Induction of somatic embryos from cotyledonary and leaf tissues of tea [Camellia sinensis L.]

Abstract

This study was carried out ot achieve efficient somatic embryogenesis from cotyledonary and leaf tissues of tea. Small cotyledon segments were taken from sterilized cotyledon (proximal to zygotic embryonic zone) of four tea cultivars (TRI 2043, TRI 2025, TRI 777 and DT1). These explants were placed on MS basal medium with 2.0 mg L' BAP and 0.2 mg L-' NAA ot express their embryogenic capacity. The results revealed that the cotyledon explants of high yielding cultivars, DT1 and TRI 2025 performed better ni embryogenic potential. As a preliminary study ot induce somatic embryos from cotyledonary petioles, smal petiole segments excised from in vitro seedlings of TRI 2025 were placed on the above medium. Results showed that somatic embryos were directly formed on cotyledonary petioles. It has potential to produce a large numbers of propagules from hybrid seeds. Further work was aimed ot induce somatic embryos indirectly from leaf explants. Leaf segments excised from in vitro shoots of TRI 2043 were cultured on MS basal medium with 2 mg L' BAP and 3mg L': NAA. After 16 weeks of culture, primary calli were culturd on MS medium contained some selected combinations of growth regulators (BAP, kinetin, NAA, GAg and adenine sulphate) to produce somatic embryos. Results showed that formations of mature somatic embryos (11.7% and 10%) were high ni MS medium with BAP 1( mg I.") and NAA (0.1 mg L') ni combination with GA, or adenine sulphate at 01. mg L' respectively. This protocol will be useful ot achieve new somatic variants from seedling explants and also ot use ni transformation technique