The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Gautam Sarath - One of the best experts on this subject based on the ideXlab platform.
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Categories of Resistance to Greenbug and Yellow Sugarcane Aphid (Hemiptera: Aphididae) in Three Tetraploid Switchgrass Populations
BioEnergy Research, 2014Co-Authors: Kyle G. Koch, Jeffrey D. Bradshaw, Tiffany M. Heng-moss, Gautam SarathAbstract:Switchgrass, Panicum virgatum L., has been targeted as a bioenergy feedstock. However, little is currently known of the mechanisms of insect resistance in this species. Here, two no-choice studies were performed to determine the categories (Antibiosis and tolerance) and relative levels of resistance of three switchgrass populations (Kanlow–lowland ecotype, Summer–upland ecotype, and third generation derivatives between Kanlow × Summer plants, K×S) previously identified with differential levels of resistance to the greenbug, Schizaphis graminum (Rondani), and yellow sugarcane aphid, Sipha flava (Forbes). No-choice studies indicated that Kanlow possessed multi-species resistance, with high levels of Antibiosis to both aphid species, based on aphid survival at 7 and 14 days after aphid introduction and cumulative aphid days, while K×S possessed low-to-moderate levels of Antibiosis to S. flava . Further, functional plant loss indices based on plant height and biomass indicated that tolerance is an important category of resistance for Summer plants to S. graminum . These studies also indicated that Summer lacks both tolerance and Antibiosis to S. flava , relative to the other switchgrasses tested, whereas K×S lack tolerance and Antibiosis to S. graminum . These studies are the first attempt to analyze the categories of resistance in switchgrass and provide critical information for characterizing the biological mechanisms of resistance and improving our knowledge of the plant–insect interactions within this system.
R J Lamb - One of the best experts on this subject based on the ideXlab platform.
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seedling and adult plant resistance to sitobion avenae hemiptera aphididae in triticum monococcum poaceae an ancestor of wheat
Bulletin of Entomological Research, 2004Co-Authors: S M Migui, R J LambAbstract:Cereal aphids are important pests of wheat, Triticum aestivum L. and Triticum durum Desf. Crop resistance is a desirable method for managing cereal aphids in central North America, where the dominant crop, spring-sown wheat, has a low value per unit area. A diploid ancestor of wheat, Triticum monococcum L., is reported to be partially resistant to Sitobion avenae (Fabricius), the most damaging cereal aphid in the region. To identify potential sources of resistance, 42 accessions of T. monococcum and three cultivated wheats were infested with aphids, seedlings for six days and adult plants for 21 days. Overall resistance was estimated by the biomass loss of foliage and spikes in relation to uninfested control plants. Antibiosis was estimated by the gain in biomass of aphids during infestation, and tolerance was estimated as a biomass conversion ratio, overall resistance divided by Antibiosis. A few T. monococcum accessions exhibited partial resistance. No relationship was found between seedling and adult plant resistance: the former exhibited primarily Antibiosis and the latter primarily tolerance. Two accessions with Antibiosis reduced aphid biomass by 60% compared with commercial wheats. Tolerance was correlated with growth potential, and was useful only in accessions with high growth potential. Four accessions exhibited tolerance levels at least 30% greater than commercial wheats. Highly susceptible accessions also were identified, which would be useful for investigating the inheritance of Antibiosis and tolerance.
Helena Havličková - One of the best experts on this subject based on the ideXlab platform.
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Level and nature of the resistance to the cereal aphid, Sitobion avenae (F.), in thirteen winter wheat cultivars.
Journal of Agronomy and Crop Science, 1993Co-Authors: Helena HavličkováAbstract:Thirteen winter wheat cultivars were tested under field and greenhouse conditions for resistance to the cereal aphid, Sitobion avenae (F.). Marked differences were recorded between cultivars in nonpreference (anti-xenosis), Antibiosis and tolerance to aphids. Nonpreference was significantly (P 0.1) on artificially infested ears (criterion for cultivar Antibiosis). Over all the cultivars, there was no correlation between nonpreference and tolerance and between Antibiosis and tolerance to aphids. Five cultivars expressed high level of resistance to S. avenae. The high resistance of three cultivars was due to high nonpreference and Antibiosis, and only in two cultivars all three mechanisms contributed to resistance. Zusammenfassung Starke und Art der Resistenz gegen Getreidelaus, Sitobion avenae (F.), bei 13 Winterweizenkultivaren 13 Winterweizenkultivare wurden unter Feldbedingungen und im Gewachshaus hinsichtlich ihrer Resistenz gegenuber der Getreidelaus (Si-tobion avenae [F.]) untersucht. Deutliche Differenzen wurden zwischen den Kultivaren hinsichtlich der Antixenosis, Antibiosis und der Toleranz gegenuber LaUsen gefunden. Ein Nichtbefall war signifikant (P 0.1) bei kunstlich infizierten Ahren (Kriterium fur KultivarAntibiosis) auftrat. Bei allen Kultivaren fand sich keine Korrelation zwischen dem Nichtbefall und der Toleranz und zwischen Antibiosis und Toleranz gegenuber Lausen. Funf Kultivare zeigten einen hohen Grad von Resistenz gegenuber S. avenae. Die hohe Resistenz von drei Kultivaren war eine Folge des hohen Nichtbefalls und der Antibiosis; nur in zwei Kultivaren waren alle drei Mechanismen an der Resistenz beteiligt.
