种子生测法鉴定转Bt基因棉抗虫性

通过室内应用单粒种子生测法鉴定转Bt基因棉抗虫性,明确了单粒棉种室内生测鉴定转Bt基因棉抗虫性的最佳生测条件。将转Bt基因棉种子25℃萌动72 h后匀浆,与0.45 g饲料混匀,以2日龄棉铃虫幼虫为试虫,测定其死亡率。建立了相应的抗性标准:棉铃虫幼虫校正死亡率小于25％为中抗,处于25％-50％为抗,50％-65％为高抗,大于65％为特高抗。准确性验证表明,种子生测法同叶片生测法的结果相符,具有较好的准确性。

Insect resistance to Bt-transgenic cotton by seed bioassay

The bioassay with neonate larvae of bollworm was carried out to test their resistance to Bt-transgenic cotton using its seed. The results showed that the bioassay with 2nd instar larvae was appropriate by soaking a seed for 72 hours at 25℃, and mixing it with 0.45 g artificial foods. The evaluation criterion was established as follows: 25% or smaller larva mortality was medium resistance, 25%-50% resistance, 50%-65% high resistance, and 65% or above particularly high resistance. It was verified that the bioassay results by using cotton seeds of different insect resistance level agreed with those by using the leaves of Bt-transgenic cotton and this method was stable and reliable.