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Investigations on the Emergence of Larvae from the Cysts of the Potato-root Eelworm, Heterodera rostochiensis.

4. Physical Conditions and their Influence on Larval Emergence in the Laboratory.

Published online by Cambridge University Press:  18 November 2009

D. W. Fenwick
Affiliation:
Nematology Department, Rothamsted Experimental Station, Harpenden.

Extract

The foregoing results throw light on the conditions under which hatching tests can be carried out. In the first place, pre-soaking cysts in water for a period of 10 days increases the rate of larval emergence but has no effect on the total number of hatchable larvae. Increase in temperature has a similar effect up to 25°C, but at 80°C. hatching is virtually inhibited. Volume of diffusate per cyst is without effect either on the number of hatchable larvae or on their rate of hatching. Neither was any effect observed from alterations in pH between 8.2 and 8.1. The effect of dilution is more or less linear when dilution is plotted geometrically against cither the number of hatchable larvae or the latter expressed as a proportion of the original cyst contents and subjected to angular transformation. For the effect to be appreciable, dilution must be of a high order. Dilution to a half or a quarter of the original concentration has little appreciable effect. The effect of dilution on the rate of hatching is not obvious and the variations in it resulting from dilution are probably random. Direct sunlight inhibits hatching, diffused daylight is without effect as compared with darkness ; cysts exposed to the action of sunlight and diffusate do not hatch when later removed to the dark. It appears reasonable to assume that this may be due to some lethal effect.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1951

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References

REFERENCES

Boyd, A.E.W., 1943.—“Stimulation of larval emergence in Heterodera schachtii Schmidt by certain concentrations of silver compounds.” Ann. apt. Biol., 30 (2). 161163. (W.L. 1025.)CrossRefGoogle Scholar
Calam, C.T., Raistrick, H. and Todd, A.R., 1949.—“The potato eelworm hatching factor. I. The preparation of concentrates of the hatching factor and a method of bioassay.” Bio-chem. J., 45 (5). 513519. (W.L. 2967.)Google Scholar
Carroll, J. and Mcmahon, E., 1934.—“ Hatching experiments on the potato eelworm.” Nature, 134 (3376). 66. (W.L. 14900.)Google Scholar
Carroll, J. and Mcmahon, E., 1935.—“ Potato eehvorm (Heterodera schachtii) investigations.” J. Helminth., 13 (2), 7790. (W.L. 112246.)CrossRefGoogle Scholar
Carroll, J. and Mcmahon, E., 1937.—“Potato eelworm (Heterodera schachtii); further investigations.J. Helminth., 15 (1). 2134. (W.L. 112246.)CrossRefGoogle Scholar
Ellenby, E., 1944a.—“Standardisation of root excretions for immunity trials on the potato eelworm.” Nature, 154 (3907). 363364. (W.L. 14900.)CrossRefGoogle Scholar
Ellenby, E., 1944b.—“Influence of earthworms on larvae emergence in the potato-root eelworm.Ann. app. Biol., 31 (4), 332339. (W.L. 1025.)CrossRefGoogle Scholar
Ellenby, E., 1945.—“The influence of crucifers and mustard oil on the emergence of larvae of the potato-root eelworm H. rostochiensis.” Ann. app. Biol., 32 (1), 6770. (WX. 1025.)Google Scholar
Ellenby, E., 1946.—“Ecology of the eelworm cyst.Nature, 157 (3988), 451452. (W.L. 14900.)CrossRefGoogle Scholar
Fenwick, D.W., 1949.—“Investigations on the emergence of larvae from the cysts of the Potato-root Eelworm Heterodera rostochiensis. I. Technique and variability.“ J.Helminth., 13 (3/4). 157170. (W.L. 112246.)CrossRefGoogle Scholar
Fenwick, D.W., 1950.—“Investigations on the emergence of larvae from the cysts of the Potato-root Eelwbrm Heterodera rostochiensis. 2. The form of the hatching curve.“ J. Helminth., 24 (1ö2), 7588. (W.L. 112246.)Google Scholar
Lownsberry, B.F., 1950.—“Stimulation of Golden Nematode larvae by root leachings.” Abstr. Phytopathology, 40 (1), 18.Google Scholar
Triffitt, M. J., 1929.—“Preliminary investigations on Mustard as a factor inhibiting cyst formation in Heterodera schachtii.J. Helmitfth., 7 (2), 8192. (W.L. 112246.)CrossRefGoogle Scholar
Triffitt, M.J., 1930.—“On the bionomics of Heterodera schachtii on potatoes with special reference to the influence of mustard on the escape of larvae from the cysts.” J. Helminth., 8 (1). 1948. (W.L. 112246.)Google Scholar
Triffitt, M.J., 1932.—“Preliminary notes on the use of root excretions as a means of controlling Heterodera schachtii.J. Helminth., 10 (2/3), 181182. (W.L. 112246.)CrossRefGoogle Scholar
Triffitt, M.J., 1934.—“Experiments with root excretions of grasses as a possible means of eliminating Heterodera schachtii from infected soil.” J. Helminth., 12 (1), 112. (W.L. 112246.)CrossRefGoogle Scholar