Feb 10 (Reuters) - Canada’s main stock index rose to a record high at open on Wednesday, helped by a jump in shares of cannabis companies as the Reddit community behind a recent trading frenzy pumped up these stocks. * At 9:30 a.m. ET (14:30 GMT), the Toronto Stock Exchange’s S&P/TSX composite index was up 86.18 points, or 0.47%, at 18,494.8.