Studies On The Introduction Of MtlD Gene Into Potato Plants Mediated By Agrobacterium Tumefaciens

Potato cultivars and dihaploid breeding lines were transformed with mtlD gene, a bacterial gene encoding mannitol- 1-phosphate dehydrogenase, via Agrobacterium twnefaciens mediated gene transfer, for the purpose of increasing potato salt tolerance and creating salt-resistance breeding material, which would help exploiting and utilizing salted soil and salt water resource. In this study, the potato transformed receptor system mediated by Agrobacterium tumefaciens was established, the optimum transformation condition were studied. transgenic plants were evaluated by PCR amplification and high salt stress .The results showed: In the optimized transformed receptor system. the transformed receptor are leaf disc and stem segment explants. The regeneration medium is: MS + NAA 0.2mg/L -6-BA 2.Om1L and the medium of MS + GA3 5nig/L + 6-BA 2.25nig/L was used after two weeks. The selective press are kanamycin 75mgIL(during the callus induction and regeneration)and 5Omg/L(rooting phase) respectively for the potato cultivars, for the potato dihaploids which are kanamycin 50mg/I. and 25mg/L. The optimum transformation condition are: the explants are pre-cultured 2 days, the bacterium density in value of 0D600 is 0.2, and the time of infection and co-culture are 10 minutes and 3 days respectively. Meanwhile, good explants. added AS ~. and high Ca> can increase the transformation frequency. ? The PCR amplification showed that the mtlD gene has been integrated into potato genome of transformants fmm Atlantic and Irish cobbier cultivars. Through the high salt stress, some transformation plants can tolerance 0.8% NaCI, which demonstrated the introduction of mtlD gene increasing potato's salt resistance.