红江橙体胚发生及影响因素的研究

红江橙花后４周的幼果，直径约１ｃｍ左右，这时期的胚珠最适于胚性愈伤组织的诱导。以ＭＴ为基本培养基，加上适当浓度的ＩＡＡ、ＢＡ和ＭＥ可显著提高胚性愈伤组织诱导率。体胚发生，以ＭＴ＋ＩＡＡ０．１ｍｇ１－１＋ＢＡ（ＺＴ）１ｍｇ１－１培养基较好，能诱导产生正常体胚，且频率较高。胚性愈伤组织继代次数对体胚发生也有一定的影响，继代６次以内，胚性愈伤组织具有旺盛产生体胚能力；继代至第９次时，产生体胚的能力明显下降；至第１２代时，不能产生胚状体。成熟胚转换成小植株，以ＭＴ＋ＧＡ２ｍｇ１－１＋ＮＡＡ０．１ｍｇ１－１培养基成苗率最高。

The study on the factors affecting embryogenesis of Citrus sinensis Osbeck cv. Hongjiang

Ovules excised from the 4-week-old fruit of Hongjiang sweet orange after anthesis were suitable for embryogenic callus induction. MT basal media containing IAA、BA and ME were effective to induce embryogenic callus with the induction frequency of 25.5%. An optimal medium for somatic embryogenesis was MT + IAA 0.1 mg 1 -1 + BA (ZT) 1 mg 1 -1 , inducing normal embryoids. Embryogenic callus was subcultured at intervals 30 days. Embryogenesis frequency was high before the 6th subcuture with 10～19 embryoid/piece callus. Embryoid numbers remarkably decreased after the 9th subculture. Continued subculturing at 12th did not induce any embryoids. A mature embryoid could develop into a whole plant in the MT basal medium with GA 3 2 mg 1 -1 and NAA 0.1 mg 1 -1