春萝卜抽薹过程中内源激素含量变化分析

采用酶联免疫吸附法(ELISA)测定了春萝卜抽薹过程中顶端生长点处嫩叶的赤霉素(GA₄)、生长素(IAA)、细胞分裂素(iPA)和脱落酸(ABA)等含量的变化情况。研究结果表明，在萝卜抽薹过程中，GA₄含量在现蕾点存在明显的峰值,表明GA₄与现蕾抽薹密切相关，起着主导作用；内源ABA含量变化与GA₄变化趋势基本一致；与GA₄和ABA含量相比，抽薹过程中叶片IAA含量相对较低；iPA含量在现蕾期逐步增加,至抽薹中后期出现一高峰值。研究发现iPA/ABA值增大，GA₄/iPA和GA₄/IAA值变小有利于花芽分化后萝卜植株抽薹开花，表明内源激素之间的平衡对萝卜抽薹开花也起着重要作用。

Hormone Content and Balance During Bolting of Spring Radish(Raphanus sativus L.)

Endogenous hormones, including gibberellin (GA4), indole acetic acid (IAA), isopentenyl adenine (iPA) and abscisic acid (ABA), were analyzed during bolting in spring radish (Raphanus sativus L.). Tissue from young leaves near the apex was analyzed with the ELISA. The results showed that an obvious peak value of GA4 content occurred at the bud-emerging point, indicating that this hormone is an important contributor to the bolting process. The ABA had a similar trend to that of GA4, while the IAA content was relatively low compared with that of GA4 and ABA. The content of iPA increased gradually during the bud-emerging stage and reached a maximum value at the late bolting period. The results also demonstrated that the balance of these endogenous hormones play an important role in the bolting process. A high ratio of iPA/ABA and low ratio of GA4/iPA and GA4/IAA were beneficial to floral bud differentiation and bolting in radish.