甘蓝下胚轴不同切段内源IAA水平与不定根发生能力的研究

对甘蓝下胚轴不同切段的不定根发生能力的研究结果表明,从切段1到切段5都不需要任何激素的诱导,能“自发生根”,且不定根发生能力逐步增强。采用酶联免疫法（ELISA）测定了不同切段的内源IAA含量,进一步又对不同切段的过氧化物酶和IAA氧化酶相对活性以及不定根发生的组织学进行了研究,结果表明,内源IAA水平和不定根发生能力不呈正相关,下胚轴不同切段的根原基原始细胞可能处在不定根发端早期的不同时期。作者认为,在甘蓝下胚轴不同切段”自发生根系统“中,内源IAA水平和不定根发生能力不呈正相关,可能是由于该切段的根原基原始细胞已越过了它们分化不定根所需的IAA峰。

Studies on Endogenous IAA Levels and Adventitious Root Formation Capactity of Different Hypocotyl Segments of Cabbage

The capactity of adventitous root formation in different hypocotyl segments of cabbage was determined. It was shown that the different hypocotyl segment of cabbage may be defined as a spontaneous rooting system, which does not need inducement of any plant hormones. There is progressively increasing capacity of adventitious root formation from segment 1 to segment 5. IAA contents have been determined in different hypocotyl segments by an enzyme-linked immunosorbent assay (ELISA). We have also analyzed the relative activity of peroxidase (PER) and IAA oxidase in 5 kinds of segments. We have also studied the histology of the formation and development of adventitous roots in different hypocotyl segments of cabbage. The results show that the endogenous IAA level at time zero does not coincide with capacity of adventitious root formation of the different segment, and that initial cells which could be deve~loped primordium lie in the distinct phase of early stage of adventitious root initiation in the different hypocotyl segments of cabbage during their ontogenesis. We suggest that an inverse correlation between endogenous IAA contents and capacity of adventitious root formation may result from the facts that the first events of induction could already have overpassed a peak of IAA levels in spontaneous rooting segments of hypocotyls of cabbage.