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

从菠菜(Spinacia Holacea L.)雌株或雄株的根愈伤组织中获得体细胞胚胎。在较长的日照下培养，直到开花。根据品种和供体植物的不同，12.5%到80.5%的再生植株在不含生长调节剂的培养基上开花。来自雌性外植体的植株都是雌性的，而来自雄性供体的植株包括雄蕊雌雄同株。对再生愈伤组织再生植株的性别表达进行了研究。起源于雌性再生植株的种群有63.7%是雌雄同株的，而来自雄性再生植株的种群中有11.8%~54.9%是雌雄同株的。以菠菜根段为试材，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。乙烯利的使用提高了胚性愈伤组织的形成率。AgNO3和AVG对胚性愈伤组织的形成有抑制作用。然而，在胚胎发生过程中使用10µM的乙烯利完全抑制了胚胎的发育。与之相比，10muM硝酸银的应用显著提高了胚胎的数量。

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.