Dichloromethane extractable resins from wood of Japanese black pine, Pinus thunbergii, inoculated with the S10 population of Bursaphelenchus xylophilus from Japan differed from those from pines either inoculated with B. mucronatus or wounded. These differences suggest that unique oleoresins, including resin acids, are synthesized in response to the pine wood nematode. There were significant differences between the profiles of resin acids from P. sylvestris inoculated with B. xylophilus VPSt-1, a pathotype which it tolerates, and the resin acid composition of blue stain fungus-infected, or wounded Scots pine. These differences suggest that the composition of resin acids in pines may change in response to specific biological stress. Dehydroabietic acid, predominant in VPSt-l-inoculated Scots pine, showed nematicidal activity, but abietic acid, predominant in uninfected, healthy pines, had no such activity. Jpn. J. Nematol. 19: 1-6 (1989).

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Mating potential varied among some populations of the pine wood nematode Bursaphelenchus xylophilus from Japan. All Japanese populations examined mated to produce a F₁ generation, but the number of F₁ juveniles produced depended on the parent populations mated. F₁ populations, from mating virulent with avirulent populations, were virulent to Pinus thunbergii. The Japanese population, S10, mated only with some populations from the U.S. and offspring from successful matings were virulent. F₁ generations from mating U. S.× Japanese populations did not retain the host specifcity of the parental U. S. populations. Chromosome number differed among the pine wood nematode populations but the difference was not related to virulence. Jpn. J. Nematol. 1 9: 7-12 (1989).

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The propagation of five isolates of Aphelenchus avenae from Fukuoka, Kagoshima, Kumamoto, Nagasaki and Saga, all in Kyushu Japan, were compared on Botrytis cinerea, Fusarium oxysporum f. sp. lagenariae, Phoma asparagi, Phytophthora nicotianae var. parasitica, Rhizoctonia solani and Verticillium dahliae growing on several substrates/media. R. solani was the best host for the five A. avenae isolates with final numbers 20 days after inoculation; 6.61 titnes greater than those propagated on F. oxysporum and 1.73 times greater than those propagated on B. cinerea. The other fungi tested supported final numbers of A. avenae 27 to 48% those of R. solani. The Kagoshima isolate had final numbers 1.97 times greater than the final numbers of the Saga isolate on the fungi tested. The other three isolates had intermediate final populations. The temperature optimum was 25°C for the Saga isolate and at least 30°C for the Kagoshima isolate. One part beet pulp to one part brewer's grain was the best substrate for propagating A. avenae on B. cinerea but this was not the best substrate for fungal growth. Jpn. J. Nematol. 19: 13-17 (1989).

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Three species of Tylenchidae, Aglenchus ainakamurae n. sp., Cephalenchus leptus leptus and Lelenchus leptosoma are reported from Japan. Aglenchus ainakamurae n. sp. collected from soil around the roots of Zanthoxylum piperitum, Acer palmatum, Lespedeza sp. and Urtica sp. in Mt. Gozenyama, Ibaraki, Japan is described and illustrated. It can be distinguished from closely related A. muktii by the absence of males, a hair-like tail terminus, and a tapering head profile. Aglenchus muktii apud GERAERT and RASKI nec PHUKAN & SANWAL, which is renamed A. geraerti nom. nov., also differs from A. ainakamurae by the presence of males, an offset head profile, number of body annules, MB-, c-, V- and V'-values. Cephalenchus daisuce is ranked as a subspecies of C. leptus, i.e. C. leptus daisuce, based on a study of the variability and the correlations between some measurements in Japanese C. leptus populations. It is also suggested that C. limichus should not be synonymized with C. leptus. Populations of the nominated subspecies C. leptus leptus that is described and illustrated were collected from soil around the roots of Acer mono var. marmoratum, a herbaceous plant and an unidentified tree. Populations of L. leptosoma from forest soil are first records of this species in Japan, and are measured and figured. Jpn. J. Nematol. 19: 18-31 (1989).

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Bursaphelenchus xylophilus pathotype MPSy-1 from Scots pine Pinus sylvestris in Missouri, USA was attracted to homogenates of, and lipid extracts from, fourth instar larvae of Monochamus carolinensis. Attraction was inhibited by protein extracts from these larvae and was not enhanced by α-and β-pinene. The attractive principle appeared to be diffusable and to induce aggregation of the nematode. Jpn. J. Nematol. 19: 32-37 (1989).

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Effects of barnyard manure amendments on tomato plants (Lycopersicon esculentum, cultivar, Fukuju 2) inoculated with Meloidogyne incognita (race 1) 2nd stage juveniles (J2) were investigated under growth chamber and green house conditions. Thirty day old tomato seedlings were planted in D-D fumigated Andosol soil amended with barnyard manure at the rates of 0, 25, 50, and 100 tons per hectare. Plant growth and root gall indices were examined 37 days after inoculation with 0, 330, 1, 980, 4, 950, and 33, 000 J2 per 2 l soil in Wagner pot (1/5, 000a). Gall indices were slightly lower in the manure amended soil than in the non-amended soil. Fresh weights of shoots/fruits and number of fruits decreased with increases in the nematode inoculum level and with decreases in the amount of manure. Contrarily, fresh root weights increased with increases in the inoculum level, however, the relative weights of roots against total plant weights decreased significantly in the manure amended soil at the highest inoculum level. Barnyard manure seemed to have improved the plant growth rather than increased the tolerance limit against nematode infection. Chemical analysis of nitrogen (N) and four inorganic salts (P, K, Ca, Mg) in the shoots and fruits revealed slight changes in the contents with increases in the nematode inoculum level, but no changes in the ratio of Ca to K.

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Thirty-one populations of three Meloidogyne species were examined electrophoretically to determine their enzyme phenotypes. Enzymes investigated included nonspecific esterase (EST), malate dehydrogenase (MDH), superoxide dismutase (SOD), glutamate-oxaloacetate transaminase (GOT), glycerol-3-phosphate dehydrogenase (GPD) and catalase (CAT). Female adults of M. incognita, M. javanica and M. hapla showed species-specific phenotypes for the six enzymes, irrespective of host plants and localities. Intraspecific differences in enzyme phenotypes were not detected in any of the populations examined. Races 1, 2 and 3 of M. incognita also showed no difference in enzyme phenotypes. All populations of the three Meloidogyne species were identified as respective species based on the phenotypes of EST, SOD, GOT and GPD. EST phenotype of the Japanese M. javanica populations differed from that reported in the United States.

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[in Japanese]

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