Abstract:

Sixty oneyearold saplings of poplar I107（Populus × euramericana cv. “74/76”） which were divided into five groups were planted in spring and artificially inclined at the angles of 0°,15°,30°,45°and 60° from the vertical. The samples were collected from secondary xylem three months later, and then anatomical characteristics of wood which separated as tension wood area（TW）and opposite wood area（OW）were analyzed, the following conclusions were drawn:1）Along with the increase of inclined angles, the eccentric and woolly area proportion became obvious, the shape of cross section changed from round to ellipsoidal, the eccentric growth and woolly area percent became bigger. The ANOVA results revealed that there were significant effects of inclined angle on eccentric and woolly proportion. 2）Characteristics of cross section view of tension wood were:the number of vessels decreased and the diameter of vessels increased along with the increase of inclined angle, the thickness and number of gelatinous increased；the surface of lumen became wavy and the shape of lumen became irregular. 3）Fiber length, width and double wall thickness fluctuated with the increase of inclined angle, the fiber length of TW were shorter than that of OW, the double wall thickness of TW were thicker than that of OW, The width didn’t present different between TW and OW. The ANOVA results revealed that there weren’t significant effects of inclined angle on fiber length；width and double wall thickness, but there were significant effects of tree and area on fiber length, width and double wall thickness. 4）Gfiber proportion of TW increased with inclined angle, other proportions didn't change obviously with inclined angle, The ANOVA results revealed that there weren't significant effects of inclined angle on tissue proportions；there were significant effects of tree and area on tissue proportions.

Key words: poplar clone I-107, seedling, artificial inclination, tension wood, anatomical characteristics