Kyle G. Koch - One of the best experts on this subject based on the ideXlab platform.
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Categories of Resistance to Greenbug and Yellow Sugarcane Aphid (Hemiptera: Aphididae) in Three Tetraploid Switchgrass Populations
BioEnergy Research, 2014Co-Authors: Kyle G. Koch, Jeffrey D. Bradshaw, Tiffany M. Heng-moss, Gautam SarathAbstract:Switchgrass, Panicum virgatum L., has been targeted as a bioenergy feedstock. However, little is currently known of the mechanisms of insect resistance in this species. Here, two no-choice studies were performed to determine the categories (Antibiosis and tolerance) and relative levels of resistance of three switchgrass populations (Kanlow–lowland ecotype, Summer–upland ecotype, and third generation derivatives between Kanlow × Summer plants, K×S) previously identified with differential levels of resistance to the greenbug, Schizaphis graminum (Rondani), and yellow sugarcane aphid, Sipha flava (Forbes). No-choice studies indicated that Kanlow possessed multi-species resistance, with high levels of Antibiosis to both aphid species, based on aphid survival at 7 and 14 days after aphid introduction and cumulative aphid days, while K×S possessed low-to-moderate levels of Antibiosis to S. flava . Further, functional plant loss indices based on plant height and biomass indicated that tolerance is an important category of resistance for Summer plants to S. graminum . These studies also indicated that Summer lacks both tolerance and Antibiosis to S. flava , relative to the other switchgrasses tested, whereas K×S lack tolerance and Antibiosis to S. graminum . These studies are the first attempt to analyze the categories of resistance in switchgrass and provide critical information for characterizing the biological mechanisms of resistance and improving our knowledge of the plant–insect interactions within this system.
Jagmohan Joshi - One of the best experts on this subject based on the ideXlab platform.
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Antibiosis in Soybean Breeding Lines for the Management of Corn Earworm for Sustainable Soybean Production
Journal of Sustainable Agriculture, 2007Co-Authors: R. B. Dadson, I. Javaid, Fawzy Hashem, Jagmohan JoshiAbstract:ABSTRACT Corn earworm (Helicoverpa zea Boddie), is one of the major insect pests of soybean in many soybean growing areas. A study was conducted during three soybean growing seasons to evaluate the Antibiosis type of resistance in soybean breeding lines which were grown in replicated field trials. A plant introduction, ‘PI 229358’, with a known Antibiosis type of resistance against corn earworm was included as a resistant check and four commercial varieties including Hutcheson, Stalwart, Charleston and Croton also were included in the experiments for comparison. The results of Antibiosis tests showed that some breeding lines such as ‘E3582019’ and ‘D6874003’ provided level of Antibiosis to corn ear-worm comparable to that found in the commercial variety Stalwart. Also, ‘M3583009’ and ‘D358B3010’ provided Antibiosis to corn earworm which was similar to a commercial variety, Stalwart. However, none of the breeding lines provided the resistance which was similar to ‘PI 229358’. The intermediate Antibiosis fo...
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Antibiosis of forage soybean as an ecological alternative for the control of corn earworm
Agronomy for Sustainable Development, 2006Co-Authors: Iqbal Javaid, R. B. Dadson, Fawzy Hashem, Jagmohan JoshiAbstract:The present study is the first to document some Antibiosis type of resistance in forage soybeans. The production of forage soybean is increasing in the United States where about 500 000 acres are now grown annually in various soybean growing areas. However, production is limited by the corn earworm Helicoverpa zea Boddie, which is a major insect pest of soybean. An in vitro study of field grown soybean leaves was conducted to select forage soybean genotypes for Antibiosis type resistance to corn earworm. The feeding tests were conducted on excised leaf material from a randomized complete block design. The results showed significant differences in the weight of corn earworm larvae, which were allowed to feed on different genotypes of fodder soybean. The mean larval weights on genotypes Tara, 7P116 and 8 GH 85-2 were 245.8, 242.1, and 169.3 mg, respectively. These genotypes were found to be most susceptible to corn earworm while the tall growing vegetable cultivar Moon Cake with the mean larval weight of 94.8 showed some Antibiosis types of resistance.
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Antibiosis to Corn Earworm, Helicoverpa zea Boddie, by Cowpea Genotypes
Journal of Sustainable Agriculture, 2005Co-Authors: I. Javaid, R. B. Dadson, Fawzy Hashem, Jagmohan Joshi, Arthur L. AllenAbstract:ABSTRACT Corn earworm (Helicovrpa zea Boddie) is a pest of cow-pea in many regions of the United States. The larvae chew round holes in cowpea pods to feed on the developing grains, and thus, affect the yield and seed quality. Studies were conducted to identify Antibiosis to corn earworm (CEW) in diverse cowpea genotypes which had been identified to provide better yields in the Delmarva (Delaware, Maryland and Virginia) peninsula region. A series of bioassays were performed to evaluate the newly formed terminal trifoliolates of field grown cowpea for Antibiosis to CEW. Results showed significant differences in larval weights in all bioassays. The genotypes which gave the lowest larval weights were Mississippi Silver and Quick pick Pinkeye, while the genotype, Champion, provided the largest weights of larvae in virtually all tests. Therefore, this genotype could probably be used as a susceptible check for future cowpea Antibiosis studies to CEW. Results also indicate that some genotypes of cowpea that prov...