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An International
Journal of The American Phytopathological
Society
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Abstracts
Phyt, 'athology
An International journal X ol the American Phytopathologica[Society
EDITOR-IN-CHIEF
North Carolina
State University,
Telephone:
Margaret E. Daub
Department of Plant Pathology,
919/515-6986
• Fax 919/515-7716
• E-mail:
Box 7616, Raleigh,
margaret
SENIOR EDITORS
NC 27695-7616
daub@ncsu.edu
ASSOCIATE
Genetics and Resistance
Martin L. Carson
USDMARS
North Carolina State University
Box 7616
Plant Pathology Department
Raleigh. NC 27695-7616
Telephone: 919/515-3516
Fax: 9191515-7716
E-maih marty carson@ncsu.edu
Genetics and Population Biology
of Fungi
Hei Leung
lntemational Rice Research Institute
Div, of Entomology and Plant Pathology
P.O. Box 933
Manila 1099 Philippines
Telephone: 63-2-845-0563 (ext. 723)
Fax: 63-2-845-1292
E-mail: h.leung@cgnet.com
Bacteriology
David L. Coplin
The Ohio State Universily
Plant Pathology Department
201 Kottman Hall
2021 Coffey Road
Columbus, OH 43210-1087
Telephone: 6141292-8503
Fax: 6141292-44-55
E-mail: dave+@osu.edu
Quantitative Epidemiology
Craig M. Liddell
Director of Informatics
Paradigm Genetics
104 Alexander Drive
P.O. Box 14528 ,
Research Triangle Park, NC 27709-4528
Telephone: 9191544-5578
Fax: 9191544-8094
E-mail: craig_liddell@paradlgmgenetics.com
Biochemistry and Cell Biology
Ralph A. Dean
Clemson University
Plant Pathology and Physiology
120 Long Hall
Clemson. SC 29634
Telephone: 8641656-5737
Fax: 864/656-4293
!nail: rdean@clemson.edu
Soilborne Fungi and Nematology
Jeanne Mihail
University of Missouri
Plant Pathology Department
108 Waters Hall
Columbia. MO 65211
Telephone: 5731882- t47 I
Fax: 5731882-0588
E-mall: mihailj@missouri.edu
_rology
Michael C. Edwards
USDA/ARS
North Dakota State University
Northern Crop Science Lab
1307 18th Street North
Fargo, ND 58105-5677
Telephone: 701/239-1337
Fax: 701/239-1369
E-mail: medwards@badlands.nodak.edu
Biological Control
David M Weller
USDA/ARS
Washington State University
Plant Pathology Department
367 Johnson Hall
Pullman. WA 99164-6430
Telephone: 509/335-6210
Fax: 509/335-7674
E-mail: wellerd@mail.wsu.edu
EDITORS
Didier Andrivon, INRA. lw Rheu, Frame
Nicole Benhamou. Universit_Laval, Sainte-Foy,Qudbec
David M. Bird. North Carohna State Universuy
Judith K. Brown. University of Arizona
Diane A. Cuppeis, Agriculture & Agri-Food Canada.
London. Ontario
Michael J. Davis, University of Florida, Homestead
Karol S. Elias, USDA/ARS, Beltsvllle, MD
Roy C. French, USDA/ARS, Universuy of Nebraska
Dean W. Gabriel. Universityof Florida
Scott E. Gold. University of Georgta
Terrence L. Graham Ohio State Umversitv
John Hammond, USDA/ARS, Beltsvitle, MD
Andrew M. Jarosz.Michigan State University
Yue Jin. South Dakota State University
Nancy P. Keller, TexasA&M University
Rober_P. Larkin, USDA/ARS, Orono. ME
Mark Mazzola, USDA/ARS. Wa.dlingtonState University
Michael G. Milgroom, Cornell Una,ersltv
Christopher C. MundL.Oregon State University"
Richard S. Nelson. Noble Foundation Oklahonla
Scot C. Nelson Univer._ltvof Hawaii at Manoa
Charles H. Opperman. North Carolina State University
Barbara W. Pennypacker Pem2svh,aniaState Umversitv
Nell B. Qutgley, University J Tennesse_
Jos M. Raaljmakers, Wagenhtgen University.Netherlandl
Herman B. ScholthoL Texas A&M Unlverslt)
Dani Shtienberg, The Valcani Center I._rael
L.C. van Loon Utrecht University, Netherlands
Mark Wilson. Colorado College
X.-B. Yang. Iowa State Universin
--
EDITORIAL AND BUSINESS
Publisher and Business Manager:
Steven C. Nelsor
Administrative Director of
[nformation and Publishing:
Males Wlmer
Bradley I. Hillman
Rutgers. The State Universit3 of New Jersey
Foran Hall Cook College
Publications Manager:
Pare Johnson
Production Supervisor:
Patti Ek
Department of Plant Pathology
59 Dudley Road
New Brunswick. NJ 08901-8520
Tele'_hone: 732/932-9375 (ext. 334/
Fax 732/932-9377
E-mail: hillman@aesop.rargers.edu
Technical Editors:
Jordana AnKer
Journals Assistant:
Susan Figueroa
lna Pfefer
Circulation Coordinator:
Janice Sampson
Virology
®
Copyright © 1999 by The American Phytopathological Society. 3340 Pgot Knob Road. St. Paul, MN 55121-2097
k
STAFF
(AUPRC) yield models were constructed by regressing AUPRC values and
area under the curve values for the two vegetation indices against yield. PR
data in the infrared region explained more of the variation in forage yield
than models based on vegetation indices. Both single point and AUPRC
Aqueous faba bean root extracts stimulate germination
and promote
infectivity of Orobanche seeds, tt. E. GUTIERREZ and J. O. Kuti. Texas
A&M University, Kingsville, TX 78363. Phytopathology 89:$31. Pub ieat on
no. P-1999-0218-AMA.
