BioProject

Wood stiffness is the most important wood quality trait of forest trees for structural timber production. More...

Wood stiffness is the most important wood quality trait of forest trees for structural timber production. We investigated genes differentially transcribed in radiate pine trees with distinct wood stiffness using bulked segregant analysis (BSA) and cDNA microarrays. Transcript accumulation in earlywood (EW) and latewood (LW) of high (HS) and low stiffness (LS) trees in two progeny trials was compared. Overall design: Radiata pine trees used for microarray experiment were selected from two progeny trials planted at Flynn and Kromelite, Australia. Based on the IML-based MOE measurement, five families with highest and lowest MOE each were selected from each trial, which represented two segregant populations with contrasting wood stiffness. Two individuals from each selected family were further sampled. Developing xylem tissues of selected trees in Flynn trial were sampled in spring (October) and autumn (April), representing earlywood (EW) and latewood (LW) of juvenile aged trees, respectively. Collection of xylem tissues from Kromelite trial was arranged in summer (late November) when latewood (LW) was formed. The xylem tissues were scraped at breast height with a sharp chisel after the bark was removed. In Flynn trial EW and LW tissues were collected from the same sampled trees on opposite sides of the trunk. Transcript accumulation was compared in trees with highest (HS) and lowest stiffness (LS) using xylem samples from Flynn collected in spring (EW) and autumn (LW), as well as Kromelite in summer (LW), respectively. Bulked segregant analysis (BSA) was used for the experiment design. Total RNA samples extracted from the five trees with HS were pooled at equal amount, and compared to the bulked five individuals with LS. This pooling strategy can partly minimize the genetic variation among different genotypes. Dye swaps were applied in each biological replicate. Less...