Study on Genetic Variation of Tracheid Microfibril Angle of Japanese Larch Clones

Genetic variations of tracheid microfibril angle of earlywood and latewood of ten 10-year-old Japanese larch clones were investigated.The result revealed that the microfibril angle of earlywood and latewood had a high significant difference among clones.The microfibril angle of earlywood and latewood showed a highly significant difference among different rings.The microfibril angle of earlywood and latewood decreased with the increase of growth ring age.The variation pattern of microfibril angle of earlywood and latewood at DBH from pith to bark was well fitted by logarithm and power equation(R2>0.8).The broad sense heritability estimates of clones were 0.767 4 and 0.804 3,indicating the microfibril angle of earlywood and latewood was under strong genetic control.The average genetic gains were 21.82% and 29.75% for the microfibril angle of earlywood and latewood if 20% of the best clones was selected.