Abstract
Trehalose 6‐phosphate (T6P) signalling regulates carbon use and allocation and is a target to improve crop yields. However, the specific contributions of trehalose phosphate synthase (TPS) and trehalose phosphate phosphatase (TPP) genes to source‐ and sink‐related traits remain largely unknown. We used enrichment capture sequencing on TPS and TPP genes to estimate and partition the genetic variation of yield‐related traits in a spring wheat (Triticum aestivum) breeding panel specifically built to capture the diversity across the 75,000 CIMMYT wheat cultivar collection. Twelve phenotypes were correlated to variation in TPS and TPP genes including plant height and biomass (source), spikelets per spike, spike growth and grain filling traits (sink) which showed indications of both positive and negative gene selection. Individual genes explained proportions of heritability for biomass and grain‐related traits. Three TPS1 homologues were particularly significant for trait variation. Epistatic interactions were found within and between the TPS and TPP gene families for both plant height and grain‐related traits. Gene‐based prediction improved predictive ability for grain weight when gene effects were combined with the whole‐genome markers. Our study has generated a wealth of information on natural variation of TPS and TPP genes related to yield potential which confirms the role for T6P in resource allocation and in affecting traits such as grain number and size confirming other studies which now opens up the possibility of harnessing natural genetic variation more widely to better understand the contribution of native genes to yield traits for incorporation into breeding programmes.
Highlights
The genetic improvement of wheat for increased yields is an urgent challenge
The trehalose pathway as a sugar signalling system consisting of trehalose phosphate synthase (TPS) and trehalose phosphate phosphatase (TPP) genes is emerging as a central regulator of both source-and sink-related traits
Our study has generated a wealth of information regarding links of TPS and TPP genes to yield traits, historical and ongoing selection which will serve to direct strategies of crossing and selection from a diverse CIMMYT genetic resource and for in-depth mode of action studies to define the specific contribution of TPS and TPP genes to yield-related traits
Summary
The genetic improvement of wheat for increased yields is an urgent challenge. In bread wheat (Triticum aestivum L.), studies are increasingly focusing on the relationship between the supply of assimilates and the capacity to utilize carbohydrates, that is source and sink and their integration to increase genetic gains for yield (Reynolds et al, 2017). Consistent with a central function in the regulation of carbon and energy balance, Kretzschmar et al, (2015) showed that a TPP gene, OsTPP7, as the genetic determinant in qAG-9 –2, a major quantitative trait locus (QTL) for the promotion of anaerobic germination under flooding in rice. All these examples show the centrality of the pathway in determining yield processes and significantly both TPS and TPP genes are listed as having been modified during domestication in maize (Hufford et al, 2012), potato (Xu et al, 2017) and sugarcane (Hu et al, 2020). Our study has generated a wealth of information regarding links of TPS and TPP genes to yield traits, historical and ongoing selection which will serve to direct strategies of crossing and selection from a diverse CIMMYT genetic resource and for in-depth mode of action studies to define the specific contribution of TPS and TPP genes to yield-related traits
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
