Research On The Insect-Resistant Identification Of Bt Transgenic Backcross Progeny In Maize

The Bt gene was introduced into the four inbred lines (87-1, 8085, ZONG3 and N808) by backcross breeding. The identification of insect-resistance firstly was made on the four BCj materials by infecting insect eggs into leaf spindle in the field. Based on the result of identification of insect-resistance to the four BCi materials, both identification of insect-resistance in the field and PCR detecting analysis were used to analyse the four BC2 materials. The result from the field test showed that the expression of insect-resistance varied with the genetic backgrounds, there was great diversity in the insect-resistance among the individuals within the progeny population of BCj and of BC2, which presented separation from high resistance to high sensitivity; there was no linear relation between rating scales and tunnel length in stalk , stalk cavaties, however there was significant linear relation between stalk cavaties and tunnel length in stalk. MPCR analysis revealed that the length of amplified results was as about lOObp as the length devised by primers, designed by sequences of CaMV35S promoter and NOS terminator, which showed that the Bt gene existed in the Backcross progeny of Bt Transgenic corn; positive individual plant numbers were over 89 percent within BCa transgenic materials. Both identification of insect-resistance in the field and PCR detecting analysis confirmed that Bt gene existed reliably in the backcross progeny of Bt transgenic corn.