The leaves of c . smyrnioides had been yellow in the end of april and the overground part of the plant had been blasted in the first of may . but at the same time , it just turned yellow for saturation treatment . and a . sylvestris and c . violaceum have similar tendency , that is , the plant in drought treatment blasted earlier than in saturation treatment 受到干旱胁迫的明党参植株在4月中旬叶片就已开始发黄， 5月中旬地上部分已枯萎，而此时饱和水分条件下植株的叶片刚开始变黄，川明参和峨参均与明党参相似，干旱条件下植株的枯萎时间均早于饱和条件下。
Based on the research of photosynthetic carbon assimilation in natural habitat , the physiecological features of net photosynthesis ( pn ) and growth of changium smyrnioides wolff and anthriscus sylvestri ( l . ) hoffm were measured under controlled soil water status ( saturation status ( ss ) , moderate status ( aw50 ) and dry status ( aw20 ) ) , the difference of photosynthesis and transpiration to environmental factors and the adaptation to environmental fluctuation compared , to analyze the mechanism of c . smyrnioides to be endangered 本文在对野外自然条件下濒危植物明党参( changiumsmyrnioideswolff )和非濒危植物峨参光合碳固定能力测定的基础上，研究了在控制土壤水分条件下明党参、峨参和另外一种濒危植物川明参( chuanminshenviolaceum )的光合和生长特点，比较它们的光合、蒸腾等对光照、温度等环境因子响应及对环境变化适应能力的差异，分析了明党参濒危的原因和机理。
2 . all the corresponding parameters of a . sylvestris were similar with c . smyrnioides in procreate period in april . but the parameters of root length , diameter of root , volume of root , leaf biomass , root biomass , total biomass , root mass ratio ( rmr ) and sla had the maximal value in moderate treatment in vegetative period in january 峨参的相应生长参数在4月生殖生长期与明党参随土壤水分的变化趋势相似；但在1月份的营养生长期，根长、根粗、根体积、叶生物量、根生物量、总生物量、 rmr和sla均以中度水分条件最大。
For c . violaceum , it is moderate treatment that all the corresponding parameters have the maximal value . but it still was maximal for leaf biomass , lar , ramose number of stem , stem biomass and umbrella number of flower . and the rgr of drought treatment in january exceeded the saturation treatment largely , but the difference among treatments was small in april 川明参与明党参和峨参相应的生长参数基本以中度水分条件下最大，但叶生物量、 lar 、葶分枝数、葶生物量和花伞数仍以饱和水分条件下最大；而1月份干旱条件下的rgr远高于其他两种水分条件， 4月份则相差很小。
The paper studied the growth of endangered plant changium smyrnioides wolff and its comparison plant anthriscus sylvestri ( l . ) hoffm and chuanminshen violacewn in different soil water from physioecology and analyzed the effect resulted of soil water and the difference of model and size of plasticity of three species 本文从生理生态学的角度研究了濒危植物明党参及对照植物峨参和川明参在不同土壤水分条件下的生长，探讨水分对三物种生长的影响及植物的可塑性响应方式。
3 . c . smyrnioides displayed larger plasticity of photosynthesis and growth than a . sylvestri to soil water status changes : the decline extant of c . smyrnioides in dry water status is higher than those of a . sylvestri . the photosynthesis of one - year - old c . smyrnioides decreased 25 - 35 % in dry water status , a . sylvestri decreased 15 - 25 % ; the two - year - old decreased 70 - 80 % and about 30 % respectively 明党参在从中度湿润到干旱条件下光合下降的幅度高于峨参，一年龄明党参在于旱比中度湿润条件下光合下降了25 - 35 ，峨参则下降了15 - 25 ；二年龄明党参在干旱条件下光合下降了70 - 80 ，峨参下降了30左右。
Under controlled soil water status , the theoretical water niche of c . smyrnioides was saturate and moderate soil water status ; chuanminshen violaceion was moderate , while a . sylvestri was the most broad , and adapted well from saturation to 20 % water sattus . the photosynthesis of one - year - old and two - year - old c . smyrnioides was higher in saturate and moderate than that of in dry , the recovery of photosynthesis in dry condition was weak when they watered to saturation . the photosynthesis of one - year - old c . violaceum was higher in moderate than in two others ; two - year - old was higher in saturate and moderate than in dry , the former two had little difference 一年龄和二年龄明党参在饱和和中度湿润条件下的光合显著地比干旱条件下大，并且在胁迫去除后，干旱条件下的明党参恢复能力弱；一年龄川明参在中度条件下光合最大，二年龄川明参在饱和和中度条件下最大，二者没有显著的差异，胁迫去除后恢复能力较明党参强；一年龄峨参饱和和中度水分条件下较干旱高，二年龄峨参则中度条件下最高，干旱条件下光合下降的幅度较小，并且胁迫去除后的恢复能力较强。
Height , crown amplitude , size of leaves and leaf number of a . sylvestris were the largest among three species , and c . smyrnioides ' s were the lest . but it was c . smyrnioides that had the 气 largest rmr , srl , rlr and rgr , and it was c . violaceum that had the minimal value . biomass of leaf , root and total plant were always maximal for c . violaceum and minimal for c . smyrnioides 三物种的株高、冠幅、叶片形态大小和叶片数目均以峨参最大，明党参最小； rmr 、 srl 、 rlr 、 rgr以明党参最高，川明参最低；根叶生物量始终以川明参最高，明党参最低；而sla则以峨参最大，川明参最小。
