Tracheid morphology characteristics and microfibrillar angle and their variation patterns of Larix gmelinii.

In this paper,4 trees aged 20-year-old of Larix gmelinii(Rupr.)from Fang-Zheng forest station in Harbin city of Heilongjiang Province were selected as the materials.The tracheid length and width,ratio of length to width,ratio of the cell wall to lumen and mircrofibrillar angle were measured,and their variation patterns were analyzed.The results show that:(1)The average tracheid length is 2125.43 μm,the average tracheid width is 35.06 μm,the average ratio of length to width of wood tracheid is 60.67,the average ratio of cell wall to lumen of wood tracheid is 0.33 and the average mircrofibrillar angle of wood tracheid is 27.37 °.The fiber of Larix gmelinii belongs to the long fiber,which is suitable for the pulp and paper fiber raw materials.(2)The average tracheid length ranges from 2259.25 μm to 2032.25 μm,the average tracheid width from 36.08 μm to 34.01 μm;the average ratio of length to width from 64.81 to 56.39;the average ratio of cell wall to lumen from 0.3916 to 0.2917 and the average mircrofibrillar angle from 27.03 ° to 27.97 °.The analysis of variance show that the difference of tracheid morphological characteristics and microfibrillar angle among different trees is not significant.(3)The radical variation pattern of tracheid length belongs to the type of Panshin II;The tracheid width and the ratio of tracheid length to width increase gradually from pith to bark;The ratio of the cell wall to lumen increases from pith outward with fluctuation and the mircrofibrillar angle decreases gradually.