Abstract
SummaryGrain size is a key yield component of cereal crops and a major quality attribute. It is determined by a genotype’s genetic potential and its capacity to fill the grains. This study aims to dissect the genetic architecture of grain size in sorghum. An integrated genome‐wide association study (GWAS) was conducted using a diversity panel (n = 837) and a BC‐NAM population (n = 1421). To isolate genetic effects associated with genetic potential of grain size, rather than the genotype’s capacity to fill the grains, a treatment of removing half of the panicle was imposed during flowering. Extensive and highly heritable variation in grain size was observed in both populations in 5 field trials, and 81 grain size QTL were identified in subsequent GWAS. These QTL were enriched for orthologues of known grain size genes in rice and maize, and had significant overlap with SNPs associated with grain size in rice and maize, supporting common genetic control of this trait among cereals. Grain size genes with opposite effect on grain number were less likely to overlap with the grain size QTL from this study, indicating the treatment facilitated identification of genetic regions related to the genetic potential of grain size. These results enhance understanding of the genetic architecture of grain size in cereal, and pave the way for exploration of underlying molecular mechanisms and manipulation of this trait in breeding practices.
Highlights
Cereal crops, including maize, rice, wheat, barley and sorghum, supply more than 75% of the calories consumed by humans (Sands et al, 2009)
This study aims to (1) investigate the genetic architecture of grain size in sorghum by conducting an integrated genome-wide association study (GWAS) in two large populations, a diversity panel of 837 individuals and a backcross-nested association mapping (BC-NAM) population of 1421 individuals, and (2) compare genetic loci affecting grain size identified in this study to those reported in rice and maize
In the DPGAT16 trial, a significant increase in average grain size of 8.54% was observed in half heads compared to full heads (Figure S2B)
Summary
Cereal crops, including maize, rice, wheat, barley and sorghum, supply more than 75% of the calories consumed by humans (Sands et al, 2009). They are critical to address global food security, which is under threat of population expansion and climate change. Grain size is a key yield component of grain yield in cereal crops and is a major quality attribute affecting planting, harvesting and processing activities (Tao et al, 2017). A better understanding of the genetic basis of grain size, including underlying molecular mechanisms, will provide new targets for improving yield and grain quality in cereal breeding
Sign-in/Register to view highlights & summary 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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
