Quantitative Trait Loci Mapping of Agronomic and Yield Traits in Two Grain Sorghum Biparental Families

Abstract

The animal industry is a major sector of agriculture in the southeastern United States, but a large deficit exists in regional feed grains needed to support the industry. An increase in production of sorghum [Sorghum bicolor (L.) Moench], a water‐ and nutrient‐use‐efficient cereal, on marginal lands could lead to an alternative crop option for growers and reduce the current grain deficit. Quantitative trait locus (QTL) mapping of grain yield components in two sorghum biparental recombinant inbred line (RIL) populations was performed to better understand the genetic basis of grain yield and characterize these traits in a marginal environment. A more robust knowledge of the genetics underlying these complex traits could provide insights into molecular breeding strategies that aim to increase genetic gain. Specific yield traits investigated were grain number per primary panicle (GNP), 1000‐grain weight (TGW), and grain yield per primary panicle (YPP). Two‐year phenotyping in the South Carolina coastal plain revealed greater than threefold variation for both GNP and YPP, whereas TGW variation was just above twofold in both RIL families. There were 16 total yield trait QTL identified across both populations. Of the 16, eight QTL colocated with previously published QTL for yield‐related traits, including a QTL on chromosome 1 that was significant for all three grain yield components. A novel QTL for TGW was identified on chromosome 5 that explained >21% of the phenotypic variance observed in one RIL population. This QTL and the seven additional novel QTL identified in this study provide new targets for grain yield improvement in sorghum.

Large‐scale GWAS in sorghum reveals common genetic control of grain size among cereals

“…Given the conservation of gene function among closely related cereal species, this presents opportunities for comparative genomics studies to investigate the genetics of grain size in other cereal crops using knowledge gained from gene cloning studies in maize and rice. The sorghum QTL atlas of Mace et al () details around 100 grain weight QTL in sorghum that have been identified through linkage analysis in 18 studies (Bai et al , ; Boyles et al , ; Brown et al , ; Feltus et al , ; Gelli et al , ; Han et al , ; Mocoeur et al , ; Murray et al , ; Paterson et al , ; Phuong et al , ; Rajkumar et al , ; Rami et al , ; Reddy et al , ; Shehzad and Okuno, ; Spagnolli et al , ; Srinivas et al , ; Tao et al , ; Tuinstra et al , ). A further 12 markers associated with grain weight have been identified in three GWAS studies (Boyles et al , ; Upadhyaya et al , ; Zhang et al , ).…”

Comparative Analysis of In Vitro Responses and Regeneration between Diverse Bioenergy Sorghum Genotypes

“…As with most crops of value, there are concerns associated with sorghum production, including losses due to abiotic and biotic stress pressure, as well as the desire to enhance composition and increase yield, indicating that a variety of targets exist for trait improvement. Improvement efforts have utilized breeding, coupled with approaches such as QTL identification and mapping, molecular marker identification and genome wide association studies, with the goal of improving germplasm 2 of 18 while also gaining an understanding of the genetic loci/genes/allelic variation contributing to the various traits [10][11][12][13][14][15][16][17][18].…”

A Deep Learning Semantic Segmentation-Based Approach for Field-Level Sorghum Panicle Counting

“…In sorghum breeding, sorghum panicles, the reproductive (flowering) part of a sorghum plant and main yield component, are among the critical components for which phenotypic data are sought [12]. Phenotypic data such as counts, number of seeds per panicle, sizes (panicle length and width) play key roles in various assessments including assessing genetic diversity, selection of new cultivars and estimation of potential yields [13][14][15][16][17][18][19][20]. However, the manual characterization of panicles has proved to a bottleneck to sorghum crop improvement.…”