Germination and Subsequent Plant Development of in vitro Cultured Zygotic Embryos and Embryonic Axes in Comparison to Conventional Seed Propagation of Tea (Camellia sinensis L.)

Abstract

The present study was carried out to achieve synchronous germination of plant materials into vigorous plants of tea (camellia sinensis 1.), under ex vitro conditions. Sterilized zygotic embryos and zygotic embryonic axes were cultured on MS basal medium supplemented with 3 mg L"1 BAPandO.5 mgL"1 IBA. To serve as controls, seeds were sown in a sand bed. At the 8* week, in vitro plantlets were transferred to ex vitro conditions for acclimatization, and seeds showing different germination responses were separately transplanted. Synchronous and significantly high germination (99%) was observed from cultured embryonic axes in vitro at the 4"' week of culture, but a lower level of germination (12.7%) from seeds that were sown in the sand bed. Further, healthy plantlets regenerated from embryonic axes in vitro had erect shoots with short internodes, as well as tap roots with abundant adventitious roots under ex vitro conditions, for better adaptation in the field, as compared with seedlings raised by conventional seed propagation.