Performance of Chinese-fir (Cunninghamia lanceolata (Lamb.) Hook.) plantlets from upper-crown and basal origins as modified by grafting and development as buried ramets before explant harvest

Trees that had sprouts at their root collar were selected from a 28-year-ol d plantation of Chinese-fir. Upper branches, which probably had achieved a less-juvenile maturation state, were taken in the forest. One-year-old seed lings were dug out from a nursery and root systems were harvested below the cotyledon trace. The branches and root systems were grafted together and t he grafts were planted as partly-buried donors for explant production. Basa l sprouts of the same trees were rooted and similarly planted as explant do nors. In addition, upper branches and basal sprouts were taken directly fro m a 20-year-old plantation as explants for culture with the above explants. It was found that the average numbers of buds and shoots per plantlet, the average shoot length, the rooting percentage and average root length of the upper-branch-origin plantlets taken directly as explants were lower than t hose of the grafted and basal-sprout- origin explants. However, there were no consistent or significant differences in these characteristics among eit her set of basal-sprout-origin and the graft-origin plantlets. The results further indicate that grafting and scion burial, and perhaps same of the ti ssue-culture protocol, have some functions in rejuvenating or at leat reinv igoration tissues of Chinese-fir.