Barley awns are highly active in photosynthesis and account for 30–50% of grain weight in barley. They are diverse in length, ranging from long to awnless, and in shape from straight to hooded or crooked. Their diversity and importance have intrigued geneticists for several decades. A large collection of awnness mutants are available—over a dozen of them have been mapped on chromosomes and a few recently cloned. Different awnness genes interact with each other to produce diverse awn phenotypes. With the availability of the sequenced barley genome and application of new mapping and gene cloning strategies, it will now be possible to identify and clone more awnness genes. A better understanding of the genetic basis of awn diversity will greatly facilitate development of new barley cultivars with improved yield, adaptability and sustainability.

Awns are extending structures from lemmas in grasses and are very active in photosynthesis, contributing directly to the filling of the developing grain. Barley (Hordeum vulgare L.) awns are highly diverse in shape and length and are known to be controlled by multiple awn-related genes. The genetic effects of these genes on awn diversity and development in barley are multiplexed and include complementary effect, cumulative effect, duplicate effect, recessive epistasis, dominant epistasis, and inhibiting effect, each giving a unique modified Mendelian ratio of segregation. The complexity of gene interactions contributes to the awn diversity in barley. Excessive gene interactions create a challenging task for genetic mapping and specific strategies have to be developed for mapping genes with specific interactive effects. Awn gene interactions can occur at different levels of gene expression, from the transcription factor-mediated gene transcription to the regulation of enzymes and metabolic pathways. A better understanding of gene interactions will greatly facilitate deciphering the genetic mechanisms underlying barley awn diversity and development.

Barley (Hordeum vulgare) awns contribute to grain yield, but the genetic basis of awn development remains largely unclear. Five barley lines differing in awn traits and row types were used to create four F₂ populations. Genetic analyses revealed that four pairs of genes were involved in awn development: A/a (awnless/awned), B/b (awnless/awned), H/h (hooded/straight), and L/l (long/short). Of these four loci, A, H and L functioned on both central rows (CR) and lateral rows (LR) of the barley spikes, while B exhibited effect only on LR. A and B had duplicate effects on LR, and both showed dominant epistasis to loci H and L, whereas H was epistatic to L. Meanwhile, A and B were found to be genetically linked, with a row-type locus V located between them. The genetic distances of A-V and B-V were estimated to be 9.6 and 7.7 cM, respectively. Literature search suggested that A, H and V may correspond to the reported Lks1, Kap1 and Vrs1, respectively, whereas B is a novel gene specifically controlling awn development on LR, designated as Lsa1 for lateral spikelet awnless 1. The only barley homolog of wheat awn inhibitor gene B1, HORVU2Hr1G077570, is a potential candidate of Lsa1.

Hygroryza aristata, an aquatic plant native to Southeast Asia, shows a high degree of adaptability to aquatic environments. H. aristata, which belongs to the Oryzeae tribe and is closely related to rice (Oryza sativa), holds potential for crop improvement, particularly in flood tolerance. This study aimed to sequence and assemble the genome of H. aristata. We assembled the genome of H. aristata using 31.91 Gb of Pacific Biosciences (PacBio) High-fidelity (HiFi) data and 22.36 Gb of ultra long Oxford Nanopore Technology (ONT) data, resulting in two gap-free haplotype genomes, hap1 (349.74 Mb) and hap2 (347.98 Mb), each with 12 chromosomes and 23 telomeres. The continuity of chromosomes was supported by High-throughput chromosome conformation capture (Hi-C) data. The assemblies demonstrated high completeness, with > 99.8% of coverage rates, 98.4% of Benchmarking Universal Single-Copy Orthologs (BUSCO) scores, and > 11.0 of Long Terminal Repeat Assembly Index (LAI) scores per haplotype. RNA sequencing (RNA-seq) data (176.06 Gb) of six tissues was generated for genome annotation, identifying 39,139 and 38,746 protein-coding genes in hap1 and hap2, respectively.