水分条件对灰化苔草根茎萌发及幼苗生长的影响  

Effects of Soil Moisture Regime on Rhizomatic Germination and Young Shoot Growth of Carex cinerascens

作　　者：杨阳[1,2] 曹昀[1,2] 张素娟[2] 

机构地区：[1]鄱阳湖湿地与流域研究教育部重点实验室,江西南昌330022 [2]江西师范大学地理与环境学院,江西南昌330022

出　　处：《生态与农村环境学报》2015年第2期180-187,共8页Journal of Ecology and Rural Environment

基　　金：国家自然科学基金(41361017);江西省自然科学基金(20142BAB204006)

摘　　要：以灰化苔草（Carex cinerascens）根状茎为试验材料,采用室内盆栽培养方式,测定不同土壤水分条件下灰化苔草根状茎萌发、幼苗生长形态和生理参数。试验设置8个土壤体积含水量梯度：C1（2%,重度干旱）、C2（10%）、C3（15%）、C4（20%）、C5（25%）、C6（30%）、C7（40%,水分饱和）和C8（51%,淹水水深为2 cm）。结果表明：（1）在重度干旱和淹水条件下灰化苔草根状茎萌发率较低;轻度干旱（C2处理）条件下萌发率虽达100%,但C2处理幼苗平均株高仅为最大值（C6处理）的2/3。灰化苔草幼苗平均株高、地上生物量均呈随土壤含水量增加而先增大后减小的趋势,幼苗株高与地上生物量之间存在指数函数关系;（2）灰化苔草叶长、叶宽、叶片数和叶面积总体也呈先增大后减小趋势;灰化苔草幼苗通过个体变小、叶片数和叶面积减少、生长速率减缓等调节自身组织结构特点以利用有限的水分维持生命活动。（3）灰化苔草幼苗叶片叶绿素（Chl a、Chl b）含量、相对叶绿素含量（SPAD）、类胡萝卜素（Car）含量具有相同的变化规律,即随土壤含水量的增加而呈先增大后减小的变化趋势;叶绿素a/b比值随土壤含水量的增加而呈先减小后增大趋势;各处理间灰化苔草叶片含水量、Car/Chl比值无明显差异;灰化苔草幼苗叶片在水分缺乏或过多时通过使Chl a/b比值升高、Car/Chl比值保持稳定、合理分配Chl a和Chl b来确保植物能正常地进行光合作用;（4）利用高斯模型定量分析得出灰化苔草根状茎萌发及幼苗生长的水分生态幅在4.15%~51.35%范围内,最适含水量在16.22%~39.55%之间。An indoor pot experiment was carried out cultivating Carex cinerascens using rhizomes to explore effects of soil moisture regime on rhizomatic germination,growth of young shoots and physiological features of the plants. The experiment,lasting 60 days,was designed to have 8 water treatments,i. e. C1（ severe drought 2%）,C2（ 10%）,C3（ 15%）,C4（ 20%）,C5（ 25%）,C6（ 30%）,C7（ 40%,water saturation） and C8（ 51%,flooded with 2-cm-thick overlying water）.Results show：（ 1） Rhizomatic germination rate of the plant was low in Treatments C1 and C8 and reached 100% though in Treatment C2,where the young shoots were only 2/3 of those in Treatment C6,the maximum in mean plant height. Average height and aboveground biomass of the young shoots increased first and then decreased as the soil water content increased,and an exponential relationship was observed between height and biomass of the shoots;（ 2） Length,width,area and number of the leaves displayed a similar trend,increasing first and then decreasing as the soil water content increased except for Treatment C4. The plants adapted themselves to variation of soil water content by regulating their plant size,leaf area,number of leaves and growth rate for survival;（ 3） Contents of Chl a,Chl b,SPAD and Car in young shoots also followed the same trend in variation,increasing first and then decreasing as soil water content increased,but Chl a/b ratio did a reverse trend,decreasing first and then increasing as soil water content increased; The 8 treatments did not differ much in leaf water content and Car/Chl ratio; Under water stress（ too much or too little）,the plants raised Chl a/b,maintained Car/Chl and rationalized distribution of Chl a and Chl b,to guarantee norm al photosynthesis process;（ 4） Quantitative analysis using the Gaussian Model shows that the ecological amplitude of water content for rhizomatic germination and growth of young shoots of Carex cinerascens was in the range of 4. 15%- 51. 35%,and the optimum water content

关 键 词：灰化苔草 土壤水分 萌发 幼苗生长 生态幅 

分 类 号：Q948[生物学—植物学]