Induction and characterization of in vitro corms of diploid-taro

When in vitro plantlets were cultured in Murashige and Skoog liquid medium supplemented with 8-10% sucrose and 22-44 mu M 6-benzylaminopurine, all of the stem explants formed corms. 170-850 mu M paclobutrazol increased corm f ormation, whereas 1700 mu M paclobutrazol inhibited corm development. Inclu sion of 66 mu M 6-benzylaminopurine in 170 mu M paclobutrazol treatment res ulted in smaller corms, and bigger corms formed in the combination of 1700 mu M paclobutrazol and 66 mu M 6-benzylaminopurine. No corms formed in 63-6 30 mu M cycocel treatments. In vitro corm growth was also affected by the c ulture methods. Deep-layer agitated culture yielded corms of up to 2.03 g, with an average fresh weight of 0.7 g, 40 days after induction. In thin lay er cultures, corms were up to 1.87 g, with an average fresh weight of 0.5 g . SDS-PAGE analysis of water-soluble proteins revealed changes of polypepti des with corm growth. Compared to smaller ones, corms over 0.2 g had higher dry matter, carbohydrate and anthocyanin content. These corms had a 99-100 % survival rate upon transplanting directly to soil after storage at 4 degr ees C for 10 months. This study indicates that the most economic production method of diploid tare seed corm is by thin-layer liquid culture in Murash ige and Skoog. medium supplemented with 22-44 mu M benzylaminopurine and 8- 10% sucrose for 6 weeks. The formed corms can be stored at 4 degrees C up t o 10 months and transplanted directly into soil without acclimatization.