Comparative Morphological, Anatomical and Physiological Analyses Explain the Difference of Wounding-Induced Agarwood Formation between Ordinary Agarwood Nongrafted Plants and Five Grafted Qi-Nan Clones (Aquilaria sinensis)

Agarwood is the dark resinous heartwood of injured ordinary Aquilaria sinensis (OA). Recently, some new clones A. (Qi-Nan) that intensively produce high-quality agarwood were selected and cultivated by grafted clonal seedlings. However, very little known about their formation mechanism, it unclear whether current method distinguishing Qi-Nan from OA observing its leaf apparent morphology scientifically reliable. In this study, differences between in correlation with morphological, anatomical physiological characteristics investigated two types trees. After mechanical injury, yield essential oil content significantly higher than OA. There was no significant difference shape parameters OA, but showed specific weight, total chlorophyll, nitrogen net photosynthetic rate. A xylem analysis had smaller vessel wall thickness, greater ray cell thickness larger interxylary phloem area Moreover, a consumption non-structural carbohydrates positive correlations capacity, cell, area, starch utilization rate trees, negative brief, has stronger basis to supply more carbon sources, efficient structural for production source rate, leading content. It not reliable distinguish simply morphology.