Abstract:

An aseptic seed germination protocol for interspecific hybrid between Cymbidium hybrida × C. sinense and C. faberi was established. The results showed that seed germination rate related to its' mature degree and seed harvested 240 days after pollination germinated well. The suitable medium for hybrid seed germination was half strength MS basal medium supplemented with 0.5 mg·L^-1 6-BA and 2.0 mg·L^-1 NAA. Germinated seeds can be multiplied in vitro via 2 pathways: PLBs and rhizomes. The optimal medium for proliferation of PLBs was half strength MS medium (Solid/Liquid) supplemented with 0.5 mg·L^-1 6-BA and 2.0 mg·L^-1 NAA, and proliferation coefficient could reach to 4.25 after 30 days culture. The development and plantlet regeneration of PLBs can be highly enhanced on medium containing 1.0 mg·L^-1 6-BA and 0.5, 1.0 mg·L^-1 NAA. On the other hand, when rhizomes developed from PLBs were cultured on the medium containing 0.5 mg·L^-1 6-BA and 1.0 mg·L^-1 NAA for 40 days, the highest proliferation coefficient reached to 6.67, and subsequently more than 80％ of the apex of rhizomes developed into shoots within 70 days culture on the medium containing 1.0 mg·L^-1BA and 0.5 mg·L^-1 NAA.

Key words: Cymbidium hybrida × C. sinense, Cymbidium fabderi, interspecific hybridization, protocorm-like bodies(PLBs), rhizome, plant regeneration