甘蔗幼叶脱分化及愈伤组织形成过程中内源细胞分裂素和ABA的变化

甘蔗幼叶片,叶鞘和幼茎在含有2.4-D的培养条件下脱分化的情况有明显差异。它们除了在形态学上有区别外,这三种材料原有的细胞分裂素和ABA的水平明显不同。在幼叶片脱分化及愈伤组织形成过程中,内源细胞分裂素和ABA的水平也发生了明显变化。据此我们认为在甘蔗组织培养中2.4-D可能通过调节内源激素的水平及其相互作用,引起培养物中某些生理生化过程发生改变,从而进行脱分化和愈伤组织形成。

CHANGES OF ENDOGENOUS CYTOKININS AND ABSCISIC ACID(ABA) LEVELS DURING THE SUGARCANE LEAF DEDIFFERENTfATION AND CALLUS FORMATION

Young leaf, sheath and stem segments are different in dedifferentiation during sugarcane plant tissue culture in vitro. Leaf segments produce more embry-ogenic callus than sheath and stem segments. This may be related with the higher level of endogenous ABA and lower level of zeatin and zeatin riboside in leaf than in sheath and stem.Endogenous levels of zeatin, zeatin riboside and ABA were determined by useness of gas chromatograph during callus induction and formation in sugarcane leaf tissue culture. During the dedifferentiation of leaf segments, the total level of zeatin and zeatin riboside gradually increased along with increasing of cell division, and the level of ABA decreased to the lowest point at 5th day of culture, and then gradually increased from the 5th day on. It appeared that the sugarcane leaf segments dedifferentiation and callus formation induced by 2.4-D may be related with the changes of endogenous levels of zeatin, zeatin riboside and ABA.