Development of EST-SSR markers related to salt tolerance and their application in genetic diversity and evolution analysis in Gossypium

Salt stress is becoming one of the major problems in global agriculture with the onset of global warming, an increasing scarcity of fresh water, and improper land irrigation and fertilization practices, which leads to reduction of crop output and even causes crop death. To speed up the exploitation of saline land, it is a good choice to grow plants with a high level of salt tolerance and economic benefits. As the leading fiber crop grown commercially worldwide, cotton is placed in the moderately salt-tolerant group of plant species, and there is promising potential to improve salt tolerance in cultivated cotton. To facilitate the mapping of salt-tolerant quantitative trait loci in cotton so as to serve the aims of salt-tolerant molecular breeding in cotton, it is necessary to develop salt-tolerant molecular markers. The objective of this research was to develop simple sequence repeat (SSR) markers based on cotton salt-tolerant expressed sequence tags. To test the efficacy of these SSR markers, their polymorphism and cross-species transferability were evaluated, and their value was further investigated on the basis of genetic diversity and evolution analysis.