Southwest‐adapted Maize Germplasm As a Potential Genetic Resource for Selection of Salinity Tolerant Cultivars

The southwestern United States-northern Mexico Borderland Region (SW) is an arid to semi-arid region characterized by high temperatures, drought, and frequently saline soil conditions. Nonetheless, maize (Zea mays) has been cultivated in the region for several millennia and recently has increasingly contributed to a growing dairy industry. Water resources are declining, and saline or brackish irrigation water is an increasing problem in the SW. Irrigation water that is highly saline can cause a buildup of salts in the soil. Adapted SW maize germplasm may offer stress tolerance that could be incorporated into breeding programs. The objective of this study was to evaluate 13 maize cultivars and compare them to four commercial hybrids across 2 yr and three locations in New Mexico. Two of the locations were characterized by saline and/or brackish conditions. Agronomic factors including forage yield, forage quality, survival rates, and plant height were examined. The landrace 'Mexican June' and the synthetic population Arizona 8601 demonstrated good forage yields and higher survival rates at one stress location during 2016 (p < .05). Most southwestern landraces showed lower forage quality when compared to silage-specific commercial hybrids. The landrace 'Montgomery County Blue and White' was an exception; it produced forage quality similar to that of one of the commercial hybrids while also producing comparable yield. Results indicate there is potential for further development of these genetic resources for selection of improved salinity tolerance in forage maize for production in semi-arid regions.