Maize inbreds for multiple resistance breeding against major foliar, ear and stalk rot diseases

Resistance breeding is considered the most effective and eco-friendly method to manage most of the crop diseases, but it can be challenging to find sources of resistance in maize for short growing season regions. In this study, 218 maize inbreds were evaluated in order to select those, which possess resistance to one or more of the following diseases: Northern Corn Leaf Blight (NCLB), common rust, eyespot, grey leaf spot (GLS), goss's bacterial wilt and leaf blight (goss's wilt), Gibberella (fusarium) ear and stalk rot, and common smut. Significant variation in disease resistance was detected in the inbreds evaluated. Twenty six inbreds, most of them of Canadian origin, were found to possess excellent resistance to multiple diseases. Three inbreds (CO428, CO470 and CO471) exhibited resistance to five foliar diseases (NCLB, common rust, eyespot, GLS, and goss's wilt), while another seven inbreds had a resistant reaction to four diseases (CO452, CO466 and CO468 to common rust, eyespot, GLS and goss's wilt; C0473 to NCLB, common rust, GLS and goss's wilt; CO464 to NCLB, eyespot, GLS, and goss's wilt, and PHZ51 to eyespot, ERSC, common smut, and goss's wilt). Five of these inbreds also had intermediate resistance against stalk and ear rot. Forty five inbreds were found to have resistance against two to three diseases. Inbreds CO457, CO458, CO459 and CO460 released as highly resistance to common rust were also found to have good resistance against eyespot, and GLS or goss's wilt. CO450 released for eyespot resistance had good resistance against common rust and GLS, and moderate resistance against goss's wilt. Three inbreds CO387, CO441 and CO449 were found to have resistance for gibberella ear rot both by silk and kernel inoculation methods and common smut. Most of these inbreds found resistant in this study were from the Stiff Stalk (BSSS), Lancaster and Iodent maize heterotic groups. Many of the resistant inbreds identified in this study are excellent sources of resistance to leaf, ear and stalk rot diseases, and could be utilized in maize breeding programs for developing new hybrids with multiple disease resistance