The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
INSTITUTE OF 0D AN AGRICULTURAL SCIENCES .
'-. __ -4 -INSTITI1 .. \OF
GAINESVILLI.E. FL-ORIDA 32611
AGRONOMY DEPARTMENT "
Agronomy Research RepY -84-2 August 1983
GREENHOUSE NEMATODE SCREENING TEST RESULTS FOR VARIOUS
FORAGE LEGUMES TESTED AT GAINESVILLE, FL., 1983
David D. Baltensperger, Mafouz Abd-Elgawad, Robert A. Dunn and
Ken H. Quesenberry
Plant breeding programs to improve the agronomic qualities and disease
resistance of crimson clover and several other legumes for use as forage or
cover crops are in progress in Florida. Nematode resistance ranks high among
the several desirable plant characteristics for legume production in Florida.
Root-knot nematodes are widely distributed and damage many plant
species in the Southeast. Many forage plants throughout the world are listed
as susceptible to one or more root-knot nematode species; however, a number
of forage plants have also been reported resistant.
The purpose of this study was to evaluate several legumes for resistance
to three Meloidogyne species.
MATERIALS AND METHODS
Plant response of 31 lines of crimson clover (Trifolium incarnatum), I
strawberry clover (T. fragiferum) cultivar, 6 lines of Desmodium heterocarpon
and one line of D. uncinatum were evaluated for resistance to three
different species of root-knot nematodes (Meloidogyne incognita, arenaria,
and javanica) in the greenhouse. Each treatment was replicated 6 times with
one plant per replication and 'a single, plant as an uninfested check.
Plants were grown in Arredondo fine sand that had been fumigated with
methyl bromide to remove all background nematodes. Each plant was grown
in an individual container which held approximately 150 cc of soil. Seedlings
.were started in petri dishes and transferred April 4, to the containers, to
assure a consistent stand. Each line was inoculated with the appropriate
Rhizobium 10 days following planting. Each plant was infested with 1500
nematodes of the appropriate species 30 days after planting. Nematode eggs
were applied as a volume of continuously stirred solution using an automatic
Assistant Professor and Post M. S. Student, Department of Agronomy,
Associate Professor, Department of Entomology and Nematology, and
Associate Professor, Department of Agronomy, Gainesville, FL 32611,
COLLEGE OF AGRICUL-TURE AGRICULTURAL. EXPERIMENT STATIONS COOPERATIVE EXTENSION SERVICE
SCHOOL OF FOREST RESOURCES AND CONSERVATION CENTER FOR TROPICAL AGRICULTURE
The Institute of Food and Agricultural Sciences is an Equal Employment Opportunity Affirmative Action Employer authorized to provide research,
educational information and other services only to individuals and institutions that function without regard to race, color, sex, or national origin.
Crimson clovel-lines came from 4-sources. These included 10 lines from
an open-pollinated spaced plant nursery in Gainesville, Florida; 2 albino
flower lines from Jay, Florida; 16 partially inbred lines from Texas; and the
cultivar Dixie. 'Fresa' strawberry clover is a recent release from New
Mexico. The Desmodium lines are all from the Florida breeding program.
Plants were scored in early July for root gall reaction. The plants were
removed from the containers and the root systems were washed gently..
Galls (root galls and mature egg masses) were scored on each root with the
following scoring system: no galls=0; 1-2 galls=l; 3-10 galls=2; 11-30 galls=3;
31-100 galls=4; and.more than 100 galls=5.
RESULTS AND DISCUSSION
The average root gall scores for the 6 replications are shown in Table 1.
None of the uninfested checks were galled indicating that the soil fumigation
adequately removed all background nematodes. Only one line tested, D.
uncinatum (line UF-40) proved to be highly resistant to any of the
nematodes, and it was highly resistant to all three nematodes. All other
lines tested were either highly susceptible (scores > 4.0) or -intermediately
susceptible (scores 2.5-3.9)
.Desmodium heterocarpon had only two entries which were less than
highly susceptible to all three nematode species. They were UF-146 and
UF-147. UF-147 showed some resistance to only M. incognita, but UF-146
appeared to have some resistance to all 3 nematode species. Kretschmer et
al., reported these two lines resistant to a mixed M. incognita and arenaria
population in21980 where they tested UF 146 and 147 as IRFL 1699 and 1946
Fresa strawberry clover was highly susceptible to all three nematodes
studied. The scores shown in Table 1 are somewhat below.five only because
stunting of the root system was so severe that there was not enough room
for over 100 galls on all of the root systems.
There was less variation between the crimson clover lines than hoped
considering the large number of lines tested. Several lines were significantly
less galled than the check cultivar Dixie and the average of all crimson lines
(incognita=3.7, arenaria=4.2, and javanica=3.6). These included FL-Chief,
TX-D-38, TX-D-75, TX-D-124, TX-CH-81, and FL-I-75&39th. The
intercrossing of these lines may be a good starting point for further
selection for nematode resistance in crimson clover.
Kretschmer, A. E. Jr., R. M. Sonoda, and G. H. Snyder, 1980.
Resistance of Desmodium heterocarpon and other tropical legumes to
root-knot nematodes. Tropical Grasslands. 14:115-120.
Table 1. Average root-knot nematode gall scores for selected forage legume entries
grown in the greenhouse in 1983.
Rooc-knot nematode species
Forage legume entries INCOGNITA ARENARIA JAVANICA
Crimson clover (Trifolium incarnatim)
FL 82 Elite Bulk
FL Asgrow 70-366
FL DWC#1 X PI378130
Strawberry clover (T. fragiferum)
UF 137-BUDS BRU-1980
UF 20-79 TRIALS
UF 146-79 ORIGINAL SEED
UF 147-79 ORIGINAL SEED
UF 143-79 ORIGINAL SEED
UF 40-79 TRIAL
*Scored on a 0-5 basis where no galls-0;
11-30 galls-3; 31-100 galls-4; and >100
1-2 galls-l; 3-10 galls-2;