摘要
将香榧(Torreya grandis‘Merrillii’)的未成熟合子胚置于SH+0.1 mg·L-1 NAA+500 mg·L-1AC+3%蔗糖+0.5 g·L-1 Gln培养基上暗培养45 d,诱导产生半透明颗粒状胚性愈伤组织;将胚性愈伤组织转入SH+20 g·L-1 PEG+10 mg·L-1 ABA培养基中暗培养3个月诱导体细胞胚。采用碘—碘化钾染色和石蜡切片技术对体胚起源、形态发育与细胞组织学进行了观察。结果表明:胚性愈伤组织起源于合子胚胚轴表皮或皮层细胞的对称分裂。胚性愈伤组织含有两类细胞,一种是细胞质浓厚、细胞核大、体积小的圆形胚性细胞,另一种是高度液泡化拉长的细胞。胚性愈伤组织包含由这两种细胞构成的原胚团Ⅰ、原胚团Ⅱ和原胚团Ⅲ,以及一些游离细胞。原胚团Ⅲ在无植物生长调节剂的SH基本培养基上形成原胚,原胚接入成熟培养基,历经球形、棒状、心形、鱼雷形胚后发育成子叶胚。将子叶胚转入萌发培养基后胚根伸长,胚芽发育长出针叶,形成完整的再生植株。同时在离体培养中合子胚胚柄处退化的裂生多胚也能重新发育形成胚体。在初生体胚发育过程中表面常伴有次生体细胞胚的形成。
An immature zygotic embryo of Torreya grandis‘Merrillii＇was dark cultured for 45 days on an SH medium supplemented with 0.1 mg · L^-1 NAA,500 mg · L^-1 AC,3% sucrose and 0.5 g · L^-1 Gln to induce embryonic callus,which was watery,semi-transparent and slimy. Then the callus was transferred to SH media supplemented with 20 g · L^-1 PEG and 10 mg · L^-1ABA and dark cultured for three months for somatic embryogenesis. The morphological and cytohistological observation of somatic embryogenesis was performed by iodine-potassium iodide staining and Paraffin technology. Results showed that the embryonic callus originated from the symmetrical division of epidermal or cortical cells of hypocotyl. The callus consisted of two types of cells,viz. small-sized circular cells with dense cytoplasm and highly elongated vacuolate cells. The two types of cells formed proembryonic masses（PEMs）expressed as PEMⅠ,PEMⅡ,and PEM Ⅲ and some free cells. The PEM Ⅲ cultured in the basic medium without hormones added developed to form a proembryo,which was then transferred to mature media to form a cotyledon embryo by being subjected to globular,rodlike,heart-shaped,and torpedo-shaped development. after transferred to SH media,the cotyledon embryo developed to form an intact plantlet through elongated radicle and growth of needles from germ. In vitro culture of polyembryony originating from division of degraded suspensor of a zygotic embryo could also produce idiosome. Development of primary somatic embryos was often accompanied by the formation of secondary somatic embryos.
出处
《园艺学报》
CAS
CSCD
北大核心
2015年第8期1477-1486,共10页
Acta Horticulturae Sinica
基金
国家星火计划重大项目(2012GA700001)
浙江省科技厅重大科技专项重点农业项目(2012C12002)
浙江省农业新品种选育重大科技专项(2012C12904-12)
关键词
香榧
体细胞胚
起源
发育
形态学
细胞学
Torreya grandis‘Merrillii＇
somatic embryogenesis
origin
development
morphology
cytology
