Research Progress on the Breeding of Salt-tolerant Rice VarietiesSUN Ming-fa, YAN Guo-hong, WANG Ai-min, ZHU Guo-yong, TANG Hong-sheng, HE Chong-xiao, REN Zhong-ling, LIU Kai, ZHANG Gui-yun, SHI Wei, ZHAO Shao-lu, SUN Yi-biao, ZHU Jing-wen, WAN Bai-jie, YAO Li-sheng