毛梾种子低温层积过程中内源激素的变化及其与发芽的关系

Variation of endogenous hormone in Cornus walteri seeds during cold stratifi cation and its relationship with germination

为了分析毛梾种子内源激素与发芽的关系,以了解种子休眠的内在机制,应用酶联免疫吸附测定法(ELISA)研究了毛梾种子低温层积过程中内源激素含量的动态变化情况。结果表明:IAA在层积处理初期剧烈降低,层积处理持续一段时间后IAA含量显著升高,但层积处理后期IAA含量下降,IAA/ABA比值的变化也出现了同样的趋势;种子中的ABA在层积处理前期较高,但随着处理时间的延长其含量趋于下降;GA1/3的变化相对较为平稳,尽管有一定的波动,但整体呈逐渐增高的趋势;ZRs含量变化幅度很小,接近一条直线;iPAs含量的变化幅度相对较大,在整个处理期内呈"M"形曲线变化。相关分析结果表明:IAA含量与IAA/ABA比值呈极显著的正相关(p<0.01);ABA含量与ZRs/ABA比值呈极显著的负相关(p<0.01),与iPA/ABA比值呈显著的负相关(p<0.05)。发芽试验结果表明:种子经层积处理后其发芽率与发芽势均明显上升,且均随处理时间的延长而增加,而未经层积处理的种子其发芽率为0;层积处理180 d毛梾种子的发芽率与发芽势最大,分别为41.34%、36.13%。文中据此推断,要解除毛梾种子的深休眠,最好对其低温层积处理150 d以上。

In order to analyze the relationship between endogenous hormone and germination of Cornus walteri seeds, to learn mechanism of seed dormancy, variation of endogenous hormone contents in C. walteri seeds during cold stratifi cation were studied with enzyme linked immu nosorbent assay（ELSA）. The results show that IAA content drops in the early phase of cold stratification, and then is significantly increased after a certain duration, but is decreased at the last stage, and ratio variation of IAA to ABA is so. ABA content is higher in the early phase of cold stratification, and then is decreased with extension of treatment time. Variation of GA1/3 is relative steady, and it gradually rise as a whole but some fluctuations. ZRs content has some small variations and nearly a straight line. iPAs content has relative bigger variations, and show M-shaped curve during whole treating period. The results of correlation analysis indicate that IAA content has very signifi cantly positive relationship with ratio of IAA to ABA（p〈0.01）. ABA content has very significantly negative relationship with ratio of ZRS to ABA（p〈0.01）, and significant negative relationship with ratio of iPA to ABA（p〈0.05）. The results of seed germination test show that germination rate and germination potential of seeds are increased obviously after stratification, and are strengthened with prolonging treating time. Germination rate of seeds without stratification is zero, germination rate and germination potential of seeds treated for 180 days are 41.34% and 36.13% respectively, which are the maximum in all treatments. It need go through above 150 days＇ cold stratifi cation to relieve deep dormancy of C.walteri seed.