农杆菌介导甜橙遗传转化的初步研究

Seedling epicotyl (intemodal stem) segments of‘Xupu’sweet orange(Citrus sinensis L.0sb.) were used as expIants to establish Agrobacterium—mediated transfomation system with chit42 and phyB genes. The results showed that trallsformed buds could be obtained after the epicotyl segments were cultured on co-culture medium(MS+3 mg／L BA) for 3 days and then on selective medium with 100 mg／L Kanamycin and 500 mg／L Cefotaxime for 2 weeks. Thle transformation efficency of Sweet orange with the chit42 and phyB genes reacbed 27.8％ and 35.6％, respectively. After the regenerated buds were cultured for 4 weeks more, they were micro—grafted onto seedlings of Carrizo citrange grown in Vitro and one month later regrafted on greenhouse grown rootstocks. Now the transgenic plants are growing well in the greenhouse, and the presence of chit42 and phyB genes in the regenerated plants were confinned by PCR anaIysis.