SELECTION OF A WHITE-GRAIN QPM MAIZE WITH HIGH ZINC CONTENT

Abstract

The adaptability and stability of white-grain maize varieties with normal endosperm, high zinc content, and quality protein maize (QPM) characteristics were evaluated across 16 locations in Panama. Field trials were conducted in collaborating farmers’ fields and at the El Ejido Experimental Station of the Panamanian Agricultural Innovation Institute (IDIAP) over three consecutive years (2022–2024). During the first year, 18 varieties were evaluated; this number was subsequently reduced to 12, and in the final year, the best-performing candidate was compared with six varieties previously released by the national maize breeding project. Experiments were established using a randomized complete block design with three replications. Data were analyzed using a combined restricted maximum likelihood (REML) analysis of variance, and treatment means were separated using the least significant difference (LSD) test. Individual and combined analyses of variance across years revealed highly significant differences among varieties for grain yield and other agronomic traits. Combined analyses across environments, together with stability analyses, identified the synthetic variety S16LTWNQHZNHGAB01 as the highest-yielding and most stable genotype across locations. After three years of evaluation, the local check variety IDIAP-MQ-09 achieved a mean grain yield of 4.70 t^.ha⁻¹, whereas S16LTWNQHZNHGAB01 produced 6.06 t^.ha⁻¹, representing a yield increment of more than 25%. The GGE-SReg biplot analysis further identified S16LTWNQHZNHGAB01 as the most stable genotype across environments. Reliability analysis of the standardized response indicated that the new variety outperformed the national check in approximately 9 out of 10 test environments. Based on its superior yield performance, stability, and adaptability, the registration and release of S16LTWNQHZNHGAB01 for cultivation by farmers in the Republic of Panama is recommended.