The Potato Leafhopper, Empoasca Fabae, Soybean Pubescence, and Hopperburn Resistance
Lee, Young-in
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/71090
Description
Title
The Potato Leafhopper, Empoasca Fabae, Soybean Pubescence, and Hopperburn Resistance
Author(s)
Lee, Young-in
Issue Date
1983
Department of Study
Entomology
Discipline
Entomology
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Biology, Entomology
Abstract
To determine the detailed interactions between soybean pubescence, potato leafhopper, and onset of hopperburn, a series of experiments was carried out with using field and laboratory colonies of the PLH, and 4 near isogenic soybean cv. 'Clark' differing in the nature of the trichome cover.
Scanning electronmicrographic analyses revealed that the PLH has a unique pretarsal structure that tips of pulvilli are modified to form a "suction-cup" and claws are very much reduced and apparently non-functional. Process of the primary orientation is described in three steps: (1) Press the tip of pulvilli against the substrate; (2) moistening pulvillar/substrate interface; (3) create a vacuum within the interface, and provide a firm attachment. Release of legs by relaxation and equalization of the pressure inside and outside of the interface. PLH is ill-suited to move and assume a normal primary orientation on pubescent plant's surfaces, which would greatly hamper both feeding and oviposition behavior.
PLH nymphs feed and grow to maturity on pubescent soybean leaves, mainly feeding on blades. The rate of feeding and oviposition were much lower on normal and dense pubescent lines than on glabrous plants. However, those rates increase a lot if PLH was on a shaved part of the same plant.
Hopperburn was never observed on normal or dense pubescent 'Clark' soybean. However, the symptom developed on the same plants if trichomes were removed by shaving before the exposure to PLH.
Significantly more trichomes cover the veins than the blades of the same leaf which places the phloem beyond the reach of the PLH. Therefore, the mechanism of hopperburn resistance by trichomes is simply due to a physical barrier (not a chemical) interfering with the ability of the PLH to feed on the phloem. The barrier effect of the trichome layer is formed by the thickness of the indumentum which is a function of trichome density, length, angle of insertion, and shape of trichomes.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
