Inter-cropping with Southern Corn Rust Resistance Maize Genotype Improved Maize (Zea mays L.) Defense Response

Intercropping is regarded as an effective and environment friendly cultivation practise in disease control. SCR infection severity and the differences of defense related enzymes activity under SCR inoculation were observed between sensitive and resistance genotypes and between mono-and inter-cropping cultivation manners of the same genotype. Compared to mono-cropping, the disease grade of SCR sensitive genotype inter-cropped with SCR resistance genotype decreased from 5 and 7 to 3 and 3 in 2006 and 2007, respectively. The defense related enzymes activities under SCR inoculation in SCR sensitive genotype were higher when inter-cropping with SCR resistance genotype than in mono-cropping. The result indicates that the disease resistance of plants is not only related to its hereditary but could also be affected by the genetic diversity of the cropping community. These results suggest that by intercropping the SCR susceptible genotype with the SCR resistant genotype can significantly enhance the defense related metabolism of the susceptible genotype under SCR inoculation and improve the resistance to SCR.