Abstract: Salt stress is one of the abiotic stresses in nature affecting crop growth and yield. Salt stress can cause DNA damage, resulting in cytotoxicity and genetic toxicity in crops. In this study, 12 pairs of random primers were selected for random amplification of polymorphic DNA (RAPD) analysis to evaluate DNA damage in roots of soybean seedlings treated with 0-150 mmol·L^-1 NaCl for five days. Our results showed that NaCl treatment significantly decreased root length, fresh and dry root weight, and fresh and dry weight of seedlings. Under salt stress, severe DNA damage was detected in roots of soybean seedlings, with damage degree being positively correlated with NaCl concentration. Under salt stress with different NaCl concentrations, the numbers of RAPD fragments amplified by 12 random primers ranged from 72 to 89. Among them, amplification using random primers 2 and 9 generated more than 10 clear bands of RAPD polymorphic fragments. Therefore, our results showed that random primers 2 and 9 could be used for RAPD assays to analyze DNA damage in soybean seedlings under salt stress.

Key words: RAPD, random primer, genetic toxicity.