# Morphological and Phenological Diversity of Pod Corn (Zea mays Var. Tunicata) from Mexico and Its Functional Traits Under Contrasting Environments

## TL;DR

This study explores the morphological and nutritional diversity of pod corn in Mexico, showing its adaptability and potential for agriculture and food applications.

## Contribution

The study quantifies morphological and compositional diversity of pod corn under contrasting environments and evaluates its functional traits.

## Key findings

- Pod corn accessions showed strong plasticity and significant accession × environment effects on ear morphology and maturation.
- Including the tunic in processing altered proximate composition, increasing moisture/ash and lowering fat and protein.
- Grain yields reached up to 10.78 t ha−1, exceeding typical yields for native Mexican corn varieties.

## Abstract

Pod corn (Zea mays var. tunicata) bears leafy glumes that enclose kernels, resembling a partial reversion to wild-forms, yet remains poorly characterized in situ in Mexico. We evaluated Mexican accessions at two contrasting locations to quantify morphological/phenological diversity and to assess functional traits via proximate kernel composition. Standard descriptors captured variation in plant architecture, tassel/ear traits (including glume length), and reproductive timing. Accessions showed strong plasticity and significant accession × environment effects on ear morphology and maturation. Grain yield ranged from 6.32 to 10.78 t ha−1, with peak values comparable to commercial hybrids and above-typical yields reported for native Mexican races (2.7–6.6 t ha−1). Proximate analysis showed that milling with the tunic increased moisture/ash (up to 3.07% vs. 1.80% in dehulled grain), tended to lower fat and protein, and yielded lower crude fiber than dehulled samples (0.78–0.96% vs. 1.59–1.77%); protein varied widely (1.05–6.64%). Thus, the tunic modulates elemental composition, informing processing choices (with vs. without tunic). Our results document a spectrum of morphotypes and highlight developmental diversity and field adaptability. The observed accession × environment responses provide a practical baseline for comparisons with native and improved varieties, and help guide product development strategies. Collectively, these data underscore the high productive potential of pod corn (up to 10.78 t ha−1 under optimal management) and show that including the tunic substantially alters proximate composition, establishing a quantitative foundation for genetic improvement and food applications. Overall, pod corn’s distinctive ear morphology and context-dependent composition reinforce its value for conservation, developmental genetics, and low-input systems.