RESEARCH ON IMPROVING THE PROPAGATION TECHNIQUES FOR Glyptostrobus pensilis BY STEM CUTTINGS

Abstract

Glyptostrobus pensilis is the unique species of the genus Glyptostrobus and is considered a living fossil of Pinophyta. It is a rare species all the world because the natural populations of Glyptostrobus pensilis are very small, remaining only in Vietnam, China and Laos. This species has both high economic and conservation value. Until now, propagation by cuttings is a commonly method with the use of plant growth regulators such as: IAA, IBA, NAA… to preserve and develop the species. The experiments were randomized complete blocks design. The results indicated that: Using cuttings 10 - 12 cm in length and 1 - 2 mm in diameter, with IBA 1,000 ppm for 2 hours in the spring - time, after 2 months, the survival rate and rooting rate of cuttings reached the highest levels of 80% and 34.29%, respectively; using IBA 1,000 ppm in the Winter - time, after 2 months, the survival rate of cuttings was 67.5%, the rooting rate was 25.83%, the average number of roots per cutting was 2.67 roots/cutting, the root length was 13.59 cm and the rooting index was 51.13; using the mixture of IBA 1,000 ppm + IAA 800 ppm, in the autumn - time brought a rooting rate of cuttings of 20%, an average of 3 roots/cutting, root length of 12.92 cm and the highest rooting index at 38.95.

Glyptostrobus pensilis is the unique species of the genus Glyptostrobus and is considered a living fossil of Pinophyta. It is a rare species all the world because the natural populations of Glyptostrobus pensilis are very small, remaining only in Vietnam, China and Laos. This species has both high economic and conservation value. Until now, propagation by cuttings is a commonly method with the use of plant growth regulators such as: IAA, IBA, NAA… to preserve and develop the species. The experiments were randomized complete blocks design. The results indicated that: Using cuttings 10 - 12 cm in length and 1 - 2 mm in diameter, with IBA 1,000 ppm for 2 hours in the spring - time, after 2 months, the survival rate and rooting rate of cuttings reached the highest levels of 80% and 34.29%, respectively; using IBA 1,000 ppm in the Winter - time, after 2 months, the survival rate of cuttings was 67.5%, the rooting rate was 25.83%, the average number of roots per cutting was 2.67 roots/cutting, the root length was 13.59 cm and the rooting index was 51.13; using the mixture of IBA 1,000 ppm + IAA 800 ppm, in the autumn - time brought a rooting rate of cuttings of 20%, an average of 3 roots/cutting, root length of 12.92 cm and the highest rooting index at 38.95.