The Impacts of Flowering Time and Tillering on Grain Yield of Sorghum Hybrids across Diverse Environments

Abstract

Sorghum in Australia is grown in water-limited environments of varying extent, generating substantial genotype × environment interaction (GEI). Much of the yield variation and GEI results from variations in flowering time and tillering through their effects on canopy development. The confounding effects of flowering and tillering complicate the interpretation of breeding trials. In this study, we evaluated the impacts of both flowering time (DTF) and tillering capacity (FTN) on yield of 1741 unique test hybrids derived from three common female testers in 21 yield testing trials (48 tester/trial combinations) across the major sorghum production regions in Australia in three seasons. Contributions of DTF and FTN to genetic variation in grain yield were significant in 14 and 12 tester/trial combinations, respectively. The proportion of genetic variance in grain yield explained by DTF and FTN ranged from 0.2% to 61.0% and from 1.4% to 56.9%, respectively, depending on trials and genetic background of female testers. The relationship of DTF or FTN with grain yield of hybrids was frequently positive, but varied across the genetic background of testers. Accounting for the effects of DTF and FTN using linear models did not substantially increase the between trial genetic correlations for grain yield. The results suggested that other factors affecting canopy development dynamics and grain yield might contribute GEI and/or the linear approach to account for DTF and FTN on grain yield did not capture the complex non-linear interactions.

Breeding crops for drought-affected environments and improved climate resilience

“…The study of yield–trait performance landscapes demonstrated these are often complex, rugged surfaces to be explored by the breeding program, and thus create multiple opportunities to improve crop drought resistance and yield reaction-norms over multiple breeding program cycles ( Figure 5 ; Cooper et al, 2005 ; Hammer et al, 2006 ; Messina et al, 2011 ; Technow et al, 2021 ). These studies also demonstrate that multiple trait pathways can create temporal dynamics at a crop level, which are all conducive to drought resistance; stomatal conductance response to vapor pressure deficit ( Sinclair et al, 2010 ; Choudhary et al, 2014 ), xylem conductance ( Passioura, 1972 ; Richards and Passioura, 1989 ), plant size ( Borrell et al, 2014 ), and propensity to tillering ( Wang et al, 2020 ) can all lead to similar patterns of water use pre- and post-flowering. Agronomic management practices such as changing planting density can further affect the soil water dynamics in ways that amplify or dampen the impacts of any trait or trait combinations (e.g., Messina et al, 2011 , 2015 , 2021 ; Cooper et al, 2023 ).…”

Genetic characterization of aSorghum bicolormultiparent mapping population emphasizing carbon-partitioning dynamics

“…The construction of this NAM complements the existing sorghum resources and the ongoing reference genome assemblies, pan-genomics projects, and database development which should increase the utility and accessibility for researchers worldwide ( Boyles et al 2019 ). The incorporation of photoperiod sensitive, nontemperately adapted material provides germplasm that is not confounded by the prevalence of dwarfing and photoperiod insensitive alleles ( Wang et al 2020 ). Here, we perform a quality assessment of the CP-NAM as a genomic resource and validate the population for use in genomic studies using pericarp and testa phenotypes as positive controls to map known genes affecting these phenotypes.…”

Grain yield, nutritional, polyphenols and antioxidant capacity in accessions of sorghum (Sorghum bicolor L. Moench)

“…The results for DF differ from those obtained by Galicia-Juárez et al (2020), who reported early genotypes with a flowering range of 51 to 71 days, and late genotypes with a range of 72 to 79 days. Early cycle sorghums are tolerant of drought and high temperatures, they can also have higher yields compared to late flowering varieties (Menezes et al, 2021), because early maturing sorghums can evade the stress of a late drought through earlier grain filling, as this becomes a limitation for sorghum production worldwide (Wang et al, 2020). However, late sorghums are characterized by reaching a greater length and diameter of the stem and number of internodes, which are used to produce ethanol because of their high content of juice and sugar (Naoura et al, 2020).…”