多花黄精种子萌发过程的内源激素含量变化研究

Study on the Changes of Endogenous Hormones Contents in Polygonatum cyrtonema Seed Germination

目的:从形态上划分多花黄精种子萌发过程的时期,测定各时期的4种内源激素的含量,分析内源激素变化规律,探索多花黄精种子休眠的机制。方法:体式镜观测多花黄精种子的形态变化情况,利用HPLC-MS测定种子萌发过程的内源激素含量动态变化。结果:(1)在多花黄精种子萌发过程中,ABA含量降低并维持在较低水平;IAA、GA3和TZR含量呈上升-下降-上升趋势。(2)刚萌发的多花黄精种子GA3和ABA含量显著低于同期未萌发的多花黄精种子。(3)多花黄精种子GA3/ABA和TZR/ABA的比值在种子开始萌发后达到峰值。(4)GA3/ABA和IAA/ABA的比值分别与GA3和IAA含量呈极显著正相关,TZR/ABA的比值与ABA含量呈极显著负相关。结论:高含量的ABA可能是导致多花黄精种子形态生理休眠的主要原因,内源激素动态变化及GA3/ABA和TZR/ABA的比值是调控多花黄精种子休眠解除与萌发的关键因素之一。

Objective:To classify the stages of seed germination of Polygonatum cyrtonema from morphology,to determine the contents of four endogenous hormones in each stage and analyze the changes of endogenous hormones,so as to explore the dormancy mechanism of Polygonatum cyrtonema seeds.Methods:The morphological changes of Polygonatum cyrtonema seeds were observed by asana mirror,and the dynamic changes of endogenous hormones contents during seed germination were determined by HPLC-MS.Results:(1)During the germination of Polygonatum cyrtonema,ABA content decreased and remained at a low level.The contents of IAA,GA3 and TZR showed a increasing-decreasing-increasing trend.(2)GA3 and ABA contents of newly sprouting Polygonatum cyrtonema seeds were significantly lower than that of ungerminated Polygonatum cyrtonema seeds.(3)The GA3/ABA and TZR/ABA ratios of Polygonatum cyrtonema seeds reached peak after seed germination.(4)GA3/ABA and IAA/ABA ratios were positively correlated with GA3 and IAA contents,while TZR/ABA ratio was negatively correlated with ABA content.Conclusion:High content of ABA may be the main cause of morphophysiological dormancy of Polygonatum cyrtonema seeds.The dynamic changes of endogenous hormones and the ratios of GA3/ABA and TZR/ABA are one of the key factors in regulating dormancy and germination of Polygonatum cyrtonema seeds.