western corn rootworm, Diabrotica virgifera virgifera LeConte, is among the most serious insect pests of maize in North America. One strategy used to manage this pest is transgenic maize that produces one or more crystalline (Cry toxins derived from the bacterium Bacillus thuringiensis (Bt. To delay Bt resistance by insect pests, refuges of non-Bt maize are grown in conjunction with Bt maize. Two factors influencing the success of the refuge strategy to delay resistance are the inheritance of resistance and fitness costs, with greater delays in resistance expected when inheritance of resistance is recessive and fitness costs are present. We measured inheritance and fitness costs of resistance for two strains of western corn rootworm with field-evolved resistance to Cry3Bb1 maize. Plant-based and diet-based bioassays revealed that the inheritance of resistance was non-recessive. In a greenhouse experiment, in which larvae were reared on whole maize plants in field soil, no fitness costs of resistance were detected. In a laboratory experiment, in which larvae experienced intraspecific and interspecific competition for food, a fitness cost of delayed larval development was identified, however, no other fitness costs were found. These findings of non-recessive inheritance of resistance and minimal fitness costs, highlight the potential for the rapid evolution of resistance to Cry3Bb1 maize by western corn rootworm, and may help to improve resistance management strategies for this pest.

  9. Relevance of traditional integrated pest management (IPM) strategies for commercial corn producers in a transgenic agroecosystem: a bygone era?

    Science.gov (United States)

    Gray, Michael E

    2011-06-08

    The use of transgenic Bt maize hybrids continues to increase significantly across the Corn Belt of the United States. In 2009, 59% of all maize planted in Illinois was characterized as a "stacked" gene variety. This is a 40% increase since 2006. Stacked hybrids typically express one Cry protein for corn rootworm control and one Cry protein for control of several lepidopteran pests; they also feature herbicide tolerance (to either glyphosate or glufosinate). Slightly more than 50 years has passed since Vernon Stern and his University of California entomology colleagues published (1959) their seminal paper on the integrated control concept, laying the foundation for modern pest management (IPM) programs. To assess the relevance of traditional IPM concepts within a transgenic agroecosystem, commercial maize producers were surveyed at a series of meetings in 2009 and 2010 regarding their perceptions on their use of Bt hybrids and resistance management. Special attention was devoted to two insect pests of corn, the European corn borer and the western corn rootworm. A high percentage of producers who participated in these meetings planted Bt hybrids in 2008 and 2009, 97 and 96.7%, respectively. Refuge compliance in 2008 and 2009, as mandated by the U.S. Environmental Protection Agency (EPA), was 82 and 75.7%, respectively, for those producers surveyed. A large majority of producers (79 and 73.3% in 2009 and 2010, respectively) revealed that they would, or had, used a Bt hybrid for corn rootworm (Diabrotica virgifera virgifera LeConte) or European corn borer (Ostrinia nubilalis Hübner) control even when anticipated densities were low. Currently, the EPA is evaluating the long-term use of seed blends (Bt and non-Bt) as a resistance management strategy. In 2010, a large percentage of producers, 80.4%, indicated they would be willing to use this approach. The current lack of integration of management tactics for insect pests of maize in the U.S. Corn Belt, due primarily to

  10. Effects of refuges on the evolution of resistance to transgenic corn by western corn rootworm, Diabrotica virgifera virgifera LeConte

    Science.gov (United States)

    Diabrotica virgifera virgifera LeConte is a major pest of corn causing millions of dollars of economic loss annually through yield reductions and preventative management practices. Corn producing toxins derived from Bacillus thuringiensis (Bt) have been developed to help manage D. v. virgifera. Sinc...

  11. Transgenic insect-resistant corn affects the fourth trophic level: effects of Bacillus thuringiensis-corn on the facultative hyperparasitoid Tetrastichus howardi

    Science.gov (United States)

    Prütz, Gernot; Brink, Andreas; Dettner, Konrad

    2004-09-01

    As hyperparasitoids may have a considerable influence on the control of herbivorous arthropods, analyzing the host-mediated impact of Bacillus thuringiensis-plants (“Bt-plants”) on hyperparasitoids is of interest. Laboratory-scale experiments were conducted in order to assess the potential effect of Bt-corn leaf material on the facultative hyperparasitoid Tetrastichus howardi (Olliff) (Hymenoptera: Eulophidae), mediated through the herbivore Chilo partellus Swinhoe (Lepidoptera: Crambidae) and its primary parasitoid Cotesia flavipes (Cameron) (Hymenoptera: Braconidae). In the Bt-group, significantly less C. flavipes larvae per host spun cocoons and pupated than in the control, and the mean fresh weight of a single C. flavipes cocoon was significantly reduced compared to the control. All C. flavipes cocoons of one host formed cocoon clusters. T. howardi females of the Bt-group parasitized significantly less cocoon clusters than in the control. Moreover, significantly fewer C. flavipes cocoons per cocoon cluster were successfully parasitized as compared to the control. As a consequence, T. howardi females of the control had more offspring than in the Bt-group. Adult female T. howardi offspring of the Bt-group weighed significantly less than in the control, but there was no significant weight difference between males of both groups. Our results suggest that transgenic insect-resistant plants could affect hyperparasitoids indirectly. However, it remains to be determined whether facultative hyperparasitoids prefer to develop as primary or secondary parasitoids under field conditions.

  12. Raspberry Crown Borer [Pennisetia marginata

    OpenAIRE

    Alston, Diane

    2015-01-01

    This fact sheet described raspberry crown borer, a pest that attacks raspberry plants in northern Utah, causing cane-wilt and death. It includes life history, host injury, monitoring and thresholds, and management techniques.

  13. Occurrence of emerald ash borer (Coleoptera: Buprestidae) and biotic factors affecting its immature stages in the Russian Far East.

    Science.gov (United States)

    Duan, Jian J; Yurchenko, Galina; Fuester, Roger

    2012-04-01

    Field surveys were conducted from 2008 to 2011 in the Khabarovsk and Vladivostok regions of Russia to investigate the occurrence of emerald ash borer, Agrilus planipennis Fairmaire, and mortality factors affecting its immature stages. We found emerald ash borer infesting both introduced North American green ash (Fraxinus pennsylvanica Marshall) and native oriental ashes (F. mandshurica Rupr. and F. rhynchophylla Hance) in both regions. Emerald ash borer densities (larvae/m(2) of phloem area) were markedly higher on green ash (11.3-76.7 in the Khabarovsk area and 77-245 in the Vladivostok area) than on artificially stressed Manchurian ash (2.2) or Oriental ash (10-59). Mortality of emerald ash borer larvae caused by different biotic factors (woodpecker predation, host plant resistance and/or undetermined diseases, and parasitism) varied with date, site, and ash species. In general, predation of emerald ash borer larvae by woodpeckers was low. While low rates (3-27%) of emerald ash borer larval mortality were caused by undetermined biotic factors on green ash between 2009 and 2011, higher rates (26-95%) of emerald ash borer larval mortality were caused by putative plant resistance in Oriental ash species in both regions. Little (emerald ash borer larvae was observed in Khabarovsk; however, three hymenopteran parasitoids (Spathius sp., Atanycolus nigriventris Vojnovskaja-Krieger, and Tetrastichus planipennisi Yang) were observed attacking third - fourth instars of emerald ash borer in the Vladivostok area, parasitizing 0-8.3% of emerald ash borer larvae infesting Oriental ash trees and 7.3-62.7% of those on green ash trees (primarily by Spathius sp.) in two of the three study sites. Relevance of these findings to the classical biological control of emerald ash borer in newly invaded regions is discussed.

  14. Role of Ostrinia Nubilalis in Vectoring Aspergillus Flavus in a Corn Field in northern Italy

    Science.gov (United States)

    The European corn borer (ECB), Ostrinia nubilalis, is a major pest of corn in Europe and in several agricultural areas of the USA. In addition to direct yield losses, the ECB is expected to act as a vector for carrying spores of the aflatoxin-producing fungus Aspergillus flavus. Therefore the object...

  15. Avaliação de progênies de algodoeiro para resistência à broca-da-raiz Progeny evaluation for resistance to the root borer in cotton

    Directory of Open Access Journals (Sweden)

    Imre Lajos Gridi-Papp

    1996-01-01

    Full Text Available Com base nos resultados de seleção, obtidos pela equipe de melhoramento do algodoeiro do Instituto Agronômico (IAC, numa gleba naturalmente infestada pela broca-da-raiz, Eutinobothrus brasiliensis (Hambleton, da Estação Experimental de Tietê, em 1966-81, três índices de avaliação foram propostos para a resistência dessa planta à praga. O coeficiente de correlação simples entre as duas repetições dos testes anuais de progênies foi adotado como parâmetro para estudar a eficiência dos índices na seleção de progênies resistentes. Pelo estudo comparativo, escolheu-se, como o mais adequado, o índice obtido pela contagem de furos (galerias observados na parte lenhosa, em corte oblíquo dos caules das plantas, feito na região do colo, no meio da parte hipertrofiada. Apresentam-se os coeficientes de correlação de 1972-81 e a discussão sobre a eficiência do índice escolhido que proporcionou, durante o período, um aumento gradual do coeficiente de correlação, significando um provável acúmulo de genes favoráveis à resistência nas progênies selecionadas. A prática de picar e enterrar a parte infestada dos caules, após a colheita dos dados, contribuiu para manter alta infestação da área pela broca. Aplicado, posteriormente, à avaliação de linhagens do programa de melhoramento do algodoeiro, o índice permitiu melhorar 50% o nível geral de resistência das linhagens em estudo.To evaluate cotton resistance to the Brazilian root borer, Eutinobothrus brasiliensis (Hambleton, three indexes were proposed, based on selection data obtained in progeny tests, on a naturally infested plot, situated at the Tietê Experiment Station, in the years of 1966 to 1981, by the cotton breeders of the Instituto Agronômico, State of São Paulo, Brazil. The simple correlation coefficient between the two repetitions of the yearly tests was used as a parameter to study the efficiency of the indexes in selecting resistant progenies

  16. Identification and Fine Mapping of rhm1 Locus for Resistance to Southern Corn Leaf Blight in Maize

    Institute of Scientific and Technical Information of China (English)

    Yuanzeng Zhao; Xiaomin Lu; Chaoxian Liu; Haiying Guan; Mei Zhang; Zhongfeng Li; Hongwei Cai; Jinsheng Lai

    2012-01-01

    rhm1 is a major recessive disease resistance locus for Southern corn leaf blight (SCLB).To further narrow down its genetic position,F2 population and BC1F1 population derived from the cross between resistant (H95rhm) and susceptible parents (H95) of maize (Zea mays) were constructed.Using newly developed markers,rhm1 was initially delimited within an interval of 2.5 Mb,and then finally mapped to a 8.56 kb interval between InDel marker IDP961-503 and simple sequence repeat (SSR) marker A194149-1.Three polymorphic markers IDP961-504,IDP B2-3 and A194149-2 were shown to be co-segregated with the rhm1 locus.Sequence analysis of the 8.56 kb DNA fragment revealed that it contained only one putative gene with a predicted amino acid sequence identical to lysine histidine transporter 1 (LHT1).Comparative sequence analysis indicated that the LHT1 in H95rhm harbors a 354 bp insertion in its third exon as compared with that of susceptible alleles in B73,H95 and Mo17.The 354 bp insertion resulted in a truncation of the predicted protein of candidate resistance allele (LHT1-H95rhm).Our results strongly suggest LHT1 as the candidate gene for rhm1 against SCLB.The tightly linked molecular markers developed in this study can be directly used for molecular breeding of resistance to Southern corn leaf blight in maize.

  17. Feasible Management of Southern Corn Leaf Blight via Induction of Systemic Resistance by Bacillus cereus C1L in Combination with Reduced Use of Dithiocarbamate Fungicides.

    Science.gov (United States)

    Lai, Yi-Ru; Lin, Pei-Yu; Chen, Chao-Ying; Huang, Chien-Jui

    2016-10-01

    Dithiocarbamate fungicides such as maneb and mancozeb are widely used nonsystemic protectant fungicides to control various plant fungal diseases. Dithiocarbamate fungicides should be frequently applied to achieve optimal efficacy of disease control and avoid either decline in effectiveness or wash-off from leaf surface. Dithiocarbamates are of low resistance risk but have the potential to cause human neurological diseases. The objective of this study was to develop a strategy to effectively control plant disease with reduced use of dithiocarbamtes. Southern corn leaf blight was the model pathosystem for the investigation. When corn plants were drench-treated with Bacillus cereus C1L, a rhizobacterium able to induce systemic resistance in corn plants against southern leaf blight, frequency of spraying dithiocarbamate fungicides could be decreased. The treatment of B. cereus C1L was able to protect maize from southern leaf blight while residues of dithiocarbamates on leaf surface were too low to provide sufficient protection. On the other hand, frequent sprays of mancozeb slightly but significantly reduced growth of corn plants under natural conditions. In contrast, application of B. cereus C1L can significantly promote growth of corn plants whether sprayed with mancozeb or not. Our results provide the information that plant disease can be well controlled by rhizobacteria-mediated induced systemic resistance in combination with reduced but appropriate application of dithiocarbamate fungicides just before a heavy infection period. An appropriate use of rhizobacteria can enhance plant growth and help plants overcome negative effects caused by dithiocarbamates.

  18. Feasible Management of Southern Corn Leaf Blight via Induction of Systemic Resistance by Bacillus cereus C1L in Combination with Reduced Use of Dithiocarbamate Fungicides

    Directory of Open Access Journals (Sweden)

    Yi-Ru Lai

    2016-10-01

    Full Text Available Dithiocarbamate fungicides such as maneb and mancozeb are widely used nonsystemic protectant fungicides to control various plant fungal diseases. Dithiocarbamate fungicides should be frequently applied to achieve optimal efficacy of disease control and avoid either decline in effectiveness or wash-off from leaf surface. Dithiocarbamates are of low resistance risk but have the potential to cause human neurological diseases. The objective of this study was to develop a strategy to effectively control plant disease with reduced use of dithiocarbamtes. Southern corn leaf blight was the model pathosystem for the investigation. When corn plants were drench-treated with Bacillus cereus C1L, a rhizobacterium able to induce systemic resistance in corn plants against southern leaf blight, frequency of spraying dithiocarbamate fungicides could be decreased. The treatment of B. cereus C1L was able to protect maize from southern leaf blight while residues of dithiocarbamates on leaf surface were too low to provide sufficient protection. On the other hand, frequent sprays of mancozeb slightly but significantly reduced growth of corn plants under natural conditions. In contrast, application of B. cereus C1L can significantly promote growth of corn plants whether sprayed with mancozeb or not. Our results provide the information that plant disease can be well controlled by rhizobacteria-mediated induced systemic resistance in combination with reduced but appropriate application of dithiocarbamate fungicides just before a heavy infection period. An appropriate use of rhizobacteria can enhance plant growth and help plants overcome negative effects caused by dithiocarbamates.

  19. Feasible Management of Southern Corn Leaf Blight via Induction of Systemic Resistance by Bacillus cereus C1L in Combination with Reduced Use of Dithiocarbamate Fungicides

    Science.gov (United States)

    Lai, Yi-Ru; Lin, Pei-Yu; Chen, Chao-Ying; Huang, Chien-Jui

    2016-01-01

    Dithiocarbamate fungicides such as maneb and mancozeb are widely used nonsystemic protectant fungicides to control various plant fungal diseases. Dithiocarbamate fungicides should be frequently applied to achieve optimal efficacy of disease control and avoid either decline in effectiveness or wash-off from leaf surface. Dithiocarbamates are of low resistance risk but have the potential to cause human neurological diseases. The objective of this study was to develop a strategy to effectively control plant disease with reduced use of dithiocarbamtes. Southern corn leaf blight was the model pathosystem for the investigation. When corn plants were drench-treated with Bacillus cereus C1L, a rhizobacterium able to induce systemic resistance in corn plants against southern leaf blight, frequency of spraying dithiocarbamate fungicides could be decreased. The treatment of B. cereus C1L was able to protect maize from southern leaf blight while residues of dithiocarbamates on leaf surface were too low to provide sufficient protection. On the other hand, frequent sprays of mancozeb slightly but significantly reduced growth of corn plants under natural conditions. In contrast, application of B. cereus C1L can significantly promote growth of corn plants whether sprayed with mancozeb or not. Our results provide the information that plant disease can be well controlled by rhizobacteria-mediated induced systemic resistance in combination with reduced but appropriate application of dithiocarbamate fungicides just before a heavy infection period. An appropriate use of rhizobacteria can enhance plant growth and help plants overcome negative effects caused by dithiocarbamates. PMID:27721698

  20. Bacillus thuringiensis toxin resistance mechanisms among Lepidoptera: progress on genomic approaches to uncover causal mutations in the European corn borer, Ostrinia nubilalis

    Science.gov (United States)

    Transgenic plants that expressed Bacillus thuringiensis (Bt) crystalline (Cry) protein toxins can suffer feeding damage from a small number of lepidopteran insect species under field conditions, which has heightened concerns about the durability of pest control tactics. Genomics research has provid...

  1. 水稻抗二化螟特性鉴定技术的评价研究%Evaluation of Appraisement Method for Rice Resistance to Striped Stem Borer

    Institute of Scientific and Technical Information of China (English)

    刘显波; 谢黎虹; 唐绍清; 凃巨民; 胡培松; 罗炬

    2016-01-01

    采用离体叶片、离体茎秆、离体剥开茎秆及活体成株4种室内抗虫性鉴定方法,对相同水稻材料进行抗二化螟特性鉴定,同时对这些水稻室内抗二化螟鉴定技术进行了综合评价。结果表明,这些方法的抗性鉴定结果高度吻合,离体叶片鉴定方法是目前最快速、有效的抗二化螟鉴定方法。并通过离体叶片和活体成株鉴定方法对转Vip3A基因水稻材料进行鉴定,再次验证了离体叶片鉴定方法的有效性。此外,初步发现对于同为鳞翅目水稻害虫稻纵卷叶螟,用离体叶片鉴定方法也可进行有效鉴定。%The identification result was consistent with the resistance evaluation to striped stem borer through four different bioassay methods, including detached-leaf bioassay, detached-stem bioassay, stripping detached-stem bioassay and whole plant bioassay. The detached-leaf bioassay is considered as the most rapid and effective method for evaluating resistance ability to striped stem borer. By both detached-leaf and whole plant bioassays, the author identified transgenic rice with Vip3A gene, and further validated the identi-fication effectiveness of the detached-leaf bioassay method. Simultaneously, our preliminary results revealed that detached-leaf bioas-say could also perform an accurate identification to rice leaf roller as lepidoptera pests of rice.

  2. Influence of Prunus spp., peach cultivars, and bark damage on oviposition choices by the lesser peachtree borer (Lepidoptera: Sesiidae).

    Science.gov (United States)

    Cottrell, T E; Fuest, J; Horton, D L

    2008-12-01

    An examination of oviposition choices by the lesser peachtree borer, Synanthedon pictipes (Grote and Robinson) (Lepidoptera: Sesiidae), showed that wounded peach, Prunus persica (L.) Batsch, bark was attractive to females for oviposition. Females responded to bark that was injured mechanically (e.g., hammer blows, knife cuts, pruning wounds), infested by lesser peachtree borer larvae or injured by disease. In fact, there was no difference in female oviposition response to knife cut wounds and knife cut wounds infested with lesser peachtree borer larvae. Oviposition on wounded bark from three different high chill peach cultivars was similar and strongly suggests that the narrow genetic base of high chill peach cultivars grown in the southeastern United States has little inherent resistance to the lesser peachtree borer. In stark contrast, when provided different Prunus spp., i.e., exotic peach and the native species P. angustifolia and P. serotina, the exotic peach was highly preferred for oviposition by the native lesser peachtree borer.

  3. Cry3Bb1-Resistant Western Corn Rootworm, Diabrotica virgifera virgifera (LeConte) Does Not Exhibit Cross-Resistance to DvSnf7 dsRNA

    Science.gov (United States)

    Khajuria, Chitvan; Pleau, Michael; Ilagan, Oliver; Chen, Mao; Jiang, Changjian; Price, Paula; McNulty, Brian; Clark, Thomas; Head, Graham

    2017-01-01

    Background and Methodology There is a continuing need to express new insect control compounds in transgenic maize against western corn rootworm, Diabrotica virgifera virgifera (LeConte) (WCR). In this study three experiments were conducted to determine cross-resistance between the new insecticidal DvSnf7 dsRNA, and Bacillus thuringiensis (Bt) Cry3Bb1; used to control WCR since 2003, with field-evolved resistance being reported. Laboratory susceptible and Cry3Bb1-resistant WCR were evaluated against DvSnf7 dsRNA in larval diet-incorporation bioassays. Additionally, the susceptibility of seven field and one field-derived WCR populations to DvSnf7 (and Cry3Bb1) was assessed in larval diet-overlay bioassays. Finally, beetle emergence of laboratory susceptible and Cry3Bb1-resistant WCR was evaluated with maize plants in the greenhouse expressing Cry3Bb1, Cry34Ab1/Cry35Ab1, or DvSnf7 dsRNA singly, or in combination. Principal Findings and Conclusions The Cry3Bb1-resistant colony had slight but significantly (2.7-fold; PIRM tool against WCR that will increase the durability of these Bt proteins. These results also illustrate the importance of using appropriate bioassay methods when characterizing field-evolved resistant WCR populations. PMID:28060922

  4. Ecological Aspects of Maize Stem Borer at Intercropping and Monoculture Planting

    OpenAIRE

    Abdullah, Tamrin; Hidayat, Purnama; Rauf, Aunu; Sartiami,Dewi

    2003-01-01

    Asian corn borer population Beberapa aspek ekologi hama penggerek batang jagung diamati pada pertanaman jagung milik petani dan pada plot percobaan di Bogor. Tingkat serangan penggerek batang jagung pada pertanaman berumur 50 hst adalah 7,59% pada tanaman tumpangsari jagung manis dengan ubi jalar, 8,66% pada tanaman monokultur jagung manis, dan 9,51% pada tanaman tumpangsari jagung manis dan singkong. Pengamatan peletakan telur pada plot percobaan menunjukkan bahwa populasi telur pada p...

  5. Impact of glyphosate-resistant corn, glyphosate applications and tillage on soil nutrient ratios, exoenzyme activities and nutrient acquisition ratios.

    Science.gov (United States)

    Jenkins, Michael B; Locke, Martin A; Reddy, Krishna N; McChesney, Daniel S; Steinriede, R Wade

    2017-01-01

    We report results of the last two years of a 7 year field experiment designed to test the null hypothesis: applications of glyphosate on glyphosate-resistant (GR) and non-resistant (non-GR) corn (Zea mays L.) under conventional tillage and no-till would have no effect on soil exoenzymes and microbial activity. Bulk soil (BS) and rhizosphere soil (RS) macronutrient ratios were not affected by either GR or non-GR corn, or glyphosate applications. Differences observed between exoenzyme activities were associated with tillage rather than glyphosate applications. In 2013, nutrient acquisition ratios for bulk and rhizosphere soils indicated P limitations, but sufficient assimilable N. In 2014, P limitations were observed for bulk and rhizosphere soils, in contrast to balanced C and N acquisition ratios in rhizosphere soils. Stoichiometric relationships indicated few differences between glyphosate and non-glyphosate treatments. Negative correlations between C:P and N:P nutrient ratios and nutrient acquisition ratios underscored the inverse relation between soil nutrient status and microbial community exoenzyme activities. Inconsistent relationships between microbial community metabolic activity and exoenzyme activity indicated an ephemeral effect of glyphosate on BS exoenzyme activity. Except for ephemeral effects, glyphosate applications appeared not to affect the function of the BS and RS exoenzymes under conventional tillage or no-till. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  6. Implications of Transgenic Corn Cultivation on the Ecology of Agricultural Streams

    Science.gov (United States)

    Vantull, L.; Swan, C.

    2005-05-01

    Corn has been genetically-modified by introducing a gene that codes for a toxic protein from a bacterium, Bacillus thuringiensis (Bt), into corn DNA. Genetically-modified crops provide internal resistance to herbivorous pests like the European Corn Borer (Ostrina nubilalis). With the use of transgenic crops on the rise, research is being done to consider its environmental effects on non-target taxa and ecosystems. Stream ecosystems occupy topographic low points in the landscape and thus are affected by agricultural land use. In many temperate streams, the main energy source is from terrestrial organic detritus, mostly in the form of dead leaves and wood, delivered via wind or natural leaf fall. Stream insects consume this material, contributing to organic matter breakdown and creating biomass for predators. With the heightened practice of no-till agriculture, crop detritus remaining on fields as a by-product of harvesting has been documented to enter adjacent streams. Given insect larvae are critical to the transformation of energy from detritus to higher trophic levels, we explored the implications of detritus containing Bt on both insect performance and litter decay in six streams. The presence of Bt in senesced corn leaf litter resulted in significant reductions in both insect feeding rate and organic matter breakdown. Furthermore, colonization of corn litter containing Bt by detritivorous insects was significantly reduced when compared to non-Bt isoline litter controls. We conclude that detritus generated from harvesting transgenic corn negatively impacts insect feeding behavior and colonization dynamics, and may contribute substantially to the reduction of organic matter breakdown rates in agricultural streams.

  7. Effects of Maize Planting Density on Occurrence of Asian Corn Borer and Trichogramma Parasitism%玉米种植密度对玉米螟发生及赤眼蜂寄生的影响

    Institute of Scientific and Technical Information of China (English)

    李丽娟; 鲁新; 周淑香; 张国红; 丁岩; 刘宏伟

    2013-01-01

    Asian corn bore(ACB) and Trichogramma were investigated with diverse maize planting density in a maize field. The results showed that the 100-maize plants egg masses amount and eggs number were relatively high of the 1st and 2nd generation ACB with low planting density. The corn was damaged serious by the 1st-generation ACB in 45 000 plants/ha maize field. In addition, The correlation analysis showed that egg masses amount, eggs number, bored-hole number, hole pass length, alive worm amount per 100-maize plants and the parasitism rate of ACB egg masses were negatively correlated with planting density. Healthy plants number was positively correlated with planting density. The broken-up ear stem rate, the broken-ear handle rate, the broken-tassel rate increased a little as maize planting density increases. The planting density had almost no effect on natural parasitism rate of Trichogramma. There were slightly higher the egg masses parasitism rate(figure 44.24%) and the eggs parasitism rate(figure 39.00%) of the 1st-generation ACB with 30 000 plants/ha than other planting density. Both were very high the egg masses par-asitism rate and the eggs parasitism rate of the 2nd-generation ACB with diverse planting density. The average values were 84.59%and 80.84%.%通过对不同种植密度玉米田内玉米螟、赤眼蜂调查,初步认为,在低种植密度下一、二代玉米螟百株落卵块数、落卵粒数较高,种植密度为45000株/hm2玉米田的一代玉米螟危害较重。相关分析表明,一、二代百株玉米的落卵块数、落卵粒数、蛀孔数、隧道长度、活虫数及一代卵块寄生率等与种植密度呈负相关;健株数与种植密度呈正相关;穗上折率、穗柄折率、雄穗折率随种植密度增加折率略有增加。玉米不同种植密度对赤眼蜂的自然寄生率影响较小,30000株/hm2种植密度一代玉米螟的卵块寄生率和卵粒寄生率略高,为44.24%和39.00%;二代玉米螟

  8. 亚致死剂量的马拉硫磷对亚洲玉米螟Ostrinia furnacalis化学通讯系统的干扰作用%EFFECTS OF SUBLETHAL MALATHION ON THE CHEM ICAL COMMUNICATION SYSTEM OF ASIAN CORN BORER, OSTRINIA FURNACALIS (GUENEE)

    Institute of Scientific and Technical Information of China (English)

    杨智化; 肖春; 杜家纬; 许少甫

    2001-01-01

    Topically applied sublethal doses of malathion may interrupt chemical communication between the two sexes of Asian corn borer, Ostrinia furnacalis (Guenee), by affecting calling and sex pheromone titre released by the females. ( 1 ) Studies on the effects of sublethal malathion on the chemical conmunication system of 0. furnacalis indicated that probability of females calling and sex pheromone titre were obviously decreased, but periodicity was not affected. (2) The recovery test indicated that the calling percentages of the 1st, 2 nd and 4 th day post-treatment were 50%, 53% and 73% respectively. Sex pheromone titre was 55%, 75% and 100% of control fenale respectively.There was a trend toward recovery. The sexual chemical communication system could control within narrow level.%胸部点滴亚致死剂量的马拉硫磷对亚洲玉米螟化学通讯产生明显的干扰作用,同时抑制了雌蛾求偶活动和性信息素释放量,但不影响求偶高峰期出现的时间;顺反异构体比例不受影响,且其变异系数能控制在10%以内,表明亚致死剂量的马拉硫磷处理使亚洲玉米螟化学通讯能控制在较为狭窄的范围之内.受马拉硫磷影响后通讯系统的恢复实验表明:随时间的推移,雌蛾求偶百分数和性信息素释放量呈回升趋势.500 ng/♀剂量处理的当天、第二天、第四天的求偶百分数分别为正常雌蛾的50%、53%、73%,释放量为正常雌蛾的55%、75%、100%.

  9. Emerald Ash Borer (Coleoptera: Buprestidae)

    Science.gov (United States)

    The emerald ash borer, Agrilus planipennis Fairmaire, is an invasive beetle from Asia that has caused large scale ash (Fraxinus spp.) mortality in North America. This book chapter reviews the taxonomy, biology, life history of this invasive pest and its associated natural enemies in both its native ...

  10. Controlling herbicide-resistant weeds: consider incorporating alfalfa in a corn/soybean rotation

    Science.gov (United States)

    Herbicide resistant weeds (HRW) are a serious problem in the U.S. In 1968, the first confirmed case of herbicide resistance in weeds was reported in Washington state. In the 46 years since, the number of HRW in the U.S. has increased dramatically. A major reason for the recent increase in HRW has be...

  11. Study of Insect-resistant Transgenic Corn%抗虫转基因玉米研究

    Institute of Scientific and Technical Information of China (English)

    魏俊杰; 陈梅香; 张晓丽

    2012-01-01

    The current methods to detect the insect-resistant transgenic com are PCR (polymerase chain reaction) and ELISA (enzyme-linked immunosorbent assay) , while the common identification methods include the antibiotics identification and the direct access to insects. With the extensive planting of insect-resistant transgenic corn, some ecological problems were brought about, such as pollen drift and harms to non-target pests, soil ecosystems, as well as some insects such as butterflies.%目前抗虫转基因玉米产品的检测方法主要有PCR(聚合酶链式反应)和ELISA(酶联免疫吸附法)等;鉴定方法主要有抗生素鉴定法和直接接虫鉴定法.随着抗虫转基因玉米的大面积商业化种植,其所带来的生态安全问题也不可忽视,包括花粉漂(飘)移,对非目标害虫、土壤生态系统和蝶类昆虫的影响等.

  12. Effect of storage time on in vitro digestion rate and resistant starch content of tortillas elaborated from commercial corn masas.

    Science.gov (United States)

    Agama-Acevedo, Edith; Rendón-Villalobos, Rodolfo; Tovar, Juscelino; Trejo-Estrada, Sergio Rubén; Bello-Pérez, Luis Arturo

    2005-03-01

    Tortilla samples were elaborated by four small commercial factories in Mexico, employing masas prepared with the traditional nixtamalization process. Samples were stored at 4 degrees C for up to 72 hours and their chemical composition and in vitro starch digestibility features were evaluated. Chemical composition did not change with the storage time, but soluble carbohydrates decreased slightly during storage. A significant decrease in available starch content upon storage was observed, concomitant with increased resistant starch (RS) levels. These changes are possibly due to retrogradation. Retrograded resistant starch (RRS) values increased with storage time; in some samples, RRS represented more than 75% of total RS whereas in others it only accounted for 25%. The digestion rate (DR) in the freshly prepared tortillas was similar for the various samples, but after 72 h storage some differences among tortillas were found. Also, when a single tortilla sample was compared throughout the different storage times, lower DRs were determined in samples subjected to prolonged storage, which is related to the concomitant. increase in RRS. The differences found among the various tortilla samples may be due to minor variations in the commercial processing conditions and to the use of different corn varieties.

  13. Effects of Pyramided Bt Corn and Blended Refuges on Western Corn Rootworm and Northern Corn Rootworm (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Keweshan, Ryan S; Head, Graham P; Gassmann, Aaron J

    2015-04-01

    The western corn rootworm, Diabrotica virgifera virgifera LeConte, and the northern corn rootworm, Diabrotica barberi Smith & Lawrence (Coleoptera: Chrysomelidae), are major pests of corn (Zea mays L). Several transgenic corn events producing insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) kill corn rootworm larvae and reduce injury to corn roots. However, planting of Bt corn imposes selection on rootworm populations to evolve Bt resistance. The refuge strategy and pyramiding of multiple Bt toxins can delay resistance to Bt crops. In this study, we assessed the impact of four treatments--1) non-Bt corn, 2) Cry3Bb1 corn, 3) corn pyramided with Cry3Bb1 and Cry34/35Ab1, and 4) pyramided corn with a blended refuge--on survival, time of adult emergence, and size of western and northern corn rootworm. All treatments with Bt corn led to significant reductions in the number of adults that emerged per plot. However, at one location, we identified Cry3Bb1-resistant western corn rootworm. In some cases Bt treatments reduced size of adults and delayed time of adult emergence, with effects most pronounced for pyramided corn. For both species, the number of adults that emerged from pyramided corn with a blended refuge was significantly lower than expected, based solely on emergence from pure stands of pyramided corn and non-Bt corn. The results of this study indicate that pyramided corn with a blended refuge substantially reduces survival of both western and northern corn rootworm, and as such, should be a useful tool within the context of a broader integrated pest management strategy.

  14. Genetic linkage analysis of the lesser grain borer Rhyzopertha dominica identifies two loci that confer high-level resistance to the fumigant phosphine.

    Science.gov (United States)

    Schlipalius, David I; Cheng, Qiang; Reilly, Paul E B; Collins, Patrick J; Ebert, Paul R

    2002-01-01

    High levels of inheritable resistance to phosphine in Rhyzopertha dominica have recently been detected in Australia and in an effort to isolate the genes responsible for resistance we have used random amplified DNA fingerprinting (RAF) to produce a genetic linkage map of R. dominica. The map consists of 94 dominant DNA markers with an average distance between markers of 4.6 cM and defines nine linkage groups with a total recombination distance of 390.1 cM. We have identified two loci that are responsible for high-level resistance. One provides approximately 50x resistance to phosphine while the other provides 12.5x resistance and in combination, the two genes act synergistically to provide a resistance level 250x greater than that of fully susceptible beetles. The haploid genome size has been determined to be 4.76 x 10(8) bp, resulting in an average physical distance of 1.2 Mbp per map unit. No recombination has been observed between either of the two resistance loci and their adjacent DNA markers in a population of 44 fully resistant F5 individuals, which indicates that the genes are likely to reside within 0.91 cM (1.1 Mbp) of the DNA markers. PMID:12072472

  15. Resistance Risk Assessment of Spodoptera frugiperda (Lepidoptera: Noctuidae) and Diatraea saccharalis (Lepidoptera: Crambidae) to Vip3Aa20 Insecticidal Protein Expressed in Corn.

    Science.gov (United States)

    Bernardi, Oderlei; Bernardi, Daniel; Amado, Douglas; Sousa, Renan S; Fatoretto, Julio; Medeiros, Fernanda C L; Conville, Jared; Burd, Tony; Omoto, Celso

    2015-12-01

    Transgenic Agrisure Viptera 3 corn that expresses Cry1Ab, Vip3Aa20, and EPSPS proteins and Agrisure Viptera expressing Vip3Aa20 are used for control of Spodoptera frugiperda (J.E. Smith) and Diatraea saccharalis (F.) in Brazil. To support a resistance management program, resistance risk assessment studies were conducted to characterize the dose expression of Vip3Aa20 protein and level of control against these species. The Vip3Aa20 expression in Agrisure Viptera 3 and Agrisure Viptera decreased from V6 to V10 stage of growth. However, Vip3Aa20 expression in Agrisure Viptera 3 at V6 and V10 stages was 13- and 16-fold greater than Cry1Ab, respectively. The Vip3Aa20 expression in lyophilized tissue of Agrisure Viptera 3 and Agrisure Viptera diluted 25-fold in an artificial diet caused complete larval mortality of S. frugiperda and D. saccharalis. In contrast, lyophilized tissue of Bt11 at the same dilution does not provide complete mortality of these species. Agrisure Viptera 3 and Agrisure Viptera also caused a high level of mortality against S. frugiperda and D. saccharalis. Moreover, 100% mortality was observed for S. frugiperda larvae (neonates through fifth-instar larvae) when fed in corn with the Vip trait technology. Viptera corn achieves a high level of control against S. frugiperda and D. saccharalis providing a high dose, which is an important determination to support the refuge strategy for an effective resistance management program.

  16. Optimization of resistant starch formation from high amylose corn starch by microwave irradiation treatments and characterization of starch preparations.

    Science.gov (United States)

    Mutlu, Selime; Kahraman, Kevser; Öztürk, Serpil

    2017-02-01

    The effects of microwave irradiation on resistant starch (RS) formation and functional properties in high-amylose corn starch, Hylon VII, by applying microwave-storing cycles and drying processes were investigated. The Response Surface Methodology (RSM) was used to optimize the reaction conditions, microwave time (2-4min) and power (20-100%), for RS formation. The starch:water (1:10) mixtures were cooked and autoclaved and then different microwave-storing cycles and drying (oven or freeze drying) processes were applied. The RS contents of the samples increased with increasing microwave-storing cycle. The highest RS (43.4%) was obtained by oven drying after 3 cycles of microwave treatment at 20% power for 2min. The F, p (oven-dried samples applied by 1 and 3 cycles of microwave with regression coefficients of 0.65 and 0.62, respectively. Quadratic equation was obtained for freeze-dried samples applied by 3 cycles of microwave with a regression coefficient of 0.83. The solubility, water binding capacity (WBC) and RVA viscosity values of the microwave applied samples were higher than those of native Hylon VII. The WBC and viscosity values of the freeze-dried samples were higher than those of the oven-dried ones.

