A comparative study of growth and leaf trait variation in twenty Cornus wilsoniana W. families in southeastern China

To investigate the genotypic differences associated with the growth potential and leaf traits of Cornus wilsoniana W., we planted twenty C. wilsoniana families in southeastern China and analyzed nineteen leaf morphological and physiological traits that have potential relationships with growth. Seedling growth and leaf traits exhibited high variability among the C. wilsoniana families. The phenotypic coefficients of variation (CVs) of these traits varied from 5.33% (leaf length/leaf width, LL/LW) to 23.17% (stomatal conductance, gs), and their heritabilities (H-2) ranged from 0.17 (chlorophyll a/chlorophyll b, Chl(a)/Chl(b)) to 0.75 (stem height, H and Chl(a)). There was greater genetic variation in the physiological traits than in the morphological traits. H was significantly positively correlated with instantaneous water use efficiency (WUE), Chl(a), Chl(b) and total Chl, and diameter (D) was significantly positively correlated with net photosynthetic rate (P-n), g(s), WUE, Chl(a), Chl(b) and total Chl and was negatively correlated with leaf phosphorus (LP). Based on cluster analysis, three families were selected as superior families for the study area due to their seedling growth and leaf traits. These results indicate that Pn, Chla, Chlb and total Chl are good indicators to use for selecting superior families of C. wilsoniana with better growth performance; additionally, high WUE and low LP are also critical leaf traits for cultivar selection because plant adaptation to environmental conditions is important for growth performance.