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);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)