Genetic variability in popcorn synthetic population

Abstract

The Brazilian popcorn has low genetic variability and the successful development of advanced lines, new popcorn cultivars with high grain yield (GY) and expansion volume (PE) is dependent on parental selection and precise determination of heterotic groups. The aim of this study was to evaluate genetic variability and identify heterotic groups in synthetic populations of popcorn, using diallel crosses. Thus, nine synthetic populations were crossed using complete diallel scheme. The GY and PE traits of 36 hybrids and reciprocals were evaluated in a randomized complete block design with 72 treatments and two replicates in two years. The effects of non-additive genes were the most important in the genetic control of these traits, indicating a favorable situation to produce hybrids. The reciprocal effect is mainly due to non-maternal effects for GY and PE. The highest GY values were obtained for the 02 x 08, 04 x 09, 05 x 09, and 01 x 09 crosses and the highest PE were obtained for the 07 x 01 and 03 x 04 crosses. The exploitation of synthetic populations from S3 lines can be an alternative to increase the genetic variability for grain yield and popping expansion in popcorn breeding programs.

Combined Dominance and Additive Gene Effects in Trait Inheritance of Drought-Stressed and Full Irrigated Popcorn

“…In contrast to the reports of Oliveira et al [35] and Santos et al [36], in this study, the number of dominant genes for PE was close to zero (−0.04 under WS and−0.08 under WW), demonstrating that there are no dominant alleles in the genes that control PE. Moreover, the determination coefficient in the narrow sense was >50%; therefore, the additive effect is predominant over the non-additive effects, regardless of the water regime [15,20].…”

“…However, in an evaluation of the same trait by SSR mapping, Babu et al [34] found QTLs with both dominant and partially dominant gene action. Similarly, in diallel studies on PE, Oliveira et al [35] and Santos et al [36] detected dominant gene action.…”

Evidence of Additive Inheritance of Popping Expansion in Popcorn

“…On the other hand, molecular marker studies identified markers associated with QTLs for popping expansion with complete dominance, partial dominance and overdominance effects (Babu et al, 2006;Li et al, 2017), clearly showing the non-exclusivity of additive effects on PE expression. More recently, Oliveira et al (2018) observed the influence of dominance effects on PE in a diallel analysis of S3 popcorn lines and recommended the exploitation of heterosis for significant increases in the trait. Moreover, in an attempt to better understand PE inheritance, Coan et al (2019) established the popcorn × dent corn cross and stated mixed inheritance in PE expression.…”

“…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).…”

Estimation and classification of popping expansion capacity in popcorn breeding programs using NIR spectroscopy

“…Owing to targeted breeding and selection, the PE capacity of popcorn has significantly increased over the last few decades. Recent reports have demonstrated that the PE values of popcorn have approximately doubled in comparison to those of the older American (25 mL.g -1 ) (Galvão et al, 2015) and Brazilian popcorn varieties (15 mL.g -1 ) (Zinsly and Machado, 1987), and the PE values of the current popcorn breeds are approximately 30 mL.g -1 (Amaral Junior et al, 2012;Oliveira et al, 2019).…”