Comprehensive selection of the wood properties of Paulownia clones grown in the hilly region of southern China

Abstract

The wood properties of Paulownia clones determine their ultimate price and uses. This study selected superior clones with good color and mechanical properties using selection indexes. Variation in 23 5-year-old Paulownia clones was analyzed using genetic parameters, correlation analysis, and a comprehensive assessment of two color characteristics [color difference (ΔE) and whiteness (WH)] and six mechanical properties [density (ρ), hardness of the tangential, radial, and end surfaces (Ht, Hr, and He), and cleavage strength of the tangential and radial surfaces (qt, qr)]. There were significant differences (p < 0.01) in each of the eight traits among the 23 clones. There were significant negative phenotypic and genetic correlations between ΔE and WH. The six mechanical properties were significantly positively correlated genetically, showing significant positive phenotypic correlations with each other, except for ρ, Ht, and qt. With a selection rate of 8.70%, clones MB04 and L01 were selected as superior using the comprehensive selection index. Compared with the control (9501), the genetic gains of clones MB04 and L01 in ΔE, WH, ρ, qr, qt, He, Hr, and Ht were 0.40, 0.21, 10.32, 12.57, 14.81, 26.05, 28.04, and 6.84%, respectively, and the actual gains were 0.59, 0.31, 17.21, 28.45, 28.09, 34.90, 40.08, and 11.12%.

Genetic Parameters and Genotype–Environment Interactions in Paulownia Clonal Tests in Temperate and Subtropical Regions of China

“…As shown in Figure 4B, the four clones (16,17,11, and 10) that were farthest from the origin were connected, and the polygon was divided into four sectors. The 20 clones tested were distributed within these sectors.…”

“…The genus Paulownia is native to China and is among the fastest-growing broad-leaved deciduous species in the world. Paulownia species are widely planted for timber production in subtropical and temperate regions [1]. With its light, silky texture, high dimensional stability, and good acoustic resonance, Paulownia wood is used in the manufacture of furniture, decorative materials, musical instruments, handicrafts, and other finished products [2,3].…”

“…However, some clones used in commercial plantations have been cultivated for multiple generations and long-term asexual propagation has produced serious problems, including species degradation. Moreover, the investigations of growth traits in superior clones have been restricted to one site per study [10,11]. Genotypes that are superior in one environment may not be correspondingly superior elsewhere [12,13].…”

Radial Variability of Selected Physical and Mechanical Parameters of Juvenile Paulownia Wood from Extensive Cultivation in Central Europe—Case Study

“…Because of the diversity of growth and development conditions of the species and its hybrids, Paulownia exhibits high variability in its wood properties [ 24 , 27 , 28 , 29 ]. For instance, wood density can range from 220 to 350 kgm −3 , although it is usually close to 270 kgm −3 [ 24 , 27 , 28 ].…”

Physical and Mechanical Properties of Paulownia tomentosa x elongata Sawn Wood from Spanish, Bulgarian and Serbian Plantations

“…Paulownia was also introduced in North America, Australia and Japan [3], and is cultivated worldwide in more than 40 countries [4]. Other objectives of Paulownia plantations are to reduce soil hazards by tree-crop intercropping in farmlands [5], to protect systems against erosion, flooding or wind damage [6], to reduce air pollution and to secure the increasing energy demand [7]. Paulownia trees have exceptional root systems and can adapt easily to various soil conditions [8].…”