Proposal of a super trait for increased grain yield, popping expansion, and ear rot resistance in popcorn

Abstract

Fusarium ear rot (FER) is a disease that causes a decrease in grain quality in several popcorn fields in tropical regions. To contribute to the development of popcorn cultivars resistant to FER and superior in the main agronomic traits, the study aimed to compare gains in popping expansion (PE), grain yield (GY), and FER resistance through direct and indirect selection strategies by proposing a new super trait. The study was conducted in Campos dos Goytacazes, RJ. The traits were evaluated in 41 inbred lines from four environments using a randomized block design with four replicates. Six selection strategies and four selection intensities were tested. Direct selection on GY resulted in losses in PE and small gains in FER in the majority of the environments. Positive selection on PE resulted in FER reduction in scenarios of lower selection intensity. Selection by popping volume showed a satisfactory increase in GY and PE but was not effective in FER reduction. Selection by multi‐trait genotype–ideotype distance index resulted in GY increase only in some environments, PE increase in all environments, and FER reduction in all environments under higher selection intensities. The newly developed super trait popping volume without Fusarium (PVwF) showed the possibility of increasing GY (32.90% at 88.8%) and PE (5.10% at 10.20%) while simultaneously reducing FER in all environments and selection intensities (−6.30% at −6.70%). PVwF is an easily executable methodology to help popcorn breeders optimize gains in their programs. The lines L214, L217, L292, and L328 are more suitable for use in mating blocks aimed to develop superior popcorn hybrids.