Nine accessions of wild Coffea arabica from Ethiopia were evaluated for resistance to Meloidogyne paranaensis. Two wellcharacterized susceptible and resistant cultivars were used as comparative controls. The experiments were conducted in a growth chamber using a clonal population of M. paranaensis (esterase phenotype P1) originating from Brazil. Resistance and susceptibility to the nematode were evaluated using the number of nematodes (eggs and J2) per plant, number of nematodes per gram of root and the reproduction factor (RF). All wild coffee accessions expressed a resistance response to M. paranaensis similar to that of the resistant control Nemaya (RF < 1.0). These results provide coffee breeders with material whose resistance can be transferred into commercial cultivars. Keywords: coffee, root-knot nematode, pathogenicity. RESUMO Avaliação da resistência de cafeeiros silvestres (Coffea arabica) a Meloidogyne paranaensisForam avaliados quanto à resistência a Meloidogyne paranaensis, nove acessos de cafeeiros silvestres incluindo dois cultivares bem caracterizados como testemunhas de suscetibilidade e resistência. Os experimentos foram realizados sob condições controladas em câmara de crescimento, utilizando uma população clonal de M. paranaensis (fenótipo de esterase P1), proveniente do Brasil. A resistência e a suscetibilidade ao nematóide foram avaliadas com base no número total de nematóides por planta (ovos + J2) e por grama de raiz e no fator de reprodução (FR). Todos os acessos mostraram resposta à infecção por M. paranaensis similar à da testemunha resistente (FR < 1,0). Com esses resultados, novos materiais, cuja resistência pode ser transferida aos cultivares comerciais, ficam disponíveis para os fitomelhoristas. Palavras-chave: café, nematóide das galhas, patogenicidade.

Ten populations of Radopholus similis from various locations and one population of Radopholus sp. from Indonesia were tested for their reproductive fitness and specific pathogenicity on Musa AAA, Cavendish cv. Poyo under controlled experimental conditions in a constant environment chamber. In addition, five of these populations were tested on Musa AAA, Ibota cv. Yangambi. Reproductive fitness of the populations tested on the two cultivars, measured as the ratio of the final number of nematodes per root system (P f ) to the number of nematodes inoculated (P i ), differed significantly. Greatest fitness was observed among R. similis populations collected from banana in different African countries (Cameroon, Uganda and the Ivory Coast) and one population from arecanut in Sri Lanka. In contrast, a population from tea in Sri Lanka and the population of Radopholus sp. from turmeric in Indonesia were the least fit. Specific pathogenicity was estimated at 8 weeks and 12 weeks after inoculation using three plant growth parameters: fresh root weight, fresh shoot weight and plant height, compared to uninfected control plants. Reduction in plant root weight was the best indicator of pathogenicity. While the R. similis populations from Uganda and the Ivory Coast were highly pathogenic, other populations with great reproductive fitness (i.e. isolates from Cameroon and Sri Lanka) did not significantly reduce root weight. In cv. Poyo, no linear correlation was found between final numbers of nematodes per gram of root (P f ) and the decrease of root weight.

In vitro rearing of Pratylenchidae nematodes on carrot discs. Abstract-Introduction. This rearing technique is applicable to migratory nematodes (e.g., Pratylenchus spp. and Radopholus similis) for mass production of nematodes for experimental purposes, conservation of nematodes, and direct studies of nematodes' multiplication or reproduction mechanisms. The principle of the method applied, key advantages, starting plant material and time required are presented. Materials and methods. Necessary laboratory materials, and details of the nine steps required for the preparation of carrot discs, preparation of nematodes, inoculation of nematodes and collection of nematodes out of petri dishes are described. Possible troubleshooting is explained. Results. Several thousands of nematodes can be extracted out of one carrot disc after 6-8 weeks of culture, depending on nematode species and geographical population. France (Guadeloupe) / Musa sp. / plant nematodes / methods / extraction / laboratory equipment / rearing systems Élevage in vitro de nématodes Pratylenchidae sur disques de carotte. Résumé-Introduction. Cette technique d'élevage s'applique aux nématodes migrateurs (par exemple, aux espèces de Pratylenchus et à Radopholus similis) pour une production de masse des nématodes à des fins expérimentales, pour leur conservation, et pour des études de leur multiplication ou de leurs mécanismes de reproduction. Le principe de la méthode appliquée, les principaux avantages, le matériel végétal nécessaire et le temps requis sont présentés. Matériel et méthodes. Le matériel de laboratoire nécessaire, ainsi que le détail des neuf étapes nécessaires à la préparation des disques de carotte, la préparation des nématodes, l'inoculation des nématodes et la récupération des nématodes hors des boîtes de Pétri sont décrits. Les problèmes potentiels sont répertoriés. Résultats. Plusieurs milliers de nématodes peuvent être extraits à partir d'un disque de carotte après 6-8 semaines de culture, selon l'espèce et la population considérées. France (Guadeloupe) / Musa sp. / nématode des plantes / méthode / extraction / matériel de laboratoire / système d'élevage

Nematode extraction from banana roots by the centrifugal-flotation technique.Abstract --Introduction. The centrifugal-flotation technique allows all nematode species and life stages to be separated from root debris and residual soil particles to facilitate their observation. The principle of the method applied, key advantages, starting plant material and time required are presented. Materials and methods. Necessary laboratory materials, and details of the 19 steps required for extracting nematodes from plant tissue for counting are described. Possible troubleshooting is explained.

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Dans un chenil d’élevage de chiens beagles une souche déficitaire en facteur VIII coagulant a été isolée. Cette souche est dénommée : «Souche Canine Beagle Hémophile Lansac» (S.C.B.H. Lansac). Initialement suspecté sur des considérations cliniques : épisodes hémorragiques mortels sur des chiots de sexe mâle, le déficit en facteur VIII coagulant a été confirmé ultérieurement au laboratoire. La possession de la chienne mère des chiots ayant succombé à la tare et de plusieurs de ses filles, très certainement «conductrices» de cette tare, permettra de constituer une colonie plus importante d’animaux hémophiles sur lesquels d'intéressants travaux pourront être entrepris. L’intérêt de l’isolement d’une telle souche est d'autant plus grand qu’il n'existe actuellement à travers le monde que 5 ou 6 colonies répertoriées de chiens hémophiles.