Physiological Responses of Ficus concinna var. subsessilis Seedingsto Salt Stress and Introduction Test

Experiments were conducted on 3-year Ficus concinna var. subsessilis by salt stress (0, 0.3%, 0.6% and 0.9%) in 2011. Determinations were made on chlorophyll content and photosynthetic index on the 10th, 20th, 30th and 40th day after treatment. In 2016, introduction was made on 1-year F. concinna var. subsessilis seedlings at reclamation area of Taizhou Bay, Zhejiang province. The results showed that under 0.3% NaCl stress, content of total chlorophyll(Chl), Chla and Chlb gradually increased. Under 0.6% NaCl stress, content of Chlb decreased, while content of Chl and Chla decreased from the 10th to 20th day and then gradually increased later. The Chla/Chlb value increased from 10th to 20th day, decreased from 21st to 30th day, and increased from 31st to 40th day under 0.3% NaCl stress. Under 0.6% NaCl stress, Chla/Chlb value decreased from the 10th to the 20th day, and then increased gradually from 21st day to 40th day. The experiment resulted that salt stress significantly inhibited the net photosynthetic rate of the seedlings, especially on the 10th day, and inhibition was increased with the NaCl concentration. Photochemical efficiency of photosystemⅡ,maximum net photosynthetic rate, apparent quantum efficiency decreased with the increase of salt concentration. Light compensation point and dark respiration rate of the seedling decreased with the increase of salt concentration on the 10th day, increased on the 20th and 30th day. Introduction test and observation from 2006 to 2014 demonstrated that survival rate of introduced seedlings topped to 100%, with annual height growth of 30cm and ground diameter of 1.26-2.14cm. Temperature under zero could cause severe injury to seedlings under 5-year.