Republican candidate for Governor Doug Gross is proposing some tax breaks he says will make Iowa’s business climate more attractive for start-up companies.Gross says the state “research and development” tax credit should be doubled for all businesses. Today, the Iowa “R-and-D” credit applies only to businesses that have invested at least 10-millon dollars. He says start-up businesses don’t qualify, but they need the help.Gross also proposes extending the number of years start-up businesses can spread out their operating losses.Gross’ third idea: an investment tax credit, particularly for advance manufacturing.Gross says Iowa can’t grow a mountain or an ocean, but it should make the tax climate better for businesses. Earlier this morning, Gross visited a Des Moines firm that’s starting a venture capitol fund for high-tech businesses.