LONDON (Reuters) - World markets fell on Wednesday as the coronavirus threat ensured an ugly start to April and the second quarter for equities and commodities.Traders headed for the safety of government bonds, the dollar [USD/] and gold [GOL/] as evidence continued to mount that the virus was sending the global economy into a deep recession.Tokyo's Nikkei slumped 4.5% after the worst plunge in factory activity in almost a decade. The pan-European STOXX 600 sank 2.7% [.EU] and Wall Street..