3种委陵菜对践踏胁迫的生长与生理响应

Study on growth and physiological responses of P.anserina,P.reptans var.sericophylla and P.reptans to trampling stress

摘要:

【目的】 为三种委陵菜的园林应用提供理论依据，为园林休憩绿地建设提供地被植物资源。 【方法】 以鹅绒委陵菜（Potentilla anserina）、绢毛匍匐委陵菜（P. reptans var.sericophylla）与匍匐委陵菜 （P. reptans）为试验材料，进行不践踏（CK）、轻度践踏（L）与重度践踏（H）3种梯度践踏后，测定植物的生长、生理及土壤指标，并进行相关性分析。【结果】 随着践踏的增强，土壤表现为容重与紧实度增加， 总孔隙度与非毛管孔隙度降低；3种委陵菜生长表现为地上部分株高、冠幅与生物量减少，地下部生物量减少、根数增加；生理指标表现为叶片相对电导率（REC）升高、过氧化物酶（POD）含量增加，丙二醛 （MDA）含量降低，叶片相对含水量（RWC）与叶绿素含量在绢毛匍匐委陵菜中降低，可溶性蛋白（SP） 含量在匍匐委陵菜中先升高后降低，在另外两种委陵菜中持续下降。相关性分析结果表明委陵菜冠幅与土壤容重、紧实度、水分呈负相关，与土壤总孔隙度、非毛管孔隙度呈正相关；地上、地下生物量与土壤紧实度、水分表现为负相关，与土壤总孔隙度呈正相关；根系构型特征与土壤紧实度、毛管孔隙度与水分存在相关性。【结论】 轻度践踏下，委陵菜通过增加根数，提高SP与POD含量，减少水分流，清除活性氧以应对胁迫；重度践踏下，其生长与生理活动均受到抑制，且短时间内难以恢复。综合生长生理响应与恢复情况，鹅绒委陵菜的耐践踏性较另外两种委陵菜强。上述研究结果也为园林中依据游客量与践踏频率因地制宜选择地被植物种类提供参考。

Abstract:

【Objective】 This study provided a theoretical basis for the garden application of three Potentilla spp. and provided groundcover plant resources for the construction of green gardens.【Method】 Potentilla anserina，P. rep- tans var. sericophylla and P. reptanswere used as experimental materials. After no trampling （CK），light trampling （L） and heavy trampling （H），wemeasuredThe growth，physiological and soil indexeswere measured，and correlation analysiswascarried out .【Result】 With the increase of trampling，soil bulk density and compaction increased，total porosity and non-capillary porosity decreased. The aboveground growth of three Potentillaspp. was characterized by a decrease inplant height，crown width and biomass，while subsurface growth was characterized by a decrease in biomass and an increase in the number of roots. Physiological indicators showed that leaf REC increased，POD content increased，MDA content decreased，leaf RWC and chlorophyll content decreased in P. reptans var. sericophylla，SP content increased first and then decreased in P. reptans，and continued to decrease inother two Potentilla spp. The results of correlation analysis show that crown width was negatively correlated with soil bulk density，compactness and water content，positively correlated with soil total porosity and non-capillary porosity. There was a negative correlation between above-ground and subsurface biomass，soil compactness and water content，and a positive correlation between above-ground and subsurface biomass and total soil porosity. There were correlations between root configuration and soil compactness，capillary porosity and water.【Conclusion】 Under light trampling，three Potentilla. spp. increased the number of fibrous roots，soluble protein and POD content to reduce water loss，clear reactive oxygen to cope with stress；however，both growth and physiological activities were significantly suppressed under heavy trampling，and difficult to recover in a short time. Based on the growth and physiological responses and recovery performance，the trampling tolerance of P. anserina is stronger than the other two. The above results also provided a reference forgroundcover plant selection according to visitor arrivals and trampling frequency in green gardens.