银杏与叶籽银杏枝丫材管胞径向变异趋势

以泰山老君堂1300年生银杏和中国发现的第1株800年生叶籽银杏木材为试材，对其管胞性状指标的径向变异趋势进行研究。结果表明：叶籽银杏枝丫材的管胞双壁厚、径向直径、弦向直径、管胞长度均大于银杏，而银杏的壁腔比大于叶籽银杏，两者的微纤丝角相差不大；两者枝丫材自髓心向树皮的径向变异规律为：双壁厚、径向直径、弦向直径、管胞长度均呈增长趋势，应压木壁腔比为增长趋势，对应木壁腔比则为下降趋势，微纤丝角为下降趋势。

The Radial Variation in Crotch Tracheid of Gingkgo biloba and Ginkgo biloba var. epiphylla

The tendency of radial variation in tracheid indexes of a 1 300 years old Gingkgo biloba growing in Laojuntang of Mount Tai and a 800 years old Gingkgo biloba var. epiphylla which was found number one in China was studied with crotch material. The results showed that the double wall thickness, radial diameter, ehordwise diameter and the length of Gingkgo biloba vat. epiphylla traeheid were greater than that of Gingkgo biloba , while the ratio of wall to cavity of Gingkgo biloba was greater than Gingkgo biloba var. epiphylla, there was no significant difference in mierofibril angle between these two trees. It was showed that the double wall thickness, radial diameter, chordwise diameter, tracheid length increased from the pith to bark. The ratio of wall to cavity in the compression wood increased from pitch to bark, while it decreased in the opposite wood, and the microfibril angle decreased from pith to the bark.