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Tiffany Heng-moss - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of Greenbug and Yellow Sugarcane Aphid Feeding Behavior on Resistant and Susceptible Switchgrass Cultivars
BioEnergy Research, 2018Co-Authors: Kyle G. Koch, Joe Louis, Teresa Donze-reiner, Lisa M. Baird, Keenan Amundsen, Gautam Sarath, Jeffrey D. Bradshaw, Tiffany Heng-mossAbstract:Switchgrass ( Panicum virgatum L.) is an emerging biofuel crop that serves as host for aphids. To discern the effects of plant age and possible resistance mechanisms, the feeding behavior of Greenbugs ( Schizaphis graminum Rondani.) and the yellow sugarcane aphid ( Sipha flava Forbes.) was monitored on three diverse switchgrasses by the electrical penetration graph (EPG) technique. Callose deposition and genes associated with callose metabolism were also analyzed to discern their association with plant resistance. There was a strong host effect on Greenbugs feeding on lowland cultivar Kanlow at the V3 stage of development, as compared to the greenbug-susceptible upland cultivar Summer and plants derived from Kanlow (♂) × Summer (♀) (K×S) crosses. These data confirmed that Kanlow at the V3 stage had antibiosis to Greenbugs, which was absent in the Summer and K×S plants. In contrast, similar effects were not observed for yellow sugarcane aphids, excluding significant differences in the time to first probe on Kanlow plants at the V1 stage and reduction in time spent on pathway processes on Kanlow plants at the V3 stage. These data demonstrated that Kanlow plants may have multiple sources of resistance to the two aphids, and possibly some were phloem based. Microscopy of leaf sections stained with aniline blue for callose was suggestive of increased callose deposition in the sieve elements in Kanlow plants relative to Summer and K×S plants. RT-qPCR analysis of several genes associated with callose metabolism in infested plants was equivocal. Overall, these studies suggest the presence of multiple defense mechanisms against aphids in Kanlow plants, relative to Summer and K×S plants.
John C Reese - One of the best experts on this subject based on the ideXlab platform.
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Relationship Between Chlorophyll Loss and Photosynthetic Rate in Greenbug (Homoptera: Aphididae) Damaged Sorghum
2016Co-Authors: Nandi Nagaraj, John C Reese, M. B. Kirkham, Ken Kofoid, Leslie R. Campbell, Thomas M. LoughinAbstract:The effect of greenbug, Schizaphis graminum (Rondani) feeding on chlorophyll content and photosynthetic rate in sorghum (Sorghum bicolor (L.) Moench) was assessed un der artificial light conditions. Between 1500-1750 Greenbugs were used to infest a 5 cm x 2.5 cm area on a sorghum leaf by means of a modified double-sided sticky cage. A treatment with cage only on the leaf was also included. The control treatment was leaves with no cages and no Greenbugs, which would allow measurement of parameters absent the internal effects of either greenbug feeding or cages. Greenbug infestation intervals of 1, 2, 3 and 4 days re duced significantly both photosynthetic rate and chlorophyll content. Photosynthetic rate showed a positive correlation with chlorophyll content (r = 0.36, d.f. = 208, P = 0.0001). With a small drop in chlorophyll content, a drastic reduction in photosynthetic rate was no ticed. Decreased chlorophyll content due to greenbug feeding partially explained the reduc tion in photosynthetic rate. Leaf age, nutritional status, and micro-environmental parameters may also have influenced the relationship between photosynthetic rate and chlorophyll con
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categories of resistance antibiosis and tolerance to biotype i greenbug schizaphis graminum rondani homoptera aphididae in four sorghum sorghum bicolor l moench poales gramineae hybrids
Journal of the Kansas Entomological Society, 2007Co-Authors: Mahmut Dogramaci, Z B Mayo, Robert J Wright, John C ReeseAbstract:Abstract Resistance categories (antibiosis and tolerance) of four sorghum (Sorghum bicolor (L.) Moench) hybrids to biotype I greenbug, Schizaphis graminum (Rondani), were determined in environmental growth chamber and field studies. Greenbug weight and fecundity were lower on ‘Cargill 607E’ compared with ‘Cargill 797’. Percentage of leaf damage area was significantly less on two resistant hybrids (Cargill 607E and Cargill 797) after a 14-d greenbug feeding period compared to two susceptible hybrids (‘Golden Harvest 510B’ and Garst 5715). In growth chamber studies on sorghum seedlings, ‘Cargill 607E’ and ‘Cargill 797’ reduced greenbug weight significantly compared with ‘Golden Harvest 510B’ and ‘Garst 5715’. Greenbug weight was 2.9 mg/25 Greenbugs on ‘Cargill 607E’, 3.1 mg/25 Greenbugs on ‘Cargill 797’, 3.9 mg/25 Greenbugs on ‘Golden Harvest 510B’, and 4.8 mg/25 Greenbugs on ‘Garst 5715’. On field grown sorghum plants, ‘Cargill 797’ did not reduce greenbug growth compared with ‘Golden Harvest 510B’. ‘Cargi...
