Evaluation of tetracycline phytotoxicity by seed germination stage and radicle elongation stage tests: A comparison of two typical methods for analysis

Yuan Luo; Jie Liang; Guangming Zeng; Xiaodong Li; Ming Chen; Longbo Jiang; Wenle Xing; Ning Tang; Yilong Fang; Xuwu Chen

doi:10.1016/j.envpol.2019.05.005

Evaluation of tetracycline phytotoxicity by seed germination stage and radicle elongation stage tests: A comparison of two typical methods for analysis

Environ Pollut. 2019 Aug:251:257-263. doi: 10.1016/j.envpol.2019.05.005. Epub 2019 May 2.

Authors

Yuan Luo¹, Jie Liang², Guangming Zeng¹, Xiaodong Li¹, Ming Chen¹, Longbo Jiang¹, Wenle Xing¹, Ning Tang¹, Yilong Fang¹, Xuwu Chen¹

Affiliations

¹ College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China.
² College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China. Electronic address: liangjie@hnu.edu.cn.

PMID: 31082610
DOI: 10.1016/j.envpol.2019.05.005

Abstract

Biological tests with plant seeds have been adopted in many studies to investigate the phytotoxicity of pollutants to facilitate the control of risks and remain to be optimized. In this work, the experiment with a small sample size (Experiment 1) and the experiment with a large one (Experiment 2) were designed to study the effect of tetracycline (TC) on Chinese cabbage (Brassica rapa L.) at seed germination and radicle elongation stages. At the former stage, germination number data were obtained to analyze the germination energy (GE) and to judge the probability of the number of germinated seeds (P_n) by the binomial distribution model in Experiment 1. While germination time-to-number data were obtained to analyze the mean time to germination (MGT), the estimate of mean time to germination (EMGT) by survival analysis method, the time to germination for 50% of total seeds (T₅₀) and the germination rate (GR) besides GE in Experiment 2. At the latter stage, the data of radicle length (RL) were obtained in all the experiments and the influence from the former stage on this stage was excluded in Experiment 2 but not in Experiment 1. Results showed that TC had universal adverse effects on the latter stage but not on the former stage in the experiments. Considering the availability of germination data for statistical analysis and the robustness of RL data, the methods adopted in Experiment 2 were more feasible than those in Experiment 1. In addition, Chinese cabbage seeds with medium size have the character of rapid germination compared with the commonly used crop species and can be used to shorten the experimental cycle to study the responses of seeds to pollutants to evaluate the phytotoxicity. We introduced survival analysis method to analyze the germination time-to-number data obtained in seed germination test to evaluate the phytotoxicity of tetracycline.

Keywords: Binomial distribution; Phytotoxicity; Sample size; Seed germination; Survival analysis; Tetracycline.

MeSH terms

Anti-Bacterial Agents / toxicity*
Brassica / drug effects
Germination / drug effects*
Seeds / drug effects
Tetracycline / toxicity*

Substances

Anti-Bacterial Agents
Tetracycline