摘要
为研究不同水位上升速度对黑藻生长的影响,本研究采用吊盆悬挂方式模拟不同水位上升速度,将栽种黑藻的吊盆以不同的速度(10、30、50和70 cm/5 d)往下降,分别记为T1、T2、T3、T4实验组.实验共进行80 d.结果表明:不同水位上升速度对黑藻株高影响极显著,各组株高排序为T3组>T2组>T1组>T4组.T2、T3组株高与稳定组差异不显著;T3组株高生长速率达3.7 cm/d;而T4组在实验第49 d完全死亡.水位上升对黑藻分枝数影响显著,分枝数随水位上升速度增大呈递减趋势,且明显少于稳定组.不同水位上升组茎节数、叶片数和节间距均差异显著.随着水位上升速度增加,黑藻茎节数先增后减,叶片数变少,而节间距不断延长;与稳定组相比,茎节数和叶片数减少,而节间距显著延长.水位上升速率增加,黑藻生物量呈递减趋势且差异极显著,水位上升降低了黑藻生物量.黑藻有较强的应对水位上升的能力,其通过改变植株形态,以最大限度地获取光照;但在适应水位上升过程中消耗了一部分光合作用形成的物质,从而使生物量下降.黑藻对水位上升有一定的耐受范围.当水位上升达到70 cm/5 d时,黑藻因无法适应低光照胁迫而死亡.
Growth responses of Hydrilla verticillata to increasing water levels were examined in this experiment. The plants were cultured in pots, which were submersed in water and dropped downward the lake bottom at different speeds. The results show that different rising rates of water level had significant influence on the stem lengths, which were 50 cm/5 d 〉 30 cm/5 d 〉 10 cm/5 d 〉 ？0 cm/5 d. However, no obvious differences in the stem length were found between the groups of 10, 30 cm/5 d and control groups. At the group of 50 cnr/5 d, the growth rate in stem length rose at 3.7 cm/d; however, the group of 70 cnr/5 d died at the 49th day. Besides, the rising of water level also significantly affects the number of branches of H. verticiUata. Comparing to the control groups, went up, the node number of H. verticiUata declined with the rising water level rates. Obvious differences were found in the number of nodes, leaves and length between different water level rising rates groups. With the water level rising rate increased, the number of nodes followed the trend of increasing first and then declined ; numbers of leaves became fewer and the node spacing extended. Compared with the control group, the numbers of nodes and leaves are less, and the node spacing en- larged. With increasing of the rising rates of water level, its biomass declined and the differences were extremely significant. These indicated that, to get as much sunlight as possible, H. verticillata changes the plant morphology and reduces the biomass to adapt to the rising water. However, owing to the inability to accommodate itself to the stresses caused by the lack of sunlight, it would die under the water rising to 70 cm/5 d.
出处
《湖泊科学》
EI
CAS
CSCD
北大核心
2012年第3期384-390,共7页
Journal of Lake Sciences
基金
国家自然科学基金项目(40873057)资助
关键词
黑藻
水位
生长
植株形态
Hydrilla verticillata
water level
growth
plant morphology
