Effect of salinity and population variability on physiological parameters for salinity tolerance in teak (Tectona grandis L.)

Teak is one of the highly demanded and planted tree species throughout the world. Teak (Tectona grandis L.) belongs to Lamiaceae family which is also known as “King of Timber” due to its wood quality and multifarious uses. Now a days, soil salinity is increasing across the globe due to climate change and sea level raising. There is an urgent need to identify the good genotypes or populations of Teak which are tolerant to soil salinity. Hence, the present research study was carried out in Green House Nursery at College of Forestry, Navsari Agricultural University, Navsari. The seed material of Teak collected from five different populations i.e., Bhenskatri, Junagadh, Padamdungari, Subir and Waghai. Seeds were sown in Forest Nursery and grown upto two months in pots before starting the salinity treatments. Thereafter, four salinity treatments along with a control was induced through irrigation with a range of diluted sea water (EC- 1 dS/m, 2 dS/m, 4 dS/m and 6 dS/m). The study revealed that there was large variation for physiological traits among all the population, salinity levels and their interaction effect. It was found that the physiological parameters of Teak in ontogeny stage was reduced when the salt concentration increased. In addition, Junagadh and Bhenskatri population was performed better among all the five populations for studied traits at all five salinity levels. However, all five populations of Teak were survived under continuous supply of saline water and the detrimental effect of salinity was evident at higher dose (EC ≥ 4 dS/m). It is interesting to see that Junagadh and Bhenskatri population does not compromise for physiological traits under salinity stress which shows resistance against salinity. Thus, Junagadh and Bhenskatri population was recommended for plantation purposes in the salt affected areas in south Gujarat region of India. Population variability should be effectively captured for further tree improvement of teak for salinity resistance.