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United States Department of Agriculture

Agricultural Research Service

Title: Genome size variation in guayule and mariola: Fundamental descriptors for polyploid plant taxa

Authors
item Sanchez, Paul
item Costich, Denise
item Friebe, Bernd -
item Coffelt, Terry
item Jenks, Matthew
item Gore, Michael -

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 30, 2013
Publication Date: January 30, 2014
Citation: Sanchez, P.L., Costich, D., Friebe, B., Coffelt, T.A., Jenks, M.A., Gore, M.A. 2014. Genome size variation in guayule and mariola: Fundamental descriptors for polyploid plant taxa. Industrial Crops and Products. 54:1-5.

Interpretive Summary: We have determined the genome size and ploidy level using flow cytometry and counted the chromosome number of 18 selected available germplasm of Parthenium, including selections from five species