匙叶翼首花种子低温层积过程中内源抑制物及激素变化研究

Study on endogenous inhibitors and hormonal changes during low-temperature accumulation of Pterocephalus hookeri seeds

【目的】探究低温层积过程中匙叶翼首花(Pterocephalus hookeri)种子生理生化变化与休眠解除的内在联系。【方法】通过低温层积处理(60 d)解除匙叶翼首花种子休眠,观测不同层积时间种子发芽率、内源抑制物及赤霉素(GA)、吲哚乙酸(IAA)和脱落酸(ABA)的活性变化。【结果】在低温层积过程中,匙叶翼首花种子发芽率在层积后期(45~60 d)显著提高(P<0.05);在层积后,GA含量显著升高(P<0.05),萌发促进物和抑制物比例(GA/ABA、IAA/ABA、GA+IAA/ABA)也呈升高趋势;种子发芽率与GA显著正相关(P<0.05)。【结论】匙叶翼首花种子内部存在内源抑制物;匙叶翼首花种子浸提液随着层积时间的延长,对种子发芽率、根长和胚轴长的抑制先增强后减弱;内源激素比例平衡及GA含量的上升也是匙叶翼首花种子解除休眠的关键因素。

【Objective】The study was carried out in order to explore the internal relationship between seed physiological and biochemical changes of Pterocephalus hookeri and dormancy removal during the process of low temperature stratification.【Method】The seed dormancy was relieved by low temperature stratification treatment(60 d).The germination rate,endogenous inhibitors and the activities of gibberellin(GA),indoleacetic acid(IAA)and abscisic acid(ABA)were observed at different stratification time.【Result】The results showed that during the low temperature stratification process,the germination rate of the seed was significantly increased at the late stage of stratification(45~60 d)(P<0.05).After stratification,GA content was significantly increased(P<0.05),and the ratio of germination promoters to inhibitors(GA/ABA,IAA/ABA,GA+IAA/ABA)also showed an increasing trend.There was a significant positive correlation between seed germination rate and GA(P<0.05).【Conclusion】It was found that there were endogenous inhibitors in the seeds of Pterocephalus hookeri.With the extension of the stratification time,the inhibition of the seed extract on the germination rate,root length and cotyl length of P.hookeri seeds first increased and then decreased.The increase of GA content was also the key factors for the release of dormancy of the seeds.