三种杨树扦插生根期间内源激素水平的比较研究

用高效液相色谱（ＨＰＬＣ）和气相色谱（ＧＣ）法，分析银白杨、毛白根和山杨的对照、ＮＡＡ处理和ＮＡＡ＋ＢＡ处理硬枝插穗（芽、皮）的内源ＡＢＡ、ＩＡＡ和玉米素含量在扦插生根期间的变化。试验表明，硬枝扦插生根是潜伏根原基存在与否和皮部内源激素平衡两方面的原因决定的。银白杨皮部的ＩＡＡ／ＡＢＡ比值和玉米素含量高，潜伏根原基有迅速恢复生长的条件，能自发生根成活。毛白杨的ＩＡＡ／ＡＢＡ比值和玉米素含量都低，需

STUDIES ON ENDOGENOUS HORMONE LEVELS IN CUTTINGS OF THREE POPLAR SPECIES DURING ROOTING PROCESS

The changes in endogenous ABA, IAA and zeatin levels of control,NAA-treated and NAA+BA-treated cuttings(bud,bark) of Populus alba,P.tomentosa and P.davidiana during rooting process were investigated by using HPLC and GC.The experiments showed that the rooting ability of hardwood cuttings was determined by both presence of latent root primodia and balance of endogenous hormones bark.The high IAA/ABA ratio and zeatin content in bark of P. alba allowed the latent root primodia to resume their growth, and the cuttings could root and survive spontaneously.For P.tomentosa, because of its low IAA/BA ratio and zeatin content,approprite amount of exogenously applied NAA and BA was needed for stimulating latent root primodia to grow.P.davidiana had no ability to form bark-or-ignated adventitious roots, although treated with NAA and BA, the cuttings needed longer time to developl callus-originated adventitious roots. Finally, the action mode of exogenous NAA and BA in rooting process of cuttings was discussed.