Abstract: The compound leaf of Fraxinus sogdiana are imparipinnate,consists of 5-13 leaflets in common.By large sampling measurement,the relationship between the phenotypic plasticity on component biomass of different compound leaves of various number leaflets and the component biomass were analyzed.The results showed that compound leaves biomass of all samples of F.sogdiana were 0.146-1.663 g,the average biomass of compound leaves with 7 leaflets was the maximum (0.781±0.366) g and significantly higher than the others,with 5 leaflets was the lowest (0.260±0.060) g and significantly lower than the others.Rachis biomass was 0.016-0.179 g,and the average maximum and minimum were compound leaves with 13 and 5 leaflets,respectively,and both the others difference reached the significant level.Leaflets biomass was 0.006-0.886 g,the average maximum 7 leaflets and significantly higher than the others.Plasticity was greater and the variation coefficient was 22.8%-138% on component biomass of different compound leaves.Biomass allocation to the opposite leaflets of different compound leaves was symmetrical,biomass allocation of the top leaflets and the same phyllotaxis decreased with the increase of the leaflets number.The relationship among component biomass of different compound leaves included isomeric growth type of the linear function and algometric growth type of the exponent function.The relative growth rate of each component biomass during the process of growth could be described specifically by the parameters of correlation equation.

Key words: Fraxinus sogdiana, compound leaf, component biomass, biomass allocation, growth model, Yili, Xinjiang