Journal of Economic Entomology (1998) 91, 1481-1491

Miguel S. Serrano and Elaine A. Backus (1998)
Differences in cellular abnormalities induced by the probing behaviors of Empoasca kraemeri (Homoptera : Cicadellidae) on tolerant and susceptible common beans
Journal of Economic Entomology 91 (6), 1481-1491
Abstract: Cellular abnormalities induced by the feeding behavior of Empoasca kraemeri Ross and Moore were studied in 2 tolerant lines ('EMP 84' and 'EMP 392'), an intermediate ('Porrillo Sintético') and a susceptible ('Calima') cultivar of Phaseolus vulgaris L. Groups of two 3- to 4-d-old female leafhoppers were placed for 3 h in 1 clip cage per plant, each covering 1 cm² of fully expanded primary leaves, 15 d after planting. Leaf tissues were fixed 48 h after this access period and prepared for light and confocal microscopy. Damage to the leaf lamina in all genotypes included cell emptying and breakage of cell walls, as well as enlarged intercellular spaces in the palisade and spongy parenchyma. In the main vascular bundle, hypertrophied parenchyma cells plus cells with enlarged nuclei and stained nucleoli were observed. In general, cellular damage was less severe in the tolerant lines than in the susceptible genotypes, although more so for EMP 84 than for EMP 392. Morphometry of autofluorescent tracheary elements showed what seems to be a compensatory response to leafhopper attack in the tolerant lines. Although control leaves from tolerant lines had fewer tracheary elements per vascular bundle after leafhopper feeding, EMP 84 had more tracheary elements in damaged tissues. Both tolerant genotypes had tracheary elements with larger internal radii, which increased their estimated relative flow rates. The implications of cellular damage for the onset of hopperburn, in bean as well as other host plants such as alfalfa and potato, and the mechanisms of tolerance are discussed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Miguel S. Serrano, Elaine A. Backus

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Empoasca kraemeri	Beans (Phaseolus)