Genomic prediction applied to reciprocal recurrent selection scheme in tropical maize for nitrogen use efficiency

• Grant number: 17/25549-6
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date until: March 01, 2018
• End date until: June 30, 2020
• Field of knowledge: Agronomical Sciences - Agronomy
• Principal Investigator: Roberto Fritsche Neto
• Grantee: Júlia Silva Morosini
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated scholarship(s): 19/06532-0 - Genomic prediction applied to reciprocal recurrent selection scheme in tropical maize for nitrogen use efficiency, BE.EP.DR

Abstract

One of the assumptions of diallel analysis is to assume parents as unrelated, which in practice does not occur and can lead to biased results. In addition, another critical factor in a hybrid breeding program is the genomic prediction being performed based on the same allelic substitution effects for two complementary heterotic groups. This may lead to a convergent selection of parents and, consequently, reduce the probability of hybrid obtention with high heterosis through the cycles. In this sense, the objective are: i) to estimate the effect of the genomic relationship matrix on the estimates in diallel analyzes; ii) to identify the effect of the differential modeling of marker effects on heterotic groups in a maize breeding population though reciprocal recurrent selection. Mixed models will be used to conduct the phenotypic, diallel and genomic prediction analyzes. Phenotypic data will be yield and response indices to nitrogen in tropical maize from two datasets, USP and Helix Sementes Ltda enterprise. For the first objective, VanRaden genomic relationship matrix will be included in diallel analyzes to verify its effect in general and specific combining ability (GCA and SCA), in the determination of heterotic groups, and in the choice of testers. In the second objective, three prediction models will be considered: i) common additive effects for the entire population; ii) common additive-dominant effects for the entire population; iii) specific additive effects for each heterotic group and interaction between them - II North Carolina design. From the results, we intend to evaluate the modeling effect on prediction ability, variability inside groups and genetic distance between heterotic groups throughout selection cycles.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MATIAS, FILIPE INACIO; MOROSINI, JULIA SILVA; ESPOLADOR, FERNANDO GARCIA; FRITSCHE-NETO, ROBERTO. Be-Breeder 2.0: A Web Application for Genetic Analyses in a Plant Breeding Context. CROP SCIENCE, v. 59, n. 4, p. 1371-1373, JUL-AUG 2019. (17/25549-6)

GALLI, GIOVANNI; ALVES, FILIPE COUTO; MOROSINI, JULIA SILVA; FRITSCHE-NETO, ROBERTO. On the usefulness of parental lines GWAS for predicting low heritability traits in tropical maize hybrids. PLoS One, v. 15, n. 2, FEB 7 2020. (13/24135-2, 17/24327-0, 17/25549-6)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

MOROSINI, Júlia Silva. Inferring heterotic patterns and the effect of incorporating dominance deviations for hybrid prediction: an example in tropical maize under nitrogen stress conditions. 2020. Doctoral Thesis - Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) Piracicaba.