Location: Crop Germplasm ResearchTitle: Molecular characterization of the Gossypium diversity reference set of the US National Cotton Germplasm Collection
|GORE, MICHAEL - Cornell University - New York|
|Frelichowski, James - Jim|
Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2014
Publication Date: 1/26/2015
Citation: Hinze, L.L., Fang, D.D., Gore, M.A., Scheffler, B.E., Yu, J., Frelichowski, J.E., Percy, R.G. 2015. Molecular characterization of the Gossypium diversity reference set of the US National Cotton Germplasm Collection. Theoretical and Applied Genetics. 128(2):313-327.
Interpretive Summary: Maintaining the genetic variation within the US National Cotton Germplasm Collection is essential to assuring that the natural resources needed for the future progress in crop health, yield and fiber improvement are preserved. To effectively and efficiently preserve the genetic variation of the collection, it is imperative that the extent and structure of this variation is understood. In an effort to analyze and characterize the genetic diversity available in the collection, this research evaluated the molecular diversity in a subset of entries representing about 20% of the collection and comprising entries from all nine genome and 33 species levels as represented in the collection. From this study we determined that it is possible to identify variation that differentiates lines within commercial species and that can partially differentiate among wild species. We demonstrated that molecular markers could be used to identify redundancies within the collection, as well as misclassifications and introgression (or inter-crossing) among species. The use of molecular markers to characterize the cotton germplasm collection will allow the curator to efficiently and effectively increase and preserve the diversity of the collection, while maintaining the purity of its individual lines. Characterization of the collection with molecular markers also allows breeders and geneticists to make more informed choices in their improvement efforts, resulting in superior cotton varieties and products for the consumer.
Technical Abstract: An understanding of the genetic diversity of cotton (Gossypium spp.) is essential to develop strategies for collection, conservation, and utilization of these germplasm resources. The US National Cotton Germplasm Collection is one of the largest world collections and includes not only accessions with improved yield and fiber quality within cultivated species, but also accessions possessing sources of abiotic and biotic stress resistance often found in wild species. We evaluated the genetic diversity of a subset of 272 diploid and 1984 tetraploid lines in the collection (designated the Gossypium Diversity Reference Set) using a core set of 105 microsatellite markers. Utility of the core set of markers in differentiating intra-species variation was much greater in commercial tetraploid species than in wild diploid species, and may have been influenced by pre-selection of markers for effectiveness in the commercial species. The marker set was capable of differentiating interspecific variation among tetraploid species, and partially differentiating among species and genomes of the wild diploid species. Putative genome- and species-specific marker bands were identified that could be used for qualitative identification of misclassifications, redundancies and introgression within species. The results provide insight and guidance for the further development of markers capable of characterizing the diversity of this multi-specific collection. This broad-scale molecular characterization demonstrates the importance of characterization of the genetic variation within the National Cotton Collection to the management and conservation of the collection and to the cotton research community in their cotton improvement efforts.