Effects of Several Physiological Factors on Embryo Formation in Unpollinated Ovary Culture of Pumpkin(Cucurbita moschata Duch.ex Poiret)

Effects of several physiological factors on embryo formation in unpollinated pumpkin ovary culture were studied using 'Miben' pumpkin(Cucurbita moschata) as experimental material.The results showed that the ovaries at the stage of 1 d before anthesis were optimal for embryo induction.Heat treatment of 35 ℃ for 6 d before embryo induction remarkably enhanced the potential of embryo formation in unpollinated ovary.High concentration of 2,4-D promoted embryo formation in unpollinated ovary and inhibited callus formation.The ovary explants cultured in MS medium containing 4.0 mg·L-1 2,4-D,0.5 mg·L-1 NAA and 0.5 mg·L-1 6-BA gave highest embryo formation rate [(20.6±3.8)%] with the mean embryo number of 11.3±3.2 per ovary segment.