垂直切根对当年羊草构件及繁殖资源分配的影响

Effect of root cutting on the components and reproductive allocation of Leymus chinensis

为探究羊草(Leymus chinensis)在外界环境干扰下的繁殖分配,本研究在羊草不同发育时期(返青期、孕穗期、抽穗初期)进行不同间距(10、20、30cm)的切根处理,对羊草叶、茎、穗、根茎的生物量以及营养元素含量(全氮、全磷)、能量累积和繁殖分配进行比较分析。结果表明,切根对羊草穗的生物量、全氮、全磷、能量等资源的繁殖分配影响显著(P<0.05),同一时期切根,羊草穗的繁殖分配表现为切根间距30cm>20cm>10cm;同一切根间距,羊草穗的繁殖分配为:抽穗初期>孕穗期>返青期;切根后羊草叶、茎、穗的全氮含量显著升高(P<0.05)。返青期切根间距10cm处理羊草根茎的资源分配比例增加,促进了羊草的无性繁殖,而抽穗初期切根间距30cm羊草穗的繁殖分配比例增加,是利于羊草有性繁殖的最佳切根处理。综上所述,垂直切根可以影响羊草繁殖分配,羊草的繁殖分配是其应对环境干扰的重要调节机制。

To investigate the reproductive allocation of Leymus chinensis under the interference of the external environment,root cutting treatments with10,20,and30cm spacing were conducted at different growth periods(regreening,booting,early heading).The biomass of leaves,stems,panicles,and rhizomes and total N and P content were measured.Results showed that root cutting significantly influenced the reproductive distribution of panicle biomass,total N,and total P.Within the same growth period,panicle reproductive distribution was highest in the30cm treatment and lowest in the10cm treatment.Within the same root cutting treatment,reproductive allocation of L.chinensis was highest for early heading and lowest for regreening growth periods.Total N content of L.chinensis leaves,stems,and panicles was significantly higher after root cutting(P<0.05).In the10cm root cutting treatment,the proportion of rhizomes increased because of the initiation of asexual reproduction.The proportion of panicles increased under the30cm root cutting treatment,indicating that this was the optimal spacing for sexual reproduction of L.chinensis.Results of this study show that vertical root cutting affects the reproductive distribution of L.chinensis and is therefore an important regulation mechanism in response to environmental disturbance.