外源生长素和细胞分裂素对莴苣幼苗侧根原基发生和内源激素含量的影响

The effect of auxins and cytokinins on the formation of lateral root primordia and the contents of endogenous hormones in lettuce seedlings

以莴苣幼苗为材料 ,以适宜浓度的生长素类物质萘乙酸 (NAA)、吲哚丁酸 (IBA)和吲哚乙酸 (IAA)处理根部2 0～ 30h ,可使大量的侧根原基得到启动和突起 ,10 0 0 0mg/L的NAA、IBA或IAA处理的侧根原基数分别为对照的 2 7 9,2 6 5和 13 6倍 ;而用 6 苄基腺嘌呤 (6 BA)和调吡脲 (KT 30 )等细胞分裂素类物质及配合生长素类物质处理 ,则抑制幼苗自发生根和生长素的促根效应。 5 0 0 0mg/L的 6 BA几乎完全抑制了这些生长素的效应 ,同浓度的KT 30对NAA、IBA和IAA的抑制率分别为 73 8% ,6 7 0 %和 6 7 7% ,这与内源生长素含量的升高和细胞分裂素含量的下降直接相关。

Lettuce(Lactuca sativa L.)was used as material and the results showed that,the initiation and formation of lateral root primordia(LRP)was significantly promoted 20?30 h after being treated with auxins such as NAA,IBA,IAA etc at a proper concentration,the number of LRP by treatment with 10 000 mg/L NAA,IBA or IAA were 27 9,26 5 or 13 6 times those of the control respectively.While CTKs such as 6 BA and KT 30 effectively inhibited the spontaneous and auxins stimulated formation of LRP,the inhibition effect of 5.000 mg/L KT 30 on the NAA,IBA of IAA were 73 8%,67 0% or 67 7% respectively,while the inhibition effect of 6 BA at the same concentration was much more significant.The formation of LRP was closely related to the increase of endogenous IAA levels and the decrease of endogenous ZRs,iPAs levels.