In order to identify major metabolic components involved in the regulation of superior clonal seedling’s growth ofPopulus davidiana, we compared various clonal growth parameters (total dry weight, stem dry weight, and leaf dry weight) withthe levels of metabolites in either leaf or stem of the corresponding rooted cutting seedlings. In leaf tissues, the contents ofsugars, including glucose, sucrose, and inositol were significantly correlated with stem dry weight. In contrast, the levels of aminoacids in stems, glutamic acid, alanine, and threonine, were correlated with leaf dry weight. Leaf tissues of superior clonescontained sugars at least 1.3-fold higher than regular clones, while stem tissues accumulated 1.2-fold higher levels of amino acidscompared to regular clones. In addition, superior clones accumulated higher amount of metabolites in tissue-dependent manner;i.e. rythronic acid, malic acid, and petanedioic acid in leaves, and succinic and maleic acid in stems. In conclusion, our resultsshowed that clonal growth performance of P. davidiana was correlated with different types of metabolites in tissue-dependentmanner, suggesting that tissue-dependent metabolic profiling might be a prerequisite process for identifying metabolic markersfor growth traits of P. davidiana.
