Differences in the Response of Diploid and Tetraploid Anthurium andraeanum Seedling Roots to Salt Stress

To investigate the effects of salt stress on the growth, development, and endogenous hormone content of roots in diploid and tetraploid seedlings of Anthurium andraeanum, the enhanced salt tolerance was elucidated. The seedlings of A. andraeanum 'Pink champion' were placed at NaCl concentrations of 0, 50, 100, 150, and 200 mmol·L⁻¹. The results indicated that NaCl stress can reduce leaf area, total root length, root volume, average root diameter, root tip number, root vitality, root hair length, root hair diameter, root hair density, and the growth rate of root hair. At the same time, it can also shorten the length of mature area, elongation area, meristem area, and root crown area. The reduction in diploids was greater than tetraploids. NaCl stress also increased mortality rate, Indoleacetic Acid (IAA) content, and Ethylene (ET) production rate, with a smaller increase in tetraploids. Overall, NaCl stress can elevate the IAA content and ET production in diploids and tetraploids, with tetraploids being less affected, indicating higher salt tolerance.