解除萤蔺种子休眠方法研究

Studies on Methods for Dormancy-breaking of Scirpus juncoides Roxb.Seeds

【目的】萤蔺(Scirpus juncoides Roxb)是世界性水稻田恶性杂草之一,筛选解除萤蔺种子休眠的最佳方法,可为萤蔺的其它生物学特性及其发生规律的研究提供依据。【方法】以哈尔滨市阿城区萤蔺种子为试验材料,采用培养皿法,分别研究了不同化学试剂(98%H2SO4、NaOH和KNO3)、不同植物生长调节剂(赤霉素和乙烯利)、5℃低温层积与植物生长调节剂相结合对萤蔺种子萌发率的影响。【结果】化学试剂浓硫酸、氢氧化钠、硝酸钾均不能有效打破萤蔺种子的休眠,且各处理间差异不显著;植物生长调节剂赤霉素和乙烯利溶液可以打破萤蔺种子休眠,但赤霉素效果并不理想,赤霉素溶液各处理下的萤蔺种子萌发率均未超过50%,2000 mg/L赤霉素溶液浸种72 h时萌发率达到最高,也仅为43.3%,而乙烯利溶液对解除萤蔺种子休眠效果理想,2000 mg/L乙烯利溶液浸种72 h处理时萌发率高达98.67%,显著高于同一质量浓度下其他浸种时间处理;5℃低温层积处理下的萤蔺种子萌发率均高于室温处理下的萌发率,5℃低温层积结合2000 mg/L乙烯利溶液浸种处理48 h,萤蔺种子的萌发率即可达98%以上。【结论】化学试剂不能打破萤蔺种子的休眠,植物生长调节剂可以打破萤蔺种子的休眠,其中乙烯利效果好于赤霉素,5℃低温层积与乙烯利相结合处理是打破萤蔺种子休眠的最佳方法,并可有效缩短打破萤蔺种子休眠所需时间。

[Objective]Scirpus juncoides Roxb is one of the worldwide malignant weeds in rice fields.The best method to break the seed dormancy of Scirpus juncoides Roxb can lay the foundation for the research of other biological characteristics and the occurrence rules of Scirpus juncoides Roxb.[Method]Using Scirpus juncoides Roxb seeds in Acheng District,Harbin City as the test material,with the petri dish method,the effects of different chemical reagents(98%H2SO4,NaOH,KNO3),different plant growth regulators(gibberellin,ethephon),low temperature stratification at 5℃combined with plant growth regulator on the germination rate of Scirpus juncoides Roxb seeds were studied.[Results]The results showed that none of the three chemical reagents(concentrated sulfuric acid,sodium hydroxide and potassium nitrate)could effectively break the dormancy of Scirpus juncoides Roxb seeds,and there was no significant difference among the treatments.The plant growth regulator gibberellin and ethephon solutions could break the dormancy of Scirpus juncoides Roxb seeds.But the effect of gibberellin was not ideal,the germination rate was not more than 50%under the treatment of each concentration of gibberellin solution.And the germination rate reached the highest when the seeds were soaked in 2000 mg/L gibberellin solution for 72 hours,which was only 43.3%.The ethephon solution had an ideal effect on breaking the dormancy of the seeds.The germination rate was as high as 98.67%when the seeds were soaked in 2000 mg/L ethephon solution for 72 hours,which was significantly higher than those of other soaking time treatments under the same concentration.The germination rate of the seeds under low-temperature stratification at 5℃was higher than that under the room temperature.Low temperature stratification at 5℃combined with ethephon soaking seeds for 48h,the germination rate of Scirpus juncoides Roxb seeds could reach more than 98%.[Conclusion]Chemical reagents can’t break the dormancy of Scirpus juncoides Roxb seeds,and plant growth regulators can break the dormancy of the seeds,the effect of ethephon is better than that of gibberellin.Low temperature stratification at 5℃combined with ethephon is the best method to break the dormancy of Scirpus juncoides Roxb seeds,and can effectively shorten the time to break the dormancy.