Annual economic growth of 7.0% is a “reasonable target” for China this year, a former adviser to the central bank said, adding that he expects the nation’s daily foreign-exchange band to be widened when conditions are right. Li Daokui, professor at Tsinghua University’s School of Economics and Management and a former adviser to the People’s Bank of China, said he believes growth in the world’s second-largest economy is now nearing its low point, adding that he expects growth rates to pick up within a year or two. “I believe we’re now at the bottom of a u-shape,” Mr. Li said at a Ministry of Foreign Affairs briefing for journalists. He said his forecast was for 7.2% year-over-year annual growth in 2015, rising to 7.5% by 2017 or 2018. Mr. Li also said he expects China’s daily currency-trading band to be loosened, but he didn’t provide a time frame. An expanded version of this report appears on WSJ.com.