三七体细胞胚胎发生及人工种子研制

三七为五加科的重要药用植物。以三七的种胚为材料接种于MS 补加2,4-D、IAA、NAA 各1 mg/L的培养基上。接种后约二个月,在MS 补加IAA 或NAA 的培养基上可以产生体细胞胚;在MS 加2,4-D 的培养基上只产生愈伤组织而无器官分化。体细胞胚在MS+IAA 0.5 mg/L+GA_3 1 mg/L 培养基上可发育成小植株。体细胞胚用4%海藻酸钠和2%氯化钙进行人工种皮包埋后,在无菌条件下,人工种子可转换成苗,转换率达89.7%。三七的体细胞胚起源于愈伤组织内或近表层的单个胚性细胞。体细胞胚经球形、心型、鱼雷形及子叶期等诸阶段发育成植株。通过PAS 法染色发现,胚性细胞、球形胚、早心形胚阶段有明显地淀粉积累,淀粉颗粒大而密集;到晚心形胚及子叶期体胚,淀粉颗粒小而少或消失。淀粉消长变化的规律与体细胞胚的发育有着密切的关系。

STUDIES ON SOMATIC EMBRYOGENESIS AND ARTIFICIAL SEED OF PANAX NOTOGINSENG

Panax notoginseng is an important me-dical plant in Araliaceae.Embryos of P.notoginseng were used as the experimentalmaterial and cultured on medium MS with2,4-D or IAA or NAA respectively.Afterculturing two months,somatic embryoswere produced on MS medium with IAA orNAA;but only calli were induced on MSmedium with 2,4-D.Somatic embryos couldbe developed into plantlets on MS medium+GA_3 1 mg/L+IAA 0.5 mg/L.Somaticembryos were encapsulated in 4% sodiumalginate and 2% CaCl_2 as artificial seeds,then they converted to plantlets under theaseptic condition.The conversion frequencyof artificial seeds is 89.7%.The somatic embryo of P.notoginsengoriginated from single embryonic cell insidecallus or near the surface layer.Somaticembryos developed into plantlets throughprocesses of globular,heart-shaped,torpedo-shaped and cotyledon stages.By use of PAShistochemical method,it was found the lar-ge,dark-stained starch granules during em-bryonic cell,gloublar-shaped embryo andearly heart-shaped embryo stages,but thestarch particles were degenerated or disap-peared in later heart-shaped embryo as wellas cotyledon embryo stages.These changeswere closely related with developmental sta-ges of somatic embryogenesis.