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tritrophic interaction of parasitoid lysiphlebus testaceipes hymenoptera aphidiidae greenbug schizaphis graminum homoptera aphididae and greenbug resistant sorghum hybrids
Journal of Economic Entomology, 2005Co-Authors: Mahmut Dogramaci, Z B Mayo, Robert J Wright, John C ReeseAbstract:Interactions of the parasitoid Lysiphlebus testaceipes (Cresson) and the greenbug, Schizaphis graminum (Rondani), on greenbug-resistant OCargill 607EO (antibiosis), OCargill 797O (pri- marily tolerance), and -susceptible OGolden Harvest 510BO sorghum, Sorghum bicolor (L.) Moench, were tested using three levels of biotype I greenbug infestation. The parasitoid infestation rate was 0.5 female and 1.0 male L. testaceipes per plant. For all three greenbug infestation levels, the parasitoid brought the greenbug under control (i.e., prevented the Greenbugs from killing the plants) on both resistant hybrids, but it did not prevent heavy leaf damage at the higher greenbug infestation rates. At the low greenbug infestation rate (50 Greenbugs per resistant plant when parasitoids were introduced), Greenbugs damaged 5 and 18% of the total leaf area on OCargill 797O and OCargill 607EO, respectively, before Greenbugs were eliminated. Leaf damage was higher for the intermediate infes- tation study (120 Greenbugs per plant), 21% and 30% leaf area were damaged on the resistant sorghum hybrids OCargill 797O and OCargill 607EO, respectively. At the high greenbug infestation rate (300 Greenbugs per plant), heavy damage occurred: 61% on OCargill 607EO and 75% on OCargill 797O. The parasitoids did not control Greenbugs on the susceptible sorghum hybrid OGolden Harvest 510BO. L. testaceipes provided comparable control on both greenbug-resistant hybrids. This study supports previous studies indicating that L. testaceipes is effective in controlling Greenbugs on sorghum with antibiosis resistance to Greenbugs. Furthermore, new information is provided indicating that L. testaceipes is also effective in controlling Greenbugs on a greenbug-tolerant hybrid.
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Categories of Resistance to Biotype I Greenbugs (Homoptera: Aphididae) in Wheat Lines Containing the Greenbug Resistance Genes Gbx and Gby
Journal of the Kansas Entomological Society, 2005Co-Authors: Dhanaraj Boina, Sheila Prabhakar, C. Michael Smith, Sharon Starkey, Lieceng Zhu, Elena V. Boyko, John C ReeseAbstract:Abstract The greenbug, Schizaphis graminum (Rondani), is a major pest of wheat in North America, reducing U.S. wheat production by $60 to $100 million each year. Experiments were conducted to determine the categories of resistance to greenbug biotype I controlled by two different resistance genes in wheat germplasm lines ‘KS89WGRC4’, containing the Gbx gene, and ‘Sando's 4040’, containing the Gby gene. Antixenosis (non-preference), antibiosis (lowered greenbug intrinsic rate of increase) and tolerance (reduced plant tissue and chlorophyll loss) assays were conducted using plants of Sando's 4040, KS89WGRC4, ‘Jagger’ (susceptible control), ‘Largo’ (antibiosis control), and ‘TA1675’ (tolerance control). Neither Sando's 4040, KS89WGRC4 nor the controls exhibited antixenosis to greenbug biotype I. There was an antibiotic effect on the Greenbugs confined to Sando's 4040 (rm = 0.122), that was no different than the rm of aphids on the resistant control, Largo (rm = 0.144). Antibiosis was not present in KS89WGRC4...
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Chlorophyll loss in a greenbug-susceptible sorghum due to pectinases and pectin fragments
Journal of the Kansas Entomological Society, 1998Co-Authors: Runlin Z., John C Reese, W.c. Iv. Black, P. J. Bramel-coxAbstract:Leaf discoloration of greenbug-susceptible sorghum NC+ 159 due to plant cell wall-degrading enzymes and pectin fragments was measured using a hand-held chlorophyll meter (SPAD-502, Minolta Corporation, Ramsey, NJ). Polygalacturonase from biotype E greenbug, Schizaphis graminum (Rondani), caused local discoloration when the enzyme was micro-injected into the plant leaves. Pectinases from two plant pathogens, Aspergillus niger and Erwinia carotovora subsp. carotovora, caused a weaker leaf discoloration when com pared to that of greenbug polygalacturonase. A significant reduction in plant chlorophyll con tent around the enzyme-treated areas was detected by the chlorophyll meter. Damage symp toms caused by the enzyme treatments were very similar to greenbug feeding damage. Surface treatment of sorghum leaves with pectic fragments caused damage symptoms similar to those induced by pectic enzymes. The results demonstrated the ability of pectinases and pectic frag ments to elicit a response similar to that due to greenbug feeding damage in greenbug-sus ceptible sorghum plants, separate and apart from any feeding Greenbugs. The potential roles of greenbug pectinases and pectic fragments in insect-plant interactions are discussed.
