O/R Apple Inc AAPL.O edged up 0.1% ahead of the unveiling of its new range of iPhone models and Apple Watches. By Sruthi Shankar and Ankika Biswas Sept 7 (Reuters) - Wall Street's main indexes made cautious gains on Wednesday, with growth stocks in the lead as bond yields eased after a recent rally. The equities selloff, sparked in August by hawkish comments from Fed Chair Jerome Powell, has continued in recent days amid signs of an economic slowdown in Europe and China as well as actions by major central banks determined to stamp out inflation.