CANADA STOCKS-TSX opens higher, CN Rail lifts

TORONTO, April 23 (Reuters) - Canada's main stock index opened higher on Wednesday, helped in part by Canadian National Railway, which reported better-than-expected results after markets on Tuesday. The Toronto Stock Exchange's S&P/TSX composite index opened up 15.44 points, or 0.11 percent, at 14,571.41. Six of the 10 main groups were in positive territory. (Reporting by Solarina Ho; Editing by Chizu Nomiyama)