不同时期休牧对秦艽根系生理特性的影响

Effects of rest grazing at different stages on rootphysiological characteristics ofGentiana macrophylla

摘要:

研究不同时期休牧下秦艽根系生理特性的变化,找出最佳休牧期,为合理发展、利用草地中的秦艽资源提供基础。在天祝高寒草甸设置了土壤解冻前期(R1)、土壤解冻中期(R2)、土壤解冻后期(R3)、草地返青期(R4)休牧及当地传统休牧(R5)5个休牧时期,测定秦艽根系生理特性。结果表明,秦艽根系中的可溶性蛋白随着休牧时期的推迟总体上先升高再降低,最终与R2、R3的可溶性蛋白含量相持平。淀粉含量和CAT活性在不同时期休牧下无显著性变化,可溶性糖、Pro、MDA含量和氧自由基产生速率随着休牧时期的推迟而增加,R5的可溶性糖、Pro、MDA含量和氧自由基产生速率分别比R1增加了49%、67%、54%和91%。SOD活性随着休牧时期的推迟先升高后降低,POD活性则表现出先降低后升高的变化趋势。综合对秦艽根系生理特性的分析,建议在土壤解冻前期(R1)进行春季休牧以保护野生秦艽资源。

Abstract:

In order to explore the effects of different periods of rest grazing on root physiological characteristics of Gentiana macrophylla,the following 5 treatments for rest grazing period were designed in alpine meadow in Tianzhu: soil pre-thawing stage (R1),soil mid-thawing stage (R2),soil late-thawing stage (R3),returning green stage (R4) and local traditional rest grazing (R5).By studying the root physiological characteristics changes of G.macrophylla under different grazing rest treatments,the optimum period for rest grazing was determined,which provided basic data for rational development and utilization of G.macrophylla resources in grassland.The results showed that the soluble protein content in roots of G.macrophylla showed a general trend of increasing first and then decreasing along with the rest grazing period.The starch content and CAT activity did not significantly change among different rest grazing treatments (P＞0.05).The contents of soluble sugar,Pro,MDA and the production rate of O2- increased with the rest grazing period.And the contents of soluble sugar,Pro,MDA and the production rate of O2- in R5 increased by 49%,67%,54% and 91% respectively compared with that in R1.The SOD content increased and then decreased with the rest grazing period,while the POD content showed a trend of decreasing first and then increasing.Based on the comprehensive analysis of root physiological characteristics,we suggest that grazing should be rested during the pre-thawing stage of soil (R1) to protect and restore wild G.macrophylla resources.