Insecticidal Capacity of Recombinant Baculoviruses to Plutella xylostella and Spodoptera exigua larvae

다국어 초록 (Multilingual Abstract)

This study was conducted to investigate the insecticidal capacity of recombinant baculoviruses to Plutella xylostella and Spodoptera exigua larvae. For recombinant viruses, Bacillus thuringiensis cry1-5 crystal protein gene was introduced into the genome by fusion of polyhedrin-cry1-5 under the control of polyhedrin gene promoter. Recombinant AcPolh5-3006BiKTT and AcPolh5-3006 AvTox2 based on BiKTT and AvTox2, respectively, were constructed under the control of early promoter from Cotesia plutellae bracovirus. Mortality of S. exigua larvae was significantly higher when they fed on cabbage coated with ApEGFP (wild type) over 5.0×106 PIBs/ml. For AcPolh5-3006BiKTT and AcPolh5-3006AvTox2, mortality of P. xylostella and S. exigua larvae was significantly higher when they fed on cabbage coated with recombinant baculoviruses over 5.0×106 PIBs/ml and 1.0×104 PIBs/ml, respectively. The value of LD50 was lower in the treatments with AcPolh5-3006BiKTT (P. xylostella:1.2×106, S. exigua:1.3×104) or AcPolh5-3006AvTox2 (P. xylostella:2.3×106, S. exigua:1.4×104) than the treatments with ApEGFP (P. xylostella: not estimated, S. exigua:5.0×105). Survival time (ST50) of P. sylostella larvae was much shorter at AcPolh5-3006BiKTT (29.6h) than AcPolh5-3006AvTox2 (46.2h) while that of S. exigua larvae was much shorter at AcPolh5-3006AvTox2 (95.1h) than AcPolh5-3006BiKTT (101.9h) or ApEGFp (130.7h). The two recombinant baculoviruses were more effective in S. exigua larvae but slower speed of action.