Addditional data on the population, content of essential oil and genetic diversity of Cupresssus tonkinensis Silba in Huu Lien NR, Huu Lung district, Lang Son province serving for assessment of its conservation status in Vietnam

In Huu Lien Natural reserve, there are 25 mature individuals comprising Cupressus tonkinensis’s native population. The production of seed- cones could reach the value of 24%. In cultivated population, there are 162 individuals, including 82 of mature plants, producing of seed- cones with the value of 25%. Global and national conservation status proposed is Critically Endangered —CR A2acd, B2ab (i-v), D.

The yield of essential oil from the air-dried leaves was 0.24% (0.10% - 0.43%), absolute-dried was 0.44% (0.28% - 0.59%) and from the air-dried small branchs was 0.05% (0.01% – 0.16%).), absolute-dried was 0.15% (0.02% - 0.31%). By using GC/MS analysis, 40 constituents have been identified from the leaves and the small branches. The main constituents of essential oil from the leaves were: 20.10% of a-pinen (7.5% - 32.75%), 18.68% of sabinen (18.23% - 40.50%), 13,53% of terpinen4-ol (8.30% - 25.02%), 4,77% of g-terpinen (3,52% - 7,67%) and 4,30% of myrcen (3.10% - 6.12%) and from the small branches were: 28,14% of a-pinen (5.23% - 41.28%), 22.56% of cedrol (12.66% - 38.10%), 5,46% of cis- thujopsen (0.53% - 14.80%).

Analysing 40 individuals indicated that genetic diversity was high at group and species levels in relation to low inbreeding among individuals in each group and the species. The cluster analysis indicated all analysed individuals form two clusters. All individuals had closely relationships in each group with high genetic identities. Our results also determine some individuals with high polymorphic loci used for ex situ conservation activities in Huu Lien.

Nguyen Tien Hiep, Nguyen Quang Hieu
Conservation Centre for Pants in Vietnam
Phan Ke Loc
Ha Noi National University of Science, VNU
Tran Huy Thai, Pham Van The, Nguyen Sinh Khang, Nguyen Tien Vinh
IEBR, VAST
Nguyen Minh Tam
Viet Nam Nature Museum, VAST