松嫩平原全叶马兰种群不同龄级分株的生长策略

Growth strategies of different age classes of ramets in Kalimeris integrifolia population at the Songnen Plains of China

全叶马兰为根蘖性多年生草本菊科植物 ,种群由 3个龄级无性系分株组成 .在松嫩平原 6月份 ,是全叶马兰营养生长的旺盛期 .研究结果表明 ,分株的生长与生产力以 1龄级最低 ,2、3龄级依次增高 .3个龄级分株的生物量分配均为茎 >叶 >主根 .叶的生物量分配为 1龄级 >2龄级 >3龄级 ,茎和主根的均为 1龄级 <2龄级 <3龄级 .3个龄级分株总重与分株高度、分株叶重与茎重、分株主根重与枝条重之间均为幂函数异速生长规律 ,主根的生物量分配则随着分株高度的增加呈线性减少 .全叶马兰无性系分株的生长与分配策略是在分株幼小时将较多的物质分配给叶 ,以保证物质生产器官叶的建造上 ,随着分株生长逐渐将生产的物质分配到茎和主根的生长与贮藏 ;分株不向主根投入较多的能量 ,但在分株幼小时向主根中分配的物质相对较多 ,随着分株的生长则按比例较小 。

As a perennial forage,Kalimeris integrifolia Turcz. Ex DC is a species of Compositea clone plant,which has a high potential in vegetative propagation by root crowns. Its population was constructed by three age classes of ramets. In the Songnen Plains,the middle ten days of June is the more vigorous vegetative growth period of the clone ramets. The results showed that the capabilities of ramet growth and production were the lowest in the 1st age class,and heightened in the 2nd and 3rd age classes. Biomass allocations were the most in stem,more in leaves,and the least in taproot of three age classes of ramets. The biomass allocation in leaves was the most in the 1st age class,more in the 2nd age class,and the least in the 3rd age class,but those in stem and in taproot were all the least in the 1st age class,lesser in the 2nd age class,and the most in the 3rd age class. The relationships between total weight and height,leaf weight and stem weight,and taproot weight and shoot weight of clone ramets were all power function,but the biomass allocation in taproot was linearly decreased with height increase in three age classes. The strategies of growth and biomass allocation of the population ramets were:1) the biomass allocation in leaves was more in the young period to ensure the productive organ constructed continuously,and hence,more productive material was gradually allocated in stem and taproot with the growth of ramets,2) the energy allocation of ramets was less in taproot,but the biomass allocation in taproot was relatively more in young period,and then,the prorate decreased with ramet growth,and the ratio kept relatively steady.