models based on 810 nm data had a better relationship with yield than models
based on other wavelengths: however, single point models using 810 nm PR
values explained 17% more of the variation in yield than AUPRC models,
Orobanche crenata is a holoparasitie weed which causes several damage to
faba bean (Viola faba). The most efficient method of control is breeding for
resistance. A laboratory method was developed to test the effect of faba bean
aqueous root extracts on germinability and infectivity of Orobancl e seeds
Ttae seeds were conditioned prior to treatment with extracts from 20 varieties
of faba beans using a standard bioassay for evaluation of potential germination stimulants. Of the root extracts from the 20 varieties used, root extracts
from 7 varieties stimulated seed germination of Orobanche and infectious
Orobanche seeds were obtained from the same varieties in pot experiments.
The results suggest that aqueous root extracts may be potentially useful for
screening faba bean susceptibility to Orobanche parasitism.
Potential of fall applications of lime, lhne-suffur and urea in reducing
pear scab inoculum in over.wintered leaves and validation of an ascospore maturation
model, W. D. Gubler (1), C. J. Felieiano (1), K. J. DELL
(I), R. g. Elkins (2), and C. A. lngels (3). (1) U.C., Davis, CA; (2) U,C. Cooperauve Extension, Lakeport, CA; (3) U.C. Cooperative Extension, Sacramemo, CA, Phytopathology 89:$31. Publication no. P-1999-0215-AMA.
The effect of lime, lime sulfur, and urea on pear scab (Venturia pirina) ascospore production was investigated. Scab infected leaves were treated in the
fall and placed in commercial orchard floors at 3 sites. Leaf samples were
examined weekly the following spring for ascospore production and matura-
Species of Pythium that affect tobacco transplants in greenhouses. W. A.
GUTIERREZ (I) and T. A. Melton (I). (1) North Carolina State University.
Raleigh, NC. Phytopathology 89:$31. Publicauon no. P-1999-0219-AMA.
tion by the squash mount and water discharge techniques. Maturation of
aseospores was predicted using a degree day model developed in Oregon.
Availability of ascospores in the orchard was monitored with a Burkard spore
trap. Lime-sulfur and urea fall treatments were effective in reducing pear
scab inoculum. Ascospore production was reduced in lime-sulfur treatments
by 97 to 100%, and in urea treatments by 56 to 100%. The model predicted
ascospore maturauon accurately at I site, and earlier at 2 other sites, com,
pared to exarmnauon of leaf samples. Spore trap catch continued for 1 to 2
weeks after the predicted date of complete mataratlon
Pythium root rot, or damping-off is an important disease of tobacco seedlings
in greenhouses. This disease appears at any stage of the seedling growth.
Pythiunz species form resting structures (chlamydospores and oospores) that
allow them to survive for long periods in soil. but survival mechanisms in the
Boat tray system in greenhouses is unknown. Pieces of tobacco reots were
taken from infected seedlings and placed on Par medium and incubated for 2
days in the dark at room temperature. Forty 1solutes were obtained frorc
commercial greenhouses in North Carolina. Pvthiunz myriolylunz I_ dissotocure. I_ trregutare. P volulum, and P spmosum were identified as potential
3athogens of tobacco seedlings. The most prevalent were /_ volutum and/_
wregutare. Pathogenicit_ tests indicated that P myrtorytum and P volutum
were the most aggressive species at water temperatures above 22 C. No
aboveground symptoms were observed with the other Pythium species at 22
C but seedlings showedroot rot and apoorroot system at transplanting time.
Pathogenicity tests at different water temperatures are nemg conducted to
determine the optimal development of these Pvthium species.
A potato tuber aspartic protease with antffungal activity. M. G. Guevara
Ill, C. R. Oliva _I), and G. R. DALEO I). Universidad Nacional de Mar
del Plata. Mar del Plata.' Argentina. Phytopathology
89:$31. Publication no.
