Location: Dale Bumpers National Rice Research Center
Title: Utilization of the USDA-ARS germplasm collection in US rice breeding programsAuthor
McClung, Anna |
Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only Publication Acceptance Date: 12/31/2021 Publication Date: 1/12/2022 Citation: McClung, A.M. 2022. Utilization of the USDA-ARS germplasm collection in US rice breeding programs. Plant and Animal Genome Conference XXIX, January 8-12, 2022. San Diego, California. Interpretive Summary: Technical Abstract: The USDA-ARS maintains a world collection of rice germplasm that consists of over 19,000 varieties in addition to a collection of some 40,000 mutants, mapping populations, and diversity panels curated in the Genetic Stocks Oryza collection. Accessions deposited in the collection date back to 1904 and were largely part of global exploration efforts to identify rice landraces that could be grown commercially in the USA. Early varieties were developed using mass selection or selections from natural outcrosses until mechanisms for making controlled pollinations were devised. US breeding programs began to seek traits in global germplasm that impact yield, agronomy, and quality that could be incorporated into new cultivars through crossing and phenotypic selection. One of the challenges in using diverse sources for novel traits, is the many undesirable traits that may also be present in unadapted germplasm. The identification of specific markers linked to major genes for blast resistance, amylose content, aroma, and semi dwarfism, for example, have facilitated the use of germplasm. However, the diverse germplasm available in the collection has been more explored by molecular geneticists than by breeders because introgressing unadapted germplasm still remains difficult. Ongoing efforts to identify novel alleles may not be fruitful as these may not be desirable alleles nor result in a unique phenotype. Moreover, research needs to be focused on understanding complex, multigene traits in response to a changing climate and evolving production systems and how to effectively use that information for developing new rice cultivars. |