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

Gabrielle Sousa Mafra,Vitor Batista Pinto,Pedro Henrique Araujo Diniz Santos,Carlos Maldonado,Freddy Mora-Poblete,Rosimeire Barboza Bispo,Antônio Teixeira Do Amaral Junior,Talles De Oliveira Santos,Samuel Henrique Kamphorst,Valter Jário De Lima,Janeo Eustáquio De Almeida Filho,Divino Rosa Dos Santos Junior,Uéliton Alves De Oliveira,Sunny Ahmar,Jhean Torres Leite,Caio Cezar Guedes Correa,Alexandre Pio Viana

doi:10.3390/plants10091845

Abstract

The method of regional heritability mapping (RHM) has become an important tool in the identification of quantitative trait loci (QTLs) controlling traits of interest in plants. Here, RHM was first applied in a breeding population of popcorn, to identify the QTLs and candidate genes involved in grain yield, plant height, kernel popping expansion, and first ear height, as well as determining the heritability of each significant genomic region. The study population consisted of 98 S1 families derived from the 9th recurrent selection cycle (C-9) of the open-pollinated variety UENF-14, which were genetically evaluated in two environments (ENV1 and ENV2). Seventeen and five genomic regions were mapped by the RHM method in ENV1 and ENV2, respectively. Subsequent genome-wide analysis based on the reference genome B73 revealed associations with forty-six candidate genes within these genomic regions, some of them are considered to be biologically important due to the proteins that they encode. The results obtained by the RHM method have the potential to contribute to knowledge on the genetic architecture of the growth and yield traits of popcorn, which might be used for marker-assisted selection in breeding programs.

Highlights

Maize (Zea mays L.) is among the most important cereal crops in the world in addition to wheat and rice [1], which has been widely cultivated due to its nutritional composition, versatility, and broad adaptability
It was confirmed that regional heritability mapping (RHM) has the potential to explain some portion of missing heritability by capturing variance caused by QTL with low MAF and multiple independent QTL within a region, as determined for grain yield
The genomic regions identified by RHM allowed further examination towards candidate genes discovery

Summary

Introduction

Maize (Zea mays L.) is among the most important cereal crops in the world in addition to wheat and rice [1], which has been widely cultivated due to its nutritional composition, versatility, and broad adaptability. Both the land area used for maize grain production and the amount of maize produced per unit area in Brazil has increased in recent years by 25% and 60%, respectively [2], which makes Brazil the third largest maize grain producer worldwide. The economically most important traits evaluated in popcorn breeding programs are grain yield (GY) and popping expansion (PE) [4]. The yield (GY and PE) and growth (PH and EH) traits of maize are usually quantitatively inherited, and their genetic basis is controlled by the interaction between multiple genetic and environmental factors [1,5,6,7]

Methods

Findings

Discussion

Conclusion