赤霉素和钙处理春小麦种子效应的研究

Study on the Effects of Gibberellin and Calcium Ions Treatment on the Seeds of Spring Wheat

分段研究了GA和Ca^(2+)对种子成苗过程的吸涨、萌发和胚芽伸长3个阶段的影响。在吸涨阶段和萌发阶段,GA具有明显促进种子吸水和加快种子萌发的作用。Ca^(2+)则表现出抑制种子吸水和萌发。GA能够促进胚芽和芽鞘的伸长。Ca^(2+)则明显抑制了胚芽和芽鞘的伸长。GA促进成苗的主要因为它增大了种苗的导水性,从而加快了种苗吸收水分,由此促进了种子萌动、萌发和胚芽伸长。GA与Ca^(2+)混合后,Ca^(2+)抑制了GA对种子吸水、萌发和胚芽生长的促进作用,由此推断,干旱条件下Ca^(2+)对种子成苗的有利作用机理不同于GA。在干旱和半干旱地区,种子萌发和出土过程常常受到干旱的威胁,因此,加快种子萌发和出土对作物产量形成有着十分重要的意义。用植物激素、营养元素和其它化学药剂处理种子已有大量报道。有试验证明,一定浓度的GA有促进多种作物种子萌发和幼苗生长的作用。Ca^(2+)对种子萌发和幼苗生长的作用也有不少研究。我们的试验也证明,中度干旱条件下,GA和Ca^(2+)分别处理种子,确有促进根芽伸长、加快出苗速度和提高出苗率的作用(2)(3),并且提出用GA和Ca^(2+)混合处理种子,有互补作用。上述研究只是证明了GA和Ca^(2+)处理种子的作用效果对GA和Ca^(2+)的作用机理深入探讨不够,并且缺乏对GA和Ca^(2+)在种子吸涨—出土这一连续成苗过程的分段作用效果的研究。因此,本试验基于原有工作,对GA和Ca^(2+)在整个成苗过程各个阶段的作用效果和机制进行了初步探讨。

The effects of gibberellin (GA) and cacium ions (Ca^(2+)) on the seedling establishment of seeds includingimbibition,germination and coleoptile elongation were studied on the basis of each individual stage avove.GA could enhance water absorption and accelerate germinoation of seeds at imbibition and germinationstanges respectively.However.Ca^(2+) inhibited the water absorption and germination. GA could slightly promote the elongation of coleoptile.Ca^(2+) obvioursly inhibited the coleop-tile elongation.Therefore,it could be concluded that the acceleration of seedling establishment with GA ap-plication was mainlyattributed to the increment of hydraulic conductance,which resulted in the promotionof water absorption by seeds and seedlings.Therefore,the imbibition,germination and coleoptile elonga-tion.were promoted.In the treatment of GA plus Ca^(2+) Ca^(2+) restricted the effects of GA on seed imbibition,germination,and coleoptile elongation.So it could be inferred that the mechanism of Ca^(2+) benifits onseedling establishmeent under drought was different from that of GA.