Optimization Of Genetic Transformation System And Transformation Of Cold Resistant Genes In Cinnamomum Camphora L

Camphor tree (Cinnamomum camphora L.) is a tall tree belonging to the genusCinnamomum of Lauraceae, located in the southern provinces of China. The camphor treehas important economic and timber value. Camphor tree can absorb dust, save andmaintain water, consolidate sand and purify air. Although camphor tree is often used inlandscaping, but its distribution is affected by climate. Due to low temperature and coldair, the northern city doesn’t get much cultivated. In order to improve the cold resistanceof C. camphora, we transferred the AtCBFS gene and LIDERB1gene into camphor tree.The results are as follows:1. The optimization of somatic embryogenesis (1) Embryo age had a significant effect on somatic embryo induction rate andaverage somatic embryos:the somatic embryo induction rate of zygotic embryo after theanthesis of60d,70d and80d were55.67%,5.92%and0%, respectively. There is nosignificant differences for the average number of somatic embryos. Therefore, the choiceof60days after flowering was the best.(2)The plant genotype had a significant effect on somatic embryogenesis:theinduction rate of three different genotypes were55.67%,36.99%and34.33%,respectively. The average somatic embryos formed from each explant were3.67,3.33and4, respectively. So embryo induction rate of different genotype was different, we shouldselect the appropriate plant.(3)The injury of zygotic embryos had a significant effect on somatic embryogenesis:somatic embryo induction rate of scratched, separated and complete embryos were21.00%,2.83%and60.33%, respectively. So, the complete embryo was the appropriateselection.2.The optimization of genetic transformation (1) The effects of mannitol concentration, pretreatment time and methods onresistant callus induction rate was significant: the resistant callus induction rate was thehighest when mannitol treatment was0.4mol/L for4hours, and resistant callus inductionrate of0.4mol/L mannitol in solid medium was significantly higher than in liquidmedium.(2) Genotype and explants types had impact on genetic transformation. Good qualityof embryogenic callus was appropriate.(3) Agrobacterium strain had a significant effect on resistance callus induction: the resistant callus induction rate for strain EHA105and LBA4404were35.33%and24.00%, respectively.3. Genetic transformation of AtCBF3and LlDREB1genesBased on the optimized genetic transformation system, the AtCBF3and LlDREB1genes were introduced into camphor tree by Agrobacterium-mediated method. The PCR analysis showed positive bands, which indicated AtCBF3and LlDREB1possibly had been integrated into the genome of transgenic plantlets. Transgenic somatic embryos of AtCBF3gene were germinated currently.