Genetic Diversity Assessment of Teak (Tectona grandis Linn. F.) in a Clonal Seed Orchard

Abstract The investigation was carried out to find out the inter-clonal variation in terms of growth performance and genetic variability of 25 Teak clones at 30 and 31-years age, planted at a spacing of 6m x 6m in the Clonal Seed Orchard of Silvicultural Research Station, Angul, Orissa, India, located at 21001’17.8” N longitude and 84055'19.6" E latitude. The experiment was laid out in Latin Square Design with 25 replications with 25 numbers of Teak clones as treatments. Maximum DBH (29.46 cm) was observed for ORANP-17 and in next year, nearly 8% increase in DBH was observed for many Teak clones. Tree height of Teak clones varied from 17.02 m to 21.16 m and 17.34 m to 21.90 m at 30 and 31 years of age and at 31st year, tree height seems to be saturated and only 3 to 4% increase was noticed. Both at 30th and 31st year, maximum volume of stem was recorded for ORANP-17 (100.62 m3 and 118.10 m3 respectively), which varied significantly with rest of the 24 Teak clones. Nearly 18% increase in volume of stem was observed between 30th and 31st year for most of the clones. Maximum value of CAI of volume of stem was recorded for ORANP-17 (17.48 m3) followed and at par with only one clone i.e. ORANP-16 (15.50 m3). Nearly three times difference was noticed between top and least performed clones. The range of MAI of stem volume at 30th year was 2.05 m3, while at 31st year, it was 2.33 m3 i.e. maximum 3.81 m3 for ORANP-17. Percentage increase in MAI of stem volume between both the years was varied between 13 to 14%. In case of DBH, higher value of genotypic coefficient of variation (6.73) was noticed than phenotypic coefficient of variation (6.67), which showed that DBH of Teak clones are more influenced by genetic characters. Higher impact of environmental factor was noticed on the traits like CAI in DBH, CAI in height, CAI of stem volume and MAI of stem volume. Maximum intra cluster divergence was noticed for cluster II (13.21), followed by I (11.48), cluster III (7.50) and cluster VI (7.22). Maximum inter-cluster divergence was noticed between cluster II and VIII (72.83), followed by cluster II and VII (72.86) and cluster VI and VIII (72.83). Clustering pattern indicated that maximum number of 10 germplasm came in cluster I. Cluster VIII consist of most superior close of Teak, because it gave maximum value for all the growth parameters. Maximum percentage contribution in divergence of Teak clones was noticed by tree height (67.67%) followed by length of straight stem (29.33%). Cluster VIII consists of most superior close of Teak (ORANP-17), because it gave maximum value for almost all the growth parameters. Next to cluster VIII, best performing cluster is VII (ORANP-16). From this study, it is recommended for the vegetative multiplication of clone ORANP-17 which manifested highest stem volume of 118.10m3/ha and MAI of 2.63m3/ha at the age of 31 years. It is also inferred that appropriate improvement is possible in MAI as well as CAI in stem volume of different Teak clones by providing adequate silvicultural and cultural practices.