[Study on Influencing Factors for Induction and Proliferation of Protocorm-like Bodies of Dendrobium officinale].

To improve the protocorms of Dendrobium officinale induction and proliferation growth rate.

Dendrobium officinale plumule was selected as experimental material and 1 /2MS + 2% sucrose + 10% banana puree + 0. 8% agar with p H value of 6. 0 was applied as minimal medium. The optimal hormone concentration for the induction of protocorm-like bodies of Dendrobium officinale was explored; effects of different physiological statuses of protocorm-like bodies,sizes of inoculated explants,days of cultured, and methods of laminated culture on the proliferation and growth of protocorm-like bodies were studied.

Addition of 6-BA0. 3 mg / L and NAA 0. 2 mg / L was the optimal concentration for the induction of protocorm-like bodies; protocorm-like bodies with light yellow color and loosened and plump form presented faster proliferation and weight gained; ten protocorm-like bodies with similar physiological statuses were inoculated as one group. The most significant proliferation and weight gained were observed after cultured for 45 d,the proliferation rate was up to 1008%. The plants presented strengthened regeneration capacity and the average amount of regenerated plants by each gram of protocorm-like bodies after proliferation was 1 132. In the process of laminated culture, protocorm-like bodies on the upper layer presented satisfactory condition of proliferation and weight gained, and this method was also applicable for rejuvenation of protocorm-like bodies.

The optimal hormone concentration and proliferation growth technical parameters are screened out for promoting the Dendrobium officinale protocorms,which improved the Dendrobium officinale protocorms induction and technology system of proliferation growth.