Studies On Insect-Resistance And Stability Of Bt Transgenic Progeny In Maize

The insect-resistance and stability of transgene in the progenies was studied by means of molecular assay and inoculating larva of maize leaf borer in the field using 91 crosses among 7 transgenic parents and 13 untransgenic parents according to incomplete diallel cross design to in this study. And the potential of transgenic progeny in heterosis breeding was studied by means of incomplete diallel cross combining ability analysis.The result told that transgenic parents and crosses showed high resistance to the insect in the field. Southern blot and PCR array test approved that Bt genes can be transmitted to the progeny and exsted stabily in the progeny. It is supposed that stable insect-resistant families can be obtained through further idiogamy and selection in breeding. By means of three tests in the field and on the basis of combining ability analysis, three elite transgenic parents W1439, W1441 and W1436 were obtained which possessed the high insect-resistance and prolificacy, also superior crosses,, namely W1439+F349, W1446+HuangC, W1441+HuangC, W1441+F349, W1445 +HuangC, Wl436+F349, W1436+HuangC, W1438+HuangC, W1439+HuangC and W1438+F349.The transgenic parents, different transgenic generations and transgenic crosses used in this study showed the high insect-resistance and the stable heredity. The superior insect-resistant parents and crosses were gained through tests in the field, which helped to breed superior transgenic varieties with high yield, high quality and high resistance.It was also found that the insect-resistance of transgenes was influenced to some extent by the different genetic ground of the parents. The transgenes did not exist in a few transgenic progenies in higher generation, which is worth studying further in using the transgenic progeny adequately.