紫花苜蓿体细胞胚胎发生及其细胞组织学观察

通过对紫花苜蓿（ Ｍｅｄｉｃａｇｏ ｓａｔｉｖａ Ｌ．）外植体愈伤组织进行诱导及对体细胞胚胎发生过程的组织学观察，得出以下结果：１）外植体在 Ｍ Ｓ附加１．０ｍ ｇ／ Ｌ６－ Ｂ Ａ 和１０．０ｍ ｇ／ Ｌ Ｉ Ａ Ａ 的培养基上愈伤组织生长良好，而愈伤组织转入 Ｍ Ｓ附加５００ｍ ｇ／ Ｌ水解酪蛋白的培养基中胚状体的分化能力较强。２）紫花苜蓿的体细胞胚大多是由单个具胚状体发生能力的胚性细胞发育而来，发育过程与合子胚的发育过程相似。在早期原胚发育过程中胚体外一直包围有厚壁。原胚时期和子叶胚时期出现两次淀粉积累现象。

HISTOLOGICAL OBSERVATIONS ON SOMATIC EMBRYOGENESIS IN MEDICAGO SATIVA L

Callus derived from cotyledon and hypocotyl of Medicago sativa L.grew rapidly and well on MS medium containing 1.0 mg/L of 6-BA and 10.0mg/L of IAA.Then the higher ability of somatic embryogenesis can be obtained when the callus were subcultured on MS medium containing 500 mg/L of caseinhydrolysat.The somatic embryos were mostly developed from single embryonic cells that possessed the ability of embryoid occurence,and all stages of normal zygotic embryos (globular-,heart-,torpedo- shaped and cotyledon embryo)were observed in there process of development.At the early development stages of proembryo the embryoid was limited in a boundary of thicken cell wall.There were two peaks of starch accumulation at the stages of early proembryo and cotyledon embryo.