Research on Cuttage Propagation by Semi -lignified Shoot Cutting of Pinus kesiya var.langbianensis

Cuttage experiments with semi -lignified apical shoots from five -month -old seedlings of Pinus kesiya var.langbianensis and with tender sprouts developed from topped seedlings treated by varied substrates, gradient concentration of plant growth regulators were carried out in the greenhouse of Southwest Forestry College.It was showed that Pinus kesiya var.langbianensis belongs to callus rooting type and the highest rooting rate could be over 90%.The highest rooting rate was obtained when perlite was applied as substrate, while the best rooting quality was produced by perlite mixed with humus soil(2:1).It was demonstrated by the experiments that plant growth regulators could shorten the rooting period, increase rooting number and length of the new roots, but they did not show much effect on promoting rooting rate of this tree species.Among the plant growth regulators tested, IAA had the best rooting results, followed by mixture of IAA and NAA, then NAA, and the rooting powder dipping got the worst result.According to rooting rate, rooting number, and average length of new roots, it was concluded that perlite +humus (2:1)as substrate, and 100 μg/g of IAA as plant growth regulator was the best treatment for semi -lignified shoot cutting of Pinus kesiya var.langbianensis.