Find in Library

<i>Impatiens walleriana</i> is of great ornamental value, but it may suffer growth inhibition when it is exposed to sub-low temperatures for a long time. Although there are many studies on the positive effect of arbuscular mycorrhizal fungi (AMF) on cold tolerance, whether AMF could alleviate the sub-low temperature injury of <i>Impatiens walleriana</i> is unknown. In this experiment, two kinds of <i>Impatiens walleriana</i> were inoculated with AMF and treated with sub-low temperature to evaluate the physiological and biochemical characteristics of <i>Impatiens walleriana</i> seedlings. The results showed that the plant height of ‘Super Elf (Rose red)’ under stress and inoculated with 50 g and 100 g AMF compared to sub-low temperature treatment increased by 4.94% and 19.01%, and the plant height of ‘Super Elf (red)’ under stress and inoculated with 50 g and 100 g AMF increased by 3.11% and 17.03%, respectively. Compared to sub-low temperature treatment, the stem diameter of ‘Super Elf (Rose red)’ under stress and inoculated with 50 g and 100g AMF increased by 47.17% and 50.94%, respectively. The same mitigation effect was observed in ‘Super Elf (red)’. Compared with sub-low temperature treatment, Fv’/Fm’, Y(II) and qP of ‘Super Elf (Rose red)’ inoculated with 50 g AMF significantly increased by 75.76%, 52.17%, and 43.48%, while NPQ significantly decreased by 2.96 times, whereas the corresponding values for ‘Super Elf (Rose red)’ inoculated with 100 g AMF increased by 87.88%, 82.61%, and 65.22%, while NPQ significantly increased by 1.47 times. Compared with sub-low temperature treatment, Fv’/Fm’, Y(II) and qP of ‘Super Elf (red)’ inoculated with 50 g AMF significantly increased by 53.49%, 28.95%, and 29.31%, while NPQ significantly decreased by 0.84 times, whereas the corresponding values for ‘Super Elf (red)’ inoculated with 100 g AMF increased by 53.49%, 23.68%, and 22.41%, while NPQ significantly increased by 3.48 times. Meanwhile, ‘Super Elf (Rose red)’ and ‘Super Elf (red)’ vaccination with AMF reduced the levels of O₂⁻ and H₂O₂ accumulation in leaves at sub-low temperatures and mitigated the extent of damage to cell membrane lipid peroxidation. Therefore, AMF inoculation can improve the tolerance of plants to sub-low temperatures.