Barley and Wheat Share the Same Gene Controlling the Short Basic Vegetative Period

Basic vegetative period（BVP） is an important trait for determining flowering time and adaptation to variable environments.A short BVP barley mutant is about 30 d shorter than its wild type.Genetic analysis using 557 F 2 individuals revealed that the short BVP is governed by a single recessive gene（BVP-1） and was further validated in 2 090 F 3 individuals.The BVP-1 gene was first mapped to barley chromosome 1H using SSR markers.Comparative genomic analysis demonstrated that the chromosome region of BVP-1 is syntenic to rice chromosome 5 and Brachypodium chromosome 2.Barley ESTs/genes were identified after comparison with candidate genes in rice and Brachypodium;seven new gene-specific markers were developed and mapped in the mapping populations.The BVP-1 gene co-segregated with the Mot1 and Ftsh4 genes and was flanked by the gene-specific markers AK252360（0.2 cM） and CA608558（0.5 cM）.Further analysis demonstrated that barley and wheat share the same short BVP gene controlling early flowering.

Highly efficient and genotype-independent barley gene editing based on anther culture

Recalcitrance to tissue culture and genetic transformation is the major bottleneck for gene manipulation in crops.In barley,immature embryos of Golden Promise have typically been used as explants for transformation.However,the genotype dependence of this approach limits the genetic modification of commercial varieties.Here,we developed an anther culture-based system that permits the effective creation of transgenic and gene-edited plants from commercial barley varieties.The protocol was tested in Golden Promise and four Australian varieties,which differed in phenology,callus induction,and green plant regeneration responses.Agrobacterium-mediated transformation was performed on microspore-derived callus to target the HvPDS gene,and T0 albinos with targeted mutations were successfully obtained from commercial varieties.Further editing of three targets was achieved with an average mutation rate of 53%in the five varieties.In 51 analyzed T0 individuals,Cas9 induced a large proportion(69%)of single-base indels and two-base deletions in the target sites,with variable mutation rates among targets and varieties.Both ontarget and off-target activities were detected in T1 progenies.Compared with immature embryo protocols,this genotype-independent platformcan deliver a high editing efficiency and more regenerant plants within a similar time frame.It shows promise for functional genomics and the application of CRISPR technologies for the precise improvement of commercial varieties.