桃儿七愈伤组织中体细胞胚起源过程的组织细胞学观察

Histocytological Observation on the Origin of Somatic Embryos in Sinopodophyllum emodi Callus

以桃儿七(Sinopodophyllum emodi (Wall.) Ying)实生苗下胚轴为外植体进行了桃儿七体细胞胚诱导,并对体细胞胚诱导不同时期的培养物进行了形态学与组织细胞学观察。结果表明:将非胚性愈伤组织转入到MS+0.5 mg/L 6-BA+0.15 mg/L NAA+0.1 mg/L GA3+300 mg/L CH+40.0 g/L sucrose上后愈伤组织逐步分化出一些胚性愈伤组织,胚性愈伤组织转入到MS+6-BA 1.0 mg/L+TDZ 0.1 mg/L+NAA 0.5 mg/L培养及分化后,愈伤组织表层的胚性细胞逐步分裂形成由多细胞组成的原胚组织,原胚细胞分生能力较强,不断生长,由长椭圆形发展至倒卵形,最后逐渐形成近球形的球形胚。与此同时,胚性愈伤组织内部也不断出现细胞分化,逐渐形成球形胚结构,内部起源于胚性愈伤组织的体细胞胚胎容易出现停止发育的情况,导致畸形胚发生,制约了桃儿七体细胞胚再生苗的形成。本研究发现,桃儿七体细胞胚发生具有内起源和外起源2种方式,且愈伤组织中体细胞胚发生还存在不同步、不均匀等现象,为后期桃儿七体细胞胚途径再生苗的培育提供了基础。

Seedling hypocotyls of Sinopodophyllum emodi(Wall)Ying were used as explants for somatic em-bryogenesis.The cultures at different stages of somatic embryo induction were observed by morphology and histo-cytology.The results showed that the callus gradually differentiated into some embryogenic callus after the non-embryonic callus were transferred to MS+0.5 mg/L 6-BA+0.15 mg/L NAA+0.1 mg/L GA,+300 mg/L CH+40.0 g/L sucrose,and the embryogenic cells on the surface of the callus gradually divided and formed a proembryonic tissue composed of multiple cells when the the embryogenic callus was transferred to MS+6-BA 1.0 mg/L+TDZ 0.1 mg/L+NAA 0.5 mg/L.The proembryonic cells have strong meristematic ability and continue to grow,develop from long oval to inverted oval,and finally gradually formed a nearly spherical spherical embryo.At the same time,there are continuous cell differentiation in the embryogenic callus and gradually form a spherical embryo structure,somatic embryos derived from embryogenic calli are easy to stop developing halfway and form abnormal embryos,which restricts the formation of somatic embryo regenerated seedlings.This study found that the somatic embryogenesis of Sinopodophyllum emodi has two ways:internal origin and external origin,and the somatic embryogenesis in callus is still asynchronous and uneven,which provided the basis for the cultivation of regenerated seedlings of Sinopodophyllum emodi through somatic embryo pathway in the later stage.