RESEARCH ARTICLE
Responses of Germlings to Acute Environmental Stress
Tang Yongzheng*, Chu Shaohua, Lu Zhicheng, Yu Yongqiang, Li Xuemeng
Article Information
Identifiers and Pagination:
Year: 2015Volume: 9
First Page: 127
Last Page: 133
Publisher ID: TOBIOTJ-9-127
DOI: 10.2174/1874070701509010127
Article History:
Received Date: 17/02/2014Revision Received Date: 21/03/2015
Acceptance Date: 09/06/2015
Electronic publication date: 10/9/2015
Collection year: 2015
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: (https://creativecommons.org/licenses/by/4.0/legalcode). This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
The responses of Sargassum thunbergii germlings to high temperature, low salinity, desiccation, combined thermal and osmotic stress (35 ºC combined with 12 psu), anthracene, and eutrophication were examined. Probit regression analysis results showed that the median lethal time (LT50) values of high temperature decreased with the increase in temperature. The 24 h median lethal temperature was 36.9 ºC. For salinity treatment, the LT50 value of fresh water was 47.6 h. Survival rates of germlings were over 60% when germlings were exposed to salinities ranging from 27 psu to 7 psu at a time interval of 108 h post-treatment. The LT50 values of desiccation and combined thermal and osmotic stress (35 ºC combined with 12 psu) were 7.0 h and 9.8 h, respectively. Anovas showed that germlings were inhibited by high concentrations of anthracene (5 mg L-1 and 10 mg L-1) with low survival rates of below 50% and low relative growth rates of below 1% after 25 days of culture; however, low concentrations (0.01-1 mg L-1) had no significant effects. In addition, neither severe eutrophication nor disproportionality of N/P showed any significant effect on the survival and growth of germlings. Of the environmental stresses tested, possible occurrence of high temperature of 40 ºC and combined thermal and osmotic stress directly impacted the survival of germlings, suggesting that the deterioration of S. thunbergii bed may be related more to increasing extreme climatic events.
