黑暗完全水淹环境下植物的生长与碳水化合物消耗——以三峡库区消落带植物狗牙根和牛鞭草为例

Growth and Carbohydrates Consumption of Plants during Dark Complete Submergence:a Case Study of Cynodon dactylon and Hemarthria altissimain Hydro-fluctuation Belt of Three Gorges Reservoir Area

【目的】明确三峡库区消落带植物狗牙根(Cynodon dactylon)和牛鞭草(Hemarthria altissima)在黑暗完全水淹环境下的生长状态和碳水化合物的储备与消耗情况。【方法】实验设置黑暗完全水淹处理30,60,90,120,150,180,210,240d共8个时间水平,研究了两种植物在黑暗完全水淹环境下的存活、生长和碳水化合物的储备与消耗情况。【结果】狗牙根和牛鞭草经历黑暗完全水淹处理240d后,都表现出较强的耐淹能力。水淹240d后2种植物存活率分别为100%和96.7%;水淹处理开始前,狗牙根茎和地下部分的碳水化合物储备分别高于牛鞭草茎和地下部分的碳水化合物储备,且差异具有统计学意义(p<0.05);黑暗完全水淹环境下,狗牙根叶与茎的生长与死亡响应比牛鞭草快;黑暗完全水淹环境下,牛鞭草植株新生比率大于狗牙根植株新生比率,且差异具有统计学意义(p<0.05);黑暗完全水淹240d后,狗牙根和牛鞭草水淹前已有的叶全部死亡,狗牙根水淹前已有的茎和地下部分的碳水化合物浓度剩余率都分别高于牛鞭草水淹前已有的茎和地下部分的碳水化合物浓度剩余率,且差异具有统计学意义(p<0.05)。【结论】狗牙根较高的碳水化合物储备及快响应、低生长的节约策略导致该物种拥有较高的碳水化合物浓度剩余率,耐淹能力比牛鞭草更强。

[Purposes]It aims to definite growth and carbohydrates consumption of Cynodon dactylon and Hemarthria altissima inhydro-fluctuation belt of Three Gorges reservoir area under dark complete submergence.[Methods]Dark complete submergence treatment and 30,60,90,120,150,180,210,240 days time point were set up for this experiment.And 2 species＇ survival,growth,carbohydrates storage and consumption were researched.[Findings]After 240 days＇ dark complete submergence,the survival ratesof C.dactylon and H.altissima are 100% and 96%,respectively.The carbohydrates storage of C.dactylonin stems and underground parts are significantly more than those of H.altissima before submergence treatment,respectively（p〈0.05）.Under dark complete submergence environment,the growth and death responses of C.dactylon are faster than H.altissima.New organ rate of C.dactylon which generated during submergence is significantly more than H.altissima（p〈0.05）.After 240 days＇ dark complete subergence,two species＇ old leaves have all dead,the residual rates of carbohydrates in stems and underground parts of C.dactylon are significantly higher than those of H.altissima,respectively（p〈0.05）.[Conclusions]The high carbohydrates storage of C.dactylon and its fast response,low growth cost-saving strategy to save carbohydrates cause its high residual carbohydrates rate,which lead to its higher submergence resistance ability than H.altissima.