Genetic Gains in the Popcorn Population Uenf-14: Developing the Ninth Generation of Intrapopulation Recurrent Selection

Abstract

The occurrence of negative correlations between grain yield (GY) and popping expansion (PE) in popcorn complicates the selection process. In an attempt to overcome this inconvenience, we proposed the use of the importance characteristic volume per popcorn per hectare (PV). The objectives of this study were to develop the ninth cycle of the UENF-14 popcorn population, to estimate the direct and indirect effects of PV and to verify the genetic progress among all selective cycles. We obtained and evaluated 200 inbred progenies in randomised blocks arranged in replicates within sets, with nine sets consisting of 25 progenies and one set with all previous eight cycles with three replicates. The average height of the plants, prolificacy, 100-grain weight, grain yield, grain popping expansion and volume per popcorn per hectare were evaluated. Track analysis was performed to determine the direct and indirect effects, and the Mulamba and Mock selection index was calculated for the selection of the 40 superior progenies. There was genetic variability among progenies in all evaluated traits, with a cause-and-effect relationship between PV with GY and PE, allowing simultaneous gains with indirect selection. The selection of the best progenies was more effective when using arbitrarily assigned weights, which provided higher predicted gains for PV (20.73%). The means obtained in all cycles indicated increases, demonstrating the efficiency of using continuous recurrent selection in popcorn breeding programs.

Exploring the use of testers to maximize selection accuracy of partially inbred S3 popcorn progenies

“…Two main breeding strategies are used to develop superior popcorn genotypes for registration and release as new cultivars, specifically recurrent selection and hybridization (Amaral Júnior et al, 2013;Guimarães et al, 2019). Recurrent selection increases the number of favorable alleles gradually, without altering the genetic variability of the population (Ribeiro et al, 2016).…”

Regional Heritability Mapping of Quantitative Trait Loci Controlling Traits Related to Growth and Productivity in Popcorn (Zea mays L.)

“…However, when partitioning the genome, as in the RHM method, the values within each genomic window may be too low to be detected by the analysis. The same is not true for GY, for which the highest heritability values were recorded by RHM, and which, despite the strong environmental influence on it [ 66 , 67 ], has been shown to remain stable in successive cycles of intrapopulation recurrent selection in the population sampled here [ 70 , 71 ].…”

“…In the UENF-14 population intrapopulation recurrent selection program, it was observed that heritability remained stable in cycles 4, 5 and 6 (45.97%, 51.94%, and 45.04%, respectively) [ 70 ]. In addition, a heritability of 91% for GY was observed in cycle 9 of the same population [ 71 ]. In research carried out by Resende and collaborators [ 24 ], the estimated genomic heritability captured a relatively large proportion (72%) of the total heritability of the traits.…”

Evidence of Additive Inheritance of Popping Expansion in Popcorn

“…In spite of increasing gains in popping expansion in intrapopulation breeding programs (Pacheco et al, 1998;Pereira and Amaral Júnior, 2001;Amaral Junior et al, 2013;Vieira et al, 2017;Guimarães et al, 2019), the existence of publications describing dominance effects for PE must lead to the recommendation of hybrid exploitation with a view to improving the popping expansion (Faria et al, 2008;Oliveira et al, 2018;Coan et al, 2019;Santos et al, 2020).…”