The double round-robin population unravels the genetic architecture of grain size in barley

Abstract

Grain number, size and weight primarily determine the yield of barley. Although the genes regulating grain number are well studied in barley, the genetic loci and the causal gene for sink capacity are poorly understood. Therefore, the primary objective of our work was to dissect the genetic architecture of grain size and weight in barley. We used a multi-parent population developed from a genetic cross between 23 diverse barley inbreds in a double round-robin design. Seed size-related parameters such as grain length, grain width, grain area and thousand-grain weight were evaluated in the HvDRR population comprising 45 recombinant inbred line sub-populations. We found significant genotypic variation for all seed size characters and observed 84 % or higher heritability across four environments. The quantitative trait locus (QTL) detection results indicate that the genetic architecture of grain size is more complex than reported previously. In addition, both cultivars and landraces contributed positive alleles at grain size QTLs. Candidate genes identified using genome-wide variant calling data for all parental inbred lines indicated overlapping and potential novel regulators of grain size in cereals. Furthermore, our results indicated that sink capacity was the primary determinant of grain weight in barley.

Genetic mapping reveals new loci and alleles for flowering time and plant height using the double round-robin population of barley

“…The population originated from the crossings of 23 parental inbred lines, including 11 cultivars and 12 landraces ( Shrestha et al , 2022 ), in a double round-robin scheme ( Stich, 2009 ) ( Supplementary Table S1 ). The parental inbred lines were chosen from a diversity panel of 224 spring barley accessions selected from the Barley Core Collection (BCC) ( Pasam et al , 2012 ) to maximize the combined genotypic and phenotypic richness index ( Weisweiler et al , 2019 ).…”

Genetic mapping reveals new loci and alleles for flowering time and plant height using the double round-robin population of barley

“…The plant material used in this study consisted of a population which is designated in the following as Hordeum vulgare Double Round-Robin (HvDRR). The population originated from the crossings of 23 parental inbred lines, including eleven cultivars and twelve landraces (Shrestha et al ., 2022), in a double round-robin scheme (Stich, 2009) (Supplementary Table 1). The parental inbred lines have been chosen from a diversity panel of 224 spring barley accessions selected from the Barley Core Collection (BCC) (Pasam et al ., 2012) to maximize the combined genotypic and phenotypic richness index (Weisweiler et al ., 2019).…”

Genome-wide screening of meta-QTL and candidate genes controlling yield and yield-related traits in barley (Hordeum vulgare L.)

“…Nevertheless, the accuracy of the QTL meta-analysis was significantly and positively correlated with the number of initial QTLs [53]. Many barley yield-related QTLs have been sequentially identified and published in recent years [10,[54][55][56][57]. Therefore, it is particularly important to integrate the newest QTL data to identify more stable MQTLs.…”