*3.2. The Effect of Different Treatments on Contamination Percentage of S. aralocaspica Seeds*

Compared with the seeds that were not disinfected, almost all sterilization treatments had a good sterilizing effect. The effects of ethanol time (*p* > 0.05) and secondary disinfectant time (*p* > 0.05) on the contamination percentage were not significant. The effects of pH (*p* < 0.05), secondary disinfectant type (*p* < 0.05) and seed type (*p* < 0.05) on the contamination percentage were significant (*p* < 0.05) (Table 4).

**Table 4.** A mixed model ANOVA on contamination percentage of dimorphic seeds of *Suaeda aralocaspica*.


When using 3.6% NaClO as the secondary disinfectant, the brown seed contamination percentages were 56.67% and 53.33% in treatments N21 and N9, respectively, followed by 33.33%, 26.67% and 23.33% in treatments N19, N12 and N5, respectively (Table 5). The black seeds were most polluted in treatments n3 and n24, and the microbial contamination percentage was 6.67% (Table 5). When using 0.1% HgCl2 as the secondary disinfectant, the sterilization effect was more significant, and only three treatments of both seeds were polluted. The highest contamination percentage of brown seeds was 23.33% in treatment

H20, and the contamination percentages in treatments H23 and H24 were 10% and 6.67%, respectively (Table 5). In treatment h1, 16.67% of the black seeds were polluted, which was the most serious, followed by treatment h17 and treatment h21, with the contamination percentage of 3.33%. Other treatment combinations were not polluted by microorganisms (Table 5).

**Table 5.** Contamination percentage of *Suaeda aralocaspica* seeds cultured with different treatments after 20 days incubation.


Different lowercase letters in each column indicate significant differences among different treatments; different uppercase letters indicate significant difference between dimorphic seeds treated with the same secondary disinfectant.

Medium pH (*p* > 0.05) at different levels had no significant effect on seed germination, but pH (*p* < 0.05) significantly affected microbial growth and reproduction. No matter whether NaClO or HgCl2 was selected as the secondary disinfectant, almost no microorganisms could grow on the MS medium under acidic conditions (pH 5.0). A small amount of bacterial or fungal contamination was observed at pH 6.0 to 8.0.
