Characterization of Plant Damage Caused by Russian Wheat Aphid (Homoptera: Aphididae)

Population increase of the Russian wheat aphid, Diuraphis noxia (Mordvilko) (Homoptera: Aphididae), and its effect on early plant growth and damage were studied under laboratory conditions on two winter wheat genotypes, susceptible ‘Stephens’ and resistant 10085-5. Three early plant growth stages (one-, two-, and three-leaf stage), and three insect densities (0, 5 and 20 aphids per plant) were compared. Insect counts, plant damage assessments, plant height, leaf number and dry weight measurements were made. Diuraphis noxia population increase was greater on ‘Stephens’ than on 10085-5, but this was highly influenced by plant growth stage at time of infestation and initial aphid density. Host quality of ‘Stephens’ decreased rapidly when plants were infested at the 1 -left stage, especially with the high initial density (20 aphids), resulting in low aphid population increase. For all plant developmental stages and genotypes, D. noxia per capita population increase was lower at initial densities of 20 compared to 5 aphids per plant, probably due to a density-dependent reduction in reproductive rate associated with a reduction in host-plant quality and/or crowding. Diuraphis noxia significantly affected plant growth, but the magnitude of the effect was influenced by genotype. In general, susceptible ‘Stephens’ had significantly more damage and a greater reduction in growth than resistant 10085-5.

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Characterization of Russian Wheat Aphid Resistance in a Hard White Spring Wheat

Crop Science ◽

10.2135/cropsci1992.0011183x003200060026x ◽

1992 ◽

Vol 32 (6) ◽

pp. 1442-1446 ◽

Cited By ~ 11

Author(s):

Cheryl A. Baker ◽

James A. Webster ◽

David R. Porter

Keyword(s):

Spring Wheat ◽

Russian Wheat Aphid ◽

Aphid Resistance

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Detection and Characterization of the Mechanisms of Resistance to Russian Wheat Aphid (Homoptera: Aphididae) in Tall Wheat grass

Journal of Economic Entomology ◽

10.1093/jee/88.5.1503 ◽

1995 ◽

Vol 88 (5) ◽

pp. 1503-1509 ◽

Cited By ~ 3

Author(s):

S. D. Kindler ◽

T. L. Springer ◽

K. B. Jensen

Keyword(s):

Russian Wheat Aphid ◽

Mechanisms Of Resistance

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Morphological Characterization of Mycobacteriophage R1

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051281 ◽

1974 ◽

Vol 32 ◽

pp. 254-255

Author(s):

B. L. Soloff ◽

T. A. Rado

Keyword(s):

Carbon Source ◽

Stationary Phase ◽

Growth Phase ◽

Minimal Medium ◽

Morphological Characterization ◽

Logarithmic Growth Phase ◽

Complete Lysis ◽

Lysogenic Culture ◽

Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

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AEM analysis of crystallization in Ti-based amorphous alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075142 ◽

1983 ◽

Vol 41 ◽

pp. 270-271

Author(s):

A.R. Pelton ◽

A.F. Marshall ◽

Y.S. Lee

Keyword(s):

Magnetic Properties ◽

Amorphous Alloys ◽

Amorphous Materials ◽

Isothermal Annealing ◽

Amorphous Matrix ◽

Nucleation And Growth ◽

Current Interest ◽

Amorphous Films ◽

Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

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