基金Supported by the National Natural Science Foundation of China (No. 30525002, 30470010 and 30700005)the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KSCX2-YW-G-025)+2 种基金the National Basic Research Program of China (No. 2009CB522300)the Joint Funds of the National Natural Science Foundation of China and Yunnan Provincial Government (No. U0836604)supported by the National Science Foundation of the USA (DEB-0321846 to DE Boufford and Richard H. Ree)