P-1999-0216-AMA
Only a few APs have been isolated
and characterized
from plants and Irttle
ts known about their bid ogical functions. Recently. we characterized a 4C
kDa AP from tuber discs. Sequence analysis of two tryptie fragments showed
homology wnth other plant APs. The sequence ADISIKEQ from one fragment had 50% identit3 with a portion of cyprosin (cardoon) and 37.5% identlty with sequences from oryzasin Irice} and phytepsin (barley). The percentage of similarity was 87.5% with all three APs. The sequence TNDPGYX
from the other one shared 43% idenuty and 85.7% similarity with other
pomons of the three proteases. Potato AP was able to inhibit the growth of:
hyphae (0.5 pM) and the germination of spores (I pM) of E eumarti_, as well
as me germination of Phytophthora iafestans zoospores at all eoncentrauons i
assayed. This antifungal activity was not detected in she presence of pepstatm-A. Two other proteases tested ttrypsin and pepsin) did not show anufungal activity indicating the specificity of the potato AP. Our results suggest I
that the potato AP may be involved in the interaction with pathogens,
Biological control of Septoria leaf spot and canker of hybrid poplar under field conditions, L GYENIS Ill, N. A. Anderson I). and M. E. Ostry
Evidence for maternal inheritance of kernel wax from maize population
GT-MAS:gk resistant taAspergiBusflavus.
B. Z. GUO (1), L. E Lei (1),
N. W Widstrom (I), T. E. Cleveland/2),
J. S. Russin (3). and R. E. Lynch
Ill. Ill USDA-ARS, Tifion. GA; (2) USDA-ARS, New Orleans. LA: (3)
Soutbem Illinois University, Carbondale. IL. Phytopathology 89:$31. Publicauonno. P-1999-0217-AMA.
reduced 44% and defoliation reduced 32% with Strain 93 as compared to
unsprayea
trees. Biocontrol potential of Strepromyces spp_ strauns agams_
diner poplar diseases is being evaluated.
............................
Kernels of maize populauon GT-MAS:gk are resistant to Aspergillusflavus.
Earlier studies showed that this resistance _s due in part to more pericarp
wax, which possesses antifungat activity against A. flavus. Composition of
thks wax was determined usm_ thin layer crtromatography. One major cornponent was umque to wax from GT-MAS:gk kernels. This wax eomponem
was present in GT-A2 and GE37. but absent in 9-54C. 8940C. and F54, To
ueterrmne whether this trait could be _seful in a breeding program, we studled the inheritance of this unique wax component m F2:3 families derived
from a cross between GT-A2 and 9-54C. Kernel wax from the two parental
trees. F1, and F3 families was extracted by dipping kernels in chloroform
bhefly and separated using TLC. The unique wax component was present in
GT-A2. F] and all 30 F3 families. Because of its non-Mendelian mode of
mheritsnce, these data suggested that this wax component is inherited materholly. Reciprocal crosses of (GE37 x 8940C) and (8940C x GE37t as well as
GE37 × F54l and (F54 x GE37j also demonstrated this maternal inheritance
of this _va_ trait
/2I. (I) Dept. Plant Pathology, Universit 3 of Minnesota. St. Paul. MN 55108;
12) USDA Forest Service. North Central Research Station. St. Paul. MN
55108. Phy topathology 89:$31. Publication no. P- 1999-f1220-AMA.
Limiting factors to expansion of hybrid poplar Populus spp. culture are their
susceptibility to leafspot and canker diseases caused by Septorta musiva
(SM). Three Streptomyces spp. strums IGS-93-3. Strain 93 and Mycostop ®)
with biocontrol potential were tested in field trials near Rosemount. MN on
one resistant and three susceptible poplar clones. Container-grown trees with
six-week old shoots were exposed to natural SM inoculum for four weeks in
a hybrid poplar plantation. Five experiments, each with four weeks exposure.
were completed dunng Summer 1998. Individual trees were sprayed once a
week with one of the biocontrol strains and evaluatea for disease development. Canker control of 100% was obtained with strain GS-93-3 on susceptible clone NE242, Leaf disease severity on susceptible clone DTAC2fi was
Quantitative
indoor assay (QIAssay) identifies quantitative trait lociS HABER. B. Gilbs. and J. Chong. Agriculture and Agfi-Food Canada.
Winnipeg, MB. Phytopathology 89:$31. Publication no. P-1999-0221-AMA
Agronomic and quality trait QTLs have been placed on the molecular linkage
map of K/O. Identifying QTLs for BYDV tolerance, however, has proved
difficult in the K/O population because the parents do not differ greatl),
symptoms are affected by environmental interactaons, and sconng is subjeetive. A QlAssay-based analysis of 68 FI0 RIL_ minimized within-treatment
variations caused by environmental intelaetrons, and used objective oarameters to score BYDV tolerance, Two disease tolerance QTLs were identified
and mapped to the same positions as those found earlier in a study of symptoms of Clintland64 (susceprible}/iL86-569g
Bolerantl RILs: QTLs were
also identified for BYD-yield loss components (height loss: loss of flag leaf
area: delay of panicle emergence_, An additive model of these QTLs with
those for disease tolerance could account for the performance of KId RILs
under BYD pressure. Strong QTLs were also identified for BYDV-ELISA
titres, but virus titres were not related to performance under disease pressure,
Vol. 89, No. 6 (Supplement),
1999
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