Kyle G. Koch - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of Greenbug and Yellow Sugarcane Aphid Feeding Behavior on Resistant and Susceptible Switchgrass Cultivars
BioEnergy Research, 2018Co-Authors: Kyle G. Koch, Joe Louis, Teresa Donze-reiner, Lisa M. Baird, Keenan Amundsen, Gautam Sarath, Jeffrey D. Bradshaw, Tiffany Heng-mossAbstract:Switchgrass ( Panicum virgatum L.) is an emerging biofuel crop that serves as host for aphids. To discern the effects of plant age and possible resistance mechanisms, the feeding behavior of Greenbugs ( Schizaphis graminum Rondani.) and the yellow sugarcane aphid ( Sipha flava Forbes.) was monitored on three diverse switchgrasses by the electrical penetration graph (EPG) technique. Callose deposition and genes associated with callose metabolism were also analyzed to discern their association with plant resistance. There was a strong host effect on Greenbugs feeding on lowland cultivar Kanlow at the V3 stage of development, as compared to the greenbug-susceptible upland cultivar Summer and plants derived from Kanlow (♂) × Summer (♀) (K×S) crosses. These data confirmed that Kanlow at the V3 stage had antibiosis to Greenbugs, which was absent in the Summer and K×S plants. In contrast, similar effects were not observed for yellow sugarcane aphids, excluding significant differences in the time to first probe on Kanlow plants at the V1 stage and reduction in time spent on pathway processes on Kanlow plants at the V3 stage. These data demonstrated that Kanlow plants may have multiple sources of resistance to the two aphids, and possibly some were phloem based. Microscopy of leaf sections stained with aniline blue for callose was suggestive of increased callose deposition in the sieve elements in Kanlow plants relative to Summer and K×S plants. RT-qPCR analysis of several genes associated with callose metabolism in infested plants was equivocal. Overall, these studies suggest the presence of multiple defense mechanisms against aphids in Kanlow plants, relative to Summer and K×S plants.
Blair D Siegfried - One of the best experts on this subject based on the ideXlab platform.
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in vitro metabolism of parathion in susceptible and parathion resistant strains of the greenbug schizaphis graminum rondani homoptera aphididae
Pesticide Biochemistry and Physiology, 1994Co-Authors: J S Richman, Blair D SiegfriedAbstract:Abstract Results of in vitro metabolism studies in a susceptible and two parathion-resistant greenbug strains indicate that hydrolytic enzymes are active toward paraoxon, but not parathion, and are partially responsible for resistance. The resistance does not involve reduced levels of oxidative metabolism and activation of parathion since NADPH-dependent microsomal formation of paraoxon in resistant and susceptible strains was similar. Paraoxon is a potent inhibitor of greenbug esterases, and the resistance mechanism apparently involves rapid and tight binding of enzyme and insecticide that prevents the insecticide from reaching its target site. Native polyacrylamide gel electrophoresis also supported this view since staining of enhanced bands associated with resistance was inhibited by incubation with paraoxon. The resistant strains apparently produce more of the isozymes that are inhibited by paraoxon and are able to sequester a greater number of paraoxon molecules than susceptible Greenbugs.
Gerald E. Wilde - One of the best experts on this subject based on the ideXlab platform.
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life history study of multiple clones of insecticide resistant and susceptible greenbug schizaphis graminum homoptera aphididae
Journal of Economic Entomology, 2000Co-Authors: Beth S Stone, Roxanne A Shufran, Gerald E. WildeAbstract:Abstract Comparative differences and similarities in prereproductive time (d), progeny production in a time equal to d (Md), and intrinsic rate of increase (rm) were established for one susceptible (S) and three resistant (R) strains of the greenbug, Schizaphis graminum (Rondani), reared on sorghum hybrids Dekalb G550E and Cargill 607E. The R strains showed three patterns of elevated esterase activity. Four R1 clones, four R2 clones, one R3 clone, and four S clones were evaluated. The interaction of sorghum hybrid and greenbug strain did not significantly influence any of the parameters measured. However, R1 Greenbugs exhibited a significantly longer prereproductive period than the other strains. In addition, the R1 strain had a significantly slower intrinsic rate of increase than the R2 or S greenbug strains, but did not differ significantly from the R3 strain. These results suggest that R1 Greenbugs may be less fit than the other strains studied.
