Screening of four lignin additives as UV protectants to baculovirus
Ahmed A. Hamed Amin, email@example.com, Salah M. Elnagar, firstname.lastname@example.org, Mohamed A.K El- Sheikh, email@example.com, Said El- Salamouny, firstname.lastname@example.org, and Magda Mohamed Khattab, email@example.com. (1) Plant Protection Res. Institute, 7, Nady El-Sayied Street, Dokki, Giza, Egypt, (2) Fac. of Agric. Cairo University, Dept. of Econ. Entomology & Pesticides, El-Gama Street, Giza, Egypt
Ultraviolet in sunlight is considered the main factor affecting persistence of the baculovirus under field conditions. Many efforts were devoted to improve the persistence of baculoviruses by using the lignin products as natural UV protectants. In present study, four lignin products designated as LP1, LP2, LP3 and LP4 were evaluated as UV protectant additives for the persistence of Spodoptera littoralis nucleopolyhedrovirus (SpliMNPV). The irradiation tests were carried out in Egypt using three irradiation exposure systems; simulated UV lamps (OSRAM), natural sunlight on Petri-dishes and natural sunlight on cotton foliage. The addition of lignin increased the half-life period of the virus up to about 6.6 fold for simulated sunlight system in Petri-dishes. Also, the best UV protectant effect additive (LP4) proved to be more efficient than either magnesium lignosulfonate (Mg-lignosulfonate) or fluorescent brightener-28 (Tinopal LPW).
Different concentrations of LP4 (1,5and 10%) resulted in a protection rate of 1.92, 3.65 and 151.89 folds which are translated to a calculated 5.31, 10.13 and 420.98 days exposure in the field.
The present study reveals the potential effect of lignin derivative as a UV protectant, especially under the sunny Egyptian field conditions.