  17. CORN FLAVOR

    Science.gov (United States)

    Corn is a large part of the modern diet through sweeteners, oil, processed foods, and animal-derived foods. In addition, corn is eaten directly in bread and cereal-type foods, snack foods, and foods made from masa flour. Corn gluten meal is a byproduct of grain processed by wet milling. Although pri...

  18. Molecular cloning, sequence analysis and tissue expression of immulectin gene from the Asian corn borer, Ostrinia furnacalis (Lepidoptera:Pyralidae)%亚洲玉米螟免疫凝集素基因的克隆、序列分析及组织表达

    Institute of Scientific and Technical Information of China (English)

    刘佳; 刘洋; 赵华福; 张文庆; 胡建

    2014-01-01

    C-type lectin, a kind of pattern recognition molecule, recognizes the lipid A portion of lipopolysaccharide (LPS) and participates the cellular defense reaction in insects. In this paper, an immulectin (OfIML), C-type lectin with two carbohydrate-recognition domains, was cloned by reverse-transcription PCR (RT-PCR) and 3′/5′RACE from the larval hemocytes of corn borer, Ostrinia furnacalis. The cDNA of OfIML is 1 241 base pairs in length, and contains an open reading frame (ORF) of 924 nucleotides, which encoding a protein of 307 amino acids with a predicted molecularmass of approximately 34.65 ku. Alignment of OfIML with C-type lectins of other insects indicates that OfIML is a member of Lepidoptera immulectins. OfIML possesses two carbohydrate-recognition domains (CRDs), an amino-terminal domain, CRD1 (residues 1-135), and a carboxyl-terminal domain, CRD2 (residues 136-287). RT-PCR analyses shows that OfIML is expressed in cuticle, fat body, midgut, tracheae, and malpighian tubules, especially in hemocytes. The cDNA sequence has been deposited with GenBank under accession No. ABZ81710. OfIML is a kind of insect immunlectin, which contains two carbohydrate-recognition domains, and it possibly plays an important role during the immune reaction of O. furnaclis depending on its molecular structure and expression in tissues.%C 型凝集素作为模式识别分子可以识别部分脂多糖(LPS),进而参与昆虫细胞的防御反应。本文通过RT-PCR和3′/5′RACE技术从亚洲玉米螟Ostrinia furnacalis 5龄幼虫血细胞中克隆得到免疫凝集素基因(OfIML)。OfIML mRNA全长为1241 bp,其中开放读码框(ORF)为924 bp,编码307个氨基酸(aa),分子量约为34.65 ku。与其它昆虫的C型凝集素比对分析结果显示,OfIML属于鳞翅目免疫凝集素,并且含有一个独特的结构特征,即一前一后2个糖识别域,氨基末端(CRD1,aa#1-135)和羧基末端(CRD2, aa#136-287)。RT-PCR

  19. Assessment of fitness costs in Cry3Bb1 resistant and susceptible western corn rootworm (Coleoptera:Chrysomelidae) laboratory colonies

    Science.gov (United States)

    Maize production in the United States is dominated by plants genetically modified with transgenes from Bacillus thuringiensis (Bt). Varieties of Bt maize expressing Cry3Bb endotoxins that specifically target corn rootworms (genus Diabrotica) have proven highly efficacious. Howeve...

  20. Biology and management of economically important lepidopteran cereal stem borers in Africa.

    Science.gov (United States)

    Kfir, Rami; Overholt, W A; Khan, Z R; Polaszek, A

    2002-01-01

    Cereals (maize, sorghum, millet, rice) are extremely important crops grown in Africa for human consumption. Of the various insect pests attacking cereal crops in Africa, lepidopteran stem borers are by far the most injurious. All 21 economically important stem borers of cultivated grasses in Africa are indigenous except Chilo partellus, which invaded the continent from India, and C. sacchariphagus, which has recently been found in sugarcane in Mozambique. C. partellus is competitively displacing indigenous stem borers in East and southern Africa. A parasitoid, Cotesia flavipes, was introduced from Pakistan for biological control of C. partellus and caused a 32-55% decrease in stem borer densities. This article is an attempt to summarize the status of knowledge about economically important cereal stem borers in Africa with emphasis on their distribution, pest status and yield losses, diapause, natural enemies, cultural control, host plant resistance, and biological control. Special attention is given to Busseola fusca and C. partellus, the most important pests of maize and grain sorghum.

  1. Knockdown of RNA Interference Pathway Genes in Western Corn Rootworms (Diabrotica virgifera virgifera Le Conte Demonstrates a Possible Mechanism of Resistance to Lethal dsRNA.

    Directory of Open Access Journals (Sweden)

    Ana María Vélez

    Full Text Available RNA interference (RNAi is being developed as a potential tool for insect pest management. Increased understanding of the RNAi pathway in target insect pests will provide information to use this technology effectively and to inform decisions related to resistant management strategies for RNAi based traits. Dicer 2 (Dcr2, an endonuclease responsible for formation of small interfering RNA's and Argonaute 2 (Ago2, an essential catalytic component of the RNA-induced silencing complex (RISC have both been associated with the RNAi pathway in a number of different insect species including the western corn rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae. We identified both genes from a transcriptome library generated from different tissues and developmental stages of the western corn rootworm, an important target pest for transgenic plants expressing dsRNA targeting essential genes. The expression of these genes was suppressed by more than 90% after injecting gene specific dsRNA into adult rootworms. The injected beetles were then fed vATPase A dsRNA which has previously been demonstrated to cause mortality in western corn rootworm adults. The suppression of both RNAi pathway genes resulted in reduced mortality after subsequent exposure to lethal concentrations of vATPase A dsRNA as well as increased vATPase A expression relative to control treatments. Injections with dsRNA for a non-lethal target sequence (Laccase 2 did not affect mortality or expression caused by vATPase A dsRNA indicating that the results observed with Argo and Dicer dsRNA were not caused by simple competition among different dsRNA's. These results confirm that both genes play an important role in the RNAi pathway for western corn rootworms and indicate that selection pressures that potentially affect the expression of these genes may provide a basis for future studies to understand potential mechanisms of resistance.

  2. Mexican rice borer (Lepidoptera: Crambidae) oviposition site selection stimuli on sugarcane, and potential field applications.

    Science.gov (United States)

    Showler, Allan T; Castro, Boris A

    2010-08-01

    The Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), a key pest of sugarcane (Saccharum spp.) and rice, Oryza sativa L., in Texas, has not been controlled with chemical insecticides or biological agents, but some sugarcane varieties have shown degrees of resistance. Assessment of selected sugarcane leaf characteristics indicate that preference for oviposition sites is mostly determined by the presence of a leaf fold and secondarily by the availability of dry leaf tissue, both of which are antixenotic nonchemical stimuli. We suggest that breeding sugarcane lines bearing leaves that do not fold on drying could provide substantial antixenotic resistance against the Mexican rice borer. Previously identified antixenotic chemical stimuli, i.e., low quantities or absence of important nutrients in green leaf tissue, only become apparent when resistant and susceptible sugarcane varieties are compared. Varietal differences in oviposition preference, however, were not observed on excised dry leaf tissue, indicating that expression of resistance in terms of chemical stimuli requires detection of biochemicals in nearby living leaf tissue. Excised dry sugarcane leaves retain the two dominant nonchemical oviposition preference stimuli for Mexican rice borers, and the leaves effectively trapped eggs away from intact plants when dry leaves were used as "mulch" at the bottom of greenhouse cages. Under commercial sugarcane field conditions, bundled dry leaves also collected Mexican rice borer eggs. Possible applications of dry sugarcane leaf substrate for egg scouting and for trapping eggs are discussed.

  3. A high-fat diet rich in corn oil reduces spontaneous locomotor activity and induces insulin resistance in mice.

    Science.gov (United States)

    Wong, Chi Kin; Botta, Amy; Pither, Jason; Dai, Chuanbin; Gibson, William T; Ghosh, Sanjoy

    2015-04-01

    Over the last few decades, polyunsaturated fatty acid (PUFA), especially n-6 PUFA, and monounsaturated fatty acid content in 'Western diets' has increased manyfold. Such a dietary shift also parallels rising sedentary behavior and diabetes in the Western world. We queried if a shift in dietary fats could be linked to physical inactivity and insulin insensitivity in mice. Eight-week old female C57/Bl6 mice were fed either high-fat (HF) diets [40% energy corn oil (CO) or isocaloric olive oil (OO) diets] or chow (n=10/group) for 6 weeks, followed by estimation of spontaneous locomotor activity, body composition and in vivo metabolic outcomes. Although lean mass and resting energy expenditure stayed similar in both OO- and CO-fed mice, only CO-fed mice demonstrated reduced spontaneous locomotor activity. Such depressed activity in CO-fed mice was accompanied by a lower respiratory ratio, hyperinsulinemia and impaired glucose disposal following intraperitoneal glucose tolerance and insulin tolerance tests compared to OO-fed mice. Unlike the liver, where both HF diets increased expression of fat oxidation genes like PPARs, the skeletal muscle of CO-fed mice failed to up-regulate such genes, thereby supporting the metabolic insufficiencies observed in these mice. In summary, this study demonstrates a specific contribution of n-6 PUFA-rich oils like CO to the loss of spontaneous physical activity and insulin sensitivity in mice. If these data hold true for humans, this study could provide a novel link between recent increases in dietary n-6 PUFA to sedentary behavior and the development of insulin resistance in the Western world.

  4. Relationships between sucrose content and resistance of corn to stalk rot%蔗糖含量与玉米对镰刀菌茎腐病的抗病性的关系

    Institute of Scientific and Technical Information of China (English)

    龙书生; 李亚玲; 时春喜; 李恩才; 张宇宏; 李鸣雷

    2003-01-01

    The relationship between sucrose content and corn resistance to corn stalk rot caused by Fusarium graminearum was investigated.The incidence of corn stalk rot was closely related to sucrose content in the pith tissues of the second internode above the ground at the physiological maturity stage.Corn hybrids resistant to stalk rot had higher sucrose contents in the pith tissues of the second internode above the ground than hybrids susceptible to the disease.In addition,disease incidence was negatively correlated with sucrose content in the pith tissues of the second internode above the ground at the physiological maturity stage. The results suggested that sucrose content could be used as an indicator of corn stalk rot resistance and for selecting corn hybrids for resistance to corn stalk rot.%就玉米茎秆蔗糖含量与玉米对由禾谷镰刀菌(Fusarium graminearum)引起的茎腐病(corn stalk rot)的抗性间的关系进行了研究.结果表明,在玉米生理成熟期地上第二茎间髓部组织内蔗糖的含量与玉米对茎腐病的抗性密切相关,抗病的玉米杂交种的蔗糖含量明显高于感病的玉米杂交种.蔗糖含量与茎腐病的发病率呈显著的负相关关系.研究结果表明,在生理成熟期地上第二茎间髓部组织内蔗糖含量可作为选育抗镰刀菌茎腐病玉米杂交种的生化指标.

  5. Corn earworm (Lepidoptera: Noctuidae) in northeastern field corn: infestation levels and the value of transgenic hybrids.

    Science.gov (United States)

    Bohnenblust, Eric; Breining, Jim; Fleischer, Shelby; Roth, Gregory; Tooker, John

    2013-06-01

    Corn earworm, Helicoverpa zea (Boddie), is a polyphagous noctuid pest of agricultural crops across the United States that is gaining attention as a pest of field corn. Before the introduction of transgenic insect-resistant hybrids, this pest was largely ignored in field corn, but now many Bacillus thuringiensis (Bt) corn hybrids have activity against corn earworm. However, the value of control in the northeastern United States is unclear because the risk posed by corn earworm to field corn has not been well characterized. To understand the threat from corn earworm and the value of Bt hybrids in field corn, we assessed corn earworm injury in Bt and non-Bt hybrids at 16 sites across four maturity zones throughout Pennsylvania in 2010, and 10 sites in 2011. We also used corn earworm captures from the PestWatch pheromone trapping network to relate moth activity to larval damage in field corn. Corn earworm damage was less than one kernel per ear at 21 of 26 sites over both years, and the percentage of ears damaged was generally corn earworm damage relative to non-Bt hybrids, but we found no differences among Bt traits. Cumulative moth captures through July effectively predicted damage at the end of the season. Currently, the additional benefit of corn earworm control provided by Bt hybrids is typically less than US$4.00/ha in northeastern field corn.

  6. Resistance evolution to the first generation of genetically modified Diabrotica-active Bt-maize events by western corn rootworm: management and monitoring considerations.

    Science.gov (United States)

    Devos, Yann; Meihls, Lisa N; Kiss, József; Hibbard, Bruce E

    2013-04-01

    Western corn rootworm (Diabrotica virgifera virgifera; WCR) is a major coleopteran maize pest in North America and the EU, and has traditionally been managed through crop rotation and broad-spectrum soil insecticides. Genetically modified Bt-maize offers an additional management tool for WCR and has been valuable in reducing insecticide use and increasing farm income. A concern is that the widespread, repeated, and exclusive deployment of the same Bt-maize transformation event will result in the rapid evolution of resistance in WCR. This publication explores the potential of WCR to evolve resistance to plant-produced Bt-toxins from the first generation of Diabrotica-active Bt-maize events (MON 863 and MON 88017, DAS-59122-7 and MIR604), and whether currently implemented risk management strategies to delay and monitor resistance evolution are appropriate. In twelve of the twelve artificial selection experiments reported, resistant WCR populations were yielded rapidly. Field-selected resistance of WCR to Cry3Bb1 is documented in some US maize growing areas, where an increasing number of cases of unexpected damage of WCR larvae to Bt-maize MON 88017 has been reported. Currently implemented insect resistance management measures for Bt-crops usually rely on the high dose/refuge (HDR) strategy. Evidence (including laboratory, greenhouse and field data) indicates that several conditions contributing to the success of the HDR strategy may not be met for the first generation of Bt-maize events and WCR: (1) the Bt-toxins are expressed heterogeneously at a low-to-moderate dose in roots; (2) resistance alleles may be present at a higher frequency than initially assumed; (3) WCR may mate in a non-random manner; (4) resistance traits could have non-recessive inheritance; and (5) fitness costs may not necessarily be associated with resistance evolution. However, caution must be exercised when extrapolating laboratory and greenhouse results to field conditions. Model predictions

  7. Bt pollen dispersal and Bt kernel mosaics: integrity of non-Bt refugia for lepidopteran resistance management in maize.

    Science.gov (United States)

    Burkness, Eric C; Hutchison, W D

    2012-10-01

    Field trials were conducted at Rosemount, MN in 2009 and 2010, to measure pollen movement from Bt corn to adjacent blocks of non-Bt refuge corn. As the use of Bt corn hybrids continues to increase in the United States, and new insect resistance management (IRM) plans are implemented, it is necessary to measure the efficacy of these IRM plans. In Minnesota, the primary lepidopteran pests of corn include the European corn borer, Ostrinia nubilalis (Hübner) and corn earworm, Helicoverpa zea (Boddie). The primary IRM plan in transgenic corn is the use of hybrids expressing a high dose of insecticidal proteins and an insect refuge containing hybrids not expressing insecticidal proteins that produce susceptible insects. Wind-assisted pollen movement in corn occurs readily, and is the primary method of pollination for corn. The combination of pollen movement and viability determines the potential for cross pollination of refuge corn. In 2009 and 2010, cross pollination occurred with the highest frequency on the north and east sides of Bt corn fields, but was found at some level in all directions. Highest levels of cross pollination (75%) were found within the first four rows (3 m) of non-Bt corn adjacent to Bt corn, and in general decreasing levels of cross pollination were found the further the non-Bt corn was planted from the Bt corn. A mosaic of Bt cross-pollinated kernels was found throughout the ear, but in both years the ear tip had the highest percentage of cross-pollinated kernels; this pattern may be linked to the synchrony of pollen shed and silking between Bt and non-Bt corn hybrids. The dominant wind direction in both years was from WNW. However, in both years, there were also prevailing winds from SSW and WSW. Further studies are needed to quantify Bt levels in cross-pollinated kernels, measure the Bt dose of such kernels and associated lepidopteran pest survival, and measure the impact of Bt pollen on lepidopteran pests, particularly when considering the

  8. Inhibition of Helicoverpa zea (Lepidoptera: Noctuidae) Growth by Transgenic Corn Expressing Bt Toxins and Development of Resistance to Cry1Ab.

    Science.gov (United States)

    Reisig, Dominic D; Reay-Jones, Francis P F

    2015-08-01

    Transgenic corn, Zea mays L., that expresses the Bacillus thuringiensis (Bt) toxin Cry1Ab is only moderately toxic to Helicoverpa zea (Boddie) and has been planted commercially since 1996. Growth and development of H. zea was monitored to determine potential changes in susceptibility to this toxin over time. Small plots of corn hybrids expressing Cry1F, Cry1F × Cry1Ab, Cry1Ab × Cry3Bb1, Cry1A.105 × Cry2Ab2 × Cry3Bb1, Cry1A.105 × Cry2Ab2, and Vip3Aa20 × Cry1Ab × mCry3A were planted in both 2012 and 2013 inNorth and South Carolina with paired non-Bt hybrids from the same genetic background. H. zea larvae were sampled on three time periods from ears and the following factors were measured: kernel area injured (cm(2)) by H. zea larvae, larval number per ear, larval weight, larval length, and larval head width. Pupae were sampled on a single time period and the following factors recorded: number per ear, weight, time to eclosion, and the number that eclosed. There was no reduction in larval weight, number of insect entering the pupal stadium, pupal weight, time to eclosion, and number of pupae able to successfully eclose to adulthood in the hybrid expressing Cry1Ab compared with a non-Bt paired hybrid. As Cry1Ab affected these in 1996, H. zea may be developing resistance to Cry1Ab in corn, although these results are not comprehensive, given the limited sampling period, size, and geography. We also found that the negative impacts on larval growth and development were greater in corn hybrids with pyramided traits compared with single traits.

  9. Kernel compositions of glyphosate-tolerant and corn rootworm-protected MON 88017 sweet corn and insect-protected MON 89034 sweet corn are equivalent to that of conventional sweet corn (Zea mays).

    Science.gov (United States)

    Curran, Kassie L; Festa, Adam R; Goddard, Scott D; Harrigan, George G; Taylor, Mary L

    2015-03-25

    Monsanto Co. has developed two sweet corn hybrids, MON 88017 and MON 89034, that contain biotechnology-derived (biotech) traits designed to enhance sustainability and improve agronomic practices. MON 88017 confers benefits of glyphosate tolerance and protection against corn rootworm. MON 89034 provides protection against European corn borer and other lepidopteran insect pests. The purpose of this assessment was to compare the kernel compositions of MON 88017 and MON 89034 sweet corn with that of a conventional control that has a genetic background similar to the biotech sweet corn but does not express the biotechnology-derived traits. The sweet corn samples were grown at five replicated sites in the United States during the 2010 growing season and the conventional hybrid and 17 reference hybrids were grown concurrently to provide an estimate of natural variability for all assessed components. The compositional analysis included proximates, fibers, amino acids, sugars, vitamins, minerals, and selected metabolites. Results highlighted that MON 88017 and MON 89034 sweet corns were compositionally equivalent to the conventional control and that levels of the components essential to the desired properties of sweet corn, such as sugars and vitamins, were more affected by growing environment than the biotech traits. In summary, the benefits of biotech traits can be incorporated into sweet corn with no adverse effects on nutritional quality.

  10. Expression of a Chimeric Gene Encoding Insecticidal Crystal Protein Cry1Aabc of Bacillus thuringiensis in Chickpea (Cicer arietinum L. Confers Resistance to Gram Pod Borer (Helicoverpa armigera Hubner.

    Directory of Open Access Journals (Sweden)

    Alok Das

    2017-08-01

    Full Text Available Domain swapping and generation of chimeric insecticidal crystal protein is an emerging area of insect pest management. The lepidopteran insect pest, gram pod borer (Helicoverpa armigera H. wreaks havoc to chickpea crop affecting production. Lepidopteran insects were reported to be controlled by Bt (cryI genes. We designed a plant codon optimized chimeric Bt gene (cry1Aabc using three domains from three different cry1A genes (domains I, II, and III from cry1Aa, cry1Ab, and cry1Ac, respectively and expressed it under the control of a constitutive promoter in chickpea (cv. DCP92-3 to assess its effect on gram pod borer. A total of six transgenic chickpea shoots were established by grafting into mature fertile plants. The in vitro regenerated (organogenetic shoots were selected based on antibiotic kanamycin monosulfate (100 mg/L with transformation efficiency of 0.076%. Three transgenic events were extensively studied based on gene expression pattern and insect mortality across generations. Protein expression in pod walls, immature seeds and leaves (pre- and post-flowering were estimated and expression in pre-flowering stage was found higher than that of post-flowering. Analysis for the stable integration, expression and insect mortality (detached leaf and whole plant bioassay led to identification of efficacious transgenic chickpea lines. The chimeric cry1Aabc expressed in chickpea is effective against gram pod borer and generated events can be utilized in transgenic breeding program.

  11. Expression of a Chimeric Gene Encoding Insecticidal Crystal Protein Cry1Aabc of Bacillus thuringiensis in Chickpea (Cicer arietinum L.) Confers Resistance to Gram Pod Borer (Helicoverpa armigera Hubner.).

    Science.gov (United States)

    Das, Alok; Datta, Subhojit; Thakur, Shallu; Shukla, Alok; Ansari, Jamal; Sujayanand, G K; Chaturvedi, Sushil K; Kumar, P A; Singh, N P

    2017-01-01

    Domain swapping and generation of chimeric insecticidal crystal protein is an emerging area of insect pest management. The lepidopteran insect pest, gram pod borer (Helicoverpa armigera H.) wreaks havoc to chickpea crop affecting production. Lepidopteran insects were reported to be controlled by Bt (cryI) genes. We designed a plant codon optimized chimeric Bt gene (cry1Aabc) using three domains from three different cry1A genes (domains I, II, and III from cry1Aa, cry1Ab, and cry1Ac, respectively) and expressed it under the control of a constitutive promoter in chickpea (cv. DCP92-3) to assess its effect on gram pod borer. A total of six transgenic chickpea shoots were established by grafting into mature fertile plants. The in vitro regenerated (organogenetic) shoots were selected based on antibiotic kanamycin monosulfate (100 mg/L) with transformation efficiency of 0.076%. Three transgenic events were extensively studied based on gene expression pattern and insect mortality across generations. Protein expression in pod walls, immature seeds and leaves (pre- and post-flowering) were estimated and expression in pre-flowering stage was found higher than that of post-flowering. Analysis for the stable integration, expression and insect mortality (detached leaf and whole plant bioassay) led to identification of efficacious transgenic chickpea lines. The chimeric cry1Aabc expressed in chickpea is effective against gram pod borer and generated events can be utilized in transgenic breeding program.

  12. Acquisition of Insect-Resistant Transgenic Maize Harboring a Truncated cry1Ah Gene via Agrobacterium-Mediated Transformation

    Institute of Scientific and Technical Information of China (English)

    LI Xiu-ying; LANG Zhi-hong; ZHANG Jie; HE Kang-lai; ZHU Li; HUANG Da-fang

    2014-01-01

    A novel insecticidal gene cry1Ah was cloned from Bacillus thuringiensis isolate BT8 previously for plant genetic engineering improvement. Truncated active Cry1Ah toxin has a toxicity level similar to that of the full-length Cry1Ah toxin. In this study, plant expression vector pMhGM harboring truncated cry1Ah gene was transformed into maize (Zea mays L.) immature embryos by Agrobacterium tumefaciens-mediated transformation at which maize alcohol dehydrogenase matrix attachment regions (madMARs) were incorporated on both sides of the gene expression cassette to improve gene expression. A total of 23 PCR positive events were obtained with a transformation efifciency of 5%around. Bioassay results showed that events 1-4 and 1-5 exhibited enhanced resistance to the Asian corn borer (Ostrinia furnacalis). These two events were further conifrmed by molecular analysis. Southern blot suggested that a single copy of the cry1Ah gene was successfully integrated into the maize genome. Western blot and ELISA showed that the foreign gene cry1Ah was expressed stably at high level in maize and could be inherited stably over generations. The results of a bioassay of T1-T4 transgenic maize plants indicated that the transgenic plants were highly toxic to the Asian corn borer and their resistance could be inherited stably from generation to generation. Thus, events 1-4 and 1-5 are good candidates for the breeding of insect-resistant maize.

  13. Silicon reduces impact of plant nitrogen in promoting stalk borer (Eldana saccharina) but not sugarcane thrips (Fulmekiola serrata) infestations in sugarcane

    OpenAIRE

    Keeping, Malcolm G.; Miles, Neil; Sewpersad, Chandini

    2014-01-01

    The stalk borer Eldana saccharina Walker (Lepidoptera: Pyralidae) is a major limiting factor in South African sugarcane production, while yield is also reduced by sugarcane thrips Fulmekiola serrata Kobus (Thysanoptera: Thripidae). Borer management options include appropriate nitrogen (N) and enhanced silicon (Si) nutrition; the effect of N on sugarcane thrips is unknown. We tested the effects of these nutrients, in combination with resistant (N33) and susceptible (N27) sugarcane cultivars, o...

  14. Aquatic degradation of Cry1Ab protein and decomposition dynamics of transgenic corn leaves under controlled conditions.

    Science.gov (United States)

    Böttger, Rita; Schaller, Jörg; Lintow, Sven; Gert Dudel, E

    2015-03-01

    The increasing cultivation of genetically modified corn plants (Zea mays) during the last decades is suggested as a potential risk to the environment. One of these genetically modified variety expressed the insecticidal Cry1Ab protein originating from Bacillus thuringiensis (Bt), resulting in resistance against Ostrinia nubilalis, the European corn borer. Transgenic litter material is extensively studied regarding the decomposition in soils. However, only a few field studies analyzed the fate of the Cry1Ab protein and the impact of green and senescent leaf litter from corn on the decomposition rate and related ecosystem functions in aquatic environments. Consequently, a microbial litter decomposition experiment was conducted under controlled semi-natural conditions in batch culture using two maize varieties: one variety with Cry1Ab and another one with the appertaining Iso-line as control treatment. The results showed no significant differences between the treatment with Cry1Ab and the Iso-line regarding loss of total mass in dry weight of 43% for Iso-line and 45% for Bt-corn litter, lignin content increased to 137.5% (Iso-line) and 115.7% (Bt-corn), and phenol loss decreased by 53.6% (Iso-line), 62.2% (Bt-corn) during three weeks of the experiment. At the end of the experiment Cry1Ab protein was still detected with 6% of the initial concentration. A slightly but significant lower cellulose content was found for the Cry1Ab treatment compared to the Iso-line litter at the end of the experiment. The significant higher total protein (25%) and nitrogen (25%) content in Bt corn, most likely due to the additionally expression of the transgenic protein, may increase the microbial cellulose degradation and decrease microbial lignin degradation. In conclusion a relevant year by year input of protein and therefore nitrogen rich Bt corn litter into aquatic environments may affect the balanced nutrient turnover in aquatic ecosystems. Copyright © 2014 Elsevier Inc. All rights

  15. Wing shape and size of the western corn rootworm (Coleoptera: Chrysomelidae) is related to sex and resistance to soybean-maize crop rotation.

    Science.gov (United States)

    Mikac, K M; Douglas, J; Spencer, J L

    2013-08-01

    The western corn rootworm, Diabrotica virgifera virgifera LeConte, is a major pest of maize in the United States and more recently, Europe. Understanding the dispersal dynamics of this species will provide crucial information for its management. This study used geometric morphometric analysis of hind wing venation based on 13 landmarks in 223 specimens from nine locations in Illinois, Nebraska, Iowa, and Missouri, to assess whether wing shape and size differed between rotated and continuously grown maize where crop rotation-resistant and susceptible individuals are found, respectively. Before assessing differences between rotation-resistant and susceptible individuals, sexual dimorphism was investigated. No significant difference in wing (centroid) size was found between males and females; however, females had significantly different shaped (more elongated) wings compared with males. Wing shape and (centroid) size were significantly larger among individuals from rotated maize where crop-rotation resistance was reported; however, cross-validation of these results revealed that collection site resistance status was an only better than average predictor of shape in males and females. This study provides preliminary evidence of wing shape and size differences in D. v. virgifera from rotated versus continuous maize. Further study is needed to confirm whether wing shape and size can be used to track the movement of rotation-resistant individuals and populations as a means to better inform management strategies.

  16. A single major QTL controls expression of larval Cry1F resistance trait in Ostrinia nubilalis (Lepidoptera: Crambidae) and is independent of midgut receptor genes.

    Science.gov (United States)

    Coates, Brad S; Sumerford, Douglas V; Lopez, Miriam D; Wang, Haichuan; Fraser, Lisa M; Kroemer, Jeremy A; Spencer, Terrence; Kim, Kyung S; Abel, Craig A; Hellmich, Richard L; Siegfried, Blair D

    2011-08-01

    The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), is an introduced crop pest in North America that causes major damage to corn and reduces yield of food, feed, and biofuel materials. The Cry1F toxin from Bacillus thuringiensis (Bt) expressed in transgenic hybrid corn is highly toxic to O. nubilalis larvae and effective in minimizing feeding damage. A laboratory colony of O. nubilalis was selected for high levels of Cry1F resistance (>12,000-fold compared to susceptible larvae) and is capable of survival on transgenic hybrid corn. Genetic linkage maps with segregating AFLP markers show that the Cry1F resistance trait is controlled by a single quantitative trait locus (QTL) on linkage group 12. The map position of single nucleotide polymorphism (SNP) markers indicated that midgut Bt toxin-receptor genes, alkaline phosphatase, aminopeptidase N, and cadherin, are not linked with the Cry1F QTL. Evidence suggests that genes within this genome interval may give rise to a novel Bt toxin resistance trait for Lepidoptera that appears independent of known receptor-based mechanisms of resistance.

  17. The cultivation of Bt corn producing Cry1Ac toxins does not adversely affect non-target arthropods.

    Science.gov (United States)

    Guo, Yanyan; Feng, Yanjie; Ge, Yang; Tetreau, Guillaume; Chen, Xiaowen; Dong, Xuehui; Shi, Wangpeng

    2014-01-01

    Transgenic corn producing Cry1Ac toxins from Bacillus thuringiensis (Bt) provides effective control of Asian corn borer, Ostrinia furnacalis (Guenée), and thus reduces insecticide applications. However, whether Bt corn exerts undesirable effects on non-target arthropods (NTAs) is still controversial. We conducted a 2-yr study in Shangzhuang Agricultural Experiment Station to assess the potential impact of Bt corn on field population density, biodiversity, community composition and structure of NTAs. On each sampling date, the total abundance, Shannon's diversity index, Pielou's evenness index and Simpson's diversity index were not significantly affected by Bt corn as compared to non-Bt corn. The "sampling dates" had a significant effect on these indices, but no clear tendencies related to "Bt corn" or "sampling dates X corn variety" interaction were recorded. Principal response curve analysis of variance indicated that Bt corn did not alter the distribution of NTAs communities. Bray-Curtis dissimilarity and distance analysis showed that Cry1Ac toxin exposure did not increase community dissimilarities between Bt and non-Bt corn plots and that the evolution of non-target arthropod community was similar on the two corn varieties. The cultivation of Bt corn failed to show any detrimental evidence on the density of non-target herbivores, predators and parasitoids. The composition of herbivores, predators and parasitoids was identical in Bt and non-Bt corn plots. Taken together, results from the present work support that Bt corn producing Cry1Ac toxins does not adversely affect NTAs.

  18. All or nothing: Area-wide approach frustrates peachtree borers in Georgia

    Science.gov (United States)

    Mating disruption research has been done in the southeast against borers attacking peach since the sex pheromones of the peachtree borer, Synanthedon exitiosa (Lepidoptera: Sesiidae) and lesser peachtree borer, S. pictipes (Lepidoptera: Sesiidae) were identified. However, replicated trials over thr...

  19. A novel interaction between plant-beneficial rhizobacteria and roots: colonization induces corn resistance against the root herbivore Diabrotica speciosa.

    Directory of Open Access Journals (Sweden)

    Franciele Santos

    Full Text Available A number of soil-borne microorganisms, such as mycorrhizal fungi and rhizobacteria, establish mutualistic interactions with plants, which can indirectly affect other organisms. Knowledge of the plant-mediated effects of mutualistic microorganisms is limited to aboveground insects, whereas there is little understanding of what role beneficial soil bacteria may play in plant defense against root herbivory. Here, we establish that colonization by the beneficial rhizobacterium Azospirillum brasilense affects the host selection and performance of the insect Diabrotica speciosa. Root larvae preferentially orient toward the roots of non-inoculated plants versus inoculated roots and gain less weight when feeding on inoculated plants. As inoculation by A. brasilense induces higher emissions of (E-β-caryophyllene compared with non-inoculated plants, it is plausible that the non-preference of D. speciosa for inoculated plants is related to this sesquiterpene, which is well known to mediate belowground insect-plant interactions. To the best of our knowledge, this is the first study showing that a beneficial rhizobacterium inoculant indirectly alters belowground plant-insect interactions. The role of A. brasilense as part of an integrative pest management (IPM program for the protection of corn against the South American corn rootworm, D. speciosa, is considered.

  20. A novel interaction between plant-beneficial rhizobacteria and roots: colonization induces corn resistance against the root herbivore Diabrotica speciosa.

    Science.gov (United States)

    Santos, Franciele; Peñaflor, Maria Fernanda G V; Paré, Paul W; Sanches, Patrícia A; Kamiya, Aline C; Tonelli, Mateus; Nardi, Cristiane; Bento, José Mauricio S

    2014-01-01

    A number of soil-borne microorganisms, such as mycorrhizal fungi and rhizobacteria, establish mutualistic interactions with plants, which can indirectly affect other organisms. Knowledge of the plant-mediated effects of mutualistic microorganisms is limited to aboveground insects, whereas there is little understanding of what role beneficial soil bacteria may play in plant defense against root herbivory. Here, we establish that colonization by the beneficial rhizobacterium Azospirillum brasilense affects the host selection and performance of the insect Diabrotica speciosa. Root larvae preferentially orient toward the roots of non-inoculated plants versus inoculated roots and gain less weight when feeding on inoculated plants. As inoculation by A. brasilense induces higher emissions of (E)-β-caryophyllene compared with non-inoculated plants, it is plausible that the non-preference of D. speciosa for inoculated plants is related to this sesquiterpene, which is well known to mediate belowground insect-plant interactions. To the best of our knowledge, this is the first study showing that a beneficial rhizobacterium inoculant indirectly alters belowground plant-insect interactions. The role of A. brasilense as part of an integrative pest management (IPM) program for the protection of corn against the South American corn rootworm, D. speciosa, is considered.

  1. Study of southern corn

    Directory of Open Access Journals (Sweden)

    Samavia Mubeen

    2017-07-01

    Full Text Available Southern corn leaf blight is considered the most devastating disease of maize crop, which causes noticeable reduction in crop yield. Inbred lines are useful because they are genotyped, multiple time phenotyping is possible, and genetic uniformity, genetic stability and its vigor make inbred lines suitable to study in diversified environment. In present investigation, 12 maize genotypes viz: NC-2703 (hybrid, NC-2003 (hybrid, SP-3 (inbred line, NCML-73 (inbred line, NRL-6 (inbred line, NRL-4 (inbred line, Soan-3 (variety, Rakaposhi (variety, Margala (variety, EV-1097 (variety, Local-Y (variety, Local-W (variety were tested against southern corn leaf blight under laboratory and field conditions. According to disease severity scale (0–5 inbreds SP-3 and NCML-73 were found highly resistant; Local-W moderately resistance and rest of the genotypes were least resistance in in vitro analysis. In field screening, Margala, NRL-4, EV-1097 showed maximum resistance followed by moderately resistant SP-3, NCML-73, NC-2703, NRL-6 and Local-Y maize genotypes. NC-2003, Rakaposhi and Soan-3 showed least resistance during field evaluation. Cochliobolus heterostrophus showed considerable effects on yield of crop. Significant difference was found in grain yield, plant height, ear height and ear weight while ear placement, ear per plant and infected ear data were non-significant. The results clearly showed the effect on maize genotypes and its yield.

  2. Biology of emerald ash borer parasitoids

    Science.gov (United States)

    Leah S. Bauer; Jian J. Duan; Jonathan P. Lelito; Houping Liu; Juli R. Gould

    2015-01-01

    The emerald ash borer (EAB) (Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), an invasive beetle introduced from China (Bray et al., 2011), was identified as the cause of ash (Fraxinus spp.) mortality in southeast Michigan and nearby Ontario in 2002 (Haack et al., 2002; Federal Register, 2003; Cappaert et al., 2005)....

  3. Emerald ash borer biology and invasion history

    Science.gov (United States)

    Robert A. Haack; Yuri Baranchikov; Leah S. Bauer; Therese M. Poland

    2015-01-01

    The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is native to eastern Asia and is primarily a pest of ash (Fraxinus) trees (Fig. 1). Established populations of EAB were first detected in the United States and Canada in 2002 (Haack et al., 2002), and based on a dendrochronology study by Siegert...

  4. Evaluación de poblaciones segregantes producidas a partir de cruzamientos entre tomate cultivado y la accesión silvestre PI134418 de Solanum habrochaites var. glabratum resistente al pasador del fruto. Evaluation of segregating populations from crosses between cultivated tomato and PI134418 wild accession of Solanum habrochaites var. glabratum with resistance to the fruit borer.

