The aim of this study was to evaluate grain yield (GY), popping expansion (PE), popping expansion disregarding the weight of unpopped kernels (PEW), and eleven other agronomic and morphological traits of 14 local popcorn varieties (LPV) from far west of the state of Santa Catarina, Southern Brazil. Two experiments were carried out, in a completely randomized block design with three replications, in different regions of Santa Catarina: one in the municipality of Florianópolis (east coast) and the other in Anchieta (western). Grain yield had the highest positive correlation with prolificacy (PRL) (r = 0.72) and number of grains per row (NGR) (r = 0.71), and a negative correlation with caryopsis circularity index (CCI) (r = −0.67). Variable PEW showed a positive correlation with CCI (r = 0.70) and with thickness/width ratio (TWR) (r = 0.70). Variety 574A stood out for high PE and PRL. The improvement of composite populations and of populations per se is a potential breeding strategy for LPV, based on the complementarity and correlation among variables and the GY, PE, and PEW values, CCI – HEP – first ear height/plant height relation, PH – plant height; PRL – WHG – weight of 100 grains; VHG - volume of 100 grains; EL – ear length; NRE – number of rows per ear; NGR – number of grains per row of ear; ED – ear diameter.

Figure S1. Spatial distribution of diversity in effective species numbers (q = 1; Shannon entropy) at Reserva Biológica União. Circles indicate the position of each camera trap station and circle sizes are proportional to diversity. Numbers in white indicate diversity. Upper right panel: RBU current area, after expansion; Middle panel: RBU position in Rio de Janeiro state.