Abstract:

The paper report the results of study on the resistance of transgenic tree Betula platyphlla with BtC peptide and spider insecticide peptide gene to the defoliator Lymantria dispar, the result showed that the transgenic B. platyphylla could prolong the duration of L. dispar larvae obviously. The Developmental Relative Value of larvae of L. dispar from 1 ^st instar to 3^rd instar feeding on birch positive to GUS or that negative to GUS were 66.8, 72.5%;90.5, 96.4%;81.6, 92.5%, respectively. Larvae in the control could finish development normally but treated larvae didn't develop to 5^th instar. The transgenic tree could repressed the pest larvae mass obviously. The mean body mass of the larvae after 40 d's feeding on non-transgenic birch were 6.75 and 7.43 times of those feeding on two type of transgenic birch, respectively. The exuviations index of the larvae after 30 d's feeding on two type of transgenic birch were 2.933 and 3.038 respectively, both lower than that of control of 3.323, indicating transgenic birch could restrain the exuviations of the larvae of gypsy moth to some extent. The feeding capacity of the larvae after 30 d's feeding on non-transgenic birch were 0.641 0 g·head^-1 and 0.529 1 g·head^-1 more than those feeding on two type of transgenic birch, respectively. Meanwhile, the corrective mortality of the larvae feeding on two types of transgenic birch were 94.64% and 72.70%, respectively, indicating that transgenic birch had the high lethal effect on gypsy moth larvae.

Key words: Betula platyphylla, transgene, insecticidal gene, exuviations, insecticidal activity