Cardinal temperatures of populations developed from native maize (Zea mays L.) from central and southern, Tamaulipas, Mexico

Abstract

Objective: To estimate the cardinal temperatures of native maize populations from Tamaulipas. Design/Methodology/Approach: Ten genotypes developed from native germplasms were established in Güémez, Tamaulipas, on 12 planting dates (2019 and 2020). The cardinal temperatures (Tb, To, and Tu) of each of the cultivars were estimated through the decomposition of a quadratic model, using the days from sowing to tasseling and the average temperature of each sowing date from that period. Results: From sowing to tasseling, the evaluated cultivars recorded 15.7-18.1 °C base temperatures (Tb), 28.3-30.1 °C optimum temperatures (To), and 32.3-34.4 °C threshold temperatures (Tu). The Tb and To values represent the high thermal requirement of the germplasm, while Tu stands for its resistance to high temperatures. The L3, L4, L5, and VHA cultivars stood out for their broader adaptation range (16.2 to 34.4 °C), while the L3, L4, and L6 cultivars have a higher resistance to high temperatures (average Tu: 34.5 °C). Study Limitations/Implications: The cardinal temperatures determined in this study depended on the evaluated genotypes and the environment in which they developed. Findings/Conclusions: The maize germplasm evaluated in this study was resistant to high temperatures. As a result of its adaptation to the conditions of central and southern Tamaulipas, this germplasm is a source of variation for the characteristics that provide resistance to the stress caused by high temperatures.