    Directory of Open Access Journals (Sweden)

    Edwin F. Restrepo S.

    2008-01-01

    Full Text Available Se realizó la evaluación de poblaciones segregantes producidas a partir de cruzamientos entre tomate S. lycopersicum L. cv. maravilla y la accesión silvestre PI134418 de S. habrochaites var. glabratum resistente al pasador del fruto N. elegantalis. Se encontró que hay dominancia de los alelos que disminuyen la expresión del caraacute;cter peso promedio de fruto. El método del retrocruzamiento resultó maacute;s eficiente que el de la autofecundación, para contrarrestar la dominancia de los alelos que codifican por el tamaño pequeño del fruto. Los tricomas y el número promedio de frutos por racimo no ejercieron ningún efecto sobre el ataque de los frutos por parte del pasador; mientras que el peso promedio de fruto sí tuvo efecto importante sobre dicho ataque, de tal manera que el insecto tiende a producir mayor daño a medida que se incrementa el peso promedio de fruto. Las poblaciones RC1 y RC2 se comportaron como las típicas segregantes para los caracteres evaluados y exhibieron amplia variabilidad en los mismos. El método del retrocruzamiento fue efectivo para romper la asociación negativa entre el peso promedio de fruto y la resistencia al insecto. El peso promedio de algunos de los frutos en los recombinantes RC2 fluctuó entre 45.1 y 68.6 g y mostraron resistencia al pasador.Evaluation of segregating populations from crosses between cultivated tomato S. lycopersicum L. cv. maravilla and PI134418 wild accession of Solanum habrochaites var. glabratum with resistance to the fruit borer N. elegantalis was made. There was dominance of alleles that decrease the expression of the character mean fruit weight. The backcrossing method was more efficient than selfing in order to counteract the dominance of alleles that encode by small fruit size. The thrichomes and the mean number of fruit per bunch did not produce any effect on the fruit attack by the fruit borer; while that mean fruit weight had important effect on this attack

  5. Research on mechanical properties of corn stalk

    Science.gov (United States)

    Zhang, Kaifei; He, Yujing; Zhang, Hongmei; Li, He

    2017-03-01

    Many domestic scholars have studied on straw utilization from lodging resistance, by breeding agricultural experts to optimization parameters, which selected by agricultural mechanical experts and efficient utilization after the harvest crush. Therefore, the study of the mechanical properties of corn stalks has great prospects. It can provide the basis for the design of agricultural machinery and comprehensive utilization of straw that study the relationship between the properties of the corn stalk and the mechanical properties. In this paper, the radial compression and bending mechanical properties of corn stalk was conducted by universal material testing machine, which contributes to the increase of corn crop and provides basis for the development of equipment.

  6. Field-Evolved Mode 1 Resistance of the Fall Armyworm to Transgenic Cry1Fa-Expressing Corn Associated with Reduced Cry1Fa Toxin Binding and Midgut Alkaline Phosphatase Expression.

    Science.gov (United States)

    Jakka, Siva R K; Gong, Liang; Hasler, James; Banerjee, Rahul; Sheets, Joel J; Narva, Kenneth; Blanco, Carlos A; Jurat-Fuentes, Juan L

    2015-12-04

    Insecticidal protein genes from the bacterium Bacillus thuringiensis (Bt) are expressed by transgenic Bt crops (Bt crops) for effective and environmentally safe pest control. The development of resistance to these insecticidal proteins is considered the most serious threat to the sustainability of Bt crops. Resistance in fall armyworm (Spodoptera frugiperda) populations from Puerto Rico to transgenic corn producing the Cry1Fa insecticidal protein resulted, for the first time in the United States, in practical resistance, and Bt corn was withdrawn from the local market. In this study, we used a field-collected Cry1Fa corn-resistant strain (456) of S. frugiperda to identify the mechanism responsible for field-evolved resistance. Binding assays detected reduced Cry1Fa, Cry1Ab, and Cry1Ac but not Cry1Ca toxin binding to midgut brush border membrane vesicles (BBMV) from the larvae of strain 456 compared to that from the larvae of a susceptible (Ben) strain. This binding phenotype is descriptive of the mode 1 type of resistance to Bt toxins. A comparison of the transcript levels for putative Cry1 toxin receptor genes identified a significant downregulation (>90%) of a membrane-bound alkaline phosphatase (ALP), which translated to reduced ALP protein levels and a 75% reduction in ALP activity in BBMV from 456 compared to that of Ben larvae. We cloned and heterologously expressed this ALP from susceptible S. frugiperda larvae and demonstrated that it specifically binds with Cry1Fa toxin. This study provides a thorough mechanistic description of field-evolved resistance to a transgenic Bt crop and supports an association between resistance and reduced Cry1Fa toxin binding and levels of a putative Cry1Fa toxin receptor, ALP, in the midguts of S. frugiperda larvae.

  7. DEVELOPMENT OF A MULTI-TIERED INSECT RESISTANCE MANAGEMENT PROGRAM FOR GENETICALLY MODIFIED CORN HYBRIDS EXPRESSING THE PLANT INCORPORATED PROTECTANT, BACILLUS THURINGIENSIS

    Science.gov (United States)

    A significant increase in genetically modified corn planting driven by biofuel demand is expected for the 2007 growing season with future planted acreages approaching 80% of total corn plantings anticipated by 2009. As demand increases, incidence of farmer non-compliance with ma...

  8. Bt转基因玉米的获得及其对玉米螟的抗性分析%Production of Bt transgenic maize resistant to corn borer

    Institute of Scientific and Technical Information of China (English)

    张红伟; 张红梅; 郑祖平; 陈刚; 王国英; 谭振波

    2004-01-01

    以玉米幼胚和愈伤组织为受体,利用基因枪法将Bt基因GFMCry1A导入玉米杂交种"京玉7号(501/京24)"的亲本自交系501中,从转基因高世代材料中筛选出高抗玉米螟的转基因株系T123.T123及其与京24配制的杂交种的田间食叶级别均小于2级,而且也没有观察到玉米螟在茎杆中运动的隧道,表现出高抗玉米螟.

  9. Preliminary study on the identification of corn borer resistance of Bt transgenic plant%玉米Bt转基因植株抗虫性鉴定研究初报

    Institute of Scientific and Technical Information of China (English)

    刘宗华; 苏海玲; 汤继华; 季洪强; 田贵军; 赵武英; 何革命

    1999-01-01

    经室内喂虫和田间接种,鉴定了Mo17,478等4个常用自交系及其与91-1-8杂交的抗虫转基因杂种F1的抗虫性.结果表明,不同转基因材料之间以及同一转基因材料的不同单株间抗虫性差异很大,有少量植株表现高度抗性,个别植株几乎没有抗性.外源Bt毒蛋白基因在不同遗传背景中的表现不尽相同,在抗性较差的Mo17背景中,表现较强的抗虫性.

  10. 不同玉米品种对玉米蚜的抗性及其与瓢虫的联合控害作用%Resistance to corn aphid (Rhopalosiphum maidis Fitch) of different corn varieties (lines) and its association with predator ladybirds in controlling aphid population

    Institute of Scientific and Technical Information of China (English)

    张衍干; 黄吉; 施伟迪; 王碧媛; 贾永超; 禹田; 李强

    2016-01-01

    调查了26个玉米品种(系)在云南昭通地区的玉米蚜及其捕食型天敌瓢虫的发生情况,采用蚜量比值法比较了玉米品种在田间对玉米蚜的抗性,并分析了不同玉米品种的抗蚜性与益害比(瓢虫/玉米蚜)的关系。结果表明:在田间自然感蚜条件下,高抗品种有9个,分别为路单15号、胜玉6号、云瑞62、靖单11号、云瑞339、云瑞407、云瑞668、云瑞89、云瑞7号;抗性品种6个,分别为云瑞392、云瑞222、临玉9号、云瑞999、云瑞10号、云瑞505;中抗品种1个,为珍禾99;感蚜品种4个,分别为云瑞666、足单808、宣黄单5号、临玉8号;高感品种6个,分别为临玉10号(白粒)、大天一号、海玉92、宣黄单2号、云瑞108、师单4号。不同玉米品种的抗蚜性与益害比有显著的正相关性,益害比与蚜量比值呈幂函数关系,说明玉米的抗蚜性与瓢虫对玉米蚜有明显的联合控制作用。%The dynamics of corn aphid ( Rhopalosiphum maidis Fitch) and predator ladybirds in 26 corn varieties (lines) were systematically investigated in Zhaotong , Yunnan Province, to compare their resistance to aphid among varieties in corn field by using the methods of aphid number ratio , and to study the relationship between resistance and the population ratio of ladybirds to aphid in different corn varieties .The results indicated that there were 9 highly resistant varieties (Ludan 15, Shengyu 6, Yunrui 62, Jingdan 11, Yunrui 339, Yunrui 407, Yunrui 668, Yunrui 89, Yunrui 7), 6 resistant varieties (Yunrui 392, Yunrui 222, Linyu 9, Yunrui 999, Yunrui 10, Yunrui 505), 1 moderately resistant varieties (Zhenhe 99), 4 susceptible varieties (Yunrui 666, Zudan 808, Xuanhuangdan 5, Linyu 8), and 6 highly susceptible varieties [Linyu 10 (white), Datian 1, Haiyu 92, Xuanhuangdan 2, Yunrui 108, Shidan 4].Among the above 26 varieties, the variety with high resistance tended to have high ratio of

  11. A comparative investigation of the metabolism of the herbicide glufosinate in cell cultures of transgenic glufosinate-resistant and non-transgenic oilseed rape (Brassica napus) and corn (Zea mays).

    Science.gov (United States)

    Ruhland, Monika; Engelhardt, Gabriele; Pawlizki, Karlheinz

    2002-10-01

    To obtain information on differences between the metabolic pathways of the herbicide glufosinate (trade names: BASTA, LIBERTY) in non-transgenic, glufosinate-sensitive plants and in transgenic, glufosinate-resistant plants, the metabolism of 14C-labeled glufosinate and its enantiomers L- and D-glufosinate was studied using cell cultures of oilseed rape and corn. Transformation of glufosinate in both sensitive and transgenic rape cells remained at a low rate of about 3-10% in contrast to corn cells, where 20% was transformed in sensitive and 43% in transgenic cells after 14 days of incubation, the rest remaining as unchanged glufosinate. In sensitive rape and corn cells the main metabolite was 4-methylphosphinico-2-oxo-butanoic acid (PPO) with 7.3 and 16.4%, respectively, together with low amounts of 3-methylphosphinicopropionic acid (MPP), 4-methylphosphinico-2-hydroxybutanoic acid (MHB), 4-methylphosphinicobutanoic acid (MPB) and 2-methylphosphinicoacetic acid (MPA). An additional metabolite formed in transgenic cell cultures was 2-acetamido-4-methylbutanoic acid (N-acetyl-L-glufosinate, NGA), which was formed at rates of 3.2% in rape and 16.1% in corn. A further minor metabolite, not yet identified, was detected in both cell types. The liberation of 0.2% 14CO2 indicates further metabolic steps prior to a limited mineralization in plant cell cultures. L-glufosinate was transformed into the same metabolites as the glufosinate racemate. D-glufosinate was not metabolized.

  12. Increased Survival of Western Corn Rootworm on Transgenic Corn Within Three Generations of Onplant Greenhouse Selection

    Science.gov (United States)

    The agricultural industry has adopted a high dose/refuge strategy as a means of delaying the onset of insect resistance to transgenic crops. Recently, Bt corn products developed for control of western corn rootworm (WCR), Diabrotica virgifera virgifera, have been introduced with less than high-dose...

  13. Silicon reduces impact of plant nitrogen in promoting stalk borer (Eldana saccharina) but not sugarcane thrips (Fulmekiola serrata) infestations in sugarcane.

    Science.gov (United States)

    Keeping, Malcolm G; Miles, Neil; Sewpersad, Chandini

    2014-01-01

    The stalk borer Eldana saccharina Walker (Lepidoptera: Pyralidae) is a major limiting factor in South African sugarcane production, while yield is also reduced by sugarcane thrips Fulmekiola serrata Kobus (Thysanoptera: Thripidae). Borer management options include appropriate nitrogen (N) and enhanced silicon (Si) nutrition; the effect of N on sugarcane thrips is unknown. We tested the effects of these nutrients, in combination with resistant (N33) and susceptible (N27) sugarcane cultivars, on E. saccharina and F. serrata infestation. Two pot trials with three levels of N (60, 120, and 180 kg ha(-1)) and two levels each of calcium silicate and dolomitic lime (5 and 10 t ha(-1)) were naturally infested with thrips, then artificially water stressed and infested with borer. Higher N levels increased borer survival and stalk damage, while Si reduced these compared with controls. Silicon significantly reduced stalk damage in N27 but not in N33; hence, Si provided relatively greater protection for susceptible cultivars than for resistant ones. High N treatments were associated with greater thrips numbers, while Si treatments did not significantly influence thrips infestation. The reduction in borer survival and stalk damage by Si application at all N rates indicates that under field conditions, the opportunity exists for optimizing sugarcane yields through maintaining adequate N nutrition, while reducing populations of E. saccharina using integrated pest management (IPM) tactics that include improved Si nutrition of the crop and reduced plant water stress. Improved management of N nutrition may also provide an option for thrips IPM. The contrasting effects of Si on stalk borer and thrips indicate that Si-mediated resistance to insect herbivores in sugarcane has mechanical and biochemical components that are well developed in the stalk tissues targeted by E. saccharina but poorly developed in the young leaf spindles where F. serrata occurs.

  14. Silicon reduces impact of plant nitrogen in promoting stalk borer (Eldana saccharina but not sugarcane thrips (Fulmekiola serrata infestations in sugarcane

    Directory of Open Access Journals (Sweden)

    Malcolm Geoffrey Keeping

    2014-06-01

    Full Text Available The stalk borer Eldana saccharina Walker (Lepidoptera: Pyralidae is a major limiting factor in South African sugarcane production, while yield is also reduced by sugarcane thrips Fulmekiola serrata Kobus (Thysanoptera: Thripidae. Borer management options include appropriate nitrogen (N and enhanced silicon (Si nutrition; the effect of N on sugarcane thrips is unknown. We tested the effects of these nutrients, in combination with resistant (N33 and susceptible (N27 sugarcane cultivars, on E. saccharina and F. serrata infestation. Two pot trials with three levels of N (60, 120 and 180 kg ha-1 and two levels each of calcium silicate and dolomitic lime (5 t ha-1, 10 t ha-1 were naturally infested with thrips, then artificially water stressed and infested with borer. Higher N levels increased borer survival and stalk damage, while Si reduced these compared with controls. Silicon significantly reduced stalk damage in N27 but not in N33; hence, Si provided relatively greater protection for susceptible cultivars than for resistant ones. High N treatments were associated with greater thrips numbers, while Si treatments did not significantly influence thrips infestation. The reduction in borer survival and stalk damage by Si application at all N rates indicates that under field conditions, the opportunity exists for optimising sugarcane yields through maintaining adequate N nutrition, while reducing populations of E. saccharina using integrated pest management (IPM tactics that include improved Si nutrition of the crop and reduced plant water stress. Improved management of N nutrition may also provide an option for thrips IPM. The contrasting effects of Si on stalk borer and thrips indicate that Si-mediated resistance to insect herbivores in sugarcane has mechanical and biochemical components that are well developed in the stalk tissues targeted by E. saccharina but poorly developed in the young leaf spindles where F. serrata occurs.

  15. 玉米田主要杂草对烟嘧磺隆的抗性%Resistance of weeds to nicosulfuron in corn fields in China

    Institute of Scientific and Technical Information of China (English)

    吴翠霞; 张宏军; 张佳; 宋敏; 孔繁华; 路兴涛

    2016-01-01

    为明确我国玉米田杂草对烟嘧磺隆的抗性水平及分布现状,于2010—2011年自山东、吉林、四川、河北4省采集连续多年施用烟嘧磺隆的玉米田杂草种子样本121个,在温室内采用盆栽法测定了其对烟嘧磺隆的抗性。结果显示:4个杂草样本对烟嘧磺隆产生了抗性,其中山东淄博张店区傅家镇高家村的牛筋草抗性种群的 GR50为25.76 g/hm2,是敏感种群(1.33 g/hm2)的19.37倍,已产生明显的抗药性;四川彭山县谢家镇岳油村的稗草、河北大城县广安镇夏屯村的虎尾草和河北邯郸的狗尾草分别产生了6.14、5.43和5.65倍的低水平抗性;其余杂草样本均无明显抗性。同一杂草不同采集地点的敏感样本对烟嘧磺隆的敏感性存在差异。%To investigate the resistance level and distribution of weed species to nicosulfuron in corn fields in Chi-na,a total of 121 populations of weed in nicosulfuron continuously used fields were collected from Shandong,Ji-lin,Sichuan and Hebei provinces from 2010 to 2011.The resistance was detected in the greenhouse by whole plant pot method.The results showed that four populations of weeds were resistant to nicosulfuron.Among them,the GR50 value of a resistant Eleusine indica population collected from Gaojia village,Fujia Town,Zhangdian Dis-trict,Zibo,Shandong Province was 25.76 g/hm2 ,which was 19.37-fold higher than the corresponding susceptible population (GR50 =1.33 g/hm2 ).The Echinochloa crusgalli from Pengshan,Sichuan Province,Chloris virgata from Dacheng,and Setaria viridis from Handan,Hebei Province showed low level resistance to nicosulfuron with resist-ance ratios of 6.14,5.43 and 5.65,respectively.The rest samples were all susceptible to the nicosulfuron.

  16. Resistência de grãos de milho à ruptura por compressão Corn grain resistance to rupture by compression

    Directory of Open Access Journals (Sweden)

    Hevandro Colonhese Delalibera

    2008-12-01

    Full Text Available A região dos Campos Gerais é considerada um importante pólo leiteiro do Paraná. No que se refere à alimentação de gado leiteiro, destaca-se a silagem de planta inteira de milho, em que a otimização no aproveitamento desta é fator importante, pois reduz os custos da produção. Com vistas a tal otimização, um dos fatores que merece destaque é a digestibilidade dos grãos, a qual é influenciada pelo híbrido, pelas condições da cultura, pelo ponto de colheita e pelo processo físico de fragmentação. Com isso, torna-se importante conhecer as propriedades mecânicas dos materiais vegetais e quantificar as exigências de força necessárias para fragmentá-los, pois são parâmetros relevantes no desenvolvimento de máquinas que desempenham esta função. Neste trabalho quantificou-se a exigência de força para romper grãos de milho por compressão para 11 híbridos comumente utilizados na região. Na avaliação foram utilizados grãos colhidos no ponto de grão seco. Para tanto, utilizou-se uma célula de carga, um sistema hidráulico com velocidade constante e uma ponteira em forma de "V". Na quantificação da força, foram encontradas exigências distintas entre os híbridos, mesmo quando estes possuem a mesma classificação quanto à textura do grão (mole e/ou semiduro. A exigência de força foi diretamente proporcional à quantidade de endosperma córneo.The region of Campos Gerais, in the State of Paraná, is considered a distinct dairy farming center. Whole-plant corn silage is a very common regional practice as complementary feeding strategy for dairy cows and the optimization of its use is considered essential in order to reduce production costs. Grain digestibility plays a major role in this process and it is influenced by the hybrid, field conditions, point of harvest and grinding level. The identification of mechanical properties of plant materials, and the quantification of the force required to fragment those

  17. Relationship between Plant Height, ASI and Ear Traits and Drought Resistance of Transgenic Corn%转基因玉米株高、ASI和穗部性状与抗旱性的关系研究

    Institute of Scientific and Technical Information of China (English)

    孙宝成; 刘成; 王天宇; 黎裕; 张登峰; 李亮; 唐怀君; 石云素; 宋燕春

    2012-01-01

    [目的]干旱是限制我国玉米生产的主要因素,利用转基因技术可有效提高玉米抗旱育种效率.对转基因玉米材料进行抗旱性鉴定评价,为筛选转基因玉米抗旱种质和转基因玉米抗旱育种提供科学依据.[方法]通过开花期干旱胁迫的方法,对61份转基因玉米材料进行抗旱性鉴定评价,研究转基因玉米材料ASI(散粉至吐丝的间隔期,天)、株高、产量与抗旱性的关系,受旱后粒重和穗重、轴粗和穗粗、百粒体积和百粒重等比值的变化;以及在受体基础上通过转基因提高玉米抗旱性的效果.[结果]正常灌水条件下株体适当、产量较高,而在受旱后株高下降少、ASI小的转基因玉米材料通常有较强的抗旱性,这与以往非转基因玉米的研究结果一致;无论受旱与否,玉米的穗粗和轴粗、穗重和粒重、百粒体积和百粒重之间存在显著的正比关系.[结论]转基因玉米的抗旱性在其受体基础上可提高25% ~53%,突破果穗和籽粒之间的正比关系可能是大幅提高玉米产量的一条关键途径.%[ Objective ] Drought is one of major factors to restrict China's corn production, and the application of transgenic technology can effectively improve the efficiency of corn drought breeding. [Method] Through the drought stress in period of flowering, and taking identification and evaluation of drought resistance on 61 transgenic corn materials, this paper studied the relationship between transgenic corn ASI, plant height, the yield and drought resistance, the change of these ratio on the kernel weight and ear weight, cob diameter and ear diameter, 100 - kernel volume and 100 - kernel weight affected by drought, and die effect of improving the drought resistance of corn by transgenosis on the basis of its receptor. [ Result] The experiments'results showed that in normal irrigation conditions, the yield was higher, but when affected by the drought later, die plant

  18. Parasitism of Lepidopterous Stem Borers in Cultivated and Natural Habitats

    Science.gov (United States)

    Mailafiya, Duna Madu; Le Ru, Bruno Pierre; Kairu, Eunice Waitherero; Dupas, Stéphane; Calatayud, Paul-André

    2011-01-01

    Plant infestation, stem borer density, parasitism, and parasitoid abundance were assessed during two years in two host plants, Zea mays (L.) (Cyperales: Poaceae) and Sorghum bicolor (L.) (Cyperales: Poaceae), in cultivated habitats. The four major host plants (Cyperus spp., Panicum spp., Pennisetum spp., and Sorghum spp.) found in natural habitats were also assessed, and both the cultivated and natural habitat species occurred in four agroecological zones in Kenya. Across habitats, plant infestation (23.2%), stem borer density (2.2 per plant), and larval parasitism (15.0%) were highest in maize in cultivated habitats. Pupal parasitism was not higher than 4.7% in both habitats, and did not vary with locality during each season or with host plant between each season. Cotesia sesamiae (Cameron) and C. flavipes Cameron (Hymenoptera: Braconidae) were the key parasitoids in cultivated habitats (both species accounted for 76.4% of parasitized stem borers in cereal crops), but not in natural habitats (the two Cotesia species accounted for 14.5% of parasitized stem borers in wild host plants). No single parasitoid species exerted high parasitism rates on stem borer populations in wild host plants. Low stem borer densities across seasons in natural habitats indicate that cereal stem borer pests do not necessarily survive the non-cropping season feeding actively in wild host plants. Although natural habitats provided refuges for some parasitoid species, stem borer parasitism was generally low in wild host plants. Overall, because parasitoids contribute little in reducing cereal stem borer pest populations in cultivated habitats, there is need to further enhance their effectiveness in the field to regulate these pests. PMID:21526933

  19. Parasitism of lepidopterous stem borers in cultivated and natural habitats.

    Science.gov (United States)

    Mailafiya, Duna Madu; Le Ru, Bruno Pierre; Kairu, Eunice Waitherero; Dupas, Stéphane; Calatayud, Paul-André

    2011-01-01

    Plant infestation, stem borer density, parasitism, and parasitoid abundance were assessed during two years in two host plants, Zea mays (L.) (Cyperales: Poaceae) and Sorghum bicolor (L.) (Cyperales: Poaceae), in cultivated habitats. The four major host plants (Cyperus spp., Panicum spp., Pennisetum spp., and Sorghum spp.) found in natural habitats were also assessed, and both the cultivated and natural habitat species occurred in four agroecological zones in Kenya. Across habitats, plant infestation (23.2%), stem borer density (2.2 per plant), and larval parasitism (15.0%) were highest in maize in cultivated habitats. Pupal parasitism was not higher than 4.7% in both habitats, and did not vary with locality during each season or with host plant between each season. Cotesia sesamiae (Cameron) and C. flavipes Cameron (Hymenoptera: Braconidae) were the key parasitoids in cultivated habitats (both species accounted for 76.4% of parasitized stem borers in cereal crops), but not in natural habitats (the two Cotesia species accounted for 14.5% of parasitized stem borers in wild host plants). No single parasitoid species exerted high parasitism rates on stem borer populations in wild host plants. Low stem borer densities across seasons in natural habitats indicate that cereal stem borer pests do not necessarily survive the non-cropping season feeding actively in wild host plants. Although natural habitats provided refuges for some parasitoid species, stem borer parasitism was generally low in wild host plants. Overall, because parasitoids contribute little in reducing cereal stem borer pest populations in cultivated habitats, there is need to further enhance their effectiveness in the field to regulate these pests.

  20. Agrobacterium-transformed rice plants expressing synthetic cryIA(b) and cryIA(c) genes are highly toxic to striped stem borer and yellow stem borer.

    Science.gov (United States)

    Cheng, X; Sardana, R; Kaplan, H; Altosaar, I

    1998-03-17

    Over 2,600 transgenic rice plants in nine strains were regenerated from >500 independently selected hygromycin-resistant calli after Agrobacterium-mediated transformation. The plants were transformed with fully modified (plant codon optimized) versions of two synthetic cryIA(b) and cryIA(c) coding sequences from Bacillus thuringiensis as well as the hph and gus genes, coding for hygromycin phosphotransferase and beta-glucuronidase, respectively. These sequences were placed under control of the maize ubiquitin promoter, the CaMV35S promoter, and the Brassica Bp10 gene promoter to achieve high and tissue-specific expression of the lepidopteran-specific delta-endotoxins. The integration, expression, and inheritance of these genes were demonstrated in R0 and R1 generations by Southern, Northern, and Western analyses and by other techniques. Accumulation of high levels (up to 3% of soluble proteins) of CryIA(b) and CryIA(c) proteins was detected in R0 plants. Bioassays with R1 transgenic plants indicated that the transgenic plants were highly toxic to two major rice insect pests, striped stem borer (Chilo suppressalis) and yellow stem borer (Scirpophaga incertulas), with mortalities of 97-100% within 5 days after infestation, thus offering a potential for effective insect resistance in transgenic rice plants.

  1. The cultivation of Bt corn producing Cry1Ac toxins does not adversely affect non-target arthropods.

    Directory of Open Access Journals (Sweden)

    Yanyan Guo

    Full Text Available Transgenic corn producing Cry1Ac toxins from Bacillus thuringiensis (Bt provides effective control of Asian corn borer, Ostrinia furnacalis (Guenée, and thus reduces insecticide applications. However, whether Bt corn exerts undesirable effects on non-target arthropods (NTAs is still controversial. We conducted a 2-yr study in Shangzhuang Agricultural Experiment Station to assess the potential impact of Bt corn on field population density, biodiversity, community composition and structure of NTAs. On each sampling date, the total abundance, Shannon's diversity index, Pielou's evenness index and Simpson's diversity index were not significantly affected by Bt corn as compared to non-Bt corn. The "sampling dates" had a significant effect on these indices, but no clear tendencies related to "Bt corn" or "sampling dates X corn variety" interaction were recorded. Principal response curve analysis of variance indicated that Bt corn did not alter the distribution of NTAs communities. Bray-Curtis dissimilarity and distance analysis showed that Cry1Ac toxin exposure did not increase community dissimilarities between Bt and non-Bt corn plots and that the evolution of non-target arthropod community was similar on the two corn varieties. The cultivation of Bt corn failed to show any detrimental evidence on the density of non-target herbivores, predators and parasitoids. The composition of herbivores, predators and parasitoids was identical in Bt and non-Bt corn plots. Taken together, results from the present work support that Bt corn producing Cry1Ac toxins does not adversely affect NTAs.

  2. 转基因抗虫耐除草剂(Cry1Ac+EPSPS)玉米对草甘膦耐受性研究%Tolerance of transgenic and herbicide-and insect-resistant corn to glyphosate

    Institute of Scientific and Technical Information of China (English)

    江帆; 刘凯强; 张天涛; 白树雄; 王振营; 何康来

    2016-01-01

    Insect-resistant cry 1Ac gene and glyphosate-tolerant gene were used to construct an insect-resistant/glyphosate-tolerant bivalent plant which had been patented.It effectively improved complex traits in corn.This study mainly evaluated the tolerance of insect-resistant/glyphosate-tolerant bivalent corn and glyphosate-tolerant corn to glyphosate,and measured the quantity of Cry1Ac and CP4 EPSPS protein expressed in corn tissues,in or-der to provide the basis for the improvement and application of the maize varieties.Insect-resistant/glyphosate-tolerant bivalent corn ‘CC-2×BT799’,insect-resistant corn ‘BT799’,herbicide-resistant corn ‘CC-2’,and con-ventional corn ‘Zheng 58’were compared by investigating the survival rates and heights of plants after spraying herbicides.Cry1Ac and CP4 EPSPS protein expression was measured by ELISA.‘CC-2’and ‘CC-2×BT799’per-formed excellent tolerance to glyphosate after spraying glyphosate with recommended and double recommended rates at the whorl stage.ELISA detection showed that CP4 EPSPS protein expression in the tassel was slightly higher than in leaves.CP4 EPSPS protein expression in ‘CC-2 ×BT799’was slightly higher than in ‘CC-2’. Cry1Ac protein expression in BT799 and ‘CC-2×BT799’was nearly the same in the tassel.However,Cry1Ac protein expression in BT799 leaves was about 2 times of that in ‘CC-2×BT799’.Insect-resistant/glyphosate-tolerant corn showed strong resistance to glyphosate.Cry1Ac protein expression varied among the corn varieties and tissues.%将具有我国自主知识产权的抗虫、耐除草剂基因转化到玉米中获得兼具抗虫和耐除草剂的复合性状转基因玉米,实现了玉米复杂性状的有效改良,研究了转耐除草剂 CC-2基因和可表达 Bt 毒素的 cry1Ac 基因的双抗玉米对除草剂的耐受性及目标蛋白表达量。通过调查喷施除草剂后玉米植株存活率及株高和生长发育情况,研究了转抗虫

  3. Emerald ash borer dispersal in Maryland: go forth young pest

    Science.gov (United States)

    Chris Sargent; Dick Bean; Michael Raupp; Alan J. Sawyer

    2009-01-01

    The emerald ash borer (EAB) (Agrilus planipennis Fairmaire), an exotic invasive pest from Asia, was introduced into Maryland in April 2003 via infested nursery stock shipped from Michigan to a nursery in southern...

  4. Structure and function of starch and resistant starch from corn with different doses of mutant amylose-extender and floury-1 alleles.

    Science.gov (United States)

    Yao, Ni; Paez, Alix V; White, Pamela J

    2009-03-11

    Four corn types with different doses of mutant amylose-extender (ae) and floury-1 (fl1) alleles, in the endosperm, including no. 1, aeaeae; no. 2, fl1fl1fl1; no. 3, aeaefl1; and no. 4, fl1fl1ae, were developed for use in making Hispanic food products with high resistant starch (RS) content. The RS percentages in the native starch (NS) of 1-4 were 55.2, 1.1, 5.7, and 1.1%, respectively. All NS were evaluated for pasting properties with a rapid viscoanalyzer (RVA) and for thermal properties with a differential scanning calorimeter (DSC). NS 1 had a low peak viscosity (PV) caused by incomplete gelatinization, whereas NS 3 had the greatest PV and breakdown of all four starch types. On the DSC, NS 2 had the lowest onset temperature and greatest enthalpy. NS 1 and 3 had similar onset and peak temperatures, both higher than those of NS 2 and 4. The gel strength of NS heated with a RVA was evaluated by using a texture analyzer immediately after RVA heating (fresh, RVA-F) and after the gel had been stored at 4 degrees C for 10 days (retrograded, RVA-R). NS 1 gel was watery and had the lowest strength (30 g) among starch gel types. NS 3 gel, although exhibiting syneresis, had greater gel strength than NS 2 and 4. The structures of the NS, the RS isolated from the NS (RS-NS), the RS isolated from RVA-F (RS-RVA-F), and the RS isolated from RVA-R (RS-RVA-R) were evaluated by using size exclusion chromatography. NS 1 had a greater percentage of amylose (AM) (58.3%) than the other NS (20.4-26.8%). The RS from all NS types (RS-NS) had a lower percentage of amylopectin (AP) and a greater percentage of low molecular weight (MW) AM than was present in the original NS materials. The RS-RVA-R from all starches had no AP or high MW AM. The percentages of longer chain lengths (DP 35-60) of NS were greater in 1 and 3 than in 2 and 4, and the percentages of smaller chain lengths (DP 10-20) were greater in 2 and 4 than in 1 and 3. In general, NS 3 seemed to have inherited some pasting

  5. Effectiveness of spinosad against seven major storedgrain insects on corn

    Institute of Scientific and Technical Information of China (English)

    FANGNENG HUANG; BHADRIRAJU SUBRAMANYAM

    2007-01-01

    In January 2005, the United States Environmental Protection Agency registered spinosad as a stored grain protectant. No referenced data on the efficacy of spinosad on corn in suppressing major stored-grain insects have been published. In this paper, we evaluated the efficacy of spinosad against seven major stored-grain insects on shelled corn in the laboratory. Insect species tested were the red flour beetle, Tribolium castaneum (Jacquelin duVal); rusty grain beetle, Cryptolestes ferrugineus (Stephens); lesser grain borer, Rhyzopertha dominica (F.); sawtoothed grain beetle, Oryzaephilus surinamensis (L.); rice weevil, Sitophilus oryzae (L.); maize weevil, Sitophilus zeamais (Motschulsky); and Indian meal moth, Plodia interpunctella (Hübner). Corn kernels were treated with spinosad at 0,0.1, 0.5, 1, and 2 active ingredient (a.i.) mg/kg for controlling the seven species. Beetle adults or P.interpunctella eggs were introduced into each container holding 100 g of untreated or insecticide-treated corn. The seven insect species survived well on the control treatment, produced 28 to 336 progeny, and caused significant kernel damage after 49 days. On spinosad-treated corn, adult mortality of C. ferrugineus, R. dominica, O. surinamensis, S. oryzae, and S. zeamais was > 98% at 1 and 2 mg/kg after 12 days. Spinosad at > 0.5 mg/kg completely suppressed egg-to-larval survival after 21 days and egg-to-adult emergence of P. interpunctella after 49 days, whereas 16% T. castaneum adults survived at 1 mg/kg after 12 days. Spinosad at 1 or 2 mg/kg provided complete or near complete suppression of progeny production and kernel damage of all species after 49 days. Our results indicate that spinosad at the current labeled rate of 1 mg/kg is effective against the seven stored-grain insect pests on corn.

  6. Development of insect resistant maize plants expressing a chitinase gene from the cotton leaf worm, Spodoptera littoralis.

    Science.gov (United States)

    Osman, Gamal H; Assem, Shireen K; Alreedy, Rasha M; El-Ghareeb, Doaa K; Basry, Mahmoud A; Rastogi, Anshu; Kalaji, Hazem M

    2015-12-14

    Due to the importance of chitinolytic enzymes for insect, nematode and fungal growth, they are receiving attention concerning their development as biopesticides or chemical defense proteins in transgenic plants and as microbial biocontrol agents. Targeting chitin associated with the extracellular matrices or cell wall by insect chitinases may be an effective approach for controlling pest insects and pathogenic fungi. The ability of chitinases to attack and digest chitin in the peritrophic matrix or exoskeleton raises the possibility to use them as insect control method. In this study, an insect chitinase cDNA from cotton leaf worm (Spodoptera littoralis) has been synthesized. Transgenic maize plant system was used to improve its tolerance against insects. Insect chitinase transcripts and proteins were expressed in transgenic maize plants. The functional integrity and expression of chitinase in progenies of the transgenic plants were confirmed by insect bioassays. The bioassays using transgenic corn plants against corn borer (Sesamia cretica) revealed that ~50% of the insects reared on transgenic corn plants died, suggesting that transgenic maize plants have enhanced resistance against S. cretica.

  7. Trapping effect of synthetic pheromone blends on two stem borers, Chilo suppressalis and Scripophaga incertulas

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Two internal feeders of rice plant, rice stem borer, Chilo suppressalis (Walker) and yellow stem borer, Scirpophaga incertulas (Walker) are major hurdles in achieving higher yields in Central China. Synthetic sex pheromone was an effective method to control the two borers. A new series of sex pheromone blends were formulated and tested.

  8. Seasonal infestations of two stem borers (Lepidoptera: Crambidae) in noncrop grasses of Gulf Coast rice agroecosystems

    Science.gov (United States)

    Infestations of two stem borers, the Mexican rice borer, Eoreuma loftini (Dyar) and the sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), were compared in non-crop grasses adjacent to rice, Oryza sativa L., fields. Three farms in the Texas Gulf Coast rice production area were sur...

  9. 76 FR 1338 - Emerald Ash Borer; Quarantined Areas; Maryland, Michigan, Minnesota, Missouri, Pennsylvania...

    Science.gov (United States)

    2011-01-10

    ... Animal and Plant Health Inspection Service 7 CFR Part 301 Emerald Ash Borer; Quarantined Areas; Maryland... to the list of areas quarantined because of emerald ash borer (EAB). The interim rule was necessary... Coordinator, Emerald Ash Borer Program, Emergency and Domestic Programs, PPQ, APHIS, 4700 River Road Unit...

  10. 75 FR 29189 - Emerald Ash Borer; Addition of Quarantined Areas in Kentucky, Michigan, Minnesota, New York...

