Premium
Stay‐green alleles individually enhance grain yield in sorghum under drought by modifying canopy development and water uptake patterns
Author(s) -
Borrell Andrew K.,
Oosterom Erik J.,
Mullet John E.,
GeorgeJaeggli Barbara,
Jordan David R.,
Klein Patricia E.,
Hammer Graeme L.
Publication year - 2014
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.12869
Subject(s) - sorghum , agronomy , canopy , anthesis , quantitative trait locus , biology , drought tolerance , crop , sweet sorghum , grain yield , biomass (ecology) , poaceae , cultivar , botany , gene , biochemistry
Summary Stay‐green is an integrated drought adaptation trait characterized by a distinct green leaf phenotype during grain filling under terminal drought. We used sorghum ( Sorghum bicolor ), a repository of drought adaptation mechanisms, to elucidate the physiological and genetic mechanisms underpinning stay‐green. Near‐isogenic sorghum lines (cv RT x7000) were characterized in a series of field and managed‐environment trials (seven experiments and 14 environments) to determine the influence of four individual stay‐green ( Stg1–4 ) quantitative trait loci ( QTL s) on canopy development, water use and grain yield under post‐anthesis drought. The Stg QTL decreased tillering and the size of upper leaves, which reduced canopy size at anthesis. This reduction in transpirational leaf area conserved soil water before anthesis for use during grain filling. Increased water uptake during grain filling of Stg near‐isogenic lines ( NIL s) relative to RT x7000 resulted in higher post‐anthesis biomass production, grain number and yield. Importantly, there was no consistent yield penalty associated with the Stg QTL in the irrigated control. These results establish a link between the role of the Stg QTL in modifying canopy development and the subsequent impact on crop water use patterns and grain yield under terminal drought.