Abstract:

The purpose of the paper was to study salt tolerance and its indexes of Ginkgo biloba varieties. The potted plants of five Ginkgo biloba varieties (Fozhi, Dajinzhui, Meihe, Dayuanling and Maling) were treated with 0%, 0.1%, 0.2% and 0.3% of NaCl. The results indicated that:(1) With the salt concentration increasing, the Na⁺ concentration and the ratio of Na⁺/K⁺ in the leaves of five varieties also increased, and the K⁺ concentration was highest in the treatment of 0.1%, then decreased in the treatment of 0.2% and 0.3%. (2) Leaf water potential increased with the salt concentration increasing, and free proline content in the leaves also increased in the treatment of 0.2% and 0.3%, but decreased in the treatment of 0.1%; A little change of root viability happened in the treatment of 0.1%, but there was a significant decrease in the treatment of 0.2% and 0.3%; SOD activity in the leaves and growth of plant height decreased gradually with the salt concentration increasing; There was a little change in membrane leakage in the treatment of 0.1% and 0.2%, but it increased obviously in the treatment of 0.3%. (3) According to the plant growth of height, the salt tolerance of five varieties in the treatment of 0.3% was Meihe>Dayuanling> Maling>Dajinzhui>Fozhi. (4) The analysis methods of BACKWARD, FORWARD and STEPWISE all showed that the ratio of Na⁺/K⁺ had the greatest influence on the plant growth of height, so the ratio of Na⁺/K⁺ was a very important index in the study on salt tolerance of plant.

Key words: Ginkgo biloba, Salt tolerance, Index