Can Genetic Progress for Drought Tolerance in Popcorn Be Achieved by Indirect Selection?

• Published in: Agronomy (Basel) Vol. 9; no. 12; p. 792
• Main Authors: Kamphorst, Samuel Henrique, Amaral Júnior, Antônio Teixeira do, Lima, Valter Jário de, Guimarães, Lauro José Moreira, Schmitt, Kátia Fabiane Medeiros, Leite, Jhean Torres, Santos, Pedro Henrique Araújo Diniz, Chaves, Marcelo Moura, Mafra, Gabrielle Sousa, Santos Junior, Divino Rosa dos, Cruz, Cosme Damião, Campostrini, Eliemar
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 22-11-2019
• Subjects: Agricultural production; Corn; direct effect; Drought; Drought resistance; drought stress; Dry matter; expanded popcorn volume per hectare; Genotype-environment interactions; Genotypes; Germplasm; Grain; Irrigation; Irrigation water; path analysis; Physiological effects; Physiology; spad; Variance analysis; Water shortages; Water supply; Brazil; United States > US
• ISSN: 2073-4395; 2073-4395
• DOI: 10.3390/agronomy9120792

The objective of this study was to estimate the direct and indirect effects of agricultural, morphological, physiological, and root traits of popcorn lines, under two conditions of water supply: full irrigation (FI) and drought stress (DS). A complete randomized block design with three replications was used to evaluate the following traits: expanded popcorn volume per hectare (EPV), 100-grain weight (100GW), mean ear length, mean ear diameter, number of grains per row (NGR), prolificacy (PRO), anthesis to silking interval, tassel length, number of tassel branches, plant height, shoot dry matter, green index (SPAD), and canopy temperature depression (CTD), root angle (RA), tap root volume (TRV), and crown root volume (CRV). Analyses of variance and path analysis, and subsequent partitioning of direct and indirect effects were performed. For the traits EPV, PRO, CTD, RA, CRV and TRV, the genotype x environment interaction was significant. Drought stress had significant effects on EPV (−7.15%), 100GW (−23.52%), SPAD (−29.31%), CTD (87.15%), RA (24.54%), and CRV (44.89%). The traits NGR and SPAD were found to be decisive for the expression of EPV. The exploitation of these traits by indirect selection is expected to induce increments in EPV in environments under DS and FI.