Pathway analyses in wheat genotypes under waterlogging stress

Abstract

Indirect selection can be considered an interesting strategy for plant breeding, especially when an easily measurable/high heritability trait is highly correlated with a target trait which has a lower heritability in segregating populations. The objective of this study was to obtain estimates of phenotypic, genotypic and environmental correlations and to evaluate the partition of genotypic correlations in direct and indirect effects of agronomic variables on the GY variable, through the analysis of two cultivated environments in fifteen wheat segregating populations. The agronomic traits grain yield per plant (GY), number of grains per ear (NGE), grain weight per ear (GWE), thousand grain weight (TGW), number of fertile tillers (NFT), days from emergence to flowering (DEF), days from flowering to maturity (DFM), total development cycle (CYC), and percentage of lodging (LODG), were evaluated in F4 populations under two cropping systems (with and without flooding). In all populations, by means of simple correlations, the selection of more productive plants can be accomplished by indirect selection for NGE, GWE and NFT. Through path analysis, it was possible to identify an indirect effect on GY by NGE. Also, the effect of GWE, NFT, CYC and DEF on the correlation between other characters (NGE x GY, GY x WTG, DFM x GY, GY x CYC and GY x LODG), emphasizing that the NGE, GWE, NFT, DEF and CYC are the main characters to consider for increasing grain yield in wheat.