Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [30771450]; Natural Science Foundation of ShanghaiNatural Science Foundation of Shanghai [08ZR1417300]; Shanghai Science and Technology CommitteeShanghai Science & Technology Committee [073419N13, 08DZ1900401, 08DZ1206000]; Specific Item of Agriculture Ministry of China [200803007hu02]; Specific Item of Environment Protection Ministry of China [2008ZX07101-005-01]; Shanghai Agriculture Committee [2004-7-4, 2006-2-2]