TABLE CONTENTS

Host-plant Resistance in Crops Cultivated in Protected systems
Robertson, L. (1), J.A. López-Pérez (2), M.A. Díez-Rojo (1), C. Ros (3), J. López Cepero (4),
C. Martınez (1) & A. Bello (1)
(1) Dpto Agroecología, Centro de Ciencias Medioambientales, CSIC. Serrano 115 dpdo, 28006 Madrid. (2)
Centro Agrario de Marchamalo, Guadalajara, JCCM Castilla-La Mancha. (3)Dpto Protección Vegetal, IMIDA,
Consejería de Agricultura, Agua y Medio Ambiente. Mayor s/n, 30150, La Alberca, Murcia (4) Univ. La
Laguna (ULL). Crta Geneto, 2, 38271 La Laguna, Tenerife, Canary Islands, Spain.
In Spain the most important crops grown in protected systems are tomato and pepper. Among
the possible non-chemical control strategies, the use of resistant cultivars is preferred, but in
order to be successful it is necessary to characterize the virulence range of the nematode
population. Pepper (Capsicum annuum L.) and tomato (Solanum lycopersicum L.) cultivars
were chosen for this study due to their economic importance, and also because there are few
crops in which nematode resistance is available. The dominant resistance gene Mi in tomato
confers resistance to Meloidogyne incognita, M. arenaria and M. javanica but not to M.
hapla. Different populations of M. arenaria, M. hapla, M. incognita and M. javanica from
representative horticultural regions of Spain were evaluated using a bioassay designed to
characterize the virulence. Seventy four percent of the M. incognita populations that were
virulent on resistant tomato did not parasitize the resistant pepper cvs. In the case of resistant
peppers none of the of M. arenaria race 2 or M. javanica populations parasitized any of the
resistant pepper cultivars used, but all of the M. hapla populations reproduced on resistant
peppers. Fortythree populations were found to parasitize both susceptible and resistant pepper
cultivars, of those, 37 populations belonged to M. incognita (all races), one to M. arenaria
(new race 3), and five to M. hapla races A and B. Seventeen of the M. incognita populations
that were virulent on resistant pepper did not parasitize the resistant tomato cv Nikita
containing the Mi gene. The results also demonstrate that there exists resistance gene
breaking populations of Meloidogyne incognita, M. arenaria and M. javanica throughout
Spain and those local nematode populations should be screened before planting such resistant
varieties. The results obtained have important implications for the design of alternative
nematode management strategies using resistant cultivars.
Disinfecting Planting Material of Nematodes
Sipes, B.S.
Department of Plant and Environmental Protection Sciences, University of Hawaii, Honolulu, HI 96822, USA.
Many crops cultivated in protected systems are vegetatively propagated. This propagation
method can lead to unintentional transfer of plant-parasitic nematodes and exacerbate
nematode damage in the new planting. Several options can be utilized to stop the continual
reintroduction of nematodes into new plantings. Tissue culture eliminates nematodes like
Meloidogyne javanica and Radopholus similis from anthuriums. Tissue culture is available
for many but not all plants. Heat treatments are effective across a range of plants and
nematodes. In anthurium, a 12 minute bath in 49̊C eliminated R. similis from plants.
However, heat treatments must be adjusted for each crop because damage can occur at high
temperatures or with lengthy exposure times. An other option to disinfect planting material of
nematodes is to used nematicides. Crops cultivated in protected environments may be grown
in individual pots and therefore lend themselves to dip treatments. Foliar nematodes were
eliminated from orchids after a single dip in recommended rates of Avid or Pylon. As high
value crops, many options are viable to eliminate plant-parasitic nematodes from planting
material used in protected cultivation systems.
5 th International Congress of Nematology, 2008 101