Effects of EMS Treatment on Leaf Regeneration and Heat Tolerance of Tissue-cultured Rhododendron chrysanthum Pall. Seedlings

[...]EMS treatment improved the heat tolerance of tissue-cultured R. chrysanthum seedlings. If introduced directly to low-altitude cities, R. chrysanthum will be inevitably damaged by high temperature, greatly restricting the large-scale promotion of R, chrysanthum in low-altitude urban areas. [...]improving the heat tolerance of R. chrysanthum is the first step to achieve the transformation from resource type to product type. Under the treatment of 0.1% EMS for 2 d, the leaf survival rate was 48.92%, and the calli showed a good growth, meeting the semi-lethal requirements of mutants. [...]the treatment of 0.1% EMS for 2 d was close to the semi-lethal dose, and could be used as a screening condition for heat-resistant mutants. 201 also found that at high temperature, the soluble sugar content in Taxiphyilum taxirameum increased with the extension of treatment time, and at 40 °C, the soluble sugar content in the treatment group was three times higher than that in the control group, indicating that in the high temperature environment, the plantlets regenerated from EMS-treated leaves accumulated more soluble sugar to maintain the osmotic balance, which was consistent with the result of this study.