Research On Propagation Of Lacquer Tree(Toxicodendron Succedanea. Mold) In Vietnam

Research on the propagation of agricultural and forestry plants has been growing and improving along with the development of science and technology,especially for some species of high economic and environmental value.In Vietnam,the propagation of some fast-growing tree species has been well studied and the results from studies can be widely applied in practice.Nevertheless,there are still some high value species that have not been the focus of study,especially in relation to propagation techniques.The Vietnamese Lacquer tree(Toxicodendron succedanea.Mold)is a multi-purposed tree and an important economic species in Vietnam.Its resin is a very precious and essential resource for many industries.There have been quite a few studies on this species.Nevertheless,currently farmers plant this species spontaneously with quite low economic efficiency.This study provides a number of solutions for successful/improved breeding of T.succedanea.Also,the aim of the study was to explore the mineral,nutrition and light requirements of the species during the nursery stage and to create a technique for quickly growing seedlings with high-yields of resin,thereby improving economic efficiency for farmers.The study was implemented mainly in the Vietnamese Academy of Forest Sciences and in the College of Forestry,Northwest Agriculture A&F University,China.Key results of the study are as follows:1)Thirty dominant trees,for which the resin yield did not differ significantly(average yield = 205g/tree/year),were selected for use as mother trees in this study.The resin yield prominent of these dominant trees is of 140.1%.Material from these trees was used to produce seedlings with high and stable resin yield;2)The T.succedanea species was propagated successfully using several grafting methods with a high survival rate.Of which,the highest survival rate(67.78%)belonged to the wedge grafting method.The best season for grafting in Vietnam was Spring;3)The best sterilization method for the propagation of lacquer trees from tissue –culture was using 0.1% HgCl2 for 4 minutes on juvenile shoots.The sprouting rate for this treatment ranged from 20.27% – 44.16%;and the rate of infection in explants was less than 50%.The most suitable medium for bud regeneration was MS* + 0.5 g/l of activated carbon(3.01 buds/clump and buds length of: 1.58cm).The best medium for rapid multiplication of buds was MS* supplemented with 5 mg/l BAP + 0.5 g/l activated carbon.4)Research on the mineral and nutrient requirements of T.succedanea during the nursery stage showed that the application of 38.17 mg N/ kg potting+ 76,33 mg P2O5 /kg potting + 22,90 mg K2 O / kg potting at 1-6 months,followed by the application of 57,3 mg N/kg potting + 114,5 mg P2O5 / kg potting + 45,8 mg K2 O / kg potting at 6-12 months,resulted in the highest seedling growth5)Research on light requirements showed that chlorophyll pigment content in leaves increased with age.From 1-6 months,the chlorophyll content obtained from fresh leaves ranged from 1.90 to 3.12mg/g fresh leaves and the ratio between chlorophyll a and b reached from 2.17 to 2.94 mg/g.From 6-12 months,the chlorophyll content in fresh leaves of T.succedenea ranged from 3.65-3,92mg/g and the ratio between cholorphyll a and be ranged from 2.97 to 3.02.We therefore concluded that the T.succedanea is shade tolerant from age 1-6 months,however from age 6-12 months the species requires light.