Improving Drought and Salinity Tolerance in Corn (Zea mays. L.) By Introgression of Regionally Developed Open Pollinated Landraces.

Both grain and silage corn are important crops in New Mexico. In 2014, 50,200 ha were planted, an increase of almost 25% since 1985. Much of that increase was due to an increase in silage production to meet the demands of the dairy industry. New Mexico production environments may experience high temperatures, drought, and increasingly salt affected soils. Corn traces back 4000 years in the Southwest, and landrace varieties have developed over centuries. Some of these landraces may serve as genetic donors to improve both drought and salinity tolerance in modern varieties. Little research has been conducted on the agronomic and genetic characteristics of Southwestern maize. We posit that the introduction of arid-adapted ÒgeneticsÓ and traits into modern varieties can increase their drought and salinity tolerance, thus conserving water resources while still meeting agricultural demands. Preliminary field studies conducted in 2015 indicate that four open-pollinated landrace populations yielded comparably when compared to a commercial check for grain yield across three environments. Early results also indicated that silage yield of some landrace populations was comparable to modern varieties. Early phase seedling salinity stress tests conducted in a growth chamber have identified several potentially salt tolerant candidate landraces. We are currently testing 12 landrace populations with desirable salt-tolerance or silage yield traits and 5 commercial checks in four different locations. Test locations include an extremely saline environment, a nitrogen limited environment, an organically managed system, and a location where effluent water is used for irrigation. Landrace populations will be identified for desirable agronomic traits and stress tolerance.