番茄离体培养过程中器官发生的细胞组织学观察

Morphogenesis in in vitro Culture of Lycopersicon esculentum Mill.

对番茄下胚轴、子叶、茎段、叶片、叶柄不同类型外植体离体培养中有关细胞启动、分裂、分化以及器官发生作了细胞组织学观察。研究结果表明 :番茄不同类型外植体在同样的培养条件下 ,愈伤组织生长表现出明显差异 ,其中下胚轴、子叶诱导产生愈伤组织时 ,细胞启动最早 ,生长最快 ,其分裂方式基本为无丝分裂 ,未见有丝分裂 ,因此我们认为以不定芽方式获得转基因植株时 ,植株的所有性状变化 ,是否纯属目的基因所为 ,应该反复考察 ,不能忽视不定芽产生过程中的种种变化 ;下胚轴诱导愈伤组织形成时 ,细胞不规则的无丝分裂少于子叶 ,故下胚轴离体培养得到的正常芽的比例高于子叶的 ;番茄离体培养中不定芽通常发生在愈伤组织的周边区 ,也可起源于维管组织结节周围的形成层状细胞。

Hypocotyl,cotyledon,stem,leaf blade,leaf petiole explants of tomato were cultured on MS medium supplemented with 2 mg/L BA and 0 2 mg/L IAA for induction of calli and bud formation.Cytohistological observations on calli and bud formation were carried out. The results are as follows:there were significant differences in callus induction and growth among 5 kinds of explants mentioned above.Calli from hypocotyl and cotyledon explants were induced earlier than others,and had a faster growth rates than others.Buds differentia ted from calli were adventitious ones.Adventitious buds were generally formed on the peripheral parts of the calli,and also originated from the cambium like cells surrounded by the vascular nodules.Adventitious roots originated from the pericycle.The caryological observation on callus paraffin section showed that as compared to the calli from hypocotyl,in the course of callus formation from cotyledon there were more kinds of nuclear division modes,but all these were of amitosis.