    Science.gov (United States)

    2010-05-25

    ... Animal and Plant Health Inspection Service 7 CFR Part 301 Emerald Ash Borer; Addition of Quarantined...: We are amending the emerald ash borer regulations by adding portions of Kentucky, Michigan, Minnesota... rule is necessary to prevent the artificial spread of the emerald ash borer to noninfested areas of...

  11. 76 FR 3077 - Notice of Decision To Revise a Heat Treatment Schedule for Emerald Ash Borer

    Science.gov (United States)

    2011-01-19

    ... Emerald Ash Borer AGENCY: Animal and Plant Health Inspection Service, USDA. ACTION: Notice. SUMMARY: We are advising the public of our decision to revise a heat treatment schedule for the emerald ash borer... revised treatment schedule will be sufficient to treat emerald ash borer. DATES: Effective Date:...

  12. Evaluation of Disease Resistance of Head Smut in Particular Corn Germplasms and Hybrids%特用玉米种质及杂交种对丝黑穗病的抗性评价

    Institute of Scientific and Technical Information of China (English)

    郭建国; 郭满库; 郭成; 魏宏玉; 金社林

    2014-01-01

    The disease resistance to Sporisorium reilianum in 131 particular germplasms and 57 particular hybrids was identified when seeds were covered by 0.1% soil carried with teliospores . The results showed that the resistant and susceptible germplasms respectively were 6 antiviral or anti-resistant and 125 susceptible or highly susceptible in 131 particular germplasms, the resistant and susceptible varieties were 8 antiviral or anti-resistant and 49 susceptible or highly susceptible varities in 57 particular hybrids,respectively . The numbered of disease manifestations were 00097153 and 00231081 and moderately resistant germplasms were 00030253、00097112、00201242 and 00211465 which importantly resistant resources in sweet and waxy corn varieties breeding in the future. The diesease-resistant hybrids Gaoyou 1 and moderately resistant hybrids Baizaonuo、Jingkenuo 120、Xingnuo 918、Huatiannian 83、Duntian 2、Tiandan 22 and Gaoyou 115 were importantly commercial varieties in sweet,waxy and high oil corn in the future .%采用菌土覆盖接种法,鉴定评价了131个玉米特用种质和57个特用杂交种对丝黑穗病的抗病性。结果表明,131份特用种质中,6份表现抗病或中抗,125份表现感病或高感;57个特用杂交种中,8个品种表现抗病或中抗,49个品种表现感病或高感。表现抗病的编号为00097153、00231081的抗病种质和编号为00030253、00097112、00201242、00211465的中抗种质可作为甜糯品种选育的重要抗源;抗病杂交种高优1号和中抗杂交种白早糯、京科糯120、星糯918、华甜粘83、敦甜2号、甜单22号、高油115可作为甜糯和高油玉米的主推广品种。

  13. Silencing of CYP6 and APN Genes Affects the Growth and Development of Rice Yellow Stem Borer, Scirpophaga incertulas

    OpenAIRE

    Vijaya Sudhakara Rao eKola; P eRenuka; Ayyagari Phani Padmakumari; Satendra Kumar Mangrauthia; Balachandran eS M; MAGANTI SHESHU MADHAV

    2016-01-01

    RNAi is a powerful tool to target the insect genes involved in host-pest interactions. Key insect genes are the choice for silencing to achieve pest derived resistance where resistance genes are not available in gene pool of host plant. In this study, an attempt was made to determine the effect of dsRNA designed from two genes Cytochrome P450 derivative (CYP6) and Aminopeptidase N (APN) of rice yellow stem borer (YSB) on growth and development of insect. The bioassays involved injection of ch...

  14. 玉米抗低温助长剂田间试验研究%Field experimental study on low-temperature-resistant and growth-helping medium for corn

    Institute of Scientific and Technical Information of China (English)

    王春乙; 郭建平; 马树庆; 郭春明; 王琪; 恽勤; 张铁林; 孙玉亭; 姜丽霞; 于荣环; 孙孟梅; 刘新安; 罗新兰; 国力

    2001-01-01

    为防御东北玉米低温冷害,研制了一种新型的玉米抗低温助长剂,其抗低温效果已为人工温控试验所证实。本项研究采用分期播种、地理播种和田间多处理对比试验方法,检验该化学制剂在影响玉米发育、生物量及产量性状方面的实用效果,并探求其适宜的浓度配比和喷施期次。研究结果表明,该制剂具有促生长、促早熟和使作物高产的性能,可防御延迟型冷害。施用时以1:400倍液和在营养生长期内两次喷施为佳。%A new low-temperature-resistant and growth-helping medium is developed for defending corn from chilling damage in Northeast China. The effect of the medium is tested by experiments with artificial controlling temperature. In this study, a comparative experiment with seeding by stages and in different regions, and multi-treatments in field were used to examine its practical effect on corn growth, biomass and yield, and search suitable concentration composition and spraying stages and times. The result shows that this medium has a performance of promoting growth and maturity, increasing yield, and can defend corn from chilling damage. The best concentration is 1:400, the best stage is in nutrent growth period and two times spray in practical usage.

  15. 海洋耐高温酸性α-淀粉酶水解玉米淀粉的研究%Marine Thermo-Resistant Acidic α-Amylase to Hydrolyze Corn Starch

    Institute of Scientific and Technical Information of China (English)

    李瑛; 吕明生; 王淑军; 李华钟; 房耀雏; 焦豫良; 刘姝

    2012-01-01

    为开发适用于工业生产的新型酶制剂,以实验室自主构建的基因工程菌所产的新型海洋耐高温酸性α-淀粉酶为液化酶,以玉米淀粉液化后的DE值为指标,研究影响玉米淀粉的液化的因素,确定该酶水解玉米淀粉的最佳工艺条件.新型海洋耐高温酸性α-淀粉酶最佳的工艺条件为温度85℃、时间90 min、粉浆浓度250 g/L、酶用量32 U/g淀粉.%The purpose of this study was to develop a new enzyme preparation suitable for industrial production. A new marine thermo-resistanl acidic ot-amylase produced by independently constructed strain by genetic engineering in the laboratory was a liquefied enzyme, and took DE value of corn starch after liquefied as an index to study the influencing factors to liquefy corn starch, and confirmed the optimum technological conditions for corn starch enzymolysis. The optimum technological conditions for the new marine thermo-resistant acidic a-amylase were as follows; temperature at 85℃, hydrolyze for 90 rain, concentration of liquid starch at 250 g/L, quantity of enzyme at 32 U/g starch.

  16. Describing head shapes of white stem borers (Schirpophaga innotata Walker that are able to survive on different rice types using Landmark based geometric morphometrics

    Directory of Open Access Journals (Sweden)

    Queenilyn B. Albutra

    2012-06-01

    Full Text Available Rice stem borers are considered as the most serious insect pest of rice in Asia. It infects itsplant host by burrowing into the stem using its mandible. However, apart from the mandible, the head ofrice stem borers is also associated in the incursion process since it facilitates the entry of larvae to the riceplant. Differences in the head capsules have a direct effect on the ability of the insects to ingest hardfoods rapidly. Different rice varieties in the Philippines serve as plant host for this pest and infestationoccurred in different geographical location. Variations in habitat and plant host were thought to generateenvironmental variation in morphometric traits and host adapted herbivore phenotype respectively.Landmark based geometric morphometric analysis was used to assess the hypothesis that the head shapeof white stem borer differ between populations with respect to different rice varieties and geographicallocation where it was obtained. Relative warp analysis showed variation in the head shape betweendifferent white stem borer (Schirpophaga innotata Walker populations infesting different varieties of rice.Non-significant head shape variations were obtained between geographically separated populations. Theseresults indicate that the rice host varieties play an important role in the selection of individuals that areable to counteract the resistance factors in plants.

  17. Interactive influence of leaf age, light intensity, and girdling on green ash foliar chemistry and emerald ash borer development.

    Science.gov (United States)

    Chen, Yigen; Poland, Therese M

    2009-07-01

    Biotic and abiotic environmental factors affect plant nutritional quality and defensive compounds that confer plant resistance to herbivory. Influence of leaf age, light availability, and girdling on foliar nutrition and defense of green ash (Fraxinus pennsylvanica Marsh) was examined in this study. Longevity of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), adults reared on green ash foliage subjected to these factors was assayed. Mature leaves generally were more nutritious with greater amino acids and a greater ratio of protein to non-structural carbohydrate (P:C) than young leaves, in particular when trees were grown in shade. On the other hand, mature leaves had lower amounts of trypsin and chymotrypsin inhibitors, and total phenolics compared to young leaves. Lower defense of mature leaves alone, or along with higher nutritional quality may lead to increased survival and longevity of emerald ash borer feeding on mature leaves. Sunlight reduced amino acids and P:C ratio, irrespective of leaf age and girdling, and elevated total protein of young foliage, but not protein of mature leaves. Sunlight also dramatically increased all investigated defensive compounds of young, but not mature leaves. Girdling reduced green ash foliar nutrition, especially, of young leaves grown in shade and of mature leaves grown in sun. However emerald ash borer performance did not differ when fed leaves from trees grown in sun or shade, or from girdled or control trees. One explanation is that emerald ash borer reared on lower nutritional quality food may compensate for nutrient deficiency by increasing its consumption rate. The strong interactions among leaf age, light intensity, and girdling on nutrition and defense highlight the need for caution when interpreting data without considering possible interactions.

  18. Role of Dehydrodiferulates in Maize Resistance to Pests and Diseases

    Directory of Open Access Journals (Sweden)

    Rosa A. Malvar

    2010-02-01

    Full Text Available Phenolic esters have attracted considerable interest due to the potential they offer for peroxidase catalysed cross-linking of cell wall polysaccharides. Particularly, feruloyl residues undergo radical coupling reactions that result in cross-linking (intra-/intermolecular between polysaccharides, between polysaccharides and lignin and, between polysaccharides and proteins. This review addresses for the first time different studies in which it is established that cross-linking by dehydrodiferulates contributes to maize’s defences to pests and diseases. Dehydrodiferulate cross-links are involved in maize defence mechanisms against insects such as the European, Mediterranean, and tropical corn borers and, storage pest as the maize weevil. In addition, cross-links are also discussed to be involved in genetic resistance of maize to fungus diseases as Gibberella ear and stalk rot. Resistance against insects and fungus attending dehydrodiferulates could go hand in hand. Quantitative trait loci mapping for these cell wall components could be a useful tool for enhancing resistance to pest and diseases in future breeding programs.

  19. Analysis of the dynamics of adaptation to transgenic corn and crop rotation by western corn rootworm (Coleoptera: Chrysomelidae) using a daily time-step model.

    Science.gov (United States)

    Crowder, D W; Onstad, D W; Cray, M E; Pierce, C M F; Hager, A G; Ratcliffe, S T; Steffey, K L

    2005-04-01

    Western corn rootworm, Diabrotica virgifera virgifera LeConte, has overcome crop rotation in several areas of the north central United States. The effectiveness of crop rotation for management of corn rootworm has begun to fail in many areas of the midwestern United States, thus new management strategies need to be developed to control rotation-resistant populations. Transgenic corn, Zea mays L., effective against western corn rootworm, may be the most effective new technology for control of this pest in areas with or without populations adapted to crop rotation. We expanded a simulation model of the population dynamics and genetics of the western corn rootworm for a landscape of corn; soybean, Glycine max (L.); and other crops to study the simultaneous development of resistance to both crop rotation and transgenic corn. Results indicate that planting transgenic corn to first-year cornfields is a robust strategy to prevent resistance to both crop rotation and transgenic corn in areas where rotation-resistant populations are currently a problem or may be a problem in the future. In these areas, planting transgenic corn only in continuous cornfields is not an effective strategy to prevent resistance to either trait. In areas without rotation-resistant populations, gene expression of the allele for resistance to transgenic corn, R, is the most important factor affecting the evolution of resistance. If R is recessive, resistance can be delayed longer than 15 yr. If R is dominant, resistance may be difficult to prevent. In a sensitivity analysis, results indicate that density dependence, rotational level in the landscape, and initial allele frequency are the three most important factors affecting the results.

  20. Emerald ash borer invasion of North America: history, biology, ecology, impacts, and management.

    Science.gov (United States)

    Herms, Daniel A; McCullough, Deborah G

    2014-01-01

    Since its accidental introduction from Asia, emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), has killed millions of ash trees in North America. As it continues to spread, it could functionally extirpate ash with devastating economic and ecological impacts. Little was known about EAB when it was first discovered in North America in 2002, but substantial advances in understanding of EAB biology, ecology, and management have occurred since. Ash species indigenous to China are generally resistant to EAB and may eventually provide resistance genes for introgression into North American species. EAB is characterized by stratified dispersal resulting from natural and human-assisted spread, and substantial effort has been devoted to the development of survey methods. Early eradication efforts were abandoned largely because of the difficulty of detecting and delineating infestations. Current management is focused on biological control, insecticide protection of high-value trees, and integrated efforts to slow ash mortality.

  1. 转Bt基因玉米叶片中Bt蛋白的表达和分泌研究%Study on Expression and Exudation of Bt Protein in Leaves of Transgenic Insect- resistant Corn

    Institute of Scientific and Technical Information of China (English)

    田晓燕; 赵蕾; 孙红炜; 李凡; 赵辉; 颜世磊; 路兴波

    2012-01-01

    With the transgenic insect - resistant corn Mon810 and its non - transgenic parent as materials , the enzyme - linked immunosorbent assay (ELISA ) method was used to detect the expression and quanti-tate the exudation of Bt protein in corn leaves. The results showed that Bt protein could be detected in tissue and on surface of leaves. The Bt content in tissues showed a rising trend from seedling stage to silking stage with the advances of vegetable growth, and reached the peak at the silking stage and then declined gradually. The variation of Bt exudation on leaf surface had no obvious regularity.%以转Bt玉米Mon810及其亲本非转基因玉米为研究对象,通过酶联免疫吸附测定法(ELISA)定量检测Mon810玉米叶中Bt蛋白表达量和叶表Bt蛋白分泌量,结果表明叶组织和叶表均可检测到Bt蛋白,组织内Bt蛋白量从苗期到抽丝期随着植株营养生长的加快呈上升趋势,至抽丝期达到顶峰,之后逐渐降低;叶表Bt蛋白分泌量变化无明显规律性.

  2. SCREENING OF MAIZE GENOTYPES AGAINST STEM BORER CHILO PARTELLUS L. IN KHARIF SEASON

    Directory of Open Access Journals (Sweden)

    Rajasekhar Lella

    2013-12-01

    Full Text Available Maize (Zea mays L. being the highest yielding cereal crop in the world is of significant importance for countries like India, where rapidly increasing population already out stripped the available food supplies. Maize crop possesses great genetic diversity. Maize Plant is attacked by 140 species of insects causing varying degree of damage causing an annual loss of over 1 billion in the Semi Arid Tropics (ICRISAT, 1992. Out of these, only 10 species cause serious damage from sowing till storage, of which the stemborer Chilo partellus (Swinhoe is the major one (Hiremath et al., 1988. The larvae of C.partellus after hatching feed on soft surface of the leaves and then enter the stem through whorl of feeding on the pith of the stem. The growth of the plants becomes shunted and resulting in dead hearts when attacked by C.partellus at their initial stages. The larvae transferred from other plants enter the stem through lower nodes by making the holes. Stem borers pupate inside the stem. They make holes before pupation for the emergence of adults. Since host plant resistance is the back bone of Insect Pest Management; hence the present investigation was initiated. Present studies were designed to identify maize genotype resistance against stem borer in order to minimize pesticide use, improve natural balance, and enhance the activity of bio control agents, and to increase crop production. The investigations were carried out on the screening of Maize genotypes against Maize stem borer Chilo partellus in kharif season were conducted on the agricultural farm of the institute of Agricultural Sciences, Banaras Hindu University, Varanasi during kharif season of 2010-2011 to screen the relative resistance /susceptibility of 19 genotypes of maize to the insect pest, maize stem borer (Chilo partellus. In order to screen the relative susceptibility of different maize genotypes to maize stem borer the following genotypes were screened under field conditions. The

  3. Transgenic approaches to western corn rootworm control.

    Science.gov (United States)

    Narva, Kenneth E; Siegfried, Blair D; Storer, Nicholas P

    2013-01-01

    The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) is a significant corn pest throughout the United States corn belt. Rootworm larvae feed on corn roots causing yield losses and control expenditures that are estimated to exceed US$1 billion annually. Traditional management practices to control rootworms such as chemical insecticides or crop rotation have suffered reduced effectiveness due to the development of physiological and behavioral resistance. Transgenic maize expressing insecticidal proteins are very successful in protecting against rootworm damage and preserving corn yield potential. However, the high rate of grower adoption and early reliance on hybrids expressing a single mode of action and low-dose traits threatens the durability of commercialized transgenic rootworm technology for rootworm control. A summary of current transgenic approaches for rootworm control and the corresponding insect resistance management practices is included. An overview of potential new modes of action based on insecticidal proteins, and especially RNAi targeting mRNA coding for essential insect proteins is provided.

  4. Western corn rootworm (Coleoptera: Chrysomelidae) dispersal and adaptation to single-toxin transgenic corn deployed with block or blended refuge.

    Science.gov (United States)

    Pan, Zaiqi; Onstad, David W; Nowatzki, Timothy M; Stanley, Bruce H; Meinke, Lance J; Flexner, J Lindsey

    2011-08-01

    A simulation model of the temporal and spatial dynamics and population genetics of western corn rootworm, Diabrotica virgifera virgifera LeConte, was created to evaluate the use of block refuges and seed blends in the management of resistance to transgenic insecticidal corn (Zea mays L.). This Bt corn expresses one transgenic corn event, DAS-59122-7, that produces a binary insecticidal protein toxin (Cry34Ab1/Cry35Ab1) and provides host-plant resistance. The model incorporates the latest information about larval and adult behavior. Results of this modeling effort indicate that the seed-blend scenarios in many cases produced equal or greater durability than block refuges that were relocated each year. Resistance evolved in the most likely scenarios in 10-16 yr. Our standard analysis presumed complete adoption of 59122 corn by all farmers in our hypothetical region, no crop rotation, and 100% compliance with Insect Resistant Management (IRM) regulations. As compliance levels declined, resistance evolved faster when block refuges were deployed. Seed treatments that killed the pest when applied to all seeds in a seed blend or just to seeds in Bt corn blocks delayed evolution of resistance. Greater control of the pest population by the seed treatment facilitated longer durability of the transgenic trait. Therefore, data support the concept that pyramiding a transgenic insecticidal trait with a highly efficacious insecticidal seed treatment can delay evolution of resistance.

  5. Actinomycetales from corn.

    Science.gov (United States)

    Lyons, A J; Pridham, T G; Rogers, R F

    1975-02-01

    Mesophilic Actinomycetales were isolated from whole corn, brewers grits, and break flour received from three different mills. In addition, strains were isolated from high-moisture (27 per cent) field corn; high-moisture, silo-stored corn (untreated); and high-moisture corn treated with ammonia, ammonium isobutyrate, or propionic-acetic acid. According to standard techniques, 139 strains were extensively characterized and 207 additional strains were partially characterized. On the basis of these characterizations, the streptomycete strains were identified by both the systems of Pridham et al. and Hütter because these systems are rapid and accurate. In general, only Streptomyces griseus (Krainsky) Waksman and Henrici was isolated from high-moisture whole corn (treated or untreated) except from grain exposed to ammonium isobutyrate. Strains isolated from high-moisture corn subjected to that treatment represented both S. griseus and S. albus (Rossi Doria) Waksman and Henrici. The strains isolated from corn and corn products from the three mills were identified with a number of streptomycete species. Of all Actinomycetales isolated, only three were not streptomycetes--two from brewer's grits and one from break flour.

  6. Susceptibility and aversion of Spodoptera frugiperda to Cry1F Bt maize and considerations for insect resistance management

    Science.gov (United States)

    Bacillus thuringiensis (Bt) maize was developed primarily for North American pests such as European corn borer (Ostrinia nubilalis Hubner). However, most Bt maize products also are cultivated outside of North America, where the primary pests are different and often have lower susceptibility to Bt to...

  7. Landscape context and scale differentially impact coffee leaf rust, coffee berry borer, and coffee root-knot nematodes.

    Science.gov (United States)

    Avelino, Jacques; Romero-Gurdián, Alí; Cruz-Cuellar, Héctor F; Declerck, Fabrice A J

    2012-03-01

    Crop pest and disease incidences at plot scale vary as a result of landscape effects. Two main effects can be distinguished. First, landscape context provides habitats of variable quality for pests, pathogens, and beneficial and vector organisms. Second, the movements of these organisms are dependent on the connectivity status of the landscape. Most of the studies focus on indirect effects of landscape context on pest abundance through their predators and parasitoids, and only a few on direct effects on pests and pathogens. Here we studied three coffee pests and pathogens, with limited or no pressure from host-specific natural enemies, and with widely varying life histories, to test their relationships with landscape context: a fungus, Hemileia vastatrix, causal agent of coffee leaf rust; an insect, the coffee berry borer, Hypothenemus hampei (Coleoptera: Curculionidae); and root-knot nematodes, Meloidogyne spp. Their incidence was assessed in 29 coffee plots from Turrialba, Costa Rica. In addition, we characterized the landscape context around these coffee plots in 12 nested circular sectors ranging from 50 to 1500 m in radius. We then performed correlation analysis between proportions of different land uses at different scales and coffee pest and disease incidences. We obtained significant positive correlations, peaking at the 150 m radius, between coffee berry borer abundance and proportion of coffee in the landscape. We also found significant positive correlations between coffee leaf rust incidence and proportion of pasture, peaking at the 200 m radius. Even after accounting for plot level predictors of coffee leaf rust and coffee berry borer through covariance analysis, the significance of landscape structure was maintained. We hypothesized that connected coffee plots favored coffee berry borer movements and improved its survival. We also hypothesized that wind turbulence, produced by low-wind-resistance land uses such as pasture, favored removal of coffee

  8. Economic analysis of emerald ash borer (Coleoptera: Buprestidae) management options.

    Science.gov (United States)

    Vannatta, A R; Hauer, R H; Schuettpelz, N M

    2012-02-01

    Emerald ash borer, Agrilus planipennis (Fairmaire) (Coleoptera: Buprestidae), plays a significant role in the health and extent of management of native North American ash species in urban forests. An economic analysis of management options was performed to aid decision makers in preparing for likely future infestations. Separate ash tree population valuations were derived from the i-Tree Streets program and the Council of Tree and Landscape Appraisers (CTLA) methodology. A relative economic analysis was used to compare a control option (do-nothing approach, only removing ash trees as they die) to three distinct management options: 1) preemptive removal of all ash trees over a 5 yr period, 2) preemptive removal of all ash trees and replacement with comparable nonash trees, or 3) treating the entire population of ash trees with insecticides to minimize mortality. For each valuation and management option, an annual analysis was performed for both the remaining ash tree population and those lost to emerald ash borer. Retention of ash trees using insecticide treatments typically retained greater urban forest value, followed by doing nothing (control), which was better than preemptive removal and replacement. Preemptive removal without tree replacement, which was the least expensive management option, also provided the lowest net urban forest value over the 20-yr simulation. A "no emerald ash borer" scenario was modeled to further serve as a benchmark for each management option and provide a level of economic justification for regulatory programs aimed at slowing the movement of emerald ash borer.

  9. Emerald ash borer biological control release and recovery guidelines

    Science.gov (United States)

    Juli S. Gould; Leah S. Bauer; Jian. Duan

    2015-01-01

    Emerald ash borer (EAB), a beetle from Asia that feeds on ash trees, was discovered as the cause of extensive ash mortality in southeast Michigan and adjacent areas of Canada in 2002. It is thought that this destructive pest was introduced in the early 1990's in infested solid wood packing material originating in Asia. Shortly after EAB was discovered in North...

  10. Emerald ash borer responses to induced plant volatiles

    Science.gov (United States)

    Cesar Rodriguez-Saona; Therese M. Poland; James Miller; Lukasz Stelinski; Linda Buchan; Gary Grant; Peter de Groot; Linda MacDonald

    2007-01-01

    Herbivore feeding and methyl jasmonate, a volatile derivative of the stress-eliciting plant hormone, jasmonic acid, induce responses in plants which include the synthesis and emission of volatiles. These induced volatiles can serve to attract or repel herbivores; therefore, they may have potential use in pest management programs. The exotic emerald ash borer (EAB),...

  11. Control of the peachtree borer using beneficial nematodes

    Science.gov (United States)

    The peachtree borer, Synanthedon exitiosa, is a major pest of peaches and other stone fruits. Our research indicates that entomopathogenic nematodes, also known as beneficial nematodes, can be used effectively to control the insect. We conducted replicated experiments in randomized block designs ov...

  12. Curative control of the peachtree borer using entomopathogenic nematodes

    Science.gov (United States)

    The peachtree borer, Synanthedon exitiosa, is a major pest of stone fruit trees in North America. Current management relies upon preventative control using broad spectrum chemical insecticides, primarily chlorpyrifos, applied in the late summer or early fall. However, due to missed applications, p...

  13. Development of kairomone based control programs for cocoa pod borer

    Science.gov (United States)

    The Cocoa Pod Borer moth presents a unique opportunity to develop host volatile attractants for control strategies for the following reasons. First, knowing what volatiles are critical for host finding by females will allow for development of mass trapping and/or attract and kill strategies to cont...

  14. Management tactics for emerald ash borer: chemical and biological control

    Science.gov (United States)

    Therese M. Poland; Deborah G. McCullough; Daniel A. Herms; Leah S. Bauer; Juli R. Gould; Andrew R. Tluczek

    2011-01-01

    Emerald ash borer (EAB) (Agrilus planipennis), an invasive buprestid native to northeast Asia, has killed tens of millions of ash (Fraxinus) trees in infested areas of eastern North America. EAB apparently arrived in infested solid wood packaging materials from China in the early 1990s near Detroit, MI, but was not identified as...

  15. Activity of Bacillis thuringiensis toxins against cocoa pod borer larvae

    NARCIS (Netherlands)

    Santoso, D.; Chaidamsari, T.; Wiryadiputra, S.; Maagd, de R.A.

    2004-01-01

    Twelve Cry proteins from Bacillus thuringiensis Berliner were tested in bioassays on cacao plantations in Indonesia for activity against the larvae of cocoa pod borer (Conopomorpha cramerella (Snellen)), an insect pest of the cacao tree. Through the damage caused by their feeding, the larvae of coco

  16. A coffee berry borer (Coleoptera: Curculionidae: Scolytinae) bibliography

    Science.gov (United States)

    One hundred years ago, one of the most significant biological invasions of an agricultural insect pest in the Americas was initiated. Endemic to Africa, the coffee berry borer (Hypothenemus hampei; Coleoptera: Curculionidae) was accidentally introduced to Brazil in 1913 and years later invaded coffe...

  17. NILAI BIOLOGIS MI KERING JAGUNG YANG DISUBSTITUSI TEPUNG JAGUNG TERMODIFIKASI MELALUI HEAT MOISTURE TREATMENT [Biological Values of Dried Corn Noodles Substituted with Heat Moisture Treated (HMT-Corn Flour

    Directory of Open Access Journals (Sweden)

    Nurheni Sri Palupi

    2015-06-01

    Full Text Available The objective of this research was to determine the effects of physical modification of corn flour by heat moisture treatment (110°C, 6 hours on the biological values of Heat Moisture Treated (HMT-corn flour obtained as well as corn noodles substituted with the HMT-corn flour. The parameters tested which were directly associated were starch and protein digestibility in vitro while indirect parameters included the resistant starch and insoluble fiber contents. The chemical composition (protein, fat, carbohydrates, starch, amylose and amylopectin of the substituted corn noodles were analyzed by chemical methods. In vitro dietary fiber of the noodles were determined gravimetrically whereas the resistant starch, starch and protein digestibility for both the HMT-corn flour and corn noodles substituted with 10% HMT-corn flour were determined using spectrophotometry. The HMT-corn flour had higher resistant starch and soluble fiber contents, but lower starch and protein digestibilities. Meanwhile, the substituted corn noodle had higher resistant starch and soluble fiber yet had significantly lower starch digestibility than those of corn noodle without HMT-corn flour.

  18. Effects of Bt-corn expressing Cry1F on the survival and fecundity of the parasitoid Macrocentrus cingulum%转cry1F基因玉米花粉对腰带长体茧蜂存活和繁殖的影响

    Institute of Scientific and Technical Information of China (English)

    白树雄; 张洪刚; 葛星; 王振营

    2011-01-01

    腰带长体茧蜂(Macrocentrus cingulum)是亚洲玉米螟(Ostrinia urnacalis)幼虫的主要寄生蜂,对亚洲玉米螟种群具有重要的控制作用.玉米花粉可以作为腰带长体茧蜂的补充营养.本研究利用转cry1F基因抗虫玉米花粉作为补充食物饲喂腰带长体茧蜂寄生亚洲玉米螟幼虫,研究其对腰带长体茧蜂存活和繁殖的影响,为转基因抗虫玉米的环境安全评价提供科学依据.结果表明,饲喂转cry1F基因抗虫玉米花粉后腰带长体茧蜂的寄生率、茧块重量、每茧块茧数、羽化率与饲喂对照玉米花粉相比无显著差异;在蜂蜜水+Bt玉米花粉处理中虽然与对照玉米花粉处理相比雌蜂的寿命并没有显著差异,但雄蜂的寿命差异显著;在取食转cry1F基因抗虫玉米花粉的腰带长体茧蜂体内未检测到Bt蛋白成分.说明转cry1F基因抗虫玉米花粉对腰带长体茧蜂的存活和繁殖没有显著影响.%Macrocentrus cingtdum is the predominant larval parasitoid of the Asian corn borer, Ostrinia furnacalis, which plays a very important role in managing the population of O. furnacalis. Corn pollen can be the supplemental food for M. cingulum. Bt corn pollen expressing Cry1F toxin was used to feed M. cingulum wasps as a supplemental food and examine the effects of the Bt corn pollen on the survival and fecundity of M. cingulum in this study, so as to provide the scientific proof for environmental risk assessment of transgenic com resistant to insect pests. The results showed that there were no significant differences in parasitism, pupal weight, number of cocoons per larvae, and emergence rate when M. cingulum fed on suspensions of Bt corn or non-Bt corn pollen. Although the average longevity of M. cingulum males was significantly longer when they fed on suspension of Bt corn pollen than those on non-Bt corn pollen, there were no significant differences in the longevity of M. cingulum female feeding on suspensions of

  19. 玉米根萤叶甲的抗逆性与防治研究进展%Advances in stress resistance and control of the western corn rootworm,Diabrotica virgifera virgifera

    Institute of Scientific and Technical Information of China (English)

    陈宏; Blair D.Siegfried; 陈乃中; 王音

    2009-01-01

    The western corn rootworm,Diabrotica virgifera virgifera Leconte,is the most important pest of corn in the US Com Belt in terms of both yield losses and control costs.The rootworm has remarkable capacity to evolve not only resistance to cyclodiene,organophosphates and carbamates,but also to cultural control practices such as crop rotation.This beetle is also highly invasive.Over the past 60 years,it has spread from the midwest to the eastem coast of the USA,and more recently has invaded Eastern Europe.Therefore,managing and quarantining rootworm populations are extremely difficult.Recently,transgenic corn varieties that express insecticidal proteins(e.g.,Cry3Bb1,Cry34Ab1/Cry35Ab1 or modified Cry3A)derived from the soil bacterium,Bacillus thuringiensis (Bt),have been developed and used as a control method for the rootworm. However,its potential adaptation to Bt corn presents an urgent challenge to sustainable pest management approaches.In this paper,the rootworm life cycle,resistance evolution and control are reviewed and discussed.%玉米根萤叶甲(Diabrotica virgifera virgifera Leconte)在美国是最重要的玉米害虫.它不仅对一些环戊二烯、有机磷类和氨基甲酸盐类化学杀虫剂产生了很强的抗药性,还对玉米-大豆轮作和调整播期等农业防治措施产生了适应性.此外,该虫有较广的适生性和扩展性.在过去的60年内,它从美国中西部传到了东北部沿海地区,并入侵欧洲定殖为害.新近采用的防治方法主要是种植转Bt基因抗虫玉米.表达经生物工程改良并导入的某个Bt毒素基因如Cry3Bb1、Cry34Ab1/Cry35Ab1或mCry3A的转基因抗虫玉米可毒杀取食的玉米根萤叶甲.但在转Bt基因玉米使用数年后,田间观察和温室筛选研究显示,玉米根萤叶甲具有对转基因玉米的潜在抗性.本文对该叶甲与防治有关的生物学特性、抗逆性及其机制、防治措施做了综述和讨论,旨在对该害虫的检疫防除有所帮助.

  20. THE STEM BORER INFESTATION ON RICE CULTIVARS AT THREE PLANTING TIMES

    Directory of Open Access Journals (Sweden)

    Hendarsih Suharto

    2016-10-01

    Full Text Available Stem borer is the second important rice pest after rats in Indonesia. A field trial was conducted in Karawang, West Java in dry season of 2003 to study the effect of planting time on the stem borer infestation on seven rice cultivars. The rice cultivars tested were Fatmawati (new plant type cultivar, Gilirang (semi-new plant type cultivar, Maro and Intani 3 (hybrid rice cultivars, and IR72, Cilosari and IR62 (inbreed rice cultivars. The three planting times (PT were: (1 the early PT, 14 days before farmer’s PT, (2 the common PT, simultaneously with farmer’s PT, and (3 the late PT, 14 days after farmer’s PT. The trial was arranged in a split plot design with four replications. Planting time is the main plot and rice cultivar is the subplot. Fourteen-day old rice seedlings were transplanted at 25 cm x 25 cm planting distance in a 5 m x 6 m plot size. Species and fluctuation of rice stem borer were determined by using water traps containing four synthetic sex pheromone lures of rice stem borer species as attractant. Results showed that the dominant species of stem borer was yellow stem borer (Scirpophaga incertulas Wlk.. Degree of stem borer infestation depended upon the planting time. Stem borer infestation at the first planting time was higher (average 37.90% compared to those found at the second and third planting time, i.e. 0.65% and 0.54%, respectively. Rice yields of Fatmawati, Gilirang, Maro, Intani-3, and Cilosari cultivars correlated with the degree of stem borer infestation, but did not correlate with planting time. Cilosari cultivar showed the most tolerant under heavily stem borer infestation. The present study implies that adjustment of planting time is the most feasible effort to reduce stem borer infestation because none of the seven rice cultivars tested were able to minimize damage under heavily infestation of yellow stem borer.

  1. Comparison of grain from corn rootworm resistant transgenic DAS-59122-7 maize with non-transgenic maize grain in a 90-day feeding study in Sprague-Dawley rats.

    Science.gov (United States)

    He, X Y; Huang, K L; Li, X; Qin, W; Delaney, B; Luo, Y B

    2008-06-01

    DAS-59122-7 (59122) is a transgenic maize (Zea mays L.) that contains genes encoding Cry34Ab1 and Cry35Ab1 proteins from Bacillus thuringiensis Berliner strain 149B1 and phosphinothricin acetyltransferase (PAT) protein from Streptomyces viridochromogenes. Expression of these proteins in planta confers resistance to corn rootworms and other Coleopteran parasites and tolerance to herbicides containing glufosinate ammonium, respectively. In the current study, processed flours from 59122 maize grain or its near isogenic control line (091) were used at two concentrations (50% and 70% wt/wt) to produce diets that were fed to rats for 90 days in accordance with Chinese toxicology guidelines (GB15193.13-2003). A commercial AIN93G diet was used as an additional negative control. No significant differences in body weight and feed utilization were observed between rats consuming diets formulated with 59122 and 091 Control corn. Statistical differences (p<0.05) were observed in certain hematology and serum chemistry response variables between rats consuming diets formulated with 59122 or 091 Control flour compared to AIN93G diet. However, the mean value of these response variables in the 59122 groups were not statistically different from those observed in diets formulated with corresponding high and low concentrations of the flour from the 091 Control maize grain. Therefore, the statistical differences were considered to be related to consumption of diets containing high concentrations of maize flour (compared to AIN93G diets) regardless of source rather than to consumption of flour from 59122 maize grain. The results from this study demonstrated that 59122 maize grain is as safe as non-transgenic maize grain.

  2. Blisters, Calluses, and Corns

    Science.gov (United States)

    ... Too Tall or Too Short All About Puberty Blisters, Calluses, and Corns KidsHealth > For Kids > Blisters, Calluses, ... the surfaces is your tender skin! What's a Blister? A blister is an area of raised skin ...

  3. Corns and calluses

    Science.gov (United States)

    ... rowers get calluses on their hands that prevent blisters from forming. People with bunions often develop a callus over the bunion because it rubs against the shoe. Corns and calluses are not serious problems. Symptoms ...

  4. Shifts in sensory neuron identity parallel differences in pheromone preference in the European corn borer

    Directory of Open Access Journals (Sweden)

    Fotini A Koutroumpa

    2014-10-01

    Full Text Available Pheromone communication relies on highly specific signals sent and received between members of the same species. However, how pheromone specificity is determined in moth olfactory circuits remains unknown. Here we provide the first glimpse into the mechanism that generates this specificity in Ostrinia nubilalis. In Ostrinia nubilalis it was found that a single locus causes strain-specific, diametrically opposed preferences for a 2-component pheromone blend. Previously we found pheromone preference to be correlated with the strain and hybrid-specific relative antennal response to both pheromone components. This led to the current study, in which we detail the underlying mechanism of this differential response, through chemotopically mapping of the pheromone detection circuit in the antenna. We determined that both strains and their hybrids have swapped the neuronal identity of the pheromone-sensitive neurons co-housed within a single sensillum. Furthermore, neurons that mediate behavioral antagonism surprisingly co-express up to five pheromone receptors, mirroring the concordantly broad tuning to heterospecific pheromones. This appears as possible evolutionary adaptation that could prevent cross attraction to a range of heterospecific signals, while keeping the pheromone detection system to its simplest tripartite setup.

