ObjectiveThis paper aims to explore the salt tolerance of ash tree clones, breed excellent salt tolerant of clones, and improve land productivity through biological measures.

MethodCutting potted seedlings of 1-year-old ash clones were taken as materials, and their growth and physiological index of 9 clones under different salt stress conditions (0, 2, 4, 6, 8 g/L) were studied.

ResultUnder salt stress, the growth of clones was significantly inhibited, and with the increase of NaCl concentration, the growth indicators (seedling height increment, ground diameter increment, biomass accumulation) of clones showed a decreasing trend, and the decline of ‘YL’ of clones was the slowest; the chlorophyll content of nine clones also decreased with the increase of salt concentration, and there was significant difference between saline wax and other clones (P < 0.05). Under salt stress, the cell membrane permeability and MDA content of clones increased, but at the same salt concentration, ‘YL’ and ‘Y3’ of clones were lower than those of other clones; when salt stress increased gradually, the contents of proline and soluble sugar showed different trends according to different varieties. Among them, osmotic regulators in ‘YL’,‘L5’, ‘QB’, ‘L2’ and ‘Y3’ had been increasing, the content of the other four clones showed a single peak curve, and the highest value reached 6 g/L. SOD activity increased first and then decreased. Its value of ‘YL’ was the highest, which was significantly different from that of other clones (P < 0.05).

ConclusionPrincipal component analysis was used to evaluate the salt tolerance of nine ash tree clones. The salt tolerance of nine ash tree clones was ordered as follows: ‘YL’, ‘Y3’, L5’, QB, JJ, JN11, HX, ‘L2’ and‘J10’. The results provided are not only theoretical basis but also breeding materials for the breeding of ash tree salt tolerant clones.