外源赤霉素对紫斑牡丹种子萌发的影响

以紫斑牡丹种子为试验材料,研究不同浓度的赤霉素(GA_3)处理对种子生根以及生根过程中营养物质、酶活性和内源激素水平变化的影响,为探讨紫斑牡丹种子萌发机制提供依据。结果表明:(1)GA_3处理能够促进种子生根,并以300 mg/L GA_3处理对种子生根效果最好,与对照相比可提前14.67 d生根,生根率可达71.00%。(2)与对照相比,GA_3处理可以在0～15 d时促进种子淀粉水解和可溶性糖的积累,并加速可溶性蛋白的消耗,在0～30 d促进过氧化物酶(POD)活性的提高,从而促进种子萌发生根。(3)在种子沙藏生根过程中,种子脱落酸(ABA)含量呈下降趋势,赤霉素(GA)、玉米素核苷(ZR)和吲哚乙酸(IAA)含量均表现出先上升后下降的趋势,与对照相比,GA_3处理可使种子GA、ZR和IAA的含量在沙藏前期明显上升,以解除种子休眠。研究发现,外源GA_3处理可以调控紫斑牡丹种子内源激素含量和POD活性的变化,促进营养物质转化,从而提前解除种子休眠使其萌发。

Effect of Exogenous Gibberellic Acid on Paeonia rockii Seeds Germination

The study used seeds of Paeonia rockii treated with different concentrations of gibberellic acid (GA₃) to investigate the effects of rooting and the variation of nutritious substances, enzyme activity and endogenous hormones content during different rooting stages to provide a basis for clarifying the mechanism of seed germination. The results showed that: (1) GA₃ treatment could effectively promote the rooting of seeds. 300 mg/L GA₃ treatment was the best to promote rooting with the highest rooting rates of 71.00% and made the first seed rooting time shorter 14.67 days than control treatment. (2) Compared with the control, GA₃ treatment could promote hydrolysis of the starch, soluble sugar accumulation and soluble protein consumption of seeds in the first 15 days. It also could accelerate improvement of activity of peroxidase (POD) in the first 30 days. (3) During sand stratification process, abscisic acid (ABA) content decreased gradually, gibberellic acid (GA), zeatin riboside (ZR) and indole 3 acetic acid (IAA) contents increased first and then decreased. Compared with the control, GA₃ treatment could increase the contents of GA, ZR and IAA which significantly improve dormancy breaking. The study found that GA₃ treatment can regulate the contents of endogenous hormones, POD activity and the transformation of nutrients, thus seeds of Paeonia rockii can break dormancy and germinate in advance.