Growth-promoting effects of six ectomycorrhizal fungi on Larix olgensis seedlings

To study the role of ectomycorrhizal fungi in the growth and physiological processes of Larix olgensis.

Larix olgensis seedlings were selected as research materials. In the constant temperature and light culture environment, and six species of ectomycorrhizal fungi, Pisolithus tinctorius, Suillus grevillei, Suillus bovinus, Macrocybe gigantea, Xerocomellus chrysenteron, and Lactarius deliciosus were used for inoculation, to analyze the effects of each strain on root infection, growth indicators, root vigor, chlorophyll content, nutritive element content, and photosynthetic parameters of L. olgensis seedlings.

P. tinctorius, S. grevillei and L. deliciosus all established a good symbiotic relationship with L. olgensis seedlings, produced strong mycorrhizal effects, and significantly increased the biomass, seedling height, ground diameter, root surface area, and root tip number of the plants, of which inoculation with P. tinctorius had the most obvious overall effect, which increased 64.2%, 30.7%, 15.0%, 35.6%, and 51.1%, respectively, compared with the control. In addition, P. tinctorius and S. grevillei also significantly increased the root length of the plants by 43.2% and 40.9%, respectively, over the control. The physiological studies showed that the three strains significantly increased the plant potassium content, moreover, P. tinctorius and L. deliciosus also significantly increased the content of the plant chlorophyll, nitrogen, and phosphorus, P. tinctorius and S. grevillei significantly enhanced the root vigor of the plant, and the transpiration rate of the plant was significantly enhanced by S. grevillei, which was 29.2% higher than the control. S. bovinus was consistent with M. gigantea and X. chrysenteron except that it significantly increased plant ground diameter and biomass, and none of the growth and physiological indices were significantly different from the control treatment.

Inoculation of appropriate ectomycorrhizal fungi can enhance the root vigor of long white larch seedlings as well as the ability to absorb nutrients, thus promoting plant growth. Among the six ectomycorrhizal fungi that were inoculated, P. tinctorius was the most effective in enhancing the growth and physiology of L. olgensis.