title: High-throughput sequencing and mutagenesis to accelerate the domestication of Microlaena stipoides as a new food crop.
abstract: Global food demand, climatic variability and reduced land availability are driving the need for domestication of new crop species. The accelerated domestication of a rice-like Australian dryland polyploid grass, Microlaena stipoides (Poaceae), was targeted using chemical mutagenesis in conjunction with high throughput sequencing of genes for key domestication traits. While M. stipoides has previously been identified as having potential as a new grain crop for human consumption, only a limited understanding of its genetic diversity and breeding system was available to aid the domestication process. Next generation sequencing of deeply-pooled target amplicons estimated allelic diversity of a selected base population at 14.3 SNP/Mb and identified novel, putatively mutation-induced polymorphisms at about 2.4 mutations/Mb. A 97% lethal dose (LD₉₇) of ethyl methanesulfonate treatment was applied without inducing sterility in this polyploid species. Forward and reverse genetic screens identified beneficial alleles for the domestication trait, seed-shattering. Unique phenotypes observed in the M2 population suggest the potential for rapid accumulation of beneficial traits without recourse to a traditional cross-breeding strategy. This approach may be applicable to other wild species, unlocking their potential as new food, fibre and fuel crops.
authors.affiliation: Southern Cross Plant Science, Southern Cross University, Lismore, New South Wales, Australia.
authors.forename: Frances M
authors.initials: FM
authors.lastname: Shapter
authors.affiliation: Southern Cross Plant Science, Southern Cross University, Lismore, New South Wales, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Cross
authors.affiliation: Southern Cross Plant Science, Southern Cross University, Lismore, New South Wales, Australia.
authors.forename: Gary
authors.initials: G
authors.lastname: Ablett
authors.affiliation: Southern Cross Plant Science, Southern Cross University, Lismore, New South Wales, Australia.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Malory
authors.affiliation: Southern Cross Plant Science, Southern Cross University, Lismore, New South Wales, Australia ; Native Seeds Pty Ltd, Sandringham, Victoria, Australia.
authors.forename: Ian H
authors.initials: IH
authors.lastname: Chivers
authors.affiliation: Southern Cross Plant Science, Southern Cross University, Lismore, New South Wales, Australia.
authors.forename: Graham J
authors.initials: GJ
authors.lastname: King
authors.affiliation: Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Henry
mesh_terms: D018556:Crops, Agricultural / Q000187:drug effects / Q000235:genetics; D005020:Ethyl Methanesulfonate / Q000494:pharmacology; D014644:Genetic Variation / Q000235:genetics; D018745:Genome, Plant / Q000235:genetics; D059014:High-Throughput Nucleotide Sequencing; D010940:Plant Proteins / Q000235:genetics; D006109:Poaceae / Q000187:drug effects / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D005020:Ethyl Methanesulfonate