菹草的生活史、生物量和断枝的无性繁殖

LIFE HISTORY, BIOMASS AND CUT-BRANCH PROPAGATION OF POT AMOGETON CRISPUS L.

  • 摘要: 菹草是一种比较典型的秋季发芽、越冬生长的沉水植物。在夏季,多数植株衰败死亡,殖芽则落入水底进入夏季休眠期。春季是菹草群落生物量和生产力的高峰期。植株生物量的垂直分布属表层分布型。植株含水量从根部向枝顶逐渐减少,全株干物质含量的周年测定值平均为风干重=湿重×0.625。水温和植物发育阶段是影响断枝的生根、生长速度和殖芽形成的重要因素。在营养生长阶段,水温3—25℃范围内,断枝均能生根,断枝的相对生长速度为5.49—30.25毫克/克/天。断枝在殖芽形成期均能生长殖芽,但个体较小。

     

    Abstract: Life history, monthly changes of biomass, vertical distribution of biomass and nutritive value of Potamogcton crispus were studied during 1963—1964 and 1981—1983. The rooting, growth rate and turion formation of the cut branches of this species were also studied during the period.Potamogeton crispus is a submerged macrophyte which germinates in the autumn and grows throughout the winter. Turion forming period is from April to July; dormant stage of turion is from July to September, while turion germinating period is from September to next January. The maximun biomass occurs during April to May.The experimental cut-branches used for the study of rooting, growth rate and turion formation were 7—13 cm long and 0.5—4 g in fresh weight. They were suspended in water during the experiment. The period for the branches to reach 100% rooting was 29± 13 days during September to March, with the water temperature ranged 3—25℃. The relative growth rate of the cut branches was found to be 5.49—30.25 mg/g/day during turion forming stage.

     

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