Generation of haploid plants and improved plant breeding

{
  "publication_number": "US10306848B2",
  "country": "US",
  "kind": "B2",
  "title": "Generation of haploid plants and improved plant breeding",
  "abstract": "Methods and compositions for generating haploid organisms are described.",
  "claims": [
    "1. A plant comprising a mutated CENH3 gene, wherein the mutated CENH3 gene encodes a mutant CENH3 polypeptide having a CENH3 tail-domain and a CENH3 histone-fold domain, wherein the mutant CENH3 polypeptide is identical to a wildtype CENH3 polypeptide but for 1-7 amino acid substitutions that occur in the CENH3 histone-fold domain, wherein the plant comprising the mutated CENH3 gene, when crossed with a wildtype diploid plant, generates haploid progeny.",
    "2. The plant of claim 1, wherein the plant comprises one copy of an allele of the mutated CENH3 gene.",
    "3. The plant of claim 1, wherein the plant comprises two copies of an allele of the mutated CENH3 gene.",
    "4. The plant of claim 1, wherein the mutant CENH3 polypeptide is at least 95% identical to any of SEQ ID NOs:49-94.",
    "5. The plant of claim 1, wherein the wildtype CENH3 polypeptide comprises any of SEQ ID NOs: 49-94.",
    "6. A method of generating an F1 progeny plant having half the ploidy of a parent plant expressing an endogenous wildtype CENH3 protein, the method comprising, crossing the parent plant to the plant of claim 1; and selecting F1 progeny generated from the crossing step having half the ploidy of the parent plant.",
    "7. The method of claim 6, wherein the parent plant is the pollen parent.",
    "8. The method of claim 6, wherein the parent plant is the ovule parent.",
    "9. The method of claim 6, further comprises converting at least one selected haploid plant into a doubled haploid plant.",
    "10. The method of claim 6, wherein the wildtype CENH3 polypeptide comprises any of SEQ ID NOs: 49-94.",
    "11. The method of claim 6, wherein the mutant CENH3 polypeptide is at least 95% identical to any of SEQ ID NOs: 49-94."
  ],
  "description_excerpt": "Although plant breeding programs worldwide have made considerable progress developing new cultivars with improved disease resistances, yields and other, useful traits, breeding as a whole relies on screening numerous plants to identify novel, desirable characteristics. Very large numbers of progeny from crosses often must be grown and evaluated over several years in order to select one or a few plants with a desired combination of traits.\n\nStandard breeding of diploid plants often requires screening and back-crossing of a large number of plants to achieve the desired genotype. One solution to the problem of screening large numbers of progeny has been to produce haploid plants, the chromosomes of which can be doubled using colchicine or other means to achieve instantly homozygous, doubled-haploid plants.\n\nThus, marked improvements in the economics of breeding can be achieved via doubled haploid production, since selection and other procedural efficiencies can be markedly improved by using true-breeding (homozygous) progenies. With doubled haploid production systems, homozygosity is achieved in one generation. Thus, the breeder can eliminate the numerous cycles of inbreeding necessary by conventional methods to achieve practical levels of homozygosity. Indeed, true homozygosity for all traits is not even achievable by conventional breeding methods.\n\nThe present invention provides for new ways for producing haploid organisms.",
  "cpc": [
    "C12N 15/8241",
    "A01H 1/02",
    "A01H 1/08",
    "C07K 14/415",
    "C12N 15/8261",
    "C12N 15/8287",
    "Y02A 40/146"
  ],
  "ipc": [
    "A01H 1/08",
    "C07K 14/415",
    "C12N 15/82",
    "A01H 1/02"
  ],
  "assignees": [
    "University of California San Diego UCSD"
  ],
  "inventors": [
    "Simon Chan",
    "Ravi Maruthachalam"
  ],
  "filing_date": "2015-11-12",
  "publication_date": "2019-06-04",
  "grant_date": "2019-06-04",
  "priority_date": "2009-10-06",
  "application_number": "US-201514939181-A",
  "family_id": "43824181",
  "cited_by_count": 4,
  "citations": [
    "US5749169A",
    "US20090144849A1",
    "US20100017908A1",
    "WO2010079432A1",
    "US8618354B2",
    "WO2012075195A1"
  ]
}