  5. Correlation between agronomic and stem borer resistant traits in ...

    African Journals Online (AJOL)

    SARAH

    2015-06-30

    Jun 30, 2015 ... influence on selection was studied in a yellow maize population, ... correlation, but if they have high heritability, then ... maximum of 13 plants per plot and a plant density of ..... performance for agronomic traits in two broad-.

  6. Biotechnology for cocoa pod borer resistance in cocoa

    NARCIS (Netherlands)

    Chaidamsari, T.

    2005-01-01

    The cocoa tree ( Theobroma cacao L.) produces the beans that are the source of cacao, the basis for chocolate production, and an important commodity crop in South America, West Africa, and Southeast Asia.Cocoa Pod

  7. Compositional equivalency of Cry1F corn event TC6275 and conventional corn (Zea mays L.).

    Science.gov (United States)

    Herman, Rod A; Phillips, Amy M; Collins, Randy A; Tagliani, Laura A; Claussen, Fred A; Graham, Christopher D; Bickers, Brenda L; Harris, Travis A; Prochaska, Lee M

    2004-05-01

    Maize (Zea mays L.) plants have been transformed to express a Cry1F insecticidal crystal protein originally isolated from Bacillus thuringiensis Berliner. This protein controls lepidopteran pests of maize, including the European corn borer, Ostrinia nubilalis (Hübner). As part of the safety assessment for crops containing transgenes, a compositional analysis of the food and feed is conducted. This analysis is designed to detect unintended changes in the nutrient and antinutrient content of the raw commodities produced by the crop due to the insertion of the genes into the genomic DNA of the plant (pleotropic effects). Samples of transgenic and nontransgenic maize forage and grain were collected from six field sites located in the U.S. and Canada. Forage samples were analyzed for proximates and minerals, and grain was further analyzed for fatty acids, amino acids, vitamins, secondary metabolites, and antinutrients. Results demonstrated that maize expressing the Cry1F protein was equivalent to nontransgenic maize with respect to these important components. Comparison of the variability within the nontransgenic and transgenic hybrid, as compared to composition values reported in the literature, suggest that factors other than transgenes may contribute more substantially to the composition of crops.

  8. Exposure and nontarget effects of transgenic Bt corn debris in streams.

    Science.gov (United States)

    Jensen, Peter D; Dively, Galen P; Swan, Christopher M; Lamp, William O

    2010-04-01

    Corn (Zea mays L.) transformed with a gene from the bacterium Bacillus thuringiensis (Bt) comprises 49% of all corn in the United States. The input of senesced corn tissue expressing the Bt gene may impact stream-inhabiting invertebrates that process plant debris, especially trichopteran species related to the target group of lepidopteran pests. Our goal was to assess risk associated with transgenic corn debris entering streams. First, we show the input of corn tissue after harvest was extended over months in a stream. Second, using laboratory bioassays based on European corn borer [Ostrinia nubilalis (Hübner)], we found no bioactivity of Cry1Ab protein in senesced corn tissue after 2 wk of exposure to terrestrial or aquatic environments. Third, we show that Bt near-isolines modify growth and survivorship of some species of invertebrates. Of the four nontarget invertebrate species fed Bt near-isolines, growth of two closely related trichopterans was not negatively affected, whereas a tipulid crane fly exhibited reduced growth rates, and an isopod exhibited reduced growth and survivorship on the Cry1Ab near-isoline but not on the stacked Cry1Ab + Cry3Bb1 near-isoline. Because of lack of evidence of bioactivity of Bt after 2 wk and because of lack of nontarget effects on the stacked near-isoline, we suggest that tissue-mediated differences, and not the presence of the Cry1Ab protein, caused the different responses among the species. Overall, our results provide evidence that adverse effects to aquatic nontarget shredders involve complex interactions arising from plant genetics and environment that cannot be ascribed to the presence of Cry1Ab proteins.

  9. Evaluation of resistance of corn hybrids against the attack of Sitophilus zeamais motschulsky (Coleoptera: Curculionidae in stored kernels/ Avaliação da resistência de híbridos de milho ao ataque de Sitophilus zeamais motschulsky (Coleoptera: Curculionidae no grão armazenado

    Directory of Open Access Journals (Sweden)

    Antônio Carlos Gerage

    2005-06-01

    Full Text Available Resistance of corn hybrids, cultivated or in phase of genetic improvement in Paraná, was evaluated against the attack of Sitophilus zeamais, main grain pest of corn storage. Samples of kernels of eleven hybrids of corn, IPD T1/3AC, IPD 029, IPT 4/029, AG 5011, IPS G/58, IPT 2/15, IPT 4/15, IPT T/23, IPT 5/T02, IPT 2/92 and IPT 9/13, were infested with adults of S. zeamais and maintained in BOD, at 27±1°C, 75±5% RH and 12 hours of photophase. After 30 days of infestation the following parameters of resistance were evaluated: susceptibility index, reduce of dry mass of the grains, number of emerged insects, biological cycle and adult mass. The most susceptible hybrids to the attack of S. zeamais were: IPD T1/3AC and IPD 029; while the most resistant were: IPT 4/029, AG 5011, IPS G/58, IPT 2/15 and IPT 4/15.A resistência de híbridos de milho, cultivados ou em fase de melhoramento genético no Paraná, foi avaliada com relação ao ataque de Sitophilus zeamais, principal praga de grãos armazenados de milho. Amostras de grãos de onze híbridos de milho, IPD T1/3AC, IPD 029, IPT 4/029, AG 5011, IPS G/58, IPT 2/15, IPT 4/15, IPT T/23, IPT 5/T02, IPT 2/92 e IPT 9/13, foram infestadas com adultos de S. zeamais e mantidas em BOD, a 27±1°C, 75±5% UR e 12 horas de fotofase. Após trinta dias da infestação foram avaliados os seguintes parâmetros de resistência: índice de suscetibilidade, perda de massa seca dos grãos, número de insetos emergidos, ciclo biológico e massa dos adultos. Os híbridos mais suscetíveis ao ataque de S. zeamais foram: IPD T1/3AC e IPD 029, enquanto que os mais resistentes foram: IPT 4/029, AG 5011, IPS G/58, IPT 2/15 e IPT 4/15.

  10. Alpha-amylase inhibitor-1 gene from Phaseolus vulgaris expressed in Coffea arabica plants inhibits alpha-amylases from the coffee berry borer pest.

    Science.gov (United States)

    Barbosa, Aulus E A D; Albuquerque, Erika V S; Silva, Maria C M; Souza, Djair S L; Oliveira-Neto, Osmundo B; Valencia, Arnubio; Rocha, Thales L; Grossi-de-Sa, Maria F

    2010-06-17

    Coffee is an important crop and is crucial to the economy of many developing countries, generating around US$70 billion per year. There are 115 species in the Coffea genus, but only two, C. arabica and C. canephora, are commercially cultivated. Coffee plants are attacked by many pathogens and insect-pests, which affect not only the production of coffee but also its grain quality, reducing the commercial value of the product. The main insect-pest, the coffee berry borer (Hypotheneumus hampei), is responsible for worldwide annual losses of around US$500 million. The coffee berry borer exclusively damages the coffee berries, and it is mainly controlled by organochlorine insecticides that are both toxic and carcinogenic. Unfortunately, natural resistance in the genus Coffea to H. hampei has not been documented. To overcome these problems, biotechnological strategies can be used to introduce an alpha-amylase inhibitor gene (alpha-AI1), which confers resistance against the coffee berry borer insect-pest, into C. arabica plants. We transformed C. arabica with the alpha-amylase inhibitor-1 gene (alpha-AI1) from the common bean, Phaseolus vulgaris, under control of the seed-specific phytohemagglutinin promoter (PHA-L). The presence of the alpha-AI1 gene in six regenerated transgenic T1 coffee plants was identified by PCR and Southern blotting. Immunoblotting and ELISA experiments using antibodies against alpha-AI1 inhibitor showed a maximum alpha-AI1 concentration of 0.29% in crude seed extracts. Inhibitory in vitro assays of the alpha-AI1 protein against H. hampei alpha-amylases in transgenic seed extracts showed up to 88% inhibition of enzyme activity. This is the first report showing the production of transgenic coffee plants with the biotechnological potential to control the coffee berry borer, the most important insect-pest of crop coffee.

  11. α-Amylase inhibitor-1 gene from Phaseolus vulgaris expressed in Coffea arabica plants inhibits α-amylases from the coffee berry borer pest

    Directory of Open Access Journals (Sweden)

    Oliveira-Neto Osmundo B

    2010-06-01

    Full Text Available Abstract Background Coffee is an important crop and is crucial to the economy of many developing countries, generating around US$70 billion per year. There are 115 species in the Coffea genus, but only two, C. arabica and C. canephora, are commercially cultivated. Coffee plants are attacked by many pathogens and insect-pests, which affect not only the production of coffee but also its grain quality, reducing the commercial value of the product. The main insect-pest, the coffee berry borer (Hypotheneumus hampei, is responsible for worldwide annual losses of around US$500 million. The coffee berry borer exclusively damages the coffee berries, and it is mainly controlled by organochlorine insecticides that are both toxic and carcinogenic. Unfortunately, natural resistance in the genus Coffea to H. hampei has not been documented. To overcome these problems, biotechnological strategies can be used to introduce an α-amylase inhibitor gene (α-AI1, which confers resistance against the coffee berry borer insect-pest, into C. arabica plants. Results We transformed C. arabica with the α-amylase inhibitor-1 gene (α-AI1 from the common bean, Phaseolus vulgaris, under control of the seed-specific phytohemagglutinin promoter (PHA-L. The presence of the α-AI1 gene in six regenerated transgenic T1 coffee plants was identified by PCR and Southern blotting. Immunoblotting and ELISA experiments using antibodies against α-AI1 inhibitor showed a maximum α-AI1 concentration of 0.29% in crude seed extracts. Inhibitory in vitro assays of the α-AI1 protein against H. hampei α-amylases in transgenic seed extracts showed up to 88% inhibition of enzyme activity. Conclusions This is the first report showing the production of transgenic coffee plants with the biotechnological potential to control the coffee berry borer, the most important insect-pest of crop coffee.

  12. 75 FR 45601 - Notice of Request for Extension of Approval of an Information Collection; Emerald Ash Borer; Host...

    Science.gov (United States)

    2010-08-03

    ... Collection; Emerald Ash Borer; Host Material from Canada AGENCY: Animal and Plant Health Inspection Service... emerald ash borer in the United States. DATES: We will consider all comments that we receive on or before... Canada to prevent the introduction and ] spread of emerald ash borer in the United States, contact...

  13. The Impact of Inter-Kernel Movement in the Evolution of Resistance to Dual-Toxin Bt-Corn Varieties in Helicoverpa zea (Lepidoptera: Noctuidae).

    Science.gov (United States)

    Caprio, Michael A; Martinez, Jeannette C; Porter, Patrick A; Bynum, Ed

    2016-02-01

    Seeds or kernels on hybrid plants are primarily F(2) tissue and will segregate for heterozygous alleles present in the parental F(1) hybrids. In the case of plants expressing Bt-toxins, the F(2) tissue in the kernels will express toxins as they would segregate in any F(2) tissue. In the case of plants expressing two unlinked toxins, the kernels on a Bt plant fertilized by another Bt plant would express anywhere from 0 to 2 toxins. Larvae of corn earworm [Helicoverpa zea (Boddie)] feed on a number of kernels during development and would therefore be exposed to local habitats (kernels) that varied in their toxin expression. Three models were developed for plants expressing two Bt-toxins, one where the traits are unlinked, a second where the traits were linked and a third model assuming that maternal traits were expressed in all kernels as well as paternally inherited traits. Results suggest that increasing larval movement rates off of expressing kernels tended to increase durability while increasing movement rates off of nonexpressing kernels always decreased durability. An ideal block refuge (no pollen flow between blocks and refuges) was more durable than a seed blend because the refuge expressed no toxins, while pollen contamination from plants expressing toxins in a seed blend reduced durability. A linked-trait model in an ideal refuge model predicted the longest durability. The results suggest that using a seed-blend strategy for a kernel feeding insect on a hybrid crop could dramatically reduce durability through the loss of refuge due to extensive cross-pollination.

  14. Investigating Transgenic Corn Hybrids as a Method for Mycotoxin Control

    Science.gov (United States)

    Transgenic Bt corn hybrids have been available for more than 10 years and are known to control specific insects. More recently, so-called “stacked-gene” hybrids, have been released with multiple insect resistance genes and genes for herbicide resistance, resulting in up to 6 traits per plant. Beca...

  15. Availability and Market Penetration of GMO Corn and Soybeans

    OpenAIRE

    Bruce A. Babcock; Michael D. Duffy; Robert Wisner

    1999-01-01

    The authors survey various types of GMO (genetically modified organism) corn and soybeans, including both pest-resistant and herbicide-resistant varieties, and then evaluate the extent to which farmers have begun to use GMO crops. Figures cited include percentages of acres planted with GMO crops, as well as comparisons of non-GMO versus GMO yields.

  16. Availability and Market Penetration of GMO Corn and Soybeans

    OpenAIRE

    Bruce A. Babcock; Duffy, Michael D.; Robert Wisner

    1999-01-01

    The authors survey various types of GMO (genetically modified organism) corn and soybeans, including both pest-resistant and herbicide-resistant varieties, and then evaluate the extent to which farmers have begun to use GMO crops. Figures cited include percentages of acres planted with GMO crops, as well as comparisons of non-GMO versus GMO yields.

  17. The impact of predators on maize stem borers in coastal Kenya

    NARCIS (Netherlands)

    Bonhof, M.J.

    2000-01-01

    Damage caused by Lepidopteran stem borers is one of the most important constraints to maize production in East and southern Africa. Of the stem borer complex, Chilo partellus Swinhoe is the most abundant species in lowland areas. Although control strategies exist, many are not effective or feasible

  18. Factors affecting stem borer parasitoid species diversity and parasitism in cultivated and natural habitats.

    Science.gov (United States)

    Mailafiya, Duna Madu; Le Ru, Bruno Pierre; Kairu, Eunice Waitherero; Calatayud, Paul-André; Dupas, Stéphane

    2010-02-01

    The effects of biotic and abiotic factors on stem borer parasitoid diversity, abundance, and parasitism were studied in cultivated and natural habitats in four agroecological zones in Kenya. Comparing habitat types, we found partial support for the "natural enemy" hypothesis, whereby, across all localities, parasitoid diversity was higher in more diverse host plant communities in natural habitats, whereas parasitoid abundance was higher in cultivated habitats. For both habitats, parasitoid richness was mainly influenced by stem borer density and/or its interaction with stem borer richness, whereas parasitoid abundance was mainly affected by stem borer abundance. Parasitoid richness was higher in localities (with bimodal rainfall distribution) with increased spatial and temporal availability of host plants that harbored the borers. Across seasons, parasitoid richness was lower in both cultivated and natural habitats in the driest locality, Mtito Andei. Overall, parasitoid diversity was low in Suam and Mtito Andei, where maize cultivation was practiced on a commercial scale and intense grazing activities persist across seasons, respectively. Across localities, habitats, and seasons, stem borer parasitism was positively correlated with parasitoid richness and abundance. Furthermore, the interaction of rainfall and altitude influenced the presence and absence of parasitoids, and consequently, stem borer parasitism. Parasitism was positively and negatively correlated with temperature in cultivated and natural habitats, respectively. Overall, natural habitats seem to serve as important refugia for sustaining parasitoid diversity, which in turn can affect stem borer parasitism in the cereal cropping system.

  19. The impact of predators on maize stem borers in coastal Kenya

    NARCIS (Netherlands)

    Bonhof, M.

    2000-01-01

    Damage caused by Lepidopteran stem borers is one of the most important constraints to maize production in East and southern Africa. Of the stem borer complex, Chilo partellus Swinhoe is the most abundant species in lowland areas. Although control strategies exist, many

  20. The coffee berry borer: the centenary of a biological invasion in Brazil

    Science.gov (United States)

    The coffee berry borer, Hypothenemus hampei, is a bark beetle endemic to Africa. This species was first detected in the field in 1897 in Mount Coffee, Liberia, and years later was reported as a pest of coffee in several African countries. In 1913 the coffee berry borer was accidentally introduced in...

  1. 转Bt cry1F基因抗虫玉米对米蛾生长发育的影响%Effect of Transgenic Insect-resistant Corn with crylF Gene on Growth and Development of Rice Moth,Corcyra cephalonica(Stainton)

    Institute of Scientific and Technical Information of China (English)

    姜松男; 丛斌; 马晓慧; 张柱亭; 吴尊曌

    2011-01-01

    In this article,three varieties of transgenic insect-resistant corn with cry1F gene, 32A91, 32W09 and X1132X,and non-transgenic corn were used as test materials to feed Corcyra cephalonica larvae.In contrast to non-transgenic corn,the survial rate of larvae in transgenic con showed a signficant decrease.For the emergence rate of adult Corcyra cephalonica, 32W09 group demostrated an obvious decline in comparison with non-transgenic corn XY420.However, the other two groups had no significant differences.%采用转Bt cry1F基因的32A91、32W09和X1132X 3个玉米品种及其对应的3种非转基因玉米为试材,分别饲养米蛾幼虫,比较转基因和非转基因玉米对米蛾生长发育的影响.结果表明,转cry1F基因玉米对米蛾幼虫存活率的影响均表现为显著降低;转基因玉米32W09饲养的米蛾成虫羽化率显著低于非转基因玉米XY420饲养的米蛾成虫羽化率.

  2. Review of History, Present Situation and Prospect of Pink Stem Borer in China%中国大螟研究历史、现状与展望

    Institute of Scientific and Technical Information of China (English)

    徐丽娜; 李昌春; 胡本进; 周子燕; 李晓霞

    2011-01-01

    为了深入研究大螟发生特点、探索其危害规律,提出合理有效的防治手段,有效防控大螟危害,笔者以近50年来中国的大螟研究为基础,综述了大螟生物学、生态学、为害特点、防治技术、人工饲养技术、抗药性和毒理以及预测预报等方面取得的进展,并提出了未来大螟研究的方向.%In order to further study the occurring characteristics and damage regularity, and develop effectivecontrol techniques of pink stem borer, the author gave an overview of the advances which had been achieved inpink stem borer during the last SO years, including biology, ecology, feeding behavior, control measures,artificial rearing techniques, forecast, toxicology and resistant to insecticides, and put forward the directions ofthe further research on pink stem borer.

  3. Influence of maize/lablab intercropping on lepidopterous stem borer infestation in maize.

    Science.gov (United States)

    Maluleke, Mary H; Addo-Bediako, Abraham; Ayisi, Kingsley K

    2005-04-01

    Lepidopterous stem borers seriously affect production of maize, Zea mays L., in sub-Saharan Africa. Intercropping maize with legumes such as lablab, Lablab purpurens (L.), is one of the effective systems to control stem borers. Sole culture maize and maize/lablab intercrop system of different lablab densities were planted at two locations to investigate the effects of intercrop system on incidence and severity of stem borers with particular reference to Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae). Stem borer infestation was found to be more severe in sole culture maize than maize in maize/lablab intercrop. There was a significantly negative relationship between lablab densities and maize grain yields, suggesting a possible competition for resources between the two crops. It was concluded that density of lablab and date of planting of lablab in maize/lablab intercropping have significant affects on stem borer populations and maize grain yields.

  4. Study on modified corn starch adhesive in reinforcing and water-resistance%玉米淀粉胶粘剂的增强及耐水改性研究

    Institute of Scientific and Technical Information of China (English)

    聂亚楠; 田孝才; 吴凯; 汪济奎

    2012-01-01

    With starch-g-PV Ac (starch grafted by polyvinyl acetate) as reinforcing component ,epoxy resin(EP) as water-resistance modified component,a new corn starch adhesive with higher bonding strength and better water-resistance was prepared. The results showed that the modified starch adhesive had the reversely best combination property and good application prospect in the field of plywood production because its dry shear strength and wet shear strength were 4.50,2.51 Mpa respectively,the viscosity was 0.875 Pa·s when mass ratio of m(starch-g-PVAc):m(EP) was 2*1 ,mass fraction of starch-g-PVAc/EP was 70% in oxidized starch emulsion.%以淀粉接枝聚醋酸乙烯酯(淀粉-g-PVAc)作为增强组分,环氧树脂(EP)作为耐水改性组分,制备了一种新型的粘接强度较高、耐水性较好的玉米淀粉胶粘剂.结果表明:当m(淀粉-g-PVAc):m(EP)=2:1、w(淀粉-g-PVAc/EP)=70%(相对于氧化淀粉乳质量而言)时,改性淀粉胶粘剂的综合性能相对最好,其干态剪切强度和湿态剪切强度分别为4.50、2.51 MPa,黏度为0.875 Pa·s;该改性淀粉胶粘剂在胶合板生产领域中具有良好的应用前景.

  5. Optimization Study on Processing Conditions of Corn Resistant Starch by Autoclaving and Acid Hydrolysis Treatment%压热酸解法制备玉米抗性淀粉的工艺优化

    Institute of Scientific and Technical Information of China (English)

    冯铄涵; 阚建全

    2011-01-01

    The resistant starch was prepared with the High amylose corn starch by autoclaving-cooling cycles combined with acids hydrolysis treatment.The effects of concentration of starch solution,autoclaved temperature,autoclaved time and times of autoclaved-cooling cycles on the content of RS were studied in the autoclaved treatment.The type,concentration and treatment time of acids were also studied in the acid hydrolysis process.The results showed that the optimum conditions is: 30% starch solution was autoclaved at 125℃ for 45min,after repeated 2 times,0.15mol/L citric acid hydrolysised for 12h.The yield of resistant starch is up to 39.27%.%以高直链玉米淀粉为原料,研究压热-冷却循环结合酸解法制备抗性淀粉的最佳工艺条件。通过单因素实验和正交实验探讨了压热-冷却循环过程中淀粉溶液浓度、压热温度、压热时间、循环次数以及酸解处理过程中酸的种类、酸的浓度、酸解时间对抗性淀粉得率的影响。结果表明,在淀粉溶液浓度为30%、压热温度125℃、压热时间45min条件下,经过2次压热-冷却循环,然后0.15mol/L柠檬酸水解处理12h,在此条件下抗性淀粉得率可达39.27%。

  6. Zapatista corn: a case study in biocultural innovation.

    Science.gov (United States)

    Brandt, Marisa

    2014-12-01

    In November 2001, Nature published a letter in which University of California Berkeley's biologists claimed to have found evidence of genetically modified (GM) DNA in regional varieties of maize in Oaxaca, even though the Mexican government had banned transgenic corn agriculture in 1998. While urban protesters marched against the genetic 'contamination' of Mexican corn by US-based agricultural biotech firms, rural indigenous communities needed a framework for understanding concepts such as GM before they could take action. This article analyzes how the indigenous organization, the Zapatistas, mobilized a program to address this novel entity. Their anti-GM project entailed educating local farmers about genetics, importing genetic testing kits, seed-banking landrace corn and sending seeds to 'solidarity growers' around the world. This article explores material-semiotic translations to explain one of the central aspects of this project, the definition and circulation of Zapatista corn--an entity defined not only through cultural geography, but also technological means. Through its circulation, Zapatista corn serves to perform a biocultural engagement with Zapatista's political project of resistance to neoliberalism. While much has been written about both regulatory policy and consumer activism against GM in the Global North, Zapatista corn also provides a case study in indigenous, anti-GM activism founded on biocultural innovation and the creation of alternative networks for circulating corn.

  7. Atividade da acetolactato sintase de plantas de milho e de amendoim-bravo (Euphorbia heterophylla resistentes e suscetíveis ao imazaquin ALS activity of wild poinsettia (Euphorbia heterophylla and corn (Zea mays resistant and susceptible to imazaquin

    Directory of Open Access Journals (Sweden)

    M.F. Oliveira

    2002-04-01

    ápida centrifugação.Wild poinsettia (Euphorbia heterophylla is an important weed in more than 56 countries, including Brazil, where resistant biotypes to ALS inhibiting herbicides have been reported in soybean crops. The objectives of this research were to evaluate the effect of imazaquin on the activity of the acetolactate synthase (ALS, extracted from two corn varieties and several biotypes of E. heterophylla from Brazilian agricultural areas. Plants were grown under greenhouse conditions for 21 days. The ALS activity of wild poinsettia has shown resistance to imazaquin herbicide in soybean crops. In vitro acetolactate synthase (ALS activity of imazaquin-resistant wild poinsettia collected in different soybean production areas from Brazil and the two corn populations was compared to that of imazaquin-sensitive populations. The activity of the ALS extracted from the leaves was measured with different imazaquin rates. The ALS purification process was substituted by centrifugation at 2800 rpm during two minutes. Linear regression equation for specific light length absorbance as a function of the log concentration of imazaquin was built to obtain I50 value (50% inhibition of the enzyme activity. The I50 values of Pioneer 3162 IR (I50 260 µM corn genotype were 4,333 times higher than BRS 473-sensitive (0,06 µM. The wild poinsettia biotypes from the state of Rio Grande do Sul had I50 values of 1,961.3 µM and 13.8 µM for the resistant and sensitive biotypes, respectively. The resistant populations from Cafelândia, Maringá (PR and Viçosa (MG had I50 values higher than 5,000 µM, while the sensitive population had values higher than 1,000 µM. The I50 value for the wild poinsettia population collected from fields that had never been sprayed with imazaquin was of 12.2 µM. Therefore, the in vitro ALS activity was a sensitive method to detect wild poinsettia-resistant imazaquin and ALS purification can be substituted for a method involving a quick centrifugation process.

  8. Modeling evolution of Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae) to transgenic corn with two insecticidal traits.

    Science.gov (United States)

    Onstad, David W; Meinke, Lance J

    2010-06-01

    A simulation model of the population dynamics and genetics of western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), was created to evaluate the use of refuges in the management of resistance to transgenic insecticidal corn, Zea mays L., expressing one or two toxin traits. Hypothetical scenarios and a case study of a corn hybrid pyramided with existing toxins are simulated. In the hypothetical situations, results demonstrated that evolution is generally delayed by pyramids compared with deployment of a single-toxin corn hybrid. However, soil insecticide use in the refuge reduced this delay and quickened the evolution of resistance. Results were sensitive to the degree of male beetle dispersal before mating and to the effectiveness of both toxins in the pyramid. Resistance evolved faster as fecundity increased for survivors of insecticidal corn. Thus, effects on fecundity must be measured to predict which resistance management plans will work well. Evolution of resistance also occurred faster if the survival rate due to exposure to the two toxins was not calculated by multiplication of two independent survival rates (one for each insect gene) but was equivalent to the minimum of the two. Furthermore, when single-trait and pyramided corn hybrids were planted within rootworm-dispersal distance of each other, the toxin traits lost efficacy more quickly than they did in scenarios without single-trait corn. For the case study involving transgenic corn expressing Cry34/35Ab1 and Cry3Bb1, the pyramid delayed evolution longer than a single trait corn hybrid and longer than a sequence of toxins based on at least one resistance-allele frequency remaining below 50%. Results are discussed within the context of a changing transgenic corn marketplace and the landscape dynamics of resistance management.

  9. Population Distribution and Range Expansion of the Invasive Mexican Rice Borer (Lepidoptera: Crambidae) in Louisiana.

    Science.gov (United States)

    Wilson, Blake E; Beuzelin, Julien M; Reagan, Thomas E

    2017-04-01

    The Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), is an invasive pest that was first introduced into southern Texas in 1980 and has been expanding its range eastward along the United States Gulf Coast. The pest attacks rice (Oryza sativa L.), sugarcane (Saccharum spp.), corn (Zea mays L.), and other graminaceous crops, and its establishment in Louisiana is expected to have severe economic impacts on crop production. Range expansion and population distribution of E. loftini were monitored with a network of 77 pheromone traps throughout southwestern Louisiana from 2013 to 2015. Eoreuma loftini was ubiquitous throughout the study region, with male moths captured in every habitat sampled. Spatial analysis revealed the population is characterized by high and low density clusters, with the greatest trap captures occurring in southeastern Calcasieu Parish and southern Jefferson Davis Parish. Trap captures in more northern regions of the study were lower than in southern parishes. Trap captures in areas where the pest has been established for >3 yr were greatest in rice habitats. The weighted mean population center moved eastward at a rate of ∼11 km per year. Human-aided movement of E. loftini was probably not involved in the eastward expansion documented during this study. Seasonal population peaks were detected in March-April, July-August, and October-November. This study indicates this species is continuing its spread eastward along the United States Gulf Coast and will likely become established throughout Louisiana within the next 20 yr. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. BIOFUEL FROM CORN STOVER

    Directory of Open Access Journals (Sweden)

    Ljiljanka Tomerlin

    2003-12-01

    Full Text Available This paper deals with production of ethyl alcohol (biofuel from corn stover acid hydrolysate by yeasts, respectively at Pichia stipitis y-7124 and Pachysolen tannophilus y-2460 and Candida shehatae y-12856. Since moist corn stover (Hybryds 619 is proving to decomposition by phyllospheric microflora. It was (conserved spattered individually by microbicids: Busan-90, Izosan-G and formalin. In form of prismatic bales, it was left in the open air during 6 months (Octobar - March. At the beginning and after 6 months the microbiological control was carried out. The only one unspattered (control and three stover corn bals being individually spattered by microbicids were fragmented and cooked with sulfur acid. The obtained four acid hydrolysates are complex substratums, containing, apart from the sugars (about 11 g dm-3 pentosa and about 5.4 g dm-3 hexose, decomposite components as lignin, caramel sugars and uronic acids. By controlling the activity of the mentioned yeasts it was confirmed that yeasts Pichia stipitis y-7124 obtained best capability of ethyl alcohol production from corn stover acid hydrolysate at 0.23 vol. % to 0.49 vol. %.

  11. Exploring the midgut transcriptome and brush border membrane vesicle proteome of the rice stem borer, Chilo suppressalis (Walker.

    Directory of Open Access Journals (Sweden)

    Weihua Ma

    Full Text Available The rice stem borer, Chilo suppressalis (Walker (Lepidoptera: Pyralidae, is one of the most detrimental pests affecting rice crops. The use of Bacillus thuringiensis (Bt toxins has been explored as a means to control this pest, but the potential for C. suppressalis to develop resistance to Bt toxins makes this approach problematic. Few C. suppressalis gene sequences are known, which makes in-depth study of gene function difficult. Herein, we sequenced the midgut transcriptome of the rice stem borer. In total, 37,040 contigs were obtained, with a mean size of 497 bp. As expected, the transcripts of C. suppressalis shared high similarity with arthropod genes. Gene ontology and KEGG analysis were used to classify the gene functions in C. suppressalis. Using the midgut transcriptome data, we conducted a proteome analysis to identify proteins expressed abundantly in the brush border membrane vesicles (BBMV. Of the 100 top abundant proteins that were excised and subjected to mass spectrometry analysis, 74 share high similarity with known proteins. Among these proteins, Western blot analysis showed that Aminopeptidase N and EH domain-containing protein have the binding activities with Bt-toxin Cry1Ac. These data provide invaluable information about the gene sequences of C. suppressalis and the proteins that bind with Cry1Ac.

  12. Exploring the midgut transcriptome and brush border membrane vesicle proteome of the rice stem borer, Chilo suppressalis (Walker).

    Science.gov (United States)

    Ma, Weihua; Zhang, Zan; Peng, Chuanhua; Wang, Xiaoping; Li, Fei; Lin, Yongjun

    2012-01-01

    The rice stem borer, Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), is one of the most detrimental pests affecting rice crops. The use of Bacillus thuringiensis (Bt) toxins has been explored as a means to control this pest, but the potential for C. suppressalis to develop resistance to Bt toxins makes this approach problematic. Few C. suppressalis gene sequences are known, which makes in-depth study of gene function difficult. Herein, we sequenced the midgut transcriptome of the rice stem borer. In total, 37,040 contigs were obtained, with a mean size of 497 bp. As expected, the transcripts of C. suppressalis shared high similarity with arthropod genes. Gene ontology and KEGG analysis were used to classify the gene functions in C. suppressalis. Using the midgut transcriptome data, we conducted a proteome analysis to identify proteins expressed abundantly in the brush border membrane vesicles (BBMV). Of the 100 top abundant proteins that were excised and subjected to mass spectrometry analysis, 74 share high similarity with known proteins. Among these proteins, Western blot analysis showed that Aminopeptidase N and EH domain-containing protein have the binding activities with Bt-toxin Cry1Ac. These data provide invaluable information about the gene sequences of C. suppressalis and the proteins that bind with Cry1Ac.

  13. Draft genome of the most devastating insect pest of coffee worldwide: the coffee berry borer, Hypothenemus hampei

    KAUST Repository

    Vega, Fernando E.

    2015-07-31

    The coffee berry borer, Hypothenemus hampei, is the most economically important insect pest of coffee worldwide. We present an analysis of the draft genome of the coffee berry borer, the third genome for a Coleopteran species. The genome size is ca. 163 Mb with 19,222 predicted protein-coding genes. Analysis was focused on genes involved in primary digestion as well as gene families involved in detoxification of plant defense molecules and insecticides, such as carboxylesterases, cytochrome P450, gluthathione S-transferases, ATP-binding cassette transporters, and a gene that confers resistance to the insecticide dieldrin. A broad range of enzymes capable of degrading complex polysaccharides were identified. We also evaluated the pathogen defense system and found homologs to antimicrobial genes reported in the Drosophila genome. Ten cases of horizontal gene transfer were identified with evidence for expression, integration into the H. hampei genome, and phylogenetic evidence that the sequences are more closely related to bacterial rather than eukaryotic genes. The draft genome analysis broadly expands our knowledge on the biology of a devastating tropical insect pest and suggests new pest management strategies.

  14. Activity of alpha-amylase inhibitors from Phaseolus coccineus on digestive alpha-amylases of the coffee berry borer.

    Science.gov (United States)

    Valencia-Jiménez, Arnubio; Arboleda Valencia, Jorge W; Grossi-De-Sá, Maria Fátima

    2008-04-09

    Seeds of scarlet runner bean ( Phaseolus coccineus L.) were analyzed for alpha-amylase inhibitor (alpha-AI) activity. Through the use of polyclonal antibodies raised against pure alpha-AI-1 from common bean ( Phaseolus vulgaris L.), typical alpha-AlphaIota polypeptides (Mr 14-18 kDa) as well as a large polypeptide of Mr 32000 Da, usually referred to as "amylase inhibitor like", were detected. The inhibitor activity present in four accessions of P. coccineus was examined, both in semiquantitative zymograms allowing the separation of different isoforms and in quantitative assays against human salivary amylase, porcine pancreatic amylase, and coffee berry borer, Hypothenemus hampei Ferrari (Coleoptera: Scolytidae) amylase. Differential inhibition curves lead to the suggestion that the gene encoding one of the inhibitors in P. coccineus (in accession G35590) would be a good candidate for genetic engineering of coffee resistance toward the coffee berry borer. An in vitro proteolytic digestion treatment of pure alpha-AlphaIota-1 resulted in a rapid loss of the inhibitory activity, seriously affecting its natural capacity to interact with mammalian alpha-amylases.

  15. Goss’s wilt incidence in sweet corn is independent of transgenic traits and glyphosate

    Science.gov (United States)

    Recently claims have been made that the use of glyphosate and transgenic crop traits increases the risk of plant diseases. Transgenic traits used widely for years in dent corn are now available in commercial sweet corn cultivars, specifically, the combination of glyphosate resistance (GR) and Lepid...

  16. Observations from a quarter century of evaluating reactions of sweet corn hybrids in disease nurseries

    Science.gov (United States)

    Sweet corn is one of the most popular vegetable crops in North America due in part to significant improvements made in eating quality in the last quarter century. Several plant diseases are major threats to sweet corn production. While resistance genes exist for many of these diseases, incorporating...

  17. Research Progress on Northern Leaf Blight in Corn

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yingnan; WANG Zhenhua

    2009-01-01

    The northern corn leaf blight is one of the most serious diseases in maize production. The research progress on etiology, generation law and control strategy, antigen identification, resistance mechanism and inheritance of this disease was discussed. And the research work which should be enhanced in China was pointed out, such as mechanism of resistance inheritance, developing function marker, gene mining, screening resistance resource and dominant physiological race in different areas.

  18. Resistance to Bt maize in Mythimna unipuncta (Lepidoptera: Noctuidae) is mediated by alteration in Cry1Ab protein activation.

    Science.gov (United States)

    González-Cabrera, Joel; García, Matías; Hernández-Crespo, Pedro; Farinós, Gema P; Ortego, Félix; Castañera, Pedro

    2013-08-01

    Bt maize cultivars based on the event MON810 (expressing Cry1Ab) have shown high efficacy for controlling corn borers. However, their efficiency for controlling some secondary lepidopteran pests such as Mythimna unipuncta has been questioned, raising concerns about potential outbreaks and its economic consequences. We have selected a resistant strain (MR) of M. unipuncta, which is capable of completing its life cycle on Bt maize and displays a similar performance when feeding on both Bt and non-Bt maize. The proteolytic activation of the protoxin and the binding of active toxin to brush border membrane vesicles were investigated in the resistant and a control strain. A reduction in the activity of proteolytic enzymes, which correlates with impaired capacity of midgut extracts to activate the Cry1Ab protoxin has been observed in the resistant strain. Moreover, resistance in larvae of the MR strain was reverted when treated with Cry1Ab toxin activated with midgut juice from the control strain. All these data indicate that resistance in the MR strain is mediated by alteration of toxin activation rather than to an increase in the proteolytic degradation of the protein. By contrast, binding assays performed with biotin labelled Cry1Ab suggest that binding to midgut receptors does not play a major role in the resistance to Bt maize. Our results emphasize the risk of development of resistance in field populations of M. unipuncta and the need to consider this secondary pest in ongoing resistance management programs to avoid the likely negative agronomic and environmental consequences.

