GA_3 and ABA mediated effect on maturation and germination of zygotic embryos in coconut (Cocos nucifera L.)

摘要

Mature nuts (12 months after fertilization) of coconut are being used conventionally for seed nut purpose. This restricts the size of collection in a germplasm expedition. Embryos (8 months old onwards) could be extracted and retrieved in vitro (Karun et al., 11). The retrieval was observed to be very low in immature embryos compared to matured ones. The retrieval chances can be increased if immature embryos are matured in vitro. Immediate transportation of field-collected embryos may not be possible when collecting sites are located in far off places. Short-term storage (Karun and Sajini 10; Karun et al., 12) of these collected embryos for maturation is necessary for further germination and development. The growth inhibitor ABA plays an importantrole in embryo maturation and inhibition of precocious germination (Pilet and Saugy, 18; Zeevarrt and Creelman, 23; Mayer and Poljakoff-Mayer, 17; Ackerson, 1), controlling morphogenesis (Quatrano 19), synthesis of storage proteins (Finkelstein et al.,6) and desiccation tolerance (Kermode and Bewley 14). Gibberellic acid often counteracts ABA for morphogenesis like root elongation. Root growth was stimulated by gibberellic acid in Zea mays (Emons et al., 5). The present study ws designed to find out the response of ABA and gibberellic acid on maturation and germination, and morphological changes in coconut zygotic embryos.