Studies on micropropagation of female spinach plants and the stability of sex expression in the regenerants.

从东方菠菜（Spinacia oleracea L.）雌雄植株的根愈伤组织中获得体细胞胚，在体外长时间培养至开花。根据品种和供体植株的不同，12.5 ~ 80.5%的再生植株在无生长调节剂的培养基上开花。由雌性外植体获得的植株均为雌性，而由雄性供体获得的植株均为雄性。对再生愈伤组织再生植株进行性别表达。雌再生种群中雌雄同株占63.7%，雄再生种群中雌雄同株占11.8 ~ 54.9%。赤霉素（GA3）的施用提高了雄雄性的比例，但没有引起绝对的性别转换，即向异性转化。利用菠菜根段组织培养，研究了乙烯利、硝酸银和氨基乙氧基乙烯基甘氨酸（AVG）对菠菜胚性愈伤组织形成和胚胎发生的影响。施用乙烯利可提高胚性愈伤组织的形成率。AgNO3和AVG抑制胚性愈伤组织的形成。然而，在胚胎发生过程中，在10muM时施用乙烯利完全抑制了胚胎的发育。相反，施用10muM AgNO3显著增加了胚胎数量。

Somatic embryos obtained from the root callus of female or male plants of a oriental variety of spinach (Spinacia oleracea L.) were grown in vitro under long day length until flowering. Depending on the varieties and donor plants, 12.5 to 80.5% of regenerated plants flowered on a growth regulator-free medium. The plants derived from female explants were all female, while those from male donors included andromonoecy. The sex expression was pursued for plants regenerated from the regenerant-derived callus. The populations originating in female regenerants included gynomonoecy up to 63.7%, while 11.8 to 54.9% of those from male regenerants were andromonoecious. The application of gibberellic acid (GA3) elevated the ratio of andromonoecy but did not induce an absolute sex conversion, i.e., to the opposite sex.The effects of Ethephon, silver nitrate and aminoethoxyvinylglycine (AVG) on the embryogenic callus formation and embryogenesis were examined using tissue cultures of spinach root segments. The application of Ethephon increased the ratio of embryogenic callus formation. AgNO3 and AVG inhibited the embryogenic callus formation. Ethephon applied at 10muM during embryogenesis, however, completely inhibited the development of embryos. In contrast, the application of 10muM AgNO3 remarkably increased the number of embryos.