Embryogenic Callus Induction And Optimization Of Agrobacterium-mediated Genetic Transformation Of Lilium Longiflorum

As a kind of ornamental plant with big and beautiful flower, lily symbolized eternal love. It is usually used for cut flower, pot culture and flower border. With so many advantages, lily still has some features that need to be improved, such as pollen pollution, stress resistance and so on. But due to the interspecific hybridization incompatibility, its features are hard to be changed rapidly by traditional breeding methods. Molecular breeding such as genetic transformation can easily overcome the shortage of traditional breeding. But some difficulties in genetic transformation of Lilium plants are still exist. The results are as following:1. The optimal culture medium for embryonic callus was investigated, and the results showed that while taking the bulb transverse thin cell layer as explants, proper callus induction medium is MS+60g/L sucrose+7.5g/L agarose+0.5mg/L NAA+0.4mg/L TDZ, and the induction rate is95.25%. The better embryonic callus induction medium is MS+60g/L sucrose+7.5g/L agarose+2mg/L PIC+O.lmg/L TDZ, and the callus induction rate is94.36%. Moreover, a higher rate of embryonic callus was found from these calli. This research also observed4kinds of calli with different morphologies by paraffin section, and find out there are more embryonic cell in PIC induction callus. So PIC is appropriate to embryonic callus induction.2. The Agrobacterium-mediated transformation rate of Lilium plant is low, so mass production of transgenic plants is difficult. Callus is a better material for transformation than bulb scale and bulb base; bacterial strain of EHA105has a stronger ability to infect target material than AGLO and GV3101; screening the transformed explants with Hyg is better than Km resistance screening system. The bulb scales being scratched show lower rate of bud regeneration (1.5%) than the normal bulb scales (25.2%). It is probably because scratching damaged the bulb cell.3. Target gene transformation:PIC induction callus are used as transformation materials, the target gene is LIDREB1,87calli are infected and three shoots derived from them are positive by PCR analysis. So the transformation rate is3.4%.