  19. Glyphosate effect on shikimate, nitrate reductase activity, yield, and seed composition in corn.

    Science.gov (United States)

    Reddy, Krishna N; Bellaloui, Nacer; Zablotowicz, Robert M

    2010-03-24

    When glyphosate is applied to glyphosate-resistant (GR) crops, drift to nonglyphosate-resistant (non-GR) crops may cause significant injury and reduce yields. Tools are needed to quantify injury and predict crop losses. In this study, glyphosate drift was simulated by direct application at 12.5% of the recommended label rate to non-GR corn (Zea mays L.) at 3 or 6 weeks after planting (WAP) during two field seasons in the Mississippi delta region of the southeastern USA. Visual plant injury, shikimate accumulation, nitrate reductase activity, leaf nitrogen, yield, and seed composition were evaluated. Effects were also evaluated in GR corn and GR corn with stacked glufosinate-resistant gene at the recommended label rate at 3 and 6 WAP. Glyphosate at 105 g ae/ha was applied once at 3 or 6 weeks after planting to non-GR corn. Glyphosate at 840 (lower label limit) or 1260 (upper label limit) g ae/ha was applied twice at 3 and 6 WAP to transgenic corn. Glyphosate caused injury (45-55%) and increased shikimate levels (24-86%) in non-GR compared to nontreated corn. In non-GR corn, glyphosate drift did not affect starch content but increased seed protein 8-21% while reducing leaf nitrogen reductase activity 46-64%, leaf nitrogen 7-16%, grain yield 49-54%, and seed oil 18-23%. In GR and GR stacked with glufosinate-resistant corn, glyphosate applied at label rates did not affect corn yield, leaf and seed nitrogen, or seed composition (protein, oil, and starch content). Yet, nitrate reductase activity was reduced 5-19% with glyphosate at 840 + 840 g/ha rate and 8-42% with glyphosate at 1260 + 1260 g/ha rate in both GR and GR stacked corn. These results demonstrate the potential for severe yield loss in non-GR corn exposed to glyphosate drift.

  20. Pretreatment of corn stover using wet oxidation to enhance enzymatic digestibility

    DEFF Research Database (Denmark)

    Varga, E.; Schmidt, A.S.; Reczey, K.

    2003-01-01

    Corn stover is an abundant, promising raw material for fuel ethanol production. Although it has a high cellulose content, without pretreatment it resists enzymatic hydrolysis, like most lignocellulosic materials. Wet oxidation (water, oxygen, mild alkali or acid, elevated temperature and pressure......) was investigated to enhance the enzymatic digestibility of corn stover. Six different combinations of reaction temperature, time, and pH were applied. The best conditions (60 g/L of corn stover, 195degreesC, 15 min, 12 bar O-2, 2 g/L of Na2CO) increased the enzymatic conversion of corn stover four times, compared...

  1. Studies On Marine Wood-Borers Of Kali Estuary, Karwar, Karnataka, India

    Science.gov (United States)

    Sanagoudra, S. N.; Neelakanton, K. B.

    2008-05-01

    The damage caused to underwater timber construction in Marine environment by Molluscan and Crustaceans borers is well known and is of great economic significance to all maritime countries having an expanding shipping and fishing industry. Biodeterioration of marine structure, fishing crafts and living in mangrove vegetation is quite severe along the Karwar coast. The destruction is caused by atleast 14 species and 1 variety of borers belonging to the moluscan and crustacean families of the Teredinidae, Pholadidae and Sphaeromatidae. The following species have been so far recorded: Dicyathifer manni, Lyrodus pedicellaatus, L.Massa, Bankia rochi, B. campanellata, Mausitora hedleyi,Martesia striata, M.NMairi,Sphaeroma terebrans, S.annandalei, S. annandalei travancorensis. These borers, particularly, the molluscs have prodigenous fecundity producing enormous number of young ones in one brood. They have unlimited appetite attacking any type woodly materials exposed in the sea. They attack in heavy intensity and, because of their fast rate of growth, destroy timber with in a short time of few months. All this together with their other highly specialized. Adaptations make marine wood borers man's number one enemy in the sea. Along Karwar costs borer damage to timber structure is heavy throughout the year, highest in September to November and lowest in June and July. Ecological and biological aspects of the borers are also discussed. Ref: L.N.Shantakumaran, Sawant S.G., Nair N.B., Anil Angre, Nagabhushanan R. STUDIES ON MARINE WOOD-BORERS OF KALI ESTUARY, KARWAR, KARNATAKA, INDIA

  2. 21 CFR 184.1321 - Corn gluten.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Corn gluten. 184.1321 Section 184.1321 Food and... Substances Affirmed as GRAS § 184.1321 Corn gluten. (a) Corn gluten (CAS Reg. No. 66071-96-3), also known as corn gluten meal, is the principal protein component of corn endosperm. It consists mainly of zein...

  3. Susceptibility of the rice stem borer, Chilo suppressalis (Lepidoptera: Crambidae), to flubendiamide in China.

    Science.gov (United States)

    Wu, Min; Zhang, Shuai; Yao, Rong; Wu, Shunfan; Su, Jianya; Gao, Congfen

    2014-06-01

    The rice stem borer, Chilo suppressalis (Walker), is an important rice pest in China, and has evolved resistance to several classes of insecticides. Flubendiamide is a phthalic diamide insecticide that shows selective insecticidal activity against lepidopterous insects. The susceptibility of 40 field populations of C. suppressalis, collected in 2011 and 2012 in seven provinces of south-eastern China, to flubendiamide was determined through rice seedling dipping bioassay method. Of these 40 populations, seven populations that were seldom exposed to flubendiamide were used to set up the baseline sensitivity, and the LC50 value was 0.092 mg/L. Variation in susceptibility among the 40 field populations was high (34-fold). The range of mean lethal concentration (LC50) values in response to this chemical was between 0.032 mg/L (FS11) and 1.090 mg/L (JH12) across the populations. Substantial variations of the susceptibility to flubendiamide were detected among different geographic populations. There was no significant difference observed between years for most populations, except for populations from Jinhua and Lujiang. Resistance ratios to the chemical ranged from 0.8 to 11.8, indicating that most colonies remained susceptible or showed certain decrease in susceptibility. It was found that 16 of the 40 populations had some level of resistance. However, moderate level of resistance was discovered in only one population from JH12 from Zhejiang province (11.8-fold). Other 15 populations showed low level of resistance (5.1-9.3-fold) to flubendiamide. These data are useful in future monitoring programs for detecting any changes in susceptibility as a result of using flubendiamide.

  4. Effects of Bt-cry1Ah corn pollen on larvae of Apis mellifera ligustica%转Bt-cry1Ah基因玉米花粉对意大利蜜蜂幼虫的影响

    Institute of Scientific and Technical Information of China (English)

    代平礼; 周玮; 张杰; 郎志宏; 周婷; 王强; 崔红娟; 姜玮瑜; 吴艳艳

    2012-01-01

    The cry1Ah gene, which displays high toxicity against Lepidopteran larvae, was one of the novel insecticidal genes cloned from Bacillus thuringiensis isolate BT8. Cry1Ah protein have higher toxicity to the Asian corn borer ( Ostrinia furnacalis( Guen6e) ) than any other cry1A genes. The crylAh gene was therefore a candidate gene for insect resistant transgenic corn research. Pollen is a significant component of the diet of honeybees. Thus the honeybee may serve as one of the key species to be tested for the potential adverse effects of transgenic crops and assessment of impacts on honeybees is an essential part of the risk assessment process for Bt cry1Ah gene corn. The effects of dietary transgenic Bt corn pollen on honeybee worker larvae of Apis mellifera ligustica Spinola was examined. We measured cap rate, emergence rate, and immature stage after 4-6-day-old larvae were fed either crylAh corn pollen, regular corn pollen, mixed bee pollen and a control. There were no significant differences in all the parameters measured between bees fed these diets. These results suggest that transgenic Bt corn pollen does not pose a threat to honeybee larval development.%新型杀虫蛋白基因crylAh基因是中国农业科学院植物保护研究所从Bt菌株BT8中鉴定克隆的,其编码蛋白对鳞翅目害虫具有强毒力,尤其对亚洲玉米螟Ostrinia furnacalis(Guenée)的毒力强于目前使用的cry1A类基因.转cry1Ah基因抗虫玉米具有很好的应用前景.花粉是蜜蜂重要的食物来源,蜜蜂是转基因植物安全性评价的关键测试生物.因此,开展转crylAh基因玉米对蜜蜂的安全性研究很有必要.给意大利蜜蜂Apis mellifera ligustica Spinola蜂群中4~6日龄幼虫饲喂转基因玉米花粉、常规玉米花粉、杂花粉,哺育蜂饲喂为对照.转基因玉米花粉对意大利蜜蜂封盖率、出房率和发育历期没有显著影响.表明转cry1Ah基因玉米花粉对意大利蜜蜂幼虫的存活和发育没有不良影响.

  5. Detoxification of zearalenone and ochratoxin A by ozone and quality evaluation of ozonised corn.

    Science.gov (United States)

    Qi, Lijun; Li, Yulin; Luo, Xiaohu; Wang, Ren; Zheng, Ruihang; Wang, Li; Li, Yongfu; Yang, Dan; Fang, Wenmiao; Chen, Zhengxing

    2016-11-01

    Zearalenone (ZEN) and ochratoxin A (OTA) are secondary toxic metabolites of fungi that can contaminate a wide range of food and feedstuff. In this study, the effects of ozone treatment on ZEN and OTA and the quality of ozonised corn are investigated. Ozone significantly affects ZEN and OTA solutions. ZEN was undetectable 5 s after being treated with 10 mg l(-1) ozone. However, OTA was resistant to ozonation with a degradation rate of 65.4% after 120 s of treatment. Moreover, ZEN and OTA solutions were difficult to degrade after being dried by a nitrogen stream. Results showed that ozone effectively degraded ZEN and OTA in corn. The degradation rates of ZEN and OTA in corn increased with ozone concentration and treatment time. The degradation of ZEN and OTA at different ozone concentrations appropriately conformed to first-order kinetics with an R(2) value > 0.8749. Furthermore, under the same conditions, corn with increased moisture content (MC) (19.6%) was more sensitive to ozone than corn with a low MC (14.1%). When treated with 100 mg l(-1) ozone for 180 min, ZEN and OTA in corn with 19.6% MC decreased by 90.7% and 70.7%, respectively. To evaluate the quality of ozonised corn, subsequent quality experiments were conducted using corn samples treated at different times with 100 mg l(-1) ozone. The MC of corn decreased after ozone treatment. The whiteness and yellowness of the corn increased and decreased with increasing time, respectively. The fatty acid value of the corn increased significantly (p ≤ 0.05) after 180 min of treatment. This study verified that ozone can effectively degrade ZEN and OTA in corn, but slightly affected corn quality.

  6. Coffee berry borer joins bark beetles in coffee klatch.

    Directory of Open Access Journals (Sweden)

    Juliana Jaramillo

    Full Text Available Unanswered key questions in bark beetle-plant interactions concern host finding in species attacking angiosperms in tropical zones and whether management strategies based on chemical signaling used for their conifer-attacking temperate relatives may also be applied in the tropics. We hypothesized that there should be a common link in chemical signaling mediating host location by these Scolytids. Using laboratory behavioral assays and chemical analysis we demonstrate that the yellow-orange exocarp stage of coffee berries, which attracts the coffee berry borer, releases relatively high amounts of volatiles including conophthorin, chalcogran, frontalin and sulcatone that are typically associated with Scolytinae chemical ecology. The green stage of the berry produces a much less complex bouquet containing small amounts of conophthorin but no other compounds known as bark beetle semiochemicals. In behavioral assays, the coffee berry borer was attracted to the spiroacetals conophthorin and chalcogran, but avoided the monoterpenes verbenone and α-pinene, demonstrating that, as in their conifer-attacking relatives in temperate zones, the use of host and non-host volatiles is also critical in host finding by tropical species. We speculate that microorganisms formed a common basis for the establishment of crucial chemical signals comprising inter- and intraspecific communication systems in both temperate- and tropical-occurring bark beetles attacking gymnosperms and angiosperms.

  7. Binding of Bacillus thuringiensis Cry1A toxins with brush border membrane vesicles of maize stem borer (Chilo partellus Swinhoe).

    Science.gov (United States)

    Sharma, Priyanka; Nain, Vikrant; Lakhanpaul, Suman; Kumar, P A

    2011-02-01

    Maize stem borer (Chilo partellus) is a major insect pest of maize and sorghum in Asia and Africa. Bacillus thuringiensis (Bt) δ-endotoxins have been found effective against C. partellus, both in diet-overlay assay and in transgenic plants. Gene stacking as one of the resistance management strategies in Bt maize requires an understanding of receptor sharing and binding affinity of δ-endotoxins. In the present study, binding affinity of three fluorescein isothiocyanate labeled Cry1A toxins showed high correlation with the toxicity of respective δ-endotoxins. Competitive binding studies showed that Cry1Ab toxins share some of the binding sites with Cry1Aa and Cry1Ac with low affinity and that Cry1Ab may have additional binding sites that are unavailable to the other two toxins tested.

  8. Padrão eletroforético de proteínas resistentes ao calor em sementes de milho Electrophorectic pattern of the heat resistant proteins of corn seeds

    Directory of Open Access Journals (Sweden)

    Solange Carvalho Barrios Roveri José

    2005-02-01

    Full Text Available Na aquisição e manutenção da tolerância à dessecação de sementes, há vários mecanismos envolvidos, entre eles a indução das proteínas resistentes ao calor. O objetivo deste trabalho foi avaliar mudanças no padrão eletroforético das proteínas resistentes ao calor de sementes de milho submetidas a alta temperatura de secagem, associando-as à sua tolerância. Foram utilizadas sementes de linhagens, híbridos simples e híbridos recíprocos colhidas com teor de água de aproximadamente 35% e secadas a 45°C. Sementes das linhagens secadas à sombra foram utilizadas como controle e sua qualidade fisiológica foi avaliada por meio do teste de germinação. As proteínas resistentes ao calor foram extraídas de eixos embrionários das sementes em tampão Tris HCl 0,05 M. Não foi possível determinar uma banda específica da fração das proteínas resistentes ao calor que possa servir como marcador da tolerância à alta temperatura de secagem. Houve estabilidade nos padrões de bandas das proteínas provenientes de sementes submetidas à secagem artificial e natural, mesmo quando foram observadas variações nos valores de germinação. Os padrões eletroforéticos das proteínas resistentes ao calor foram semelhantes entre as sementes híbridas e os respectivos recíprocos.Several mechanisms are involved in the acquisition and maintenance of desiccation tolerance by the seeds. One of these mechanisms is related to the induction of heat resitant proteins. The objective of this work was to evaluate changes in the electophorectic patterns of the heat resistant proteins of corn seeds submitted to high drying temperature associating their expression with drying tolerance. Seeds of breeding lines, simple hybrids and respective reciprocals hybrids were utilized. The seeds were harvested with approximately 35% of water content and dried at 45°C. Seeds of lines dried under shadow were used as control and the physiological quality was

  9. Damage and economical threshold of yellow stem borer (Tryporyza incertulas) on rice

    Institute of Scientific and Technical Information of China (English)

    WANGHuadi; ZHANGZuosheng

    1997-01-01

    Systematic measurements to damage and yield loss due to yellow stem borer (YSB) were made in the single crop and double crop areas of Hangzhou, Jiaxing, and Huzhou cities,northern Zhejiang Province in 1987-1994.

  10. Illustrated guide to the emerald ash borer, Agrilus planipennis Fairmaire and related species (Coleoptera, Buprestidae)

    Science.gov (United States)

    The 33 species of Agrilus (Coleoptera: Buprestidae) hypothesized to be most closely related to Agrilus planipennis Fairmaire (the emerald ash borer), are described and illustrated. Morphology (adults and immatures), biology, distribution, detailed taxonomic history and systematics are presented fo...

  11. Increment-borer methods for determining fire history in coniferous forests

    Science.gov (United States)

    Stephen W. Barrett; Stephen F. Arno

    1988-01-01

    Describes use of increment borers for interpreting fire history in coniferous forests. These methods are intended for use in wildernesses, parks, and other natural areas where sawing cross-sections from fire-scarred trees is prohibited.

  12. Impact of drought genetics on irrigated corn production

    Science.gov (United States)

    Corn is the major irrigated crop in the High Plains of Colorado, Nebraska, and Kansas. Declining water levels in the High Plains Aquifer have reduced well capacity such that limited irrigation strategies must be employed. Crop breeding advances have led to the introduction of drought resistant hybri...

  13. All European Ash Species are Susceptible to Emerald Ash Borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae – a Far Eastern Invader

    Directory of Open Access Journals (Sweden)

    Yu. N. Baranchikov

    2014-12-01

    Full Text Available Emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae – an example of a destructive invasive insect which abruptly enlarged its initially East-Asian area in 80–90s of the previous century. Nowadays this species is the main pest of ash (Fraxinus trees in USA and Canada and is quickly spreading over 11 administrative regions of Russia. It is very important to determine a list of possible host plants of A. planipennis for the pest risk assessment of invasion of this pest over the territory of Central and Western Europe. In its native area – North-Eastern Asia – this buprestid is a secondary consumer of dying trees of East-Asian ash species F. сhinensis and F. mandshurica. Healthy trees of these species are highly resistant to the pest. No examples of resistant ash species were found at North American continent. Documentary data are presented for the first time on infestation of three European ash species at the territory of the Main Botanical Garden of the Russian Academy of Sciences in Moscow, Russia by the emerald ash borer. At the first time this pest was registered at the garden in 2011. During the period of 2010–2014 EAB killed from 70 to 100 % of trees of European ash species: Fraxinus excelsior, F. angustifolia (= F. oxycarpa and F. ornus. At the same period from 81 to 90 % of specimens of North American ash species (F. pennsylvanica and F. americana were killed by this buprestid. Simultaneously dead trees of Asian species F. mandshurica and F. chinensis (= F. rhynchophyla did not carry any trace of EAB infestation. This case study is a good example of the «sentinel trees» concept’s usefulness. Arboretums with collections of non-native plants may serve as «ecological traps» for the local pests and pathogens – potential invasive organisms in the source regions of introduced plants.

  14. Susceptibility of field populations of sugarcane borer from non-Bt and Bt maize plants to five individual Cry toxins

    Institute of Scientific and Technical Information of China (English)

    Fangneng Huang; Mukti N.Ghimire; B.Rogers Leonard; Yu-Cheng Zhu; Graham P.Head

    2012-01-01

    Sugarcane borer,Diatraea saccharalis (F.),is a major target of transgenic maize expressing Bacillus thuringiensis (Bt) proteins in South America and the US midsouth region.Resistance development in targct pest populations is a major threat to the sustainable use of Bt crops.In our field trials in 2009,a significant number of live borers and plant injury from D.saccharalis were observed in an experimental SmartStaxTM maize line.The objective of this study was to assess the relative susceptibility of two field populations ofD.saccharalis collected from non-Bt and Bt maize plants containing SmartStaxTM traits to five individual Cry proteins.The five Bt proteins included two proteins (Cry1A.105 and Cry2Ab2) that were expressed in SmartStaxTM maize plants and three other common Bt proteins (Cry1Aa,Cry1Ab and Cry1Ac) that were not produced in SmartStaxTM.Larval mortality and growth inhibition on Bt diet of the fourth gcneration after field collections were evaluated 7 days after release of neonates on the diet surface.The laboratory bioassays showed that 50% lethal concentration (LC50) values for Cry1 A.105 and Cry2Ab2 for the population originated from Bt plants were 3.55-and 1.34-fold greater,respectively,than those of the population collected from non-Bt plants.In contrast,relative to the population from non-Bt plants,the LC50 of the population sampled from Bt plants were 3.85-,2.5-and 1.64-fold more sensitive to Cry1Aa,Cry1Ab and Cry1Ac,respectively.The resuits did not provide clear evidence to conclude that the observed field survival of D.saccharalis on Bt plants was associated with increased levels of resistance.

  15. Biotic and abiotic factors affect green ash volatile production and emerald ash borer adult feeding preference.

    Science.gov (United States)

    Chen, Yigen; Poland, Therese M

    2009-12-01

    The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an exotic woodborer first detected in 2002 in Michigan and Ontario and is threatening the ash resource in North America. We examined the effects of light exposure and girdling on green ash (Fraxinus pennsylvanica Marsh) volatile production, and effects of light exposure, girdling, and leaf age on emerald ash borer adult feeding preferences and phototaxis. Green ash seedlings grown under higher light exposure had lower amounts of three individual volatile compounds, (Z)-3-hexenol, (E)-beta-ocimene, and (Z,E)-alpha-farnesene, as well as the total amount of six detected volatile compounds. Girdling did not affect the levels of these volatiles. Emerald ash borer females preferred mature leaves, leaves from girdled trees, and leaves grown in the sun over young leaves, leaves from nongirdled trees, and leaves grown in the shade, respectively. These emerald ash borer preferences were most likely because of physical, nutritional, or biochemical changes in leaves in response to the different treatments. Emerald ash borer females and males showed positive phototaxis in laboratory arenas, a response consistent with emerald ash borer preference for host trees growing in sunlight.

  16. Establishing alfalfa in silage corn

    Science.gov (United States)

    According to recent agricultural statistics, alfalfa was planted on 0.44 million acres and harvested from 2.2 million acres and silage corn was planted and harvested from 1.0 million acres per year in Wisconsin. Because both crops are often grown in rotation, alfalfa could be interseeded at corn pla...

  17. Establishing alfalfa in corn silage

    Science.gov (United States)

    According to recent agricultural statistics, alfalfa was planted on 0.44 million acres and harvested from 2.2 million acres, and corn silage was planted and harvested from 1.0 million acres per year in Wisconsin. Because both crops are often grown in rotation, alfalfa could be interseeded at corn pl...

  18. Resistência de genótipos de sorgo ao pulgão Rhopalosiphum maidis (Fitch, 1856 (Hemiptera: Aphididae: III. Efeito no desenvolvimento da planta Resistance of sorghum genotypes to the corn leaf aphid Rhopalosiphum maidis (Fitch, 1856 (Hemiptera: Aphididae: III. Effect in plant development

    Directory of Open Access Journals (Sweden)

    Alysson Rodrigo Fonseca

    2004-06-01

    Full Text Available Realizou-se este trabalho com o objetivo de estudar, em casa-de-vegetação, a tolerância como mecanismo de resistência do sorgo ao pulgão Rhopalosiphum maidis (Fitch, em experimentos conduzidos no Centro Nacional de Pesquisa de Milho e Sorgo - CNPMS/ EMBRAPA, Sete Lagoas, MG. Oito genótipos de sorgo, sendo sete de resistência conhecida ao pulgão Schizaphis graminum (Rondani e a cultivar comercial BRS303, foram semeados em uma densidade de três sementes por vaso com capacidade para 5 Kg de solo. Após a emergência, realizou-se um desbaste, deixando-se apenas uma planta, que foi coberta por uma gaiola cilíndrica revestida com "voil". Aos onze dias após o plantio, metade dos vasos contendo cada genótipo foi infestada com 25 pulgões adultos por planta, enquanto a outra metade foi utilizada como tratamento-testemunha, avaliando-se, semanalmente, a altura e o peso fresco e seco das plantas infestadas e não-infestadas. O delineamento experimental foi o inteiramente casualizado, em parcela subdividida, alocando-se, nas parcelas, os genótipos e, nas subparcelas, os períodos de avaliação, com 10 repetições. Observou-se que 'GR1.1.1.1.1', 'BRS303', 'IS2293', 'GSBTx399', 'TX430 (GR' e 'TX2567' apresentaram a tolerância como mecanismo de resistência, embora essa tenha sido mais evidente nos três primeiros genótipos.The objective of this work was to investigate in a greenhouse, the tolerance as a resistance mechanism of sorghum to the corn leaf aphid Rhopalosiphum maidis (Fitch in experiments conducted in the National Corn and Sorghum Research Center of EMBRAPA, in Sete Lagoas, MG, Brazil. Eight sorghum genotypes, seven of them being known as resistant to the greenbug Schizaphis graminum (Rondani and the commercial cultivar BRS303, were sown at a density of three seeds per pot with a capacity for 5 kg of soil. After emergence, a thinning was accomplished leaving only one plant, which was covered with a cylindrical cage, "voil

  19. Determination of Cry9C protein in processed foods made with StarLink corn.

    Science.gov (United States)

    Diaz, Carmen; Fernandez, Cecilia; McDonald, Regina; Yeung, Jupiter M

    2002-01-01

    StarLink (Aventis CropScience US) hybrid corn has been genetically modified to contain a pesticidal protein, Cry9C, which makes it more resistant than traditional varieties to certain types of corn insect pests. Unlike other varieties of genetically engineered corn, the U.S. Environmental Protection Agency authorized the use of StarLink corn for animal feed and industrial use only, not for human consumption. However, some Cry9C-containing corn was mistakenly or inadvertently comingled with yellow corn intended for human food use. Because corn containing the Cry9C construct was not approved for human use, the U.S. Food and Drug Administration considers food containing it to be adulterated. Consequently, this regulatory violation resulted in hundreds of recalls of corn-based products, such as taco shells, containing cry9C DNA. Detecting the novel protein in StarLink corn is an emerging issue; therefore, there is no standardized or established analytical method for detecting Cry9C protein in processed foods. We developed a procedure for quantitation of Cry9C protein, with validation data, in processed food matrixes with a limit of quantitation at 1.7 ng/g (ppb), using a commercial polyclonal antibody-based Cry9C kit that was intended for corn grain samples. Intra- and interassay coefficients of variation were 2.8 and 11.8%, respectively. Mean recoveries were 73 and 85% at 2 and 5 ng/g Cry9C fortifications, respectively, for 19 control non-StarLink corn-based matrixes. Our data demonstrate only 0-0.5% of Cry9C protein survived the processing of tortilla chips and soft tortillas made from 100% StarLink corn, resulting in levels from below the detection limit to 45 ppb.

  20. Corn in consortium with forages

    Directory of Open Access Journals (Sweden)

    Cássia Maria de Paula Garcia

    2013-12-01

    Full Text Available The basic premises for sustainable agricultural development with focus on rural producers are reducing the costs of production and aggregation of values through the use crop-livestock system (CLS throughout the year. The CLS is based on the consortium of grain crops, especially corn with tropical forages, mainly of the genus Panicum and Urochloa. The study aimed to evaluate the grain yield of irrigated corn crop intercropped with forage of the genus Panicum and Urochloa. The experiment was conducted at the Fazenda de Ensino, Pesquisa e Extensão – FEPE  of the Faculdade de Engenharia - UNESP, Ilha Solteira in an Oxisol in savannah conditions and in the autumn winter of 2009. The experimental area was irrigated by a center pivot and had a history of no-tillage system for 8 years. The corn hybrid used was simple DKB 390 YG at distances of 0.90 m. The seeds of grasses were sown in 0.34 m spacing in the amount of 5 kg ha-1, they were mixed with fertilizer minutes before sowing  and placed in a compartment fertilizer seeder and fertilizers were mechanically deposited in the soil at a depth of 0.03 m. The experimental design used was a randomized block with four replications and five treatments: Panicum maximum cv. Tanzania sown during the nitrogen fertilization (CTD of the corn; Panicum maximum cv. Mombaça sown during the nitrogen fertilization (CMD of the corn; Urochloa brizantha cv. Xaraés sown during the occasion of nitrogen fertilization (CBD of the corn; Urochloa ruziziensis cv. Comumsown during the nitrogen fertilization (CRD of the corn and single corn (control. The production components of corn: plant population per hectare (PlPo, number of ears per hectare (NE ha-1, number of rows per ear (NRE, number of kernels per row on the cob (NKR, number of grain in the ear (NGE and mass of 100 grains (M100G were not influenced by consortium with forage. Comparing grain yield (GY single corn and maize intercropped with forage of the genus Panicum

  1. Study on Transferring Gene of Salt Tolerance and Drought Resistance into Corn Inbred Line by Pollen Tube Path%用花粉管通道法将抗旱耐盐基因导入玉米自交系的研究

    Institute of Scientific and Technical Information of China (English)

    董春林; 张明义; 林忠平; 张彦芹; 杨丽莉; 梁改梅; 孙洁

    2011-01-01

    Using the improved pollen tube path method, trehalose synthase gene (TPS) was transferred into corn inbred line Zheng 58.In the 3 ~ 5 leaf stage, the selection of spraying Basta (0.7%)solution was combined with PCR test, the new gene had been imported into the plants and integrated into the plant chromosomes.The initial drought-tolerance investigation in fields confirmed that the drought-tolerance of transgenic plants was higher than the non-transformed.The results showed that the new corn drought resistance germplasm could be gained by pollen tube path,and it is a new feasible and effective way for corn drought resistance breeding.%采用改进的花粉管通道法,将海藻糖合酶基因(TPS)导入玉米自交系郑58中.3~5叶期时喷雾Basta(0.7%)溶液筛选,进行PCR检测,结果表明,目的基因已导入转化植株并整合到植株染色体上.田间初步抗旱性检测显示,转化植株(株系)的抗旱性高于对照植株.应用改进的花粉管通道法导入抗旱目的基因,可以得到玉米抗旱新资源,是一种切实有效的抗旱育种新方法.

  2. 21 CFR 184.1262 - Corn silk and corn silk extract.

    Science.gov (United States)

    2010-04-01

    ... filaments are extracted with dilute ethanol to produce corn silk extract. The extract may be concentrated at... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Corn silk and corn silk extract. 184.1262 Section... SAFE Listing of Specific Substances Affirmed as GRAS § 184.1262 Corn silk and corn silk extract....

  3. Milho verde: avaliação da resistência à lagarta da espiga, da espessura do pericarpo e outras características agronômicas Green corn: evaluation of earworm resistance, pericarp thickness and other agronomic characters

    Directory of Open Access Journals (Sweden)

    Eduardo Sawazaki

    1990-01-01

    Full Text Available Em Pariquera-Açu, SP, em maio de 1987, foi plantado um ensaio com o objetivo de avaliar as variedades IAC Azteca Centenário, IAC Maya Latente, IAC-1 e IAC-VD 2 e dois híbridos comerciais de milho verde, Agroceres 162 e Cargill 742, quanto à resistência à lagarta da espiga, espessura do pericarpo do grão e outros caracteres de importância agronômica. O ataque da lagarta foi avaliado utilizando-se a escala modificada por Widstrom e a contagem do furo de saída da lagarta. A espessura do pericarpo, medida através de um relógio comparador, foi retirada de duas posições de grãos embebidos em solução de glicerol e de uma posição em grãos secos. Outros caracteres agronômicos estudados foram: germinação e vigor das sementes usadas; estande final; altura da planta e da espiga; porcentagem de palha na espiga; número, rendimento, peso total e peso médio das espigas comerciáveis; peso de grãos e resistência a Exserohilum turticum (Pass. Leonard e Suggs. As variedades, com exceção da IAC-VD 2, apresentaram produção inferior aos híbridos. Quanto ao ataque do E. turcicum, o Cargill 742, IAC-VD 2 e IAC Maya Latente foram resistentes, e 'Agroceres 162', intermediário, 'IAC-1' e IAC Azteca Centenário', suscetíveis. Os resultados obtidos pelos métodos de avaliação do ataque da lagarta da espiga - a escala de Widstrom e a contagem do furo de saída - foram equivalentes na discriminação dos genótipos. A 'IAC Azteca Centenária foi a mais resistente e a IAC Maya Latente, a mais suscetível. A espessura do pericarpo variou entre os genótipos, sendo maior no 'Agroceres 162' e IAC Azteca Centenário'.The varieties IAC Azteca Centenário, IAC Maya Latente, IAC-1 and IAC-VD 2 and the hybrid Cargill 742 and Agroceres 162 were evaluated for resistance to corn earworm, pericarp thickness and other agronomic characters, in a trial planted at May 1987 in the Pariquera-Açu Experimental Station, State of São Paulo, Brazil. The earworm

  4. 9 CFR 319.100 - Corned beef.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Corned beef. 319.100 Section 319.100... Corned beef. “Corned Beef” shall be prepared from beef briskets, navels, clods, middle ribs, rounds... A or Subchapter B. Canned product labeled “Corned Beef” shall be prepared so that the weight of...

  5. Life stage and resistance effects in modelling phosphine fumigation of Rhyzopertha dominica (F.)

    OpenAIRE

    Thorne, J.; Fulford, G.; Ridley, A.; Schlipalius, D.; P. Collins

    2010-01-01

    Resistance to phosphine in insect pests of stored grain is a serious problem and there is a world-wide need for the development of sustainable resistance management strategies. Here we introduce results from a new mathematical model of resistance development that includes all life stages, rates of oviposition, natural mortality and mortality under fumigation in relation to resistant genotype. The example we discuss is phosphine resistance in the lesser grain borer, Rhyzopertha dominica where ...

  6. Ethanol extraction of phytosterols from corn fiber

    Science.gov (United States)

    Abbas, Charles; Beery, Kyle E.; Binder, Thomas P.; Rammelsberg, Anne M.

    2010-11-16

    The present invention provides a process for extracting sterols from a high solids, thermochemically hydrolyzed corn fiber using ethanol as the extractant. The process includes obtaining a corn fiber slurry having a moisture content from about 20 weight percent to about 50 weight percent solids (high solids content), thermochemically processing the corn fiber slurry having high solids content of 20 to 50% to produce a hydrolyzed corn fiber slurry, dewatering the hydrolyzed corn fiber slurry to achieve a residual corn fiber having a moisture content from about 30 to 80 weight percent solids, washing the residual corn fiber, dewatering the washed, hydrolyzed corn fiber slurry to achieve a residual corn fiber having a moisture content from about 30 to 80 weight percent solids, and extracting the residual corn fiber with ethanol and separating at least one sterol.

  7. The lost p1 allele in sh2 sweet corn: Quantitative effects of p1 and a1 genes on the concentrations of maysin, apimaysin, methoxymaysin, and chlorogenic acid in maize silk, and the antibiotic activity against corn earworm

    Science.gov (United States)

    The flavor of sh2 super-sweet corn is preferred by consumers. Unfortunately, sh2 sweet corn has very little genetic variation for resistance to insects. This presentation will review and summarize the studies of the functions of two loci, p1 and a1. The P1 allele can have a major role in the resista...

  8. The Comparison of Sugar Components in the Developing Grains of Sweet Corn and Normal Corn

    Institute of Scientific and Technical Information of China (English)

    LIU Peng; HU Chang-hao; DONG Shu-ting; WANG Kong-jun; ZHANG Ji-wang

    2003-01-01

    The sugar components and their dynamic variation in the developing grains of sweet corn(Zeamays L. seccharata Sturt)and normal corn (Zea mays L. indentata Sturt) were compared. There are WSP(water-soluble polysaccharides), sucrose, fructose, glucose, mannitol and sorbitol in both sweet corn and nor-mal corn, but no maltose. Two components with different degrees of polymerization (D. P. N) were detected inthe sweet corn; only one of them was detected in the normal corn 20 days after pollination. With the develop-ment of grains, the total soluble sugar content(TSS)in sweet corn increased, but in normal corn it decreased.The dynamic variation of WSP, sucrose, glucose, fructose, mannitol and sorbitol in sweet and normal corngrains are different. The contents of sugar components in the sweet corn grains are higher than that in the nor-mal corn. Sweet corn accumulates less starch than normal corn.

  9. Relations between two rice borers in Surinam, Rupela albinella (Cr.) and Diatraea saccharalis (F.), and their hymenopterous larval parasites

    NARCIS (Netherlands)

    Hummelen, P.J.

    1974-01-01

    In many tropical countries, lepidopterous stem borers are major pests of the rice crop. Study of the rice borers in Surinam, Rupela albinella and Diatraea saccharalis, was made in the Paramaribo area, at the experimental station 'CELOS' during 1971, 1972 and 1973, since data on the ecology and econo

  10. Monitoring the establishment and abundance of introduced parasitoids of emerald ash borer larvae in Maryland, U.S.A

    Science.gov (United States)

    Classical biological control can be an important tool for managing invasive species such as emerald ash borer, Agrilus planipennis Fairmaire. Emerald ash borer is now widespread throughout the United States, and was first detected in Maryland in 2003. The biological control program to manage emera...

  11. Observations on the ecology and epidemiology of Xyleborus destruens Bldf., the near-primary borer in teak plantations in Java

    NARCIS (Netherlands)

    Kalshoven, L.G.E.

    1961-01-01

    While looking for a suitable plot for girth-increment investigations in a thriving 8-year old teak plantation near Batang, Central Java, in June 1918, officers of the Forest Research Institute discovered an unknown, rather conspicuous borer infestation of the trunks. The borer, recognized to be a

  12. Ecological and physiological aspects of aestivation-diapause in the larvae of twe pyralid stalk borers of maize in Kenya

    NARCIS (Netherlands)

    Scheltes, P.

    1978-01-01

    Stalk borers are highly destructive to a large number of important graminaceous crops all over the world. Some examples of economically important stalk borers and a general description of their life-cycle are mentioned in chapter 1. In the same chapter difficulties in controlling the insects are des

  13. Strategic removal of host trees in isolated, satellite infestations of emerald ash borer can reduce population growth

    Science.gov (United States)

    Samuel J. Fahrner; Mark Abrahamson; Robert C. Venette; Brian H. Aukema

    2017-01-01

    Emerald ash borer is an invasive beetle causing significant mortality of ash trees (Fraxinus spp.) in North America and western Russia. The invasive range has expanded to more than half of the states in the United States since the initial detection in Michigan, USA in 2002. Emerald ash borer is typically managed with a combination of techniques...

