Early performance and genetic gain of Cedrela odorata families from wide-ranging sites in Mexico
2016
Vargas-Hernández, J. J. | López-Upton, J. | Salazar-García, J. G. | Hernández-Máximo, E. | Sánchez-Monsalvo, V.
Cedrela odorata is a tree of utmost importance. Thus a progeny trial was established in Veracruz, Mexico, with 168 families from 19 provenances of southeast Mexico. Significant differences among provenances and families were found at 3, 5, 7 and 11 years of age for height, diameter at breast height [dbh] and volume, and stem straightness and branch thickness at 11 years of age. Individualheritability (h2 i) fluctuated between years from 0.16 to 0.29, improving with age. For straightness and branch thickness, h2 i = 0.12 and 0.10 respectively. Growth traits showed a genetic correlation (rg ≥ 0.99) among them. Genetic correlation (rg) of straightness with height, dbh, volume and branch thickness were-0.24, -0.13, -0.18 and 0.56 respectively, and rg of branch thickness with height, dbh and volume were 0.04 0.11 and 0.13 respectively. Age-age genetic correlations were ≥ 0.93 for growth traits. A 56% gain in volume was obtained by using this variable as the selection criterion, leaving 20% of the best trees standing. Early selection at three years old, based on dbh was efficient to improve volume at 11 years with 37.3% gain, whereas at seven years the volume gain was 54%. None of the options dramatically altered form variables.
显示更多 [+] 显示较少 [-]