摘要
[目的]确定有利于垂穗披碱草(Elymus nutans)种子生长和提高种子萌发特性的休牧时期.[方法]在东祁连山天祝高寒草甸设置土壤解冻临界期—牧草枯黄期(RP1)、土壤解冻后期—牧草枯黄期(RP2)、牧草返青初期—牧草枯黄期(RP3)、牧草返青后期—牧草枯黄期(RP4)和当地传统休牧(优势牧草高5 cm—牧草枯黄期)(RP5)5个休牧时期,研究不同时期休牧对垂穗披碱草种子大小、萌发特性及二者之间相关关系的影响.[结果]RP1休牧垂穗披碱草种子面积、周长、长宽比和长度均最大,其中面积、周长和长度较RP5休牧分别增加了15.14％、10.22％和11.97％.RP4休牧千粒重显著高于RP1、RP2和RP5.与RP5相比,提前休牧显著提高了垂穗披碱草种子的发芽势、发芽指数、发芽率、芽长和活力指数,RP1、RP2、RP3和RP4休牧种子的发芽率较RP5分别提高了84.86％、121.23％、127.27％和127.27％.相关性分析表明,垂穗披碱草种子千粒重与发芽势、芽长呈极显著正相关.[结论]RP1休牧可提高垂穗披碱草种子面积、周长、长宽比和长度,且种子具有较好的萌发特性,有利于保护和恢复垂穗披碱草.
Abstract
[Objective]The objective of this study was to determine the rest grazing period conducive to the seed size and germination characteristics of Elymus nutans.[Method]Five rest grazing periods were set up in Tianzhu al-pine meadow of east Qilian Mountain,including the critical period of soil thawing-grass withering period (RP1),the late period of soil thawing-grass withering period (RP2),the initial period of grass regreening-grass withering period (RP3),the late period of grass regreening—grass withering period(RP4) and the local traditional rest grazing(when the dominant plant height was 5 cm—grass withering period) (RP5). The effects of rest grazing in different periods on the seed size and germination characteristics of E. nutans and the relationship between them were studied.[Re-sult]The seed area,perimeter,length width ratio and length were the largest in RP1,and the area,perimeter and length were increased by 15.14％,10.22％ and 11.97％,respectively,compared with RP5. The thousand-grain weight of RP4 was significantly higher than that of RP1,RP2 and RP5.Compared with RP5,early rest grazing signifi-cantly improved the germination potential,germination index,germination percentage,bud length and vigor index. The germination percentages of RP1,RP2,RP3 and RP4 were 84.86％,121.23％,127.27％ and 127.27％ higher than RP5,respectively. Correlation analysis showed that thousand-grain weight was significantly positively corre-lated with germination potential and bud length.[Conclusion]RP1 rest grazing could improve the seed area,perim-eter,length width ratio and lengthof E. nutans,and the seeds have better germination characteristics,which is condu-cive to the protection and restoration of E. nutans vegetation.
维普
万方数据