  14. Artificial diet sandwiches reveal sub-social behavior in the coffee berry borer Hypothenemus hampei (Coleoptera: Scolytinae)

    Science.gov (United States)

    A diet sandwich, consisting of coffee berry borer artificial diet within two glass panes, has been developed to elucidate the behavior of the coffee berry borer, an insect that in nature spends most of its life cycle inside the coffee berry. Various types of behavior have been observed for the first...

  15. Relations between two rice borers in Surinam, Rupela albinella (Cr.) and Diatraea saccharalis (F.), and their hymenopterous larval parasites

    NARCIS (Netherlands)

    Hummelen, P.J.

    1974-01-01

    In many tropical countries, lepidopterous stem borers are major pests of the rice crop. Study of the rice borers in Surinam, Rupela albinella and Diatraea saccharalis, was made in the Paramaribo area, at the experimental station 'CELOS' during

  16. Spatial and temporal distribution of fungi and wood-borers in the coastal tropical waters of Goa, India

    Digital Repository Service at National Institute of Oceanography (India)

    Vishwakiran, Y.; Thakur, N.L.; Raghukumar, S.; Yennawar, P.L.; Anil, A.C.

    on the wood throughout the year. On the contrary, growth of most fungi and five species of wood-borers was adversely affected during the low salinity monsoons. Two fungi and one wood-borer colonized wood preferentially during the monsoon season. Contrary...

  17. Draft genome of the most devastating insect pest of coffee worldwide: the coffee berry borer, Hypothenemus hampei

    Science.gov (United States)

    The coffee berry borer, Hypothenemus hampei, is the most economically important insect pest of coffee worldwide, causing millions of dollars in yearly losses to coffee growers. We present the third genomic analysis for a Coleopteran species, a draft genome of female coffee berry borers. The genome s...

  18. Susceptibility of field populations of the fall armyworm (Lepidoptera: Noctuidae) from Florida and Puerto Rico to purified Cry1F protein and corn leaf tissue containing single and pyramided Bt genes

    Science.gov (United States)

    Larval survival of Cry1F-susceptible (FL), -resistant (PR and Cry1F-RR), and -heterozygous (FL x PR and Cry1F-RS) populations of the fall armyworm, Spodoptera frugiperda (J.E. Smith) to purified Cry1F protein and corn leaf tissue of seven Bacillus thuringiensis (Bt) corn hybrids and five non-Bt corn...

  19. Development of Corn Stover Biofuel: Impacts on Corn and Soybean Markets and Land Rotation

    OpenAIRE

    Taheripour, Farzad; Tyner, Wallace E.; Fiegel, Julie

    2013-01-01

    This paper first develops a partial equilibrium (PE) model to examine impacts of converting corn stover to biofuel on markets for corn and soybeans at the national market level. The PE model links gasoline, corn ethanol, dried distiller grains, corn, soybeans, and soybean meal markets in the presence and absence of a viable market for corn stover. The model also includes a technology which converts corn stover to bio-gasoline (a drop-in biofuel). The model evaluates profitability of the ethan...

  20. Corn prices and alcohol production

    Energy Technology Data Exchange (ETDEWEB)

    Wangsness, W.

    1979-09-01

    Corn has attracted the most attention as a feedstock for alcohol production. The economics are computed on the basis of fixed costs for labor, taxes, depreciation, heat, and enzymes. Changes in feedstock prices are shown to determine whether corn is used for energy or protein as cattle feed. Comparisons of gasoline refined from imported oil and gasohol are made for a range of prices per bushel and oil prices per barrel. (DCK)

  1. Aerial insecticide treatments for management of Dectes stem borer, Dectes texanus, in soybean.

    Science.gov (United States)

    Sloderbeck, P E; Buschman, L L

    2011-01-01

    The Dectes stem borer, Dectes texanus LeConte (Coleoptera: Cerambycidae), is an increasingly important pest of soybean and sunflower in central North America. Nine large-scale field trials were conducted over a 3-year period to determine if Dectes stem borer could be managed with insecticide treatments. Aerial applications of lambda on July 6, 12 and 15 were successful in significantly reducing adults, but applications on July 1, 20 and 24 were less successful. These data suggest that for central Kansas two aerial applications may be required to control Dectes stem borers in soybean. Based on our experience the first application should be made at the peak of adult flight about July 5(th) and the second application 10 days later. The local treatment schedule should be developed to follow the local Dectes stem borer adult emergence pattern. Treated aerial strips 59 m (195 ft) wide were not large enough to prevent reinfestation, but treated half-circles (24 ha or 60 acres) were successful in reducing in Dectes stem borer infestation of soybean. Sweep net samples of adults were not successful in identifying a treatment threshold, so treatment decisions will need to be based on field history of infestation. Further studies are needed to identify better sampling methods that can be used to establish treatment thresholds and to refine the best timing for treatments.

  2. Do rice water weevils and rice stem borers compete when sharing a host plant?

    Institute of Scientific and Technical Information of China (English)

    Sheng-wei SHI; Yan HE; Xiang-hua JI; Ming-xing JIANG; Jia-an CHENG

    2008-01-01

    The rice water weevil (RWW) Lissorhoptrus oryzophilus Knsehel (Coleoptera: Curculionidae) is an invasive insect pest office Oryza sativa L. in China. Little is known about the interactions of this weevil with indigenous herbivores. In the present study, adult feeding and population density of the weevil, injury level of striped stem borer Chilo suppressalis (Walker) (Lepi-doptera: Pyralidae) and pink stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) to rice, as well as growth status of their host plants were surveyed in a rice field located in Southeastern Zhejiang, China, in 2004 with the objective to discover interspecific interactions on the rice. At tillering stage, both adult feeding of the weevil and injury of the stem borers tended to occur on larger tillers (bearing 5 leaves) compared with small tillers (bearing 24 leaves), but the insects showed no evident competition with each other. At booting stage, the stem borers caused more withering/dead hearts and the weevil reached a higher density on the plants which had more productive tillers and larger root system; the number of weevils per tiller correlated nega-tively with the percentage of withering/dead hearts of plants in a hill. These observations indicate that interspecific interactions exist between the rice water weevil and the rice stem borers with negative relations occurring at booting or earlier developmental stages of rice.

  3. Assessment of maize stem borer damage on hybrid maize varieties in Chitwan, Nepal

    Directory of Open Access Journals (Sweden)

    Buddhi Bahadur Achhami

    2015-12-01

    Full Text Available Maize is the second most important cereal crop in Nepal. However, national figure of grain production still remains below than the world's average grain production per unit area. Thus, this experiment was designed to determine the suitable time of maize planting, and to assess the peak period of one of the major insects, maize stem borer, in Chitwan condition. The results showed that plant damage percentage as per the maize planting month varies significantly, and the average plant damage percentage by stem borer was up to 18.11%. Length of the feeding tunnel in maize stem was significantly higher in January than July. In case of exit holes made by borer counted more than four holes per plant that were planted in the month of January. All in all, except the tunnel length measurement per plant, we observed similar pattern in other borer damage parameters such as exit whole counts and plant damage percentage within the tested varieties. Stem borer damage was not significantly affect on grain yield.

  4. Biology and damage traits of emerald ash borer (Agrilus planipennis Fairmaire) in China

    Institute of Scientific and Technical Information of China (English)

    XIA WEI; YUN WU; RICHARD REARDON; TIE-HUAN SUN; MIN LU; JIANG-HUA SUN

    2007-01-01

    Emerald ash borer (Agrilusplanipennis Fairmaire)(Coleoptera: Buprestidae) is a major stem borer of ash (Fraxinus spp.). It is univoltine in Tianjin, while it is semivoltine in Heilongjiang Province, and both univoltine and semivoltine in Changchun, Jilin Province,where the majority is univoltine. The longevity of emerald ash borer adults is 17.2 ± 4.6 days (n = 45), eggs 9.0 ± 1.1 days (n = 103), univoltine larvae 308 days, semivoltine larvae 673 days, and pupae 61.2± 1.6 days (n = 45). It takes about 100 days from the time larvae bore into the phloem to when they complete the pupal cell. In a 10-year-old velvet ash (Fraxinus velutina Torr.) plantation in Tianjin, emerald ash borer preferred to oviposit on the regions of boles from 50-150 cm above ground, accounting for 76.7% of the total girdling.Girdling on the south side of the tree boles accounted for 43.40% of the total girdling. The emerald ash borer population density is higher at the edge of the plantation compared with the center.

  5. The relationship between trees and human health: evidence from the spread of the emerald ash borer.

    Science.gov (United States)

    Donovan, Geoffrey H; Butry, David T; Michael, Yvonne L; Prestemon, Jeffrey P; Liebhold, Andrew M; Gatziolis, Demetrios; Mao, Megan Y

    2013-02-01

    Several recent studies have identified a relationship between the natural environment and improved health outcomes. However, for practical reasons, most have been observational, cross-sectional studies. A natural experiment, which provides stronger evidence of causality, was used to test whether a major change to the natural environment-the loss of 100 million trees to the emerald ash borer, an invasive forest pest-has influenced mortality related to cardiovascular and lower-respiratory diseases. Two fixed-effects regression models were used to estimate the relationship between emerald ash borer presence and county-level mortality from 1990 to 2007 in 15 U.S. states, while controlling for a wide range of demographic covariates. Data were collected from 1990 to 2007, and the analyses were conducted in 2011 and 2012. There was an increase in mortality related to cardiovascular and lower-respiratory-tract illness in counties infested with the emerald ash borer. The magnitude of this effect was greater as infestation progressed and in counties with above-average median household income. Across the 15 states in the study area, the borer was associated with an additional 6113 deaths related to illness of the lower respiratory system, and 15,080 cardiovascular-related deaths. Results suggest that loss of trees to the emerald ash borer increased mortality related to cardiovascular and lower-respiratory-tract illness. This finding adds to the growing evidence that the natural environment provides major public health benefits. Published by Elsevier Inc.

  6. White Fringetree as a Novel Larval Host for Emerald Ash Borer.

    Science.gov (United States)

    Cipollini, Don

    2015-02-01

    Emerald ash borer is an invasive Asian pest of ash species in North America. All North American species of ash tested so far are susceptible to it, but there are no published reports of this insect developing fully in non-ash hosts in the field in North America. I report here evidence that emerald ash borer can attack and complete development in white fringetree, Chionanthus virginicus L., a species native to the southeastern United States that is also planted ornamentally. Four of 20 mature ornamental white fringetrees examined in the Dayton, Ohio area showed external symptoms of emerald ash borer attack, including the presence of adult exit holes, canopy dieback, and bark splitting and other deformities. Removal of bark from one of these trees yielded evidence of at least three generations of usage by emerald ash borer larvae, several actively feeding live larvae, and a dead adult confirmed as emerald ash borer. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Genome-wide analysis of esterase-like genes in the striped rice stem borer, Chilo suppressalis.

    Science.gov (United States)

    Wang, Baoju; Wang, Ying; Zhang, Yang; Han, Ping; Li, Fei; Han, Zhaojun

    2015-06-01

    The striped rice stem borer, Chilo suppressalis, a destructive pest of rice, has developed high levels of resistance to certain insecticides. Esterases are reported to be involved in insecticide resistance in several insects. Therefore, this study systematically analyzed esterase-like genes in C. suppressalis. Fifty-one esterase-like genes were identified in the draft genomic sequences of the species, and 20 cDNA sequences were derived which encoded full- or nearly full-length proteins. The putative esterase proteins derived from these full-length genes are overall highly diversified. However, key residues that are functionally important including the serine residue in the active site are conserved in 18 out of the 20 proteins. Phylogenetic analysis revealed that most of these genes have homologues in other lepidoptera insects. Genes CsuEst6, CsuEst10, CsuEst11, and CsuEst51 were induced by the insecticide triazophos, and genes CsuEst9, CsuEst11, CsuEst14, and CsuEst51 were induced by the insecticide chlorantraniliprole. Our results provide a foundation for future studies of insecticide resistance in C. suppressalis and for comparative research with esterase genes from other insect species.

  8. Silencing of CYP6 and APN genes affects the growth and development of rice yellow stem borer, Scirpophaga incertulas

    Directory of Open Access Journals (Sweden)

    Vijaya Sudhakara Rao eKola

    2016-02-01

    Full Text Available RNAi is a powerful tool to target the insect genes involved in host-pest interactions. Key insect genes are the choice for silencing to achieve pest derived resistance where resistance genes are not available in gene pool of host plant. In this study, an attempt was made to determine the effect of dsRNA designed from two genes Cytochrome P450 derivative (CYP6 and Aminopeptidase N (APN of rice yellow stem borer (YSB on growth and development of insect. The bioassays involved injection of chemically synthesized 5ꞌ FAM labeled 21-nt dsRNA into rice cut stems and allowing the larvae to feed on these stems which resulted in increased mortality and observed growth and development changes in larval length and weight compared with its untreated control at 12-15 days after treatment. These results were further supported by observing the reduction in transcripts expression of these genes in treated larvae. Fluorescence detection in treated larvae also proved that dsRNA was readily taken by larvae when fed on dsRNA treated stems. These results from the present study clearly show that YSB larvae fed on dsRNA designed from Cytochrome P450 and Aminopeptidase N has detrimental effect on larval growth and development. These genes can be deployed to develop YSB resistance in rice using RNAi approach.

  9. Silencing of CYP6 and APN Genes Affects the Growth and Development of Rice Yellow Stem Borer, Scirpophaga incertulas.

    Science.gov (United States)

    Kola, Vijaya Sudhakara Rao; Renuka, P; Padmakumari, Ayyagari Phani; Mangrauthia, Satendra K; Balachandran, Sena M; Ravindra Babu, V; Madhav, Maganti S

    2016-01-01

    RNAi is a powerful tool to target the insect genes involved in host-pest interactions. Key insect genes are the choice for silencing to achieve pest derived resistance where resistance genes are not available in gene pool of host plant. In this study, an attempt was made to determine the effect of dsRNA designed from two genes Cytochrome P450 derivative (CYP6) and Aminopeptidase N (APN) of rice yellow stem borer (YSB) on growth and development of insect. The bioassays involved injection of chemically synthesized 5' FAM labeled 21-nt dsRNA into rice cut stems and allowing the larvae to feed on these stems which resulted in increased mortality and observed growth and development changes in larval length and weight compared with its untreated control at 12-15 days after treatment. These results were further supported by observing the reduction in transcripts expression of these genes in treated larvae. Fluorescence detection in treated larvae also proved that dsRNA was readily taken by larvae when fed on dsRNA treated stems. These results from the present study clearly show that YSB larvae fed on dsRNA designed from Cytochrome P450 and Aminopeptidase N has detrimental effect on larval growth and development. These genes can be deployed to develop YSB resistance in rice using RNAi approach.

  10. RNAi in the striped stem borer, Chilo suppressalis, establishes a functional role for aminopeptidase N in Cry1Ab intoxication.

    Science.gov (United States)

    Wang, X Y; Du, L X; Liu, C X; Gong, L; Han, L Z; Peng, Y F

    2017-02-01

    The striped stem borer, Chilo suppressalis, is a major target pest of transgenic rice expressing the Cry1Ab protein from the bacterium Bacillus thuringiensis (Bt) in China. Evolution of resistance in this pest is a major threat to the durability of Bt rice. Since Bt exerts its activity through binding to specific receptors in the midgut of target insects, identification of functional Cry1Ab receptors in the midgut of C. suppressalis larvae is crucial to evaluate potential resistance mechanisms and develop effective strategies for delaying insect resistance. In this work, we identified the putative Cry1Ab toxin-binding protein, aminopeptidase-N (APN), in the midgut of C. suppressalis by ligand blot and mass spectrometry. After cloning the full-length cDNAs encoding APN isoforms from the C. suppressalis larval midgut, we studied their spatiotemporal expression in different gut tissues and developmental stages. Furthermore, RNA interference (RNAi) against C. suppressalis aminopeptidases (CsAPNs) was employed to illustrate a functional role for CsAPNs in Cry1Ab toxicity to C. suppressalis larvae using injection and oral delivery of Stealth™ siRNA. Down-regulating the expression of CsAPNs by RNAi was closely associated with reduced susceptibility of C. suppressalis to Cry1Ab. These data provide the first direct evidence that CsAPNs participate in the mode of Cry1Ab action and may act as the functional receptor of Cry1A in C. suppressalis larvae.

  11. Effects of water availability on emerald ash borer larval performance and phloem phenolics of Manchurian and black ash.

    Science.gov (United States)

    Chakraborty, Sourav; Whitehill, Justin G A; Hill, Amy L; Opiyo, Stephen O; Cipollini, Don; Herms, Daniel A; Bonello, Pierluigi

    2014-04-01

    The invasive emerald ash borer (EAB) beetle is a significant threat to the survival of North American ash. In previous work, we identified putative biochemical and molecular markers of constitutive EAB resistance in Manchurian ash, an Asian species co-evolved with EAB. Here, we employed high-throughput high-performance liquid chromatography with photodiode array detection and mass spectrometry (HPLC-PDA-MS) to characterize the induced response of soluble phloem phenolics to EAB attack in resistant Manchurian and susceptible black ash under conditions of either normal or low water availability, and the effects of water availability on larval performance. Total larval mass per tree was lower in Manchurian than in black ash. Low water increased larval numbers and mean larval mass overall, but more so in Manchurian ash. Low water did not affect levels of phenolics in either host species, but six phenolics decreased in response to EAB. In both ashes, pinoresinol A was induced by EAB, especially in Manchurian ash. Pinoresinol A and pinoresinol B were negatively correlated with each other in both species. The higher accumulation of pinoresinol A in Manchurian ash after attack may help explain the resistance of this species to EAB, but none of the responses measured here could explain increased larval performance in trees subjected to low water availability.

  12. Biotic mortality factors affecting emerald ash borer (Agrilus planipennis) are highly dependent on life stage and host tree crown condition.

    Science.gov (United States)

    Jennings, D E; Duan, J J; Shrewsbury, P M

    2015-10-01

    Emerald ash borer (EAB), Agrilus planipennis, is a serious invasive forest pest in North America responsible for killing tens to hundreds of millions of ash trees since it was accidentally introduced in the 1990 s. Although host-plant resistance and natural enemies are known to be important sources of mortality for EAB in Asia, less is known about the importance of different sources of mortality at recently colonized sites in the invaded range of EAB, and how these relate to host tree crown condition. To further our understanding of EAB population dynamics, we used a large-scale field experiment and life-table analyses to quantify the fates of EAB larvae and the relative importance of different biotic mortality factors at 12 recently colonized sites in Maryland. We found that the fates of larvae were highly dependent on EAB life stage and host tree crown condition. In relatively healthy trees (i.e., with a low EAB infestation) and for early instars, host tree resistance was the most important mortality factor. Conversely, in more unhealthy trees (i.e., with a moderate to high EAB infestation) and for later instars, parasitism and predation were the major sources of mortality. Life-table analyses also indicated how the lack of sufficient levels of host tree resistance and natural enemies contribute to rapid population growth of EAB at recently colonized sites. Our findings provide further evidence of the mechanisms by which EAB has been able to successfully establish and spread in North America.

  13. Cold hardiness and overwintering strategy of the pink maize stalk borer,Sesamia nonagrioides Lef (lepidoptera, noctuidae).

    Science.gov (United States)

    Gillyboeuf, N; Anglade, P; Lavenseau, L; Peypelut, L

    1994-09-01

    The cold-hardening capacity of larvae of the pink maize stalk borer,Sesamia nonagrioides Lef., was examined. Supercooling points (SCPs) of field collected diapausing larvae from south-east and south-west France and non-diapausing and diapausing laboratory-reared larvae did not differ and ranged between -5 and -8°C. Thus, this insect possesses sufficient supercooling ability to avoid freezing over its normal environmental temperature ranges. Despite this, we found thatSesamia presents paradoxical cold reactions. Mortality of cold acclimated diapausing larvae after short-term exposure to temperatures above the SCP is high, supporting the view thatSesamia is cold-sensitive. On the other hand,Sesamia could survive freezing for at least 24 h to temperatures close to the SCP. This ability does not seem to be related to haemolymph trehalose, the sole cold-accumulated compound detected by gas chromatography and mass spectrometry. Despite the mildness of the winter 1990-1991, only 5% of the field population survive and pupate in April. The main part of the population died from November to January, the period during which larvae were mainly located in the part of the corn stem above the ground and experienced air temperatures. After January, all surviving larvae were excuusively located in the root, 10 cm below the soil, where they experienced milder temperatures than air. They exhibited a constant low rate of mortality, possibly independent of the cold. In their current distribution area, survival of overwintering larvae ofS. nonagrioides is only related to the microclimate of the overwintering site and freezing tolerance capacity seems to be irrelevant. This study allows us to propose a non-pollutant pest control method based on the "behavioral strategy" of this insect.

  14. Determination of host-associated variability in the shape of the mandible of white rice stem borer Scirpophaga innotata (Lepidoptera: Pyralidae

    Directory of Open Access Journals (Sweden)

    Alma L. I. Alegre

    2011-06-01

    Full Text Available Host-plant modifications are known to promote high taxonomic diversity andecomorphological disparity among its insect-herbivores. Studies on mouthpart morphology specificallythe mandible are central to understanding these adaptive modifications as they are used as majorfeeding apparatus. In this study, mandible shape of a monophagous white rice stem borer, Scirpophagainnotata Walker (Lepidoptera: Pyralidae which were obtained from different host-plant rice cultivarswere assessed using image analysis and Elliptic Fourier techniques. Contours of the mandibles wereextracted via chain-coding and principal component analyses were performed to determine patterns ofshape differences. Observed variation ranges from the arrangement and length of its teeth, from thebasal and external margins and the contour of the side of attachment from the body. The greatestvariations accounted by the first two principal components (PC’s are on the arrangement, length andnumber of its teeth which is attributable to continuous wear of the individual mandible in effect of thebiochemical properties of the plant. Intra-population variation is associated with the influence of riceplant morphological characteristics associated with resistance or susceptibility to white stem borer.

  15. Influence of trap placement and design on capture of the emerald ash borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Francese, Joseph A; Oliver, Jason B; Fraser, Ivich; Lance, David R; Youssef, Nadeer; Sawyer, Alan J; Mastro, Victor C

    2008-12-01

    The key to an effective pest management program for the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera Buprestidae), is a survey program equipped with tools for detecting and delimiting populations. We studied the effects of trap design, color, and placement on the efficacy of sticky traps for capturing the emerald ash borer. There were significant differences in trap catch along a transect gradient from wooded to open field conditions, with most beetles being caught along the edge, or in open fields, 15-25 m outside an ash (Fraxinus spp. L.) (Oleaceae) woodlot. Greater emerald ash borer catch occurred on purple traps than on red or white traps. Traps placed in the mid-canopy of ash trees (13 m) caught significantly more beetles than those placed at ground level. We also describe a new trap design, a three-sided prism trap, which is relatively easy to assemble and deploy.

  16. The overwintering physiology of the emerald ash borer, Agrilus planipennis fairmaire (coleoptera: buprestidae).

    Science.gov (United States)

    Crosthwaite, Jill C; Sobek, Stephanie; Lyons, D Barry; Bernards, Mark A; Sinclair, Brent J

    2011-01-01

    Ability to survive cold is an important factor in determining northern range limits of insects. The emerald ash borer (Agrilus planipennis) is an invasive beetle introduced from Asia that is causing extensive damage to ash trees in North America, but little is known about its cold tolerance. Herein, the cold tolerance strategy and mechanisms involved in the cold tolerance of the emerald ash borer were investigated, and seasonal changes in these mechanisms monitored. The majority of emerald ash borers survive winter as freeze-intolerant prepupae. In winter, A. planipennis prepupae have low supercooling points (approximately -30°C), which they achieve by accumulating high concentrations of glycerol (approximately 4M) in their body fluids and by the synthesis of antifreeze agents. Cuticular waxes reduce inoculation from external ice. This is the first comprehensive study of seasonal changes in cold tolerance in a buprestid beetle.

  17. Fact sheet: Ethanol from corn

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-31

    This fact sheet is intended to provide an overview of the advantages of ethanol from corn, emphasizing ethanol`s contribution to environmental protection and sustainable agriculture. Ethanol, an alternative fuel used as an octane enhancer is produced through the conversion of starch to sugars by enzymes, and fermentation of these sugars to ethanol by yeast. The production process may involve wet milling or dry milling. Both these processes produce valuable by-products, in addition to ethanol and carbon dioxide. Ethanol contains about 32,000 BTU per litre. It is commonly believed that using state-of-the-art corn farming and corn processing processes, the amount of energy contained in ethanol and its by-products would be more than twice the energy required to grow and process corn into ethanol. Ethanol represents the third largest market for Ontario corn, after direct use as animal feed and wet milling for starch, corn sweetener and corn oil. The environmental consequences of using ethanol are very significant. It is estimated that a 10 per cent ethanol blend in gasoline would result in a 25 to 30 per cent decrease in carbon monoxide emissions, a 6 to 10 per cent decrease in net carbon dioxide, a slight increase in nitrous oxide emissions which, however, would still result in an overall decrease in ozone formation, since the significant reduction in carbon monoxide emissions would compensate for any slight increase in nitrous oxide. Volatile organic compounds emission would also decrease by about 7 per cent with a 10 per cent ethanol blend. High level blends could reduce VOCs production by as much as 30 per cent. 7 refs.

  18. Predicting stem borer density in maize using RapidEye data and generalized linear models

    Science.gov (United States)

    Abdel-Rahman, Elfatih M.; Landmann, Tobias; Kyalo, Richard; Ong'amo, George; Mwalusepo, Sizah; Sulieman, Saad; Ru, Bruno Le

    2017-05-01

    Average maize yield in eastern Africa is 2.03 t ha-1 as compared to global average of 6.06 t ha-1 due to biotic and abiotic constraints. Amongst the biotic production constraints in Africa, stem borers are the most injurious. In eastern Africa, maize yield losses due to stem borers are currently estimated between 12% and 21% of the total production. The objective of the present study was to explore the possibility of RapidEye spectral data to assess stem borer larva densities in maize fields in two study sites in Kenya. RapidEye images were acquired for the Bomet (western Kenya) test site on the 9th of December 2014 and on 27th of January 2015, and for Machakos (eastern Kenya) a RapidEye image was acquired on the 3rd of January 2015. Five RapidEye spectral bands as well as 30 spectral vegetation indices (SVIs) were utilized to predict per field maize stem borer larva densities using generalized linear models (GLMs), assuming Poisson ('Po') and negative binomial ('NB') distributions. Root mean square error (RMSE) and ratio prediction to deviation (RPD) statistics were used to assess the models performance using a leave-one-out cross-validation approach. The Zero-inflated NB ('ZINB') models outperformed the 'NB' models and stem borer larva densities could only be predicted during the mid growing season in December and early January in both study sites, respectively (RMSE = 0.69-1.06 and RPD = 8.25-19.57). Overall, all models performed similar when all the 30 SVIs (non-nested) and only the significant (nested) SVIs were used. The models developed could improve decision making regarding controlling maize stem borers within integrated pest management (IPM) interventions.

  19. Densities of Agrilus auroguttatus and Other Borers in California and Arizona Oaks

    Directory of Open Access Journals (Sweden)

    Laurel J. Haavik

    2014-03-01

    Full Text Available We investigated within-tree population density of a new invasive species in southern California, the goldspotted oak borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae, with respect to host species and the community of other borers present. We measured emergence hole densities of A. auroguttatus and other borers on the lower stem (bole of naïve oaks at 18 sites in southern California and on co-evolved oaks at seven sites in southeastern Arizona. We sampled recently dead oaks in an effort to quantify the community of primary and secondary borers associated with mortality—species that were likely to interact with A. auroguttatus. Red oaks (Section Lobatae produced greater densities of A. auroguttatus than white oaks (Section Quercus. On red oaks, A. auroguttatus significantly outnumbered native borers in California (mean ± SE of 9.6 ± 0.7 versus 4.5 ± 0.6 emergence holes per 0.09 m2 of bark surface, yet this was not the case in Arizona (0.9 ± 0.2 versus 1.1 ± 0.2 emergence holes per 0.09 m2. In California, a species that is taxonomically intermediate between red and white oaks, Quercus chrysolepis (Section Protobalanus, exhibited similar A. auroguttatus emergence densities compared with a co-occurring red oak, Q. kelloggii. As an invasive species in California, A. auroguttatus may affect the community of native borers (mainly Buprestidae and Cerambycidae that feed on the lower boles of oaks, although it remains unclear whether its impact will be positive or negative.

  20. Effectiveness of differing trap types for the detection of emerald ash borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Marshall, Jordan M; Storer, Andrew J; Fraser, Ivich; Beachy, Jessica A; Mastro, Victor C

    2009-08-01

    The early detection of populations of a forest pest is important to begin initial control efforts, minimizing the risk of further spread and impact. Emerald ash borer (Agrilus planipennis Fairmaire) is an introduced pestiferous insect of ash (Fraxinus spp. L.) in North America. The effectiveness of trapping techniques, including girdled trap trees with sticky bands and purple prism traps, was tested in areas with low- and high-density populations of emerald ash borer. At both densities, large girdled trap trees (>30 cm diameter at breast height [dbh], 1.37 m in height) captured a higher rate of adult beetles per day than smaller trees. However, the odds of detecting emerald ash borer increased as the dbh of the tree increased by 1 cm for trap trees 15-25 cm dbh. Ash species used for the traps differed in the number of larvae per cubic centimeter of phloem. Emerald ash borer larvae were more likely to be detected below, compared with above, the crown base of the trap tree. While larval densities within a trap tree were related to the species of ash, adult capture rates were not. These results provide support for focusing state and regional detection programs on the detection of emerald ash borer adults. If bark peeling for larvae is incorporated into these programs, peeling efforts focused below the crown base may increase likelihood of identifying new infestations while reducing labor costs. Associating traps with larger trees ( approximately 25 cm dbh) may increase the odds of detecting low-density populations of emerald ash borer, possibly reducing the time between infestation establishment and implementing management strategies.

  1. Evaluation of heat treatment schedules for emerald ash borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Myers, Scott W; Fraser, Ivich; Mastro, Victor C

    2009-12-01

    The thermotolerance of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), was evaluated by subjecting larvae and prepupae to a number of time-temperature regimes. Three independent experiments were conducted during 2006 and 2007 by heating emerald ash borer infested firewood in laboratory ovens. Heat treatments were established based on the internal wood temperature. Treatments ranged from 45 to 65 degrees C for 30 and 60 min, and the ability of larvae to pupate and emerge as adults was used to evaluate the success of each treatment. A fourth experiment was conducted to examine heat treatments on exposed prepupae removed from logs and subjected to ambient temperatures of 50, 55, and 60 degrees C for 15, 30, 45, and 60 min. Results from the firewood experiments were consistent in the first experiment. Emergence data showed emerald ash borer larvae were capable of surviving a temperatures-time combination up to 60 degrees C for 30 min in wood. The 65 degrees C for 30 min treatment was, however, effective in preventing emerald ash borer emergence on both dates. Conversely, in the second experiment using saturated steam heat, complete mortality was achieved at 50 and 55 degrees C for both 30 and 60 min. Results from the prepupae experiment showed emerald ash borer survivorship in temperature-time combinations up to 55 degrees C for 30 min, and at 50 degrees C for 60 min; 60 degrees C for 15 min and longer was effective in preventing pupation in exposed prepupae. Overall results suggest that emerald ash borer survival is variable depending on heating conditions, and an internal wood temperature of 60 degrees C for 60 min should be considered the minimum for safe treatment for firewood.

  2. Multicolored sweet-waxy corn variety-Caitiannuo 1

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    @@ Corn, as the third largest grain crop in China, isgrown on approximately 200 million ha per year. With theimprovement of people's living standard, variousrequirements for corn breeding have presented. Nowadays,the aim of corn breeding is not only for increasing yield,but also for higher quality and other special demands, suchas sweet corn, waxy corn, colored corn, oil-rich corn,lysine-rich corn, etc.

  3. Multiscale deconstruction of molecular architecture in corn stover

    Science.gov (United States)

    Inouye, Hideyo; Zhang, Yan; Yang, Lin; Venugopalan, Nagarajan; Fischetti, Robert F.; Gleber, S. Charlotte; Vogt, Stefan; Fowle, W.; Makowski, Bryan; Tucker, Melvin; Ciesielski, Peter; Donohoe, Bryon; Matthews, James; Himmel, Michael E.; Makowski, Lee

    2014-01-01

    Lignocellulosic composite in corn stover is a candidate biofuel feedstock of substantial abundance and sustainability. Its utilization is hampered by resistance of constituent cellulose fibrils to deconstruction. Here we use multi-scale studies of pretreated corn stover to elucidate the molecular mechanism of deconstruction and investigate the basis of recalcitrance. Dilute acid pretreatment has modest impact on fibrillar bundles at 0.1 micron length scales while leading to significant disorientation of individual fibrils. It disintegrates many fibrils into monomeric cellulose chains or small side-by-side aggregates. Residual crystalline fibrils lose amorphous surface material, change twist and where still cross-linked, coil around one another. Yields from enzymatic digestion are largely due to hydrolysis of individual cellulose chains and fragments generated during pretreatments. Fibrils that remain intact after pretreatment display substantial resistance to enzymatic digestion. Optimization of yield will require strategies that maximize generation of fragments and minimize preservation of intact cellulosic fibrils.

  4. Influence of corn oil recovery on life-cycle greenhouse gas emissions of corn ethanol and corn oil biodiesel

    OpenAIRE

    Wang, Zhichao; Dunn, Jennifer B.; Han, Jeongwoo; Wang, Michael Q.

    2015-01-01

    Background Corn oil recovery and conversion to biodiesel has been widely adopted at corn ethanol plants recently. The US EPA has projected 2.6 billion liters of biodiesel will be produced from corn oil in 2022. Corn oil biodiesel may qualify for federal renewable identification number (RIN) credits under the Renewable Fuel Standard, as well as for low greenhouse gas (GHG) emission intensity credits under California’s Low Carbon Fuel Standard. Because multiple products [ethanol, biodiesel, and...

  5. Measuring the impact of biotic factors on populations of immature emerald ash borers (Coleoptera: Buprestidae).

    Science.gov (United States)

    Duan, Jian J; Ulyshen, Michael D; Bauer, Leah S; Gould, Juli; Van Driesche, Roy

    2010-10-01

    Cohorts of emerald ash borer larvae, Agrilus planipennis Fairmaire, were experimentally established in July of 2008 on healthy green ash (Fraxinus pennsylvanica) trees in two wooded plots at each of three sites near Lansing, MI, by caging gravid emerald ash borer females or placing laboratory-reared eggs on trunks (0.5-2 m above the ground) of selected trees. One plot at each site was randomly chosen for release of two introduced larval parasitoids, Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius agrili Yang (Hymenoptera: Braconidae), whereas the other served as the control. Stage-specific mortality factors and rates were measured for all experimentally established cohorts and for associated wild (i.e., naturally occurring) emerald ash borer immature stages via destructive sampling of 2.5 m (above the ground) trunk sections of cohort-bearing trees in the spring and fall of 2009. Host tree defense was the most important mortality factor, causing 32.0 to 41.1% mortality in the experimental cohorts and 17.5 to 21.5% in wild emerald ash borer stages by spring 2009, and 16.1 to 29% for the remaining experimental cohorts, and 9.9 to 11.8% for wild immature emerald ash borer stages by fall 2009. Woodpecker predation was the second most important factor, inflicting no mortality in the experimental cohorts but causing 5.0 to 5.6% mortality to associated wild emerald ash borer stages by spring 2009 and 9.2 to 12.8% and 3.2 to 17.7%, respectively, for experimental cohorts and wild emerald ash borer stages by fall 2009. Mortality from disease in both the experimental and wild cohorts was low (emerald ash borer stages were parasitized by T. planipennisi. While there were no significant differences in mortality rates because of parasitism between parasitoid-release and control plots, T. planipennisi was detected in each of the three release sites by the end of the study but was not detected in the experimental cohorts or associated wild larvae in any of the

  6. Biology and control of the raspberry crown borer (Lepidoptera: Sesiidae).

    Science.gov (United States)

    McKern, Jacquelyn A; Johnson, Donn T; Lewis, Barbara A

    2007-04-01

    This study explored the biology of raspberry crown borer, Pennisetia marginata (Harris) (Lepidoptera: Sesiidae), in Arkansas and the optimum timing for insecticide and nematode applications. The duration of P. marginata's life cycle was observed to be 1 yr in Arkansas. Insecticide trials revealed that bifenthrin, chlorpyrifos, imidacloprid, metaflumizone, and metofluthrin efficacy were comparable with that of azinphosmethyl, the only labeled insecticide for P. marginata in brambles until 2005. Applications on 23 October 2003 for plots treated with bifenthrin, chlorpyrifos, and azinphosmethyl resulted in >88% reduction in larvae per crown. Applications on 3 November 2004 of metaflumizone, metofluthrin, and bifenthrin resulted in >89% reduction in larvae per crown. Applications on 7 April 2005 for metofluthrin, imidacloprid, bifenthrin, metaflumizone, and benzoylphenyl urea resulted in >64% reduction in the number of larvae per crown. Applications on 6 May 2004 did not reduce larval numbers. The optimum timing for treatments was found to be between October and early April, before the larvae tunneled into the crowns of plants. Applying bifenthrin with as little as 468 liters water/ha (50 gal/acre) was found to be as effective against larvae as higher volumes of spray. Nematode applications were less successful than insecticides. Nematode applications of Steinernemafeltiae, Steinernema carpocapsae, and Heterorhabditis bacteriophora reduced larvae counts per plant by 46, 53, and 33%, respectively.

