草业学报2017，Vol.26Issue(10)：64-76,13.DOI:10.11686/cyxb2016506
遮阴和干旱对荩草光合特性影响的协同作用
Synergistic effects of shade and drought on the photosynthetic characteristics of Arthraxon hispidus
摘要
Abstract
The objective of this study was to clarify the synergistic effects of shade and drought on the photosynthetic characteristics of Arthraxon hispidus and to explore the resistance and ecological characteristics of this plant under shade and drought stress.Wild A.hispidus,a plant with potential use in sloping lawn development,was subjected to different 20 treatments,combining five shading intensities (0,10％,30％,50％,70％) and four drought intensities;sufficient moisture (W0),mild drought (W1),moderate drought (W2),and severe drought (W3).After 36 days of treatment,the leaf biomass allocation ratio,photosynthetic pigment content,light response ability,and photosynthetic parameters were determined.The extent of shade and drought and the synergy between shade and drought significantly affected the area,number,biomass,and allocation ratio of A.hispidus leaves (P＜0.05).Shade and drought had a strong synergistic effect on leaf area,number,biomass,and biomass allocation ratio (P＜0.01),with the strongest effect on the allocation ratio,followed by leaf number,leaf area,and then leaf biomass.Shade,drought,and the synergy between shade and drought also significantly affected the contents of chlorophyll a (Chla),chlorophyll b (Chlb),Chla+b,and Chla/b (P＜0.05).The Chlb content was more sensitive to habitat than was Chla content.Compared with drought,shade had stronger effects on chlorophyll content and photosynthetic rate.Shade and drought had significant synergistic effects on Chlb,Chla+b,and Chla/b (P＜0.05).Shade,drought,and the synergy between shade and drought had highly significant effects on the light response capability (P＜0.01).Shade and drought had significant synergistic effects on the light saturation point (LSP),light compensation point (LCP),and maximum net photosynthetic rate (Pnmax),with the strongest effect on Pn max followed by LSP and then LCP.Shade,drought,and the synergy between shade and drought significantly affected the photosynthetic rate (Pn),transpiration rate (Tr),intercellular CO2 concentration (Ci),and stomatal velocity (Gs) (P＜0.05).Shade and drought had a strong and significant synergistic effect on photosynthetic parameters (P＜0.01).Shade mainly affected Pn,drought main affected Gs,Ci,and Tr,and their synergy mainly affected Tr,Shade of 30％ or less reduced the size of the decrease in Pn,Tr,Ci,and Gs caused by drought,but shade of more than 30％ exacerbated these decreases.Compared to each single stress,the synergistic effect of shade and drought increased the photosynthetic leaf area and chlorophyll content and altered the light response ability and photosynthetic parameters of A.hispidus.These changes contributed to the stress resistance and ecological adaptation of A.hispidus.关键词
荩草/遮阴/干旱/光合特性/协同作用/生长策略Key words
Arthraxon hispidus/shade/drought/photosynthetic characteristics/synergy/growth strategy引用本文复制引用
谢瑞娟,张小晶,刘金平,游明鸿,伍德..遮阴和干旱对荩草光合特性影响的协同作用[J].草业学报,2017,26(10):64-76,13.基金项目
四川省植物资源共享平台(TJPT20160021)和四川省科技支撑计划(2011NZ0064)项目资助. （TJPT20160021）
