柑桔胚珠培养及胚状体发生的研究

STUDIES ON THE OVULE OULTURE AND SOMATIC EMBRYOGENESIS OF CITRUS

选用‘椪柑’、‘锦橙’、‘桃叶橙’、‘华农本地早’花后7周幼果胚珠进行培养.其胚状体发生的百分率分别是:48.5%、21.2%、19.8%、6.4%;胚性愈伤组织则为:28.2%、13.5%、15.8%、5.8%.各品种胚状体和胚性愈伤组织发生的百分率明显不同.与品种胚数多少相一致.不同激素和有机物对柑桔胚珠培养、胚状体的发生及胚性愈伤组织形成产生不同的影响.多单胚的‘华农本地早’仅从基本培养基中产生胚状体和胚性愈伤组织.胚珠培养中,胚状体发生的方式,根据来源不同分为三种:第一种是由胚珠(或已黄的球形胚上)长出白色的胚性愈伤组织,继而产生胚状体:第二种是在已分化的幼苗下胚轴或根部产生胚性愈伤组织和胚状体;第三种是在畸形胚上直接不断的分化出胚状体.

The ovules of immature fruit of Citrus cultivars were in vitro cultured 7weeks after anthesis.The results revealed that the rate of somatic embryogen-esis and embryogenic callus formation was different with cultivars.Embryoid:Ponkan 48.5%,Jincheng 21.2%,Taoyecheng 19.8%,Huanonbendizao 6.4%;embryogenic callus:28.2%,13.5%,15.8% and 5.8% respectively.The percen-tage of embryoids and embryogenic callus formation was in accordance with theumber of seed embryo.The ovule culture,embryogenesis and embryoid develop-ment were affected by growth regulators and organic organic compounds.Theovule of Hunongbendizo tagerine which has high percentage of monoembryo seedcould devolope embryoid and embryogenic callus only in MT medium withoutErowth regulator.According to the origin of embryoid,the somatic embryo-genesis in citrus could be classified into three categories:1.Embryoids deve-loped from the white oallus tissue which had originated from the ovules orbrown embryoid;2.Embryoids or embryogenic callus produced from the hypo-cotyl after the seedlings differentiated;3.Green embryoids developed directlyfrom the abnormal embryoid which had differentiated.These three Kinds ofCitrus somatic embryogenesis and their future application are discussed.