Morphological variance and natural types' division of plus trees ofLarix principis-rupprechtii Mayr.

Abstract

The phenotypic characteristics of the plus trees ofLarix principis-rupprechtii such as stem form, branch angle, branch/stem ratio, branch density, the crown width, crown length, number of short branch over 5-cm branch segment in length, and the leaf number of each short branch were investigated in seed orchard in the Changcheng Mountain, Shaanxi Province. According to the morphological characters, the plus tree clones ofLarix principis-rupprechtii were classified into 4 natural types: the narrow-dense-crown type, wide-dense-crown type, wide-sparse-crown type, and the narrow-sparse-crown type. The result of the cluster analysis showed there was a very significant difference in tree growth among the four natural types. While comparing the tree growth of four natural types for the last ten years, it was found that the performance order of various types from good to bad is as follows: the narrow-dense crown type > the wide-dense crown type > the wide-sparse crown type > the narrow-sparse crown type. The plus trees of narrow-dense-crown, as a fine type, should be paid great attention to production and prepared to popularize.

Keywords

Larix principis-rupprechtii / Plus tree / Natural types / Morphological variance / S791.22.01 / S718.42 / B

References

[1] Shunchang Chui Characteristics of Shaanxi forest plant flora [J]. Shaanxi Forestry Science and Technology, 1985, 1: 8-10.

[2] Nanjiing College of Forest Product Industry Genetic Breeding [M], 1980 Beijing: Science Press 5-13.

[3] Shuwen Xu Resource of tree species quality and division of Shaanxi Province [M], 2000 Beijing: China Forestry Publishing House 125-123.

[4] Xinbo Zhang A Preliminary Investigation into Natural Types ofPinus tablaeformis Seed Forest [J]. Shaanxi Forestry Science and Technology, 1993, 4: 10-12.