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Genetics of esterase-mediated insecticide resistance in the aphid Schizaphis graminum
Heredity, 1998Co-Authors: Stanley Dean Rider, Gerald E. Wilde, Srinivas KambhampatiAbstract:The genetics of organophosphate resistance, including the pattern of inheritance and the underlying genetic mechanism, were investigated in the aphid Schizaphis graminum (the greenbug). Resistant Greenbugs with pattern 1 (R1) and pattern 2 (R2) esterase and susceptible (S) Greenbugs were induced into the sexual cycle and crossed. Each resistance-associated esterase pattern in the greenbug was inherited in a Mendelian fashion as a single gene. An aphid clone that displayed both resistance-associated esterase patterns was produced in the F_1 generation of a cross between R2 and R1 insects, and was designated pattern 3 (R3). DNA from different R1 aphids and the R3 aphid clone displayed a restriction fragment pattern different from that of R2 and S clones, and about a twofold increase in hybridization compared with S aphids. DNA from R2 clones showed no restriction fragment differences or increased hybridization signal compared to S insects. These findings suggest that the mechanism behind the R1 esterase activity may be gene amplification, but that the R2 elevated esterase activity may result from a different genetic mechanism.
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occurrence of insecticide resistant Greenbugs homoptera aphididae in kansas texas oklahoma and colorado and suggestions for management
Journal of Economic Entomology, 1997Co-Authors: Roxanne A Shufran, Gerald E. Wilde, P E Sloderbeck, William P MorrisonAbstract:Polyacrylamide gel electrophoresis was used to resolve esterase isozymes that were related to insecticide resistance in greenbug, Schizaphis graminum (Rondani). This report documents the occurrence of esterase polymorphisms in the Midwest and assesses differences in regional occurrences. In total, 13,863 individual Greenbugs from Kansas, Texas, Oklahoma, and Colorado were tested between 1991 and 1995. The occurrence of resistant Greenbugs appeared to be greatest in the southwest crop reporting district of Kansas and the north plains crop reporting district of Texas. The overall incidence of pattern 1 resistant Greenbugs declined from 7.1% in 1991 to <1% in 1994 and 1995. Pattern 2 resistant greenbug occurrence varied from year to year (5.7-29.8%). Several explanations for the spatial occurrence of resistant Greenbugs and several techniques for managing resistant greenbug populations are offered.
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Occurrence of insecticide resistant Greenbugs (Homoptera: Aphididae) in Kansas, Texas, Oklahoma, and Colorado and suggestions for management
Journal of Economic Entomology, 1997Co-Authors: Roxanne A Shufran, Gerald E. Wilde, P E Sloderbeck, William P MorrisonAbstract:Polyacrylamide gel electrophoresis was used to resolve esterase isozymes that were related to insecticide resistance in greenbug, Schizaphis graminum (Rondani). This report documents the occurrence of esterase polymorphisms in the Midwest and assesses differences in regional occurrences. In total, 13,863 individual Greenbugs from Kansas, Texas, Oklahoma, and Colorado were tested between 1991 and 1995. The occurrence of resistant Greenbugs appeared to be greatest in the southwest crop reporting district of Kansas and the north plains crop reporting district of Texas. The overall incidence of pattern 1 resistant Greenbugs declined from 7.1% in 1991 to
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Response of Three Greenbug (Homoptera: Aphididae) Strains to Five Organophosphorous and Two Carbamate Insecticides
Journal of Economic Entomology, 1997Co-Authors: Roxanne A Shufran, Gerald E. Wilde, P E SloderbeckAbstract:Insecticide resistance in insects often is associated with elevated acetylcholin esterases and carboxylesterases. Three greenbug, Schizaphis graminum (Rondani), strains with different general esterase patterns were tested for differences in insecticide response. The standard strain had no noticeable elevated esterase activity. Pattern 1 and pattern 2 strains had different elevated esterase patterns. Toxicity of 5 organophosphorous (chlorpyrifos, dimethoate, disulfoton, malathion, and parathion) and 2 carbamate (carbofuran and methomyl) insecticides were tested using surface residue bioassays. Esterase pattern 1 Greenbugs had significantly higher LC50s for each of the organophosphorous insecticides, but the LC50 for the 2 carbamate insecticides were not higher than the standard strain. Esterase pattern 2 Greenbugs had significantly higher LC50s for 4 of the 5 organophosphorus insecticides (chlorpyrifos, dimethoate, disulfoton, and parathion) and the 2 carbamate insecticides, but the LC50 for malathion was not higher than the standard strain. Pattern 2 Greenbugs had significantly higher tolerance to disulfoton than did pattern 1 Greenbugs. This indicates that certain strains of the greenbug are cross resistant to many of the organophosphorous and carbamate insecticides currently labeled for greenbug control in wheat and sorghum. There is an urgent need to find alternative control measures.
