关键词: 土沉香, 叶片解剖特征, 生物量分配, 光照强度, 适应性

Abstract: In order to understand the light requirement and adaptability of Aquilaria sinensis（Lour.） Spreng， seedlings morphology and leaf anatomical characteristics of Aquilaria sinensis seedlings under different light treatments （100%， 50%， 25% and 5% natural light） were studied. The results showed that different shade treatments had different effects on the leaf anatomical structure and seedling growth parameters of three Aquilaria sinensis provenances （Dabai， Dahuang and Yunnan）. For all the three provenances， with the weakening of light intensity， the main veins， leaf thickness， palisade tissue thickness and leaf epidermal cells were generally decreased significantly （P<0.05）， the thickness of spongy tissue increased， and the lower leaf epidermis cell thickness showed varying change degrees. With the decrease of light intensity， leaf area ratio and leaf area increased in all the three provenances. For Yunnan provenance， the total biomass and absolute growth rate decreased as light intensity decreased， but for Dabai and Dahuang， growth parameter values under 50% and 25% light intensity were higher than that under 100% and 5% light intensity. The specific leaf weight and root weight ratio generally showed decrease trends with the decrease of light intensity in all the three provenances， except that the specific leaf weight of Dahuang in 50% light intensity was higher than other light treatments. In short， the seedlings of three Aquilaria sinensis provenances could make a series of changes in morphology to adapt to the light environment; Yunnan provenance had the best growth in natural light （100%），while Dabai and Dahuang were more suitable in moderate light intensity（50%）.

Key words: Aquilaria sinensis（Lour.） Spreng., leaf anatomic characteristics, biomass allocation, light intensity, adaptability