Effect of gamma-irradiated entomopathogenic nematodeSteinernema carpocapsae (Fil.) on the larvae of the potato tuber moth,Phthorimaea operculella (Zell.)
The effect of gamma irradiation on the pathogenicity of the entomopathogenic nematodeSteinernema carposapsae was studied by infecting the larvae of the potato tuber moth,Phthorimaea operculella. Full grown larvae of the host were gamma-irradiated with different doses ranged from 2.5 to 160 Gray (Gy) and subsequently infected with either unirradiated or irradiated infective juveniles (IJs) ofS. carpocapsae using the same doses. For comparison, two groups of unirradiated and irradiated host larvae were left without nematode infection. Another group of larval host was also infected with nematodes either unexposed or exposed to the previous doses.
The results revealed that there was a rapid mortality in the irradiated host infected with either unexposed nematodes or nematodes irradiated with different doses similar to the mortality in the nematode treatment alone. On the other hand, the pathogenicity of the nematodes was affected as a result of gamma irradiation with high doses, i. e. irradiation of nematodes delayed their efficiencyvis à vis the unirradiated host. However, lower doses of gamma irradiation exhibited worthily stimulating effect on the pathogenic nematodes, one week post irradiation, as it reduced by half the period of time required for killing all irradiated host larvae with regard to nematode treatment alone. Furthermore, nematode treatment whether applied alone or combined with gamma irradiation appears very promising as compared with single irradiation treatment of the host.
KeywordsPlant Physiology Plant Pathology Gamma Irradiation Potato Tuber Irradiation Treatment
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