  7. A transcriptomic survey of Migdolus fryanus (sugarcane rhizome borer) larvae.

    Science.gov (United States)

    Nakayama, Darlan Gonçalves; Santos Júnior, Célio Dias; Kishi, Luciano Takeshi; Pedezzi, Rafael; Santiago, Adelita Carolina; Soares-Costa, Andrea; Henrique-Silva, Flavio

    2017-01-01

    Sugarcane, a major crop grown in the tropical and subtropical areas of the world, is produced mainly for sucrose, which is used as a sweetener or for the production of bioethanol. Among the numerous pests that significantly affect the yield of sugarcane, the sugarcane rhizome borer (Migdolus fryanus, a cerambycidae beetle) is known to cause severe damage to the crops in Brazil. The absence of molecular information about this insect reinforces the need for studies and an effective method to control this pest. In this study, RNA-Seq technology was employed to study different parts of M. fryanus larvae. The generated data will help in further investigations about the taxonomy, development, and adaptation of this insect. RNA was extracted from six different parts (head, fat body, integument, hindgut, midgut, and foregut) using Trizol methodology. Using Illumina paired-end sequencing technology and the Trinity platform, trimming and de novo assembly was performed, resulting in 44,567 contigs longer than 200 nt for a reunion of data from all transcriptomes, with a mean length of 1,095.27 nt. Transcripts were annotated using BLAST against different protein databanks (Uniprot/Swissprot, PFAM, KEEG, SignalP 4.1, Gene Ontology, and CAZY) and were compared for similarity using a Venn diagram. Differential expression patterns were studied for select genes through qPCR and FPKM comprising important protein families (digestive peptidases, glucosyl hydrolases, serine protease inhibitors and otopetrin), which allowed a better understanding of the insect's digestion, immunity and gravity sensorial mechanisms.

  8. 9 CFR 319.102 - Corned beef round and other corned beef cuts.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Corned beef round and other corned beef cuts. 319.102 Section 319.102 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... Meats, Unsmoked and Smoked § 319.102 Corned beef round and other corned beef cuts. In preparing...

  9. Emergence and Abundance of Western Corn Rootworm (Coleoptera: Chrysomelidae) in Bt Cornfields With Structured and Seed Blend Refuges.

    Science.gov (United States)

    Hughson, Sarah A; Spencer, Joseph L

    2015-02-01

    To slow evolution of western corn rootworm (Diabrotica virgifera virgifera LeConte) resistance to Bt (Bacillus thuringiensis Berliner) corn hybrids, non-Bt "refuges" must be planted within or adjacent to Bt cornfields, allowing susceptible insects to develop without exposure to Bt toxins. Bt-susceptible adults from refuges are expected to find and mate with resistant adults that have emerged from Bt corn, reducing the likelihood that Bt-resistant offspring are produced. The spatial and temporal distribution of adults in four refuge treatments (20, 5, and 0% structured refuges and 5% seed blend) and adjacent soybean fields was compared from 2010 to 2012. Adult emergence (adults/trap/day) from refuge corn in structured refuge treatments was greater than that from Bt corn, except during the post-pollination period of corn phenology when emergence from refuge and Bt plants was often the same. Abundance of free-moving adults was greatest in and near refuge rows in structured refuge treatments during vegetative and pollination periods. By post-pollination, adult abundance became evenly distributed. In contrast, adult abundance in 5% seed blends and 0% refuges was evenly distributed, or nearly so, across plots throughout the season. The persistent concentration of adults in refuge rows suggests that structured refuge configurations may not facilitate the expected mixing of adults from refuge and Bt corn. Seed blends produce uniform distributions of adults across the field that may facilitate mating between Bt and refuge adults and ultimately delay the evolution of Bt resistance.

  10. A Δ11 desaturase gene genealogy reveals two divergent allelic classes within the European corn borer (Ostrinia nubilalis

    Directory of Open Access Journals (Sweden)

    Harrison Richard G

    2010-04-01

    Full Text Available Abstract Background Moth pheromone mating systems have been characterized at the molecular level, allowing evolutionary biologists to study how changes in protein sequence or gene expression affect pheromone phenotype, patterns of mating, and ultimately, the formation of barriers to gene exchange. Recent studies of Ostrinia pheromones have focused on the diversity of sex pheromone desaturases and their role in the specificity of pheromone production. Here we produce a Δ11 desaturase genealogy within Ostrinia nubilalis. We ask what has been the history of this gene, and whether this history suggests that changes in Δ11 desaturase have been involved in the divergence of the E and Z O. nubilalis pheromone strains. Results The Δ11 desaturase gene genealogy does not differentiate O. nubilalis pheromone strains. However, we find two distinct clades, separated by 2.9% sequence divergence, that do not sort with pheromone strain, geographic origin, or emergence time. We demonstrate that these clades do not represent gene duplicates, but rather allelic variation at a single gene locus. Conclusions Analyses of patterns of variation at the Δ11 desaturase gene in ECB suggest that this enzyme does not contribute to reproductive isolation between pheromone strains (E and Z. However, our genealogy reveals two deeply divergent allelic classes. Standing variation at loci that contribute to mate choice phenotypes may permit novel pheromone mating systems to arise in the presence of strong stabilizing selection.

  11. Tissue Distribution and Purification of Prophenoloxidase in Larvae of Asian Corn Borer, Ostriniafurnacalis Guenée (Lepidoptera:Pyralidae)

    Institute of Scientific and Technical Information of China (English)

    Cong-Jing FENG; Wen-Jun FU

    2004-01-01

    Using ammonium sulphate precipitation, Blue-Sepharose CL-6B, Phenyl-Sepharose CL-4B, prophenoloxidase (PPO) was isolated and purified from hemolymph of Ostriniafurnacalis larvae. This zy- mogen was a heterodimer, and composed of two subunits with the relative molecular mass ranging from 66.2 kD to 97.4 kD determined by SDS-PAGE. Western blotting and indirect immunofluorescence test showed that PPO was present in integument, hemolymph plasma and cell membrane of granular hemocytes and oenocytoids of O. furnacalis larvae.

  12. Sex-linked pheromone receptor genes of the European corn borer, Ostrinia nubilalis, are in tandem arrays.

    Directory of Open Access Journals (Sweden)

    Yuji Yasukochi

    Full Text Available BACKGROUND: Tuning of the olfactory system of male moths to conspecific female sex pheromones is crucial for correct species recognition; however, little is known about the genetic changes that drive speciation in this system. Moths of the genus Ostrinia are good models to elucidate this question, since significant differences in pheromone blends are observed within and among species. Odorant receptors (ORs play a critical role in recognition of female sex pheromones; eight types of OR genes expressed in male antennae were previously reported in Ostrinia moths. METHODOLOGY/PRINCIPAL FINDINGS: We screened an O. nubilalis bacterial artificial chromosome (BAC library by PCR, and constructed three contigs from isolated clones containing the reported OR genes. Fluorescence in situ hybridization (FISH analysis using these clones as probes demonstrated that the largest contig, which contained eight OR genes, was located on the Z chromosome; two others harboring two and one OR genes were found on two autosomes. Sequence determination of BAC clones revealed the Z-linked OR genes were closely related and tandemly arrayed; moreover, four of them shared 181-bp direct repeats spanning exon 7 and intron 7. CONCLUSIONS/SIGNIFICANCE: This is the first report of tandemly arrayed sex pheromone receptor genes in Lepidoptera. The localization of an OR gene cluster on the Z chromosome agrees with previous findings for a Z-linked locus responsible for O. nubilalis male behavioral response to sex pheromone. The 181-bp direct repeats might enhance gene duplications by unequal crossovers. An autosomal locus responsible for male response to sex pheromone in Heliothis virescens and H. subflexa was recently reported to contain at least four OR genes. Taken together, these findings support the hypothesis that generation of additional copies of OR genes can increase the potential for male moths to acquire altered specificity for pheromone components, and accordingly, facilitate differentiation of sex pheromones.

  13. Molecular cloning, characterization and expression profiling of a ryanodine receptor gene in Asian corn borer, Ostrinia furnacalis (Guenee.

    Directory of Open Access Journals (Sweden)

    Li Cui

    Full Text Available Ryanodine receptor (RyR Ca(2+ release channel is the target of diamide insecticides, which show selective insecticidal activity against lepidopterous insects. To study the molecular mechanisms underlying the species-specific action of diamide insecticides, we have cloned and characterized the entire cDNA sequence of RyR from Ostrinia furnacalis (named as OfRyR. The OfRyR mRNA has an Open Reading Frame of 15324 bp nucleotides and encodes a 5108 amino acid polypeptide that displays 79-97% identity with other insects RyR proteins and shows the greatest identity with Cnaphalocrocis medinalis RyR (97%. Quantitative real-time PCR showed that the OfRyR was expressed at the lowest level in egg and the highest level in adult. The relative expression level of OfRyR in first, third and fifth-instar larva were 1.28, 1.19 and 1.99 times of that in egg. Moreover, two alternative splicing sites were identified in the OfRyR gene. One pair of mutually exclusive exons (a/b were present in the central part of the predicted SPRY domain, and an optional exon (c was located between the third and fourth RyR domains. Diagnostic PCR demonstrated that exons a and b existed in all developmental stages of OfRyR cDNA, but exon c was not detected in the egg cDNA. And the usage frequencies of these exons showed a significant difference between different developmental stages. These results provided the crucial basis for the functional expression of OfRyR and for the discovery of compound with potentially selective insect activtity.

  14. Effects of Bacillus thuringiensis toxin Cry1Ac and Beauveria bassiana on Asiatic corn borer (Lepidoptera: Crambidae).

    Science.gov (United States)

    Ma, Xiao-Mu; Liu, Xiao-Xia; Ning, Xia; Zhang, Bo; Han, Fei; Guan, Xiu-Min; Tan, Yun-Feng; Zhang, Qing-Wen

    2008-10-01

    In this study, interactions between Cry1Ac, a toxic crystal protein produced by Bacillus thuringiensis (Berliner), and Beauveria bassiana on the mortality and survival of Ostrinia furnacalis was evaluated in the laboratory. The results showed that Cry1Ac is toxic to O. furnacalis. Not only were larval growth and development delayed, but pupation, pupal weight and adult emergency also decreased when larvae were fed on artificial diet containing purified Cry1Ac toxin. When third instars O. furnacalis were exposed to combination of B. bassiana (1.8x10(5), 1.8x10(6) or 1.8x10(7) conidia ml(-1)) and Cry1Ac, (0.2 or 0.8 microg g(-1)), the effect on mortality was additive, however, the combinations of sublethal concentrations showed antagonism between Cry1Ac (3.2 or 13 microg g(-1)) and B. bassiana (1.8x10(5) or 1.8x10(6) conidia ml(-1)). When neonates were reared on sublethal concentrations of Cry1AC until the third instar, and survivors exposed B. bassiana conidial suspension, such treatments showed additive effect on mortality of O. furnacalis except for the combination of Cry1Ac (0.2 microg g(-1)) and B. bassiana (1.8x10(6) conidia ml(-1)) that showed antagonism.

  15. Failure to phytosanitize ash firewood infested with emerald ash borer in a small dry kiln using ISPM-15 standards.

    Science.gov (United States)

    Goebel, P Charles; Bumgardner, Matthew S; Herms, Daniel A; Sabula, Andrew

    2010-06-01

    Although current USDA-APHIS standards suggest that a core temperature of 71.1 degrees C (160 degrees F) for 75 min is needed to adequately sanitize emerald ash borer, Agrilus planipennis Fairmaire-infested firewood, it is unclear whether more moderate (and economical) treatment regimes will adequately eradicate emerald ash borer larvae and prepupae from ash firewood. We constructed a small dry kiln in an effort to emulate the type of technology a small- to medium-sized firewood producer might use to examine whether treatments with lower temperature and time regimes successfully eliminate emerald ash borer from both spilt and roundwood firewood. Using white ash (Fraxinus americana L.) firewood collected from a stand with a heavy infestation of emerald ash borer in Delaware, OH, we treated the firewood using the following temperature and time regime: 46 degrees C (114.8 degrees F) for 30 min, 46 degrees C (114.8 degrees F) for 60 min, 56 degrees C (132.8 degrees F) for 30 min, and 56 degrees C (132.8 degrees F) for 60 min. Temperatures were recorded for the outer 2.54-cm (1-in.) of firewood. After treatment, all firewood was placed under mesh netting and emerald ash borer were allowed to develop and emerge under natural conditions. No treatments seemed to be successful at eliminating emerald ash borer larvae and perpupae as all treatments (including two nontreated controls) experienced some emerald ash borer emergence. However, the 56 degrees C (132.8 degrees F) treatments did result in considerably less emerald ash borer emergence than the 46 degrees C (114.8 degrees F) treatments. Further investigation is needed to determine whether longer exposure to the higher temperature (56 degrees C) will successfully sanitize emerald ash borer-infested firewood.

  16. Geographic information systems in corn rootworm management

    Science.gov (United States)

    Corn rootworms (Diabrotica spp. Coleoptera: Chrysomelidae) are serious pests of corn (Zea mays) in the United States and Europe. Control measures for corn rootworms (CRW) were historically based upon chemical pesticides and crop rotation. Pesticide use created environmental and economic concerns. In...

  17. A built-in strategy to mitigate transgene spreading from genetically modified corn.

    Directory of Open Access Journals (Sweden)

    Jing Li

    Full Text Available Transgene spreading is a major concern in cultivating genetically modified (GM corn. Cross-pollination may cause the spread of transgenes from GM cornfields to conventional fields. Occasionally, seed lot contamination, volunteers, mixing during sowing, harvest, and trade can also lead to transgene escape. Obviously, new biological confinement technologies are highly desired to mitigate transgene spreading in addition to physical separation and isolation methods. In this study, we report the development of a built-in containment method to mitigate transgene spreading in corn. In this method, an RNAi cassette for suppressing the expression of the nicosulfuron detoxifying enzyme CYP81A9 and an expression cassette for the glyphosate tolerant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS gene G10 were constructed and transformed into corn via Agrobacterium-mediated transformation. The GM corn plants that were generated were found to be sensitive to nicosulfuron but resistant to glyphosate, which is exactly the opposite of conventional corn. Field tests demonstrated that GM corn plants with silenced CYP81A9 could be killed by applying nicosulfuron at 40 g/ha, which is the recommended dose for weed control in cornfields. This study suggests that this built-in containment method for controlling the spread of corn transgenes is effective and easy to implement.

  18. Utilisation of corn (Zea mays) bran and corn fiber in the production of food components.

    Science.gov (United States)

    Rose, Devin J; Inglett, George E; Liu, Sean X

    2010-04-30

    The milling of corn for the production of food constituents results in a number of low-value co-products. Two of the major co-products produced by this operation are corn bran and corn fiber, which currently have low commercial value. This review focuses on current and prospective research surrounding the utilization of corn fiber and corn bran in the production of potentially higher-value food components. Corn bran and corn fiber contain potentially useful components that may be harvested through physical, chemical or enzymatic means for the production of food ingredients or additives, including corn fiber oil, corn fiber gum, cellulosic fiber gels, xylo-oligosaccharides and ferulic acid. Components of corn bran and corn fiber may also be converted to food chemicals such as vanillin and xylitol. Commercialization of processes for the isolation or production of food products from corn bran or corn fiber has been met with numerous technical challenges, therefore further research that improves the production of these components from corn bran or corn fiber is needed.

  19. INNOVATIVE TECHNOLOGY EVALUATION REPORT, SEDIMENT SAMPLING TECHNOLOGY, AQUATIC RESEARCH INSTRUMENTS, RUSSIAN PEAT BORER

    Science.gov (United States)

    The Russian Peat Borer designed and fabricated by Aquatic Research Instruments was demonstrated under the U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation Program in April and May 1999 at sites in EPA Regions 1 and 5, respectively. In additio...

  20. Abundance and Spatial Dispersion of Rice Stem Borer Species in Kahama, Tanzania.

    Science.gov (United States)

    Leonard, Alfonce; Rwegasira, Gration M

    2015-01-01

    Species diversity, abundance, and dispersion of rice stem borers in framer's fields were studied in four major rice growing areas of Kahama District. Stem borer larvae were extracted from the damaged tillers in 16 quadrants established in each field. Adult Moths were trapped by light traps and collected in vials for identification. Results indicated the presence of Chilo partellus, Maliarpha separatella, and Sesamia calamistis in all study areas. The most abundant species was C. partellus (48.6%) followed by M. separatella (35.4%) and S. calamistis was least abundant (16.1%). Stem borers dispersion was aggregated along the edges of rice fields in three locations (wards) namely: Bulige, Chela, and Ngaya. The dispersion in the fourth ward, Kashishi was uniform as established from two of the three dispersion indices tested. Further studies would be required to establish the available alternative hosts, the extent of economic losses and the distribution of rice stem borers in the rest of the Lake zone of Tanzania.

  1. Hymenopteran Parasitoids Attacking the Invasive Emerald Ash Borer (Coleoptera: Buprestidae) in Western and Central Pennsylvania

    Science.gov (United States)

    We conducted field surveys of the emerald ash borer (EAB), Agrilus planipennis Fairmaire, and associated larval parasitoids in western and central Pennsylvania (Cranberry and Granville Townships) in the spring and fall of 2009. The survey procedure involved destructively debarking sections of the m...

  2. Evaluation of recovery and monitoring methods for parasitoids released against emerald ash borer

    Science.gov (United States)

    Michael S. Parisio; Juli R. Gould; John D. Vandenberg; Leah S. Bauer; Melissa K. Fierke

    2017-01-01

    Emerald ash borer (Agrilus planipennis Fairmaire, EAB) is an invasive forest pest and the target of an extensive biological control program designed to mitigate EAB-caused ash (Fraxinus spp.) mortality. Since 2007, hymenopteran parasitoids of EAB from northeastern Asia have been released as biological control agents in North...

  3. Host boring preferences of the tea shot-hole borer Euwallacea fornicatus (Coleoptera: Curculionidae: Scolytinae)

    Science.gov (United States)

    The non-native shot-hole borer, Euwallacea nr. fornicatus Eichhoff (Coleoptera: Curculionidae: Scolytinae), was discovered in Florida’s avocado production area in Homestead in 2010. It is a highly polyphagous ambrosia beetle that carries Fusarium fungal symbionts. In susceptible host trees, the fung...

  4. Natural enemies of lepidopterous borers on maize and elephant grass in the forest zone of Cameroon.

    Science.gov (United States)

    Ndemah, R; Schulthess, F; Poehling, M; Borgemeister, C; Goergen, G

    2001-06-01

    The importance, geographical and temporal distributions of parasitoids of lepidopterous borers on maize and elephant grass, Pennisetum purpureum, were assessed during surveys in farmers' fields in six villages and two on-station trials in the forest zone of Cameroon between 1995 and 1996. The borer species encountered were Busseola fusca (Fuller), Sesamia calamistis Hampson, Eldana saccharina Walker on both host plants, and Mussidia nigrivenella Ragonot on maize only. Busseola fusca was the predominant host accounting for 44-57% and 96% on maize and elephant grass, respectively, followed by E. saccharina on maize with 27-39%. Fifteen hymenopterous, two dipterous and one fungal species were found on these stem and cob-borers. Among those were six pupal, six larval, four egg, one larval-pupal parasitoid and four hyperparasitoids. The scelionid parasitoids Telenomus busseolae Gahan and T. isis Polaszek were found on B. fusca eggs in all locations. During the first season, mean egg parasitism was low and ranged between 3.1% and 27% versus 54-87% during the second season. Species belonging to the Tetrastichus atriclavus Waterston complex were recovered from all four borer species. The majority and most common larval and pupal parasitoid species belonged to the ingress-and-sting guild. Larval and pupal parasitism were very erratic and on more than 50% of the sampling occasions no parasitoids were recovered. Parasitoid diversity was higher on elephant grass than maize.

  5. An assessment of the relationship between emerald ash borer presence and landscape pattern

    Science.gov (United States)

    Susan J. Crocker; Dacia M. Meneguzzo

    2009-01-01

    Six years after its 2002 detection near Detroit, MI, the emerald ash borer (EAB) (Agrilus planipennis Fairmaire) has spread hundreds of miles across the Upper Midwest and Mid-Atlantic regions of the United States. Human-assisted transportation of infested ash materials is the primary mechanism of EAB dispersal over long distances. Natural spread...

  6. Suitability of immature emerald ash borers to Tetrastichus planipennisi (Hymenoptera: Eulophidae)

    Science.gov (United States)

    Since first detected in Michigan in 2002, the emerald ash borer (EAB) (Agrilus planipennis Fairmaire), a buprestid native to Asia, has killed millions of ash trees in northeastern North America and continues to expand into new areas. Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae), a gregar...

  7. Patterns among the ashes: Exploring the relationship between landscape pattern and the emerald ash borer

    Science.gov (United States)

    Susan J. Crocker; Dacia M. Meneguzzo; Greg C. Liknes

    2010-01-01

    Landscape metrics, including host abundance and population density, were calculated using forest inventory and land cover data to assess the relationship between landscape pattern and the presence or absence of the emerald ash borer (EAB) (Agrilus planipennis Fairmaire). The Random Forests classification algorithm in the R statistical environment was...

  8. Evaluation of recovery and monitoring methods for parasitoids released against Emerald Ash Borer

    Science.gov (United States)

    The emerald ash borer (Agrilus planipennis Fairmaire, EAB) is an invasive insect pest, and the target of an extensive biological control campaign designed to mitigate EAB driven ash tree (Fraxinus spp.) mortality. Since 2007, environmental releases of three species of hymenopteran parasitoids of EA...

  9. Monitoring ash (Fraxinus spp.) decline and emerald ash borer (Agrilus planipennis) symptoms in infested areas

    Science.gov (United States)

    Kathleen S. Knight; Britton P. Flash; Rachel H. Kappler; Joel A. Throckmorton; Bernadette Grafton; Charles E. Flower

    2014-01-01

    Emerald ash borer (A. planipennis) (EAB) has had a devastating effect on ash (Fraxinus) species since its introduction to North America and has resulted in altered ecological processes across the area of infestation. Monitoring is an important tool for understanding and managing the impact of this threat, and the use of common...

  10. Effect of seasonal variations on jackfruit trunk borer (Batocera rufomaculata De Geer) infestation.

    Science.gov (United States)

    Rahman, M M; Alam, M Z; Hossain, M M; Miah, M G

    2013-04-01

    The study of seasonal influence on incidence of trunk borer infestation was undertaken during 2010 at Kapasia upazila under district of Gazipur, Bangladesh. The borer was found in orchard from June to September with a peak emergence in mid July. The larval population of Jackfruit trunk borer is the destructive pest stage, which evokes concern in jackfruit growing areas of Bangladesh. The highest percentage of infestation was in July (7.33%) followed by June and August (6.00%). The cumulative infestation over the year in the study area was 35.33% in October. The lowest infestation was observed in February (0.67%) whereas no activity was found during November to January. The incidence of infestation of trunk borer was influenced by temperature, rainfall and relative humidity due to seasonal variations and their contribution of the regression (R2) were 63, 65 and 31%, respectively. Five independent weather factors in stepwise regression equation pooled responsible for 67.4% of the total variance. Stepwise regression showed that maximum temperature was the most important to influence 35.3% and the influence was lowest (2.1%) in case of average rainfall.

  11. Biology and Sampling of Red Oak Borer Populations in the Ozark Mountains of Arkansas

    Science.gov (United States)

    Damon Crook; Fred Stephen; Melissa Fierke; Dana Kinney; Vaughn Silisbury

    2004-01-01

    A complex interaction of multiple factors has resulted in >75 percent mortality/decline of more than 1 million acres of red oak (Quercus, subgenus Erythrobalanus) on the Ozark-St. Francis National Forests. The most striking feature of this oak decline event is an unprecedented outbreak of red oak borer. A visual stand assessment...

  12. Population biology of emerald ash borer and its natural enemies in China

    Science.gov (United States)

    Houping Liu; Leah S. Bauer; Tonghai Zhao; Ruitong Gao

    2008-01-01

    Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), also known as emerald ash borer (EAB), was first discovered in Michigan and Ontario, Canada, in 2002 following investigations of declining and dying ash trees (Fraxinus spp.). Agrilus planipennis has also spread to Ohio, Indiana, Maryland, Virginia,...

  13. Pod Borer of Peanut and Potential Entomopathogenic Fungi for its Control in West Sumatera

    Directory of Open Access Journals (Sweden)

    Reflinaldon Reflinaldon

    2014-01-01

    Full Text Available Pod borer (Etiella zinckenella is a serious pest on peanuts in West Sumatera since the last four years. The larvae lived and bored on pods under soil surfaces and it is often undetected.  E. zinckenella is very limited reporting as a pest on peanuts especially in Indonesia. We described about pod borer attacking in West Sumatera and as alternative strategic control using entomopathogenic fungi bicontrol agents is  safety and more efective and it will be promoted for controlling of  larvae in pods under soil. The objective of this research were to determine severity of damage of pod borer with survey and  observation methods , and to find out potential entomopathogenic fungi  by in both of baiting and  dilution method. The severity of attacking of pod borer on groundnut was 14 to 70%. Five group of fungi i.e: Metharizium sp, Aspergillus sp, Trichoderma, Fusarium and Paecillomyces were isolated from soil of groundnut’s rhizosphere in  several districts of West Sumatera and they were able to infected of Tribolium molitor 8-30%.

  14. Heat treatment of Firewood for Emerald Ash Borer (Agrilus planipennis Fairmaire): Case Studies

    Science.gov (United States)

    Xiping Wang; Richard D. Bergman; Brian K. Brashaw; Scott W. Myers

    2014-01-01

    The movement of firewood within emerald ash borer (Agrilus planipennis Fairmaire) (EAB)-infested states and into adjoining areas has been a contributor to its spread throughout the United States and Canada. In an effort to prevent further human-aided spread of EAB and to facilitate interstate commerce, the USDA Animal and Plant Health Inspection Service and cooperating...

  15. The coffee berry borer, Hypothenemus hampei: how many instars are there?

    Science.gov (United States)

    After more than a century since the description of the coffee berry borer, Hypothenemus hampei (Ferrari), and dozens of scientific articles on the basic biology of the insect, there is still debate on the number of female larval instars. This paper analyzes the metamorphosis of H. hampei females thr...

  16. On the eyes of the coffee berry borer as rudimentary organs

    Science.gov (United States)

    The coffee berry borer, Hypothenemus hampei, is the most damaging insect pest of coffee worldwide. Females bore into the coffee berries and deposit eggs within galleries in the endosperm, with a 10:1 sex ratio favoring females. There is sibling mating followed by females exiting the berry, while mal...

  17. Oak mortality associated with crown dieback and oak borer attack in the Ozark Highlands

    Science.gov (United States)

    Zhaofei Fan; John M. Kabrick; Martin A. Spetich; Stephen R. Shifley; Randy G. Jensen

    2008-01-01

    Oak decline and related mortality have periodically plagued upland oak–hickory forests, particularly oak species in the red oak group, across the Ozark Highlands of Missouri, Arkansas and Oklahoma since the late 1970s. Advanced tree age and periodic drought, as well as Armillaria root fungi and oak borer attack are believed to contribute to oak decline and mortality....

  18. Core RNAi machinery and gene knockdown in the emerald ash borer (Agrilus planipennis)

    Science.gov (United States)

    Chaoyang Zhao; Miguel A. Alvarez Gonzales; Therese M. Poland; Omprakash. Mittapalli

    2015-01-01

    The RNA interference (RNAi) technology has been widely used in insect functional genomics research and provides an alternative approach for insect pest management. To understand whether the emerald ash borer (Agrilus planipennis), an invasive and destructive coleopteran insect pest of ash tree (Fraxinus spp.), possesses a strong...

  19. Putative role of pith cell wall phenylpropanoids in Sesamia nonagrioides (Lepidoptera: Noctuidae) resistance.

    Science.gov (United States)

    Santiago, Rogelio; Butron, Ana; Arnason, John T; Reid, Lana M; Souto, Xose C; Malvar, Rosa A

    2006-03-22

    The stem borer Sesamia nonagrioides (Lefèbvre) is the most important insect pest that attacks maize, Zea mays L., in northwestern Spain. Host plant resistance to this borer was investigated in relation to the cell wall phenylpropanoids content in the pith. Eight inbred lines that differ in resistance were analyzed. Three major simple phenolic acids, p-coumaric, trans-ferulic, and cis-ferulic acids, and three isomers of diferulic acid, 8-5', 8-O-4', and 8-5'b (benzofuran form), were identified. The amount of all these compounds was correlated with the resistance level in the genotypes, with the resistant inbreds having the highest concentrations. The role of these compounds in cell wall fortification and lignification is well-documented, suggesting their possible intervention in S. nonagrioides resistance. Future studies that focus on these compounds could be useful to enhance S. nonagroides resistance.

  20. Decreased emergence of emerald ash borer from ash treated with methyl jasmonate is associated with induction of general defense traits and the toxic phenolic compound verbascoside.

    Science.gov (United States)

    Whitehill, Justin G A; Rigsby, Chad; Cipollini, Don; Herms, Daniel A; Bonello, Pierluigi

    2014-12-01

    The emerald ash borer (EAB; Agrilus planipennis Fairmaire) is causing widespread mortality of ash (Fraxinus spp.) in North America. To date, no mechanisms of host resistance have been identified against this pest. Methyl jasmonate was applied to susceptible North American and resistant Asian ash species to determine if it can elicit induced responses in bark that enhance resistance to EAB. In particular, phenolic compounds, lignin, and defense-related proteins were quantified, and compounds associated with resistance were subsequently tested directly against EAB larvae in bioassays with artificial diet. MeJA application decreased adult emergence in susceptible ash species, comparable to levels achieved by insecticide application. Concentration of the phenolic compound verbascoside sharply increased after MeJA application to green and white ash. When incorporated in an artificial diet, verbascoside decreased survival and growth of EAB neonates in a dose-dependent fashion. Lignin and trypsin inhibitors were also induced by MeJA, and analogs of both compounds reduced growth of EAB larvae in artificial diets. We conclude that the application of MeJA prior to EAB attack has the ability to enhance resistance of susceptible ash trees by inducing endogenous plant defenses, and report evidence that induction of verbascoside is a mechanism of resistance to EAB.

  1. The Active Space of Mexican Rice Borer Pheromone Traps.

    Science.gov (United States)

    Wilson, Blake E; Beuzelin, Julien M; Allison, Jeremy D; Reagan, Thomas E

    2016-09-01

    The Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), is an invasive pest of sugarcane, Saccharum spp., rice, Oryza sativa L., and other graminaceous crops in the United States. Traps baited with the synthetic female sex pheromone of E. loftini are used for monitoring and management of this invasive pest. However, the active space, or radius of attraction, of these traps is not known. Two field experiments examined the effect of intertrap distance on trap captures with hexagonal arrays of traps deployed in rice stubble habitat in Texas (2011) and Louisiana (2013). Trap capture increased with increasing intertrap distance. Trap interference occurred at intertrap distances ≤50 m in the 2011 experiment. Results from the experiment conducted in 2013 indicate that trap interference occurs at intertrap distances of 50 m, but not at distances ≥100 m. These results suggest that under field conditions, E. loftini pheromone traps attract males from distances of 50-100 m. The active space of pheromone traps also was examined under controlled wind conditions by direct observation of male response to detection of the female sex pheromone. Eoreuma loftini males responded to the pheromone blend by becoming active, fanning their wings, and rapidly walking in circles. The mean distance from the pheromone source at which males responded was 47.6 m. This work provides the first documentation of active space for traps baited with female sex pheromone for a crambid species, and these data will improve pheromone trap deployment strategies for E. loftini monitoring and management.

  2. A transcriptomic survey of Migdolus fryanus (sugarcane rhizome borer) larvae

    Science.gov (United States)

    Nakayama, Darlan Gonçalves; Santos Júnior, Célio Dias; Kishi, Luciano Takeshi; Pedezzi, Rafael; Santiago, Adelita Carolina; Soares-Costa, Andrea; Henrique-Silva, Flavio

    2017-01-01

    Sugarcane, a major crop grown in the tropical and subtropical areas of the world, is produced mainly for sucrose, which is used as a sweetener or for the production of bioethanol. Among the numerous pests that significantly affect the yield of sugarcane, the sugarcane rhizome borer (Migdolus fryanus, a cerambycidae beetle) is known to cause severe damage to the crops in Brazil. The absence of molecular information about this insect reinforces the need for studies and an effective method to control this pest. In this study, RNA-Seq technology was employed to study different parts of M. fryanus larvae. The generated data will help in further investigations about the taxonomy, development, and adaptation of this insect. RNA was extracted from six different parts (head, fat body, integument, hindgut, midgut, and foregut) using Trizol methodology. Using Illumina paired-end sequencing technology and the Trinity platform, trimming and de novo assembly was performed, resulting in 44,567 contigs longer than 200 nt for a reunion of data from all transcriptomes, with a mean length of 1,095.27 nt. Transcripts were annotated using BLAST against different protein databanks (Uniprot/Swissprot, PFAM, KEEG, SignalP 4.1, Gene Ontology, and CAZY) and were compared for similarity using a Venn diagram. Differential expression patterns were studied for select genes through qPCR and FPKM comprising important protein families (digestive peptidases, glucosyl hydrolases, serine protease inhibitors and otopetrin), which allowed a better understanding of the insect’s digestion, immunity and gravity sensorial mechanisms. PMID:28248990

  3. Improved corn protein based articles

    Science.gov (United States)

    Developing higher value uses for zein (corn protein), a potential major co-product of the bio-ethanol industry, will improve the economics of this business. Historically, zein was predominantly used in the textile fiber industry. Unfortunately the techniques used at that time to modify the zein cann...

  4. Compatibility with corn: N credits

    Science.gov (United States)

    Productive and efficient short rotations of alfalfa and corn are needed to reduce energy inputs, produce food, feed, and energy, and yield the environmental quality benefits from the perennial legume. After decades of research, however, farmers and their advisors still question how much fertility ...

  5. Enzymatic hydrolysis of corn bran arabinoxylan

    DEFF Research Database (Denmark)

    Agger, Jane

    This thesis concerns enzymatic hydrolysis of corn bran arabinoxylan. The work has focused on understanding the composition and structure of corn bran with specific interest in arabinoxylan with the main purpose of targeting enzymatic hydrolysis for increased yields. Corn bran has been used...... as a model substrate because it represents a readily available agroindustrial side product with upgrading potentials. Corn bran originates from the wet-milling process in corn starch processing, is the outmost layers of the corn kernel and is particularly rich in pentose monosaccharides comprising the major...... components of arabinoxylan. Corn bran is one of the most recalcitrant cereal byproducts with arabinoxylans of particular heterogeneous nature. It is also rich in feruloyl derived substitutions, which are responsible for extensive cross-linking between arabinoxylan molecules and thereby participate...

  6. Reproductive and developmental biology of the emerald ash borer parasitoid Spathius galinae (Hymenoptera: Braconidae) as affected by temperature

    Science.gov (United States)

    Emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) is an invasive pest of serious concern in North America. To complement ongoing biological control efforts, Spathius galinae Belokobylskij and Strazenac (Hymenoptera: Braconidae), a recently-described specialist parasitoid of ...

  7. Identifying drivers for consumer acceptance and purchase intent of corn tortilla.

    Science.gov (United States)

    Herrera-Corredor, J A; Saidu, J E P; Khachatryan, A; Prinyawiwatkul, W; Carballo-Carballo, A; Zepeda-Bautista, R

    2007-11-01

    The traditional production of corn tortilla has been modified by new processing technologies to make possible a commercial-scale production; this practice has resulted in products having sensory properties different from those produced by the traditional method. There is no published information on sensory attributes driving acceptance and purchase intent of corn tortillas. Identifying sensory drivers for acceptance and purchase intent of corn tortillas will help commercially produce products that satisfy consumers' expectations. A consumer study was conducted to evaluate acceptance and purchase intent of corn tortillas and determine drivers of acceptance and purchase intent of the products. Ten samples of corn tortillas were selected to represent a variety of corn tortillas available in the Mexican market. Three hundred Mexican consumers evaluated acceptability of appearance, color, thickness, rollability, resistance to tearing, aroma, chewiness, taste and aftertaste, and overall liking using a 9-point hedonic scale. Overall acceptance and purchase intent were determined with a yes/no scale. Analysis of variance and multivariate analysis of variance revealed that consumers were able to differentiate differences in sensory acceptability among 10 samples. For example, 2 homemade and 1 small commercial-scale samples, with an overall liking score of 6.6 to 6.7, were more acceptable than others. Rollability, resistance to tearing, and chewiness were attributes underlying overall differences among 10 samples. Attributes determining overall acceptance of corn tortillas were chewiness and overall liking. Purchase intent was influenced by overall appearance, rollability, chewiness, taste, and overall liking. This study revealed critical sensory attributes and their weights given by Mexican consumers when making decisions for acceptance and purchase intent of corn tortilla.

  8. The U2U Corn Growing Degree Day tool: Tracking corn growth across the US Corn Belt

    Directory of Open Access Journals (Sweden)

    James R. Angel

    2017-01-01

    Full Text Available The Corn Growing Degree Day (Corn GDD tool is a web-based product that can provide decision support on a variety of issues throughout the entire growing season by integrating current conditions, historical climate data, and projections of Corn GDD through the end of the growing season based on both National Weather Service computer model forecasts and climatology. The Corn GDD tool can help agricultural producers make a variety of important decisions before and during the growing season. This support can include: assessing the risk of early and late frosts and freezes that can cause crop damage; comparing corn hybrid maturity requirements and Corn GDD projections to select seed varieties and plan activities such as spraying; guiding marketing decisions based on historical and projected Corn GDDs when considering forward crop pricing (i.e., futures market. The Corn GDD tool provides decision support for corn producers in the central U.S. corn-producing states. Survey results, web statistics, and user feedback indicate that this tool is being actively used by decision makers.