Maize responsiveness to Azospirillum brasilense: Insights into genetic control, heterosis and genomic prediction

Author(s)

Vidotti, Miriam Suzane ^[1] ; Matias, Filipe Inacio ^[1] ; Alves, Filipe Couto ^[2] ; Perez-Rodriguez, Paulino ^[3] ; Alvarado Beltran, Gregorio ^[4] ; Burgueno, Juan ^[4] ; Crossa, Jose ^[4] ; Fritsche-Neto, Roberto ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Genet, Luiz de Queiroz Coll Agr, Piracicaba, SP - Brazil

^[2] Michigan State Univ, Dept Epidemiol & Biostat, E Lansing, MI 48824 - USA

^[3] Colegio Postgrad, Dept Stat, Texcoco, Estado De Mexic - Mexico

^[4] Int Maize & Wheat Improvement Ctr CIMMYT, Biometr & Stat Unit, Texcoco, Estado De Mexic - Mexico

• Document type: Journal article
• Source: PLoS One; v. 14, n. 6 JUN 7 2019.
• Web of Science Citations: 0

Abstract

Several studies have shown differences in the abilities of maize genotypes to facilitate or impede Azospirillum brasilense colonization and to receive benefits from this association. Hence, our aim was to study the genetic control, heterosis effect and the prediction accuracy of the shoot and root traits of maize in response to A. brasilense. For that, we evaluated 118 hybrids under two contrasting scenarios: i) N stress (control) and ii) N stress plus A. brasilense inoculation. The diallel analyses were performed using mixed model equations, and the genomic prediction models accounted for the general and specific combining ability (GCA and SCA, respectively) and the presence or not of GxE effects. In addition, the genomic models were fitted considering parametric (G-BLUP) and semi-parametric (RKHS) kernels. The genotypes showed significant inoculation effect for five root traits, and the GCA and SCA were significant for both. The GCA in the inoculated treatment presented a greater magnitude than the control, whereas the opposite was observed for SCA. Heterosis was weakly influenced by the inoculation, and the heterozygosity and N status in the plant can have a role in the benefits that can be obtained from this Plant Growth-Promoting Bacteria (PGPB). Prediction accuracies for N stress plus A. brasilense ranged from 0.42 to 0.78, depending on the scenario and trait, and were higher, in most cases, than the non-inoculated treatment. Finally, our findings provide an understanding of the quantitative variation of maize responsiveness to A. brasilense and important insights to be applied in maize breeding aiming the development of superior hybrids for this association. (AU)

• FAPESP's process: 15/01188-9 - Phenotypic and genome-wide association studies of the interaction between Burkholderia ambifaria RZ2MS16, a plant growth promoter rhizobacteria, and the tropical maize
• Grantee: João Lúcio de Azevedo
• Support Opportunities: Regular Research Grants