苹果砧木M26离体叶片愈伤组织发生及分类研究

Studies on the Formation and Classification of M26 Leaf Explants derived from Callus

对苹果砧木Ｍ２６ 离体叶片愈伤组织的发生研究表明，取继代后３０ ～３５ ｄ 的试管苗顶部１～４ 叶位的叶片，沿与主脉垂直方向横切后，以叶背面朝上方式置于愈伤组织诱导培养基上，经观察在叶片近柄端切口处愈伤组织发生较早，产生量较多。最适的愈伤组织诱导培养基为：ＭＳ＋２ ，４ － Ｄ０ ．２ ～２ ．０ ｍｇ·ｌ－ １ ＋ＩＡＡ０ ．２ ～２．０ ｍｇ·ｌ－ １ ＋ ＢＡ０ ．５ ～１．０ ｍｇ·ｌ－ １ ＋ 蔗糖３ ％ ＋ 琼脂０．６％ 。将诱导产生的愈伤组织按外部形态、细胞特点及生理生化指标等分为三类，其中表面干燥致密、细胞内含物丰富、淀粉、蛋白质及干物质含量均较高的Ⅲ类愈伤组织的芽再生频率最高，可达８３ ．３３ ％ ，是能利用的愈伤组织类型。

Callus formation of leaf explants from in vitro cultured M26 was studied. The results showed that when the apical part of shoots was subcultured for 30～35 days and crosscut in the vertical direction to the main veins and with the back of the leaves upward on the callus induction medium, the highest callus yield produced with the earliest initial formation at the cutting areas near the stem than the other treatments. The suitable medium for callus formation was MS supplemented with 0.2 ～ 2.0 mg·l -1 2,4 D, 0.2 ～ 2.0 mg·l -1 IAA, 0.5 ～ 1.0 mg·l -1 BA, 3% sucrose and 0.6% agar. By classifying the induced callus from morphology, cell characteristic and physiological targets, the results showed that the third type callus had the highest plant regenerating frequency of 83.33% , and was available. The morphology of the third type callus was dry and compact, the cell inner substance was rich and the contents of starch, protein and dry substance were all the highest.