Working group session:
Germplasm and Genetic Stocks
Presentation type:
poster
Authors:
Jin, Shuangxia ; Li, Lebin; Zhu, Yi; Zhang, Xianlong
Presenter:
Correspondent:
Jin, Shuangxia
Abstract:
A binary plasmid vector harboring Bacillus thuringiensis Cry 9C gene was introduced into an elite cotton cultivar Simian-3 by Agrobacterium tumefaciens -mediated transformation for control of Spodoptera litura. Integration and expression of the Cry 9C genes in three transgenic lines were confirmed by polymerase chain reaction (PCR) and reverse transcription-polymerase chain reaction (RT-PCR). Among these transgenic lines, line 16 (L-16) with normal phenotypes and higher expression level were selected by ELISA and subjected to insect bioassay. The ELISA data revealed that the expression level of Cry 9C in the T1 population ( L-16) ranged from 29-45 μg/g fresh leaf. The insect bioassay showed that transgenic S3-35S::Cry9C cotton plants exhibited moderate toxicity to Heliothis armigera but strong toxicity to Spodoptera litura compared to the transgenic plants with Cry 1Ac gene. We pyramided Cry 9C gene with Cry 2A or Cry 1Ac by crossing two parents plants with single Bt gene each. The Cry 9C protein expression in the F1 progeny has a similar level as the parent plants. The higher heritability of Bt gene between parents and progeny made it possible to pyramid different Bt genes by sexual crossing. Progeny from Cry 9C ×Cry 2A and Cry 9C ×Cry 1Ac exhibited higher resistance to Spodoptera litura, which is the most destructive insect to the Cry1Ac Bt cotton in most cotton cultivation region of China. These transgenic plants may be used for field test of resistance management strategies involving gene pyramiding and serve as novel insect-resistant resources in cotton breeding.