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tobacco stunting, control of dagger nematode [Xiphinema spp.J on grapevincs by fumigatton with Vorlcx, the ust of nematicides to control P. penetrans on fruit trccs, production of an illustrated kcy to thc plant-parasitic nematodes of Canada, taxonomic work on inscct parasitic mcrmithids and plant-parasitic spec i es, rapeseed as an aitemative host of the sugar bcet cyst nematode [Heterodr.ra schachtii] and thc use of nemoticides on maize.

*0162 Johnson, P. W.; Potter. J. W. Winter sumvai of root-knot nematodes IMeloidogyne incognito and Al tapla) under selected host crops in Southern Ontario. Canadian Journal of Plant Science (1980) 60 (1) 203-207 [En, fr) Res. Stn., Agric. Canada, Vineland Stn., Ontario LOR 2E0, Canada.

In field experimenls. at Harrow, Ontario, Canada. Meloidogyne incognito was capabłe of overwintering on peach only under moderatc conditions. At Vineland Station, Ontario, M. incognito a id not overwinter helów the frost linę (30 cm) under luceme in moderate conditions but did so under red clover [Tnfolium repens) and tornato even during a severe winter. M. bapla survived well under all 3 hosts in both winters at depths from 0 to 90 cm.

*0 163 lOWSHEND, J. L.; POTTER, J. W. Population behariour of Meloidogyne bapla under four forage legumes in microplots. Canadian Journal of Plant Science (1980) 60 (1) 293-295 (En) Res. Stn., Agric. Canada, Vineland Stn., Ontario LOR 2E0, Canada.

Populations of Meloidogyne bapla fluctuated under forage legumes (luceme, red clover, white clover, birdsfoot trefoil) in microplots sampled in the spring and autumn for 2.5 years, in Ontario. Canada. With a Iow initial moculum density lhe nematode population had inereased by the First autumn. wbereas witb a high inoculum density, the nematode population decreased by autumn. Over the next 1.5 years the nematode population decreased or remained static. At the end of tbe 2.5 year period the number of !arvae extracted from the rest of tbe 4 legumes ranged from 125 larvae/g of root (luceme) to 1600 larvae/g of root (red clover).

016 4 BOOKBINDER, M G.; BLOOM, J. K.; LUKEZIC, K L.

Interactions of nematodes and hacteria on alfalfa. [Ann. Meet. Aroer. Phytopatb. Soc., Northeasiem Div., 31 Oct. - 2 Nov., 1979. Abstract.]. Phytopathology (1980) 70 (5) <59 [En) Dep. of PI. Pathol., The Pennsylvania State Univ., Univ. Park, PA 16802, USA.

Meloidogyne bapla, Pratylcncbus pene trans, Hclicotylencbus dibystera, Tylenchorbynchus claytoni. Trichodorus cbristiei and Ditylenchus dipsaci reduced the growth of ‘Saranac AR¹ luceme. The first 4 nemaudes interacted synergistically with isolates of Pseudomonas syrineae, P. cerrugato and P. marginalis in reducinę seedling growih. TyJcncbus sp. acted as vectors on the baciena.

This pubłicaiion characterizes 179 domestic and foreign cullWars of Medicago sativa and 9 experimenta) lines for resistance to Ditylenchus dipsaci and Meloidogyne bapla. Results indicated that most cultivars are susceptible to the 2 nematodes. Hpwever, 21 cultisars and 6 cxperimenia! check lines exhibited resistance to D. dipsaci at 50% or higher, thesc included thc Washington-resistant experimentals WDS3, WISI and W2S1. Only 4 cultivars had 50% or higher resistance to M■ bapla. Tables of results are given.

0 16 7 Manninger. S. [Results achieved in breeding luceme for resistance.) A lucemarezisziencia nemesitesben dert credmenyek. Agrartudomónyi Kdzlcmenyck (1978) 37 (2/3) 201-202 (Hu) Gódóllói Agrartudomanyi Egyetera Kutatóintezete, Kompoit. Hungary. From Plant Breeding Abstract 50, 3041.

An outline ts given of Hungarian attempts to breed for resistance to viruses and to pathogens involved in the luceme wilt comple.t, which includes Ditylenchus dipsaci.

