Canadian Journal of Botany - Revue Canadienne de Botanique (1995) 73, 288-298

Carol L. Ecale and Elaine A. Backus (1995)
Time course of anatomical changes to stem vascular tissues of alfalfa, Medicago sativa, from probing injury by the potato leafhopper, Empoasca fabae
Canadian Journal of Botany - Revue Canadienne de Botanique 73 (2), 288-298
Abstract: We used a videomicrography technique to apply standard-duration pulses of leafhopper probing damage to alfalfa stems, or manually punctured stems with an implement resembling leafhopper stylets, to compare damage induction and chronicle the plant's anatomical responses over time. Plants were examined at 0.5, 1, 2, 4, and 8 days after probing. Leafhopper probing occurred primarily in phloem tissue: stylets damaged and deposited sheath saliva primarily in phloem. Between days 1 and 4, collapsed phloem cells and sheath saliva deposits were dissolved and removed as surviving cells adjacent to stylet pathways underwent enlargement and division. By day 8, phloem tissue assumed a near-normal appearance when viewed in cross section, although it is not known whether phloem functionality was restored. In contrast, xylem tissue suffered reduction in size, quantity, and total cross-sectional area of mature tracheary elements. These effects to vascular tissue may be responsible for all subsequent symptoms of hopperburn in alfalfa. Damage to phloem and xylem in mechanically punctured stems was slight and was similar for all time points.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Elaine A. Backus

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Empoasca fabae	Alfalfa/lucerne (Medicago sativa)