Genetic Variability in Maize Lines (Zea mays L.) with Multiple Ears under High-Andean Conditions

Abstract

Maize cultivated in Peru's central highlands faces productive limitations that compromise local food security. Prolificity, defined as the capacity to produce two or more ears per plant, represents a promising strategy to increase yield without expanding cultivated area. This study reports the identification of prolific lines in the germplasm bank of Agencia Agraria Chincheros Apurímac, contributing to the development of genetic alternatives for mountain agriculture. A total of 520 maize lines were phenotypically evaluated under open pollination conditions in two experimental plots located between 2,850 and 3,600 meters altitude. A descriptive observational design was applied, sampling 10 plants per line and recording the number of ears per plant as the main variable. Data were analyzed using descriptive statistics and classified into prolificity ranges. Results revealed that 97 lines (18.7%) presented prolific capacity, producing between two and five ears per plant. The distribution showed greater concentration in medium ranges (34.8%), while three exceptional lines reached the very high range (1.75-2.10 ears per plant). No adverse effects associated with multiple ear proliferation were recorded, maintaining normal vegetative vigor. The identification of prolific germplasm represents a valuable genetic resource for breeding programs oriented toward yield improvement. These lines offer potential to increase productivity between 50 and 100 percent per plant, constituting a sustainable alternative to strengthen food security in central highland ecosystems without requiring additional inputs.