*0168 SULLWAN. J. A.; CHRISTIE, B. R.; POTTER. J. W. Inheritance of northern root-knot nematode resistance in alfalfa. Canadian Journal of Plant Science Xl980) 60 (2) 533-537 (En, fr. 10 ref.) Crop Sci. Dep., Univ. of Guelph. Ontario, Canada NIG 2Wl.

Ninę clones were selected from the cutlivar Vemal to dciermine the inheritance of resistance to Meloidogyne bapla in luceme. The Si and F, progenies of these 9 clones were screened for their reaction to M. bapla. Ratios showed that resistance to M bapla was controlled by 2 loci which seprepaied tetrasomically. This study showed that at łeast 2 dominant alleies musi be present at both loci for a genotype to show resisuince. Resistance was dominant. Gcnotypes was proposed for 8 of 9 clones to explain lhe reaction of their progenies to M. hapla. Sicnificant reciprocal difTerences were observed in 2 of 7 crosces. 7‘he scrccninc technique allowcd cach plant to be grown in an indmdual Container filled with soil uniformk tnfested with nematodes. After retesting a samplr of piams showing zero galls. il was concluded that 13% ucrc escapes.

*0169 Nath, R. P.; BANERJEE, A. K.; HA1DAR, M. G.; Sinha, B. K.    Stu di es on the nematodes of puise crops in

India. I. Pathogenicity of Meloidogyne incognito on gram. Indian Phytopathology (1979) 32 (1) 28-31 (En) Dep. ot Nematol., Sugarcane Res. Inst., Ra jen dra Agric. Univ., Pusa, Bihar-848125, India.

In a pot experiment gram {Cicer arietinum) seedlings were inoculated with 10, 100, 1000, 10 000 or 100 000 Meloidogyne incognito juveniles/500 g soil. Root and shoot growth and pod number decreased with inereasing inoculum density. Flowering was delayed by 10 to 15 days following inoculation with 100 or morę juveniles and at a density of 100 000 nematodes the seedlings failed to flower. Mortality was 60% at the highest inoculum density after 30 days. The pathogenic threshold was 100 juveniles/500 g soil. HistopathologicaJ examination showed nematodes feeding on vascular tissue. In the early stages of infcction the protoplasm of the cełts around the head of the !arvae became granular with enlarged nuclei, later giant cells deve!oped. The cortical and vascular tissue surrounding the feeding site was blackened in some plants. Nematodes were observed in the root nodules and bacterial numbers and nodule size decreased with inereasing nematode density.

0166 ELGIN, j. H., Jr.; HaRTMAN, B. J.; EvaNS, D. W.; Thyr, B. D.; Faulkner, L. R.; Hunt, O. J. Stem nematode and norlbem root-knot nematode resistance ratings for aifalfa cultitars and experimentai lines. Lcaflet, USDA. Science and Education Administration, Agricultural Research Results, Northeasiem Senes (1980) No.7, 14 pp. (En) Field Crops Lab., Beltsville Agric. Res. Center-West, Beltsville MD 20705, USA.

0 170 NC. O. C.; CHEN. T. A. Hislopathologicfll stuóy of alfalfa root infectcd by Hoplnlaimus paicatus. [Ann. Meet. Amer. Phytoph. Soc., Northeasiem Div., 31 Oct. - 2 Nov., 1979. Abstract.). Phytopathology (1980) 70 (5) 466^67 [En) Dep. of PI. Pathol., Rutgers L¹niv., New Brunswick, NJ 08903, USA.

Damace to luceme root tissues caused by feeding by H. 109 caleatus is (iescribed.

1

0165 DONNELLY, E. D. Registratiou of Cababa White, Tantage, Nora II, and Vanguard Tetch. Crop Science (1979) 19 (3) 414 [En] Dep. of Agron. & Soils, Aubum Univ., Ala.. USA. From Plant Breeding Abstracts 50, 3050.

Cahaba White, Vantage and Nova II from the cross Vicia sativa 'Ala. 1894¹ X V. cordato ‘PI 121275¹. and Vanguard. 8 composite from the cross V. sativa ‘Ala. 1894’ X V. narbonensis 'PI 170017’, are resistant to Meloidogyne incognito and M. incognito acrito.