Abstract: Effects of sodium sulphate, sodium bisulfite and sodium sulfite on germination, growth and cell division were investigated in maize (Zea may L.) seedlings. Our results showed that germination rate and seedling growth had linear respond to treated concentration and duration time. Germination rate, root length and bud height decreased with increasing concentrations of sodium bisulfite and sulfite in the range of 2.5~20.0 mmol·L^-1 or sodium sulphate at above 20.0 mmol·L^-1 while other treatments, such as 0.1 mmol·L^-1 sodium bisulfite, sodium sulfite and sodium sulphate, promoted the proceeding of germination and seedling growth. The difference among different treatment groups enhanced with exposed time. With different effective concentrations, sodium bisulfite at 2.5 mmol·L^-1 and sodium sulfite over 20 mmol·L^-1 inhibited mitosis division in seedling root tips. However, mitotic index increased after seedlings incubated for 72 h with three kinds of chemicals, respectively, sodium bisulfite in the range of 0.1~0.5 mmol·L^-1, sodium sulfite in the range of 0.1~10 mmol·L^-1 and sodium sulphate in the range of 0.1~20 mmol·L^-1. At the same time, pycnosis were also observed in root tip cells. Our results indicated that sodium sulphate, sodium bisulfite and sodium sulfite, with their different effective concentrations each, were toxic to seedling growth, seed germination and cell division, and also their toxicity increased with exposed time. The sequence of their toxicity is bisulfite＞sulfite＞sulphate.

Key words: sulfur dioxide derivatives, maize, germination and growth inhibition, abnormal cell