Provenance variation in growth, stem-form, and wood basic density of 24-year-old Liriodendron

We studied phenotypic variation among provenances of Liriodendron at near-mature stage to identify those with the most desirable traits for production. To provide a scientific basis for the selection of superior provenances of Liriodendron, a provenance trial was established with five provenances of Liriodendron tulipifera and 15 provenances of Liriodendron chinense. This trial was established in 1992 at the Subtropical Experimental Center in the Chinese Academy of Forestry. The growth, stem-form qualities, and wood basic density of each provenance were investigated in December 2015. The findings indicated that the growth traits of Liriodendron possess significant genetic differences in terms of interaction between provenance and site. Analysis of growth related traits revealed that the choice of fast-growing provenances might improve trunk straightness but decrease the wood basic density. Ring width variance analysis showed that the variation coefficients increased for ring width of four 5-year ring segments between provenances, but the width decreased from pith to cambium, which suggested genetic improvement of wood productivity and density could be realized by provenance selection. Monan (MN) of Guizhou Province and Fuyang (FY) of Zhejiang Province were selected as two high-yield and high-quality provenances based on the analysis of radial variation patterns.