虉草种子休眠机理与休眠破除方法初探

Preliminary Study on The Dormancy Mechanism and Dormancy Breaking Methods in Phalaris arundinaceaSeeds

种子休眠程度深、发芽率低是限制虉草栽培利用的重要因子。通过对3个年份采收的虉草种子发芽试验、吸水率测定及种子萌发抑制物活性的生物鉴定,揭示虉草种子休眠机理;并利用植物激素、硝酸钾和有机溶剂浸泡处理虉草种子,以探寻打破虉草种子休眠的最佳方法。结果表明:虉草种子休眠属于种皮吸水障碍、存在萌发抑制物和胚生理休眠的综合性休眠,其中萌发抑制物是限制种子萌发的首要因素。用100mg/L GA3、100mg/L 6BA、150mg/L KT或4g/L KNO3浸泡虉草种子24h可显著提高其发芽势、发芽率和发芽指数,其中以4g/L KNO3浸种24h效果最好,平均发芽率可提高到91%,比对照高137%;其次是100mg/L GA3浸种24h,平均发芽率为84%,比对照高118%。

Seed dormancy of Phalaris arundinacea is one of the most important factors limiting culture and utilization.The seed dormancy mechanism was investigated by seed germination test,water absorption rate test and inner germination inhibitory substance test,treating seeds of P.arundinacea with hormones and KNO3 and organic solvent were carried out to find the best dormancy breaking method.The results showed that the reasons of seed dormancy were water absorption barrier by seed coat,physiological dormancy and germination inhibitors existing in seed.It is comprehensive dormancy for P.arundinacea.seeds,but germination inhibitors was the primary limit factor.Treatments of 100mg/L GA3,100mg/L 6BA,150mg/L KT and 4g/L KNO3 for 24hours improved the germination rate of P.arundinacea seeds significantly,but the best method was treating with 4g/L KNO3 for 24hours,average germination rate was 91%,increased by 137% compared with control,and the second method was treating with 100mg/L GA3 for 24hours,average germination rate was 84%,increased by 118% compared with control.