TY - JOUR

T1 - Co-Evolution of Sink and Source in the Recent Breeding History of Winter Wheat in Germany

AU - Lichthardt, Carolin

AU - Chen, Tsu Wei

AU - Stahl, Andreas

AU - Stützel, Hartmut

N1 - Funding information: This research was funded by the German Federal Ministry of Education and Research (BMBF) grant 031A354 provided to HS within the project Breeding Innovations in Wheat for Resilient Cropping Systems (BRIWECS) as part of the funding initiative Innovative Plant Breeding in the Production Systems (IPAS). We thank Leibniz Open Access Publishing Fund for covering the publication cost. The authors gratefully acknowledge Katharina Meyer, Deike Stadler-Wördehoff, Petra Plinke, and Tino Schulenberg for their technical assistance, the group of Prof. Dr. Jens Leon (Department of Plant Breeding, University of Bonn) for providing SNP data, and Dr. Huey Tyng Lee (Department of Plant Breeding, Justus Liebig University, Giessen) for providing physical positions of the SNP markers on the reference genome.

PY - 2020/2/7

Y1 - 2020/2/7

N2 - Optimizing the interplay between sinks and sources is of crucial importance for breeding progress in winter wheat. However, the physiological limitations of yield from source (e.g. green canopy duration, GCD) and sink (e.g. grain number) are still unclear. Furthermore, there is little information on how the source traits have been modified during the breeding history of winter wheat. This study analyzed the breeding progress of sink and source components and their relationships to yield components. Field trials were conducted over three years with 220 cultivars representing the German breeding history of the past five decades. In addition, genetic associations of QTL for the traits were assessed with genome-wide association studies. Breeding progress mainly resulted from an increase in grain numbers per spike, a sink component, whose variations were largely explained by the photosynthetic activity around anthesis, a source component. Surprisingly, despite significant breeding progress in GCD and other source components, they showed no direct influence on thousand grain weights, indicating that grain filling was not limited by the source strength. Our results suggest that, 1) the potential longevity of the green canopy is predetermined at the time point that the number of grains is fixed; 2) a co-evolution of source and sink strength during the breeding history contribute to the yield formation of the modern cultivars. For future breeding we suggest to choose parental lines with high grain numbers per spike on the sink side, and high photosynthetic activity around anthesis and canopy duration on the source side, and to place emphasis on these traits throughout selection.

AB - Optimizing the interplay between sinks and sources is of crucial importance for breeding progress in winter wheat. However, the physiological limitations of yield from source (e.g. green canopy duration, GCD) and sink (e.g. grain number) are still unclear. Furthermore, there is little information on how the source traits have been modified during the breeding history of winter wheat. This study analyzed the breeding progress of sink and source components and their relationships to yield components. Field trials were conducted over three years with 220 cultivars representing the German breeding history of the past five decades. In addition, genetic associations of QTL for the traits were assessed with genome-wide association studies. Breeding progress mainly resulted from an increase in grain numbers per spike, a sink component, whose variations were largely explained by the photosynthetic activity around anthesis, a source component. Surprisingly, despite significant breeding progress in GCD and other source components, they showed no direct influence on thousand grain weights, indicating that grain filling was not limited by the source strength. Our results suggest that, 1) the potential longevity of the green canopy is predetermined at the time point that the number of grains is fixed; 2) a co-evolution of source and sink strength during the breeding history contribute to the yield formation of the modern cultivars. For future breeding we suggest to choose parental lines with high grain numbers per spike on the sink side, and high photosynthetic activity around anthesis and canopy duration on the source side, and to place emphasis on these traits throughout selection.

KW - breeding progress

KW - complementary crosses

KW - green canopy duration

KW - sink and source

KW - winter wheat

UR - http://www.scopus.com/inward/record.url?scp=85079768456&partnerID=8YFLogxK

U2 - 10.3389/fpls.2019.01771

DO - 10.3389/fpls.2019.01771

M3 - Article

C2 - 32117340

AN - SCOPUS:85079768456

VL - 10

JO - Frontiers in Plant Science

JF - Frontiers in Plant Science

SN - 1664-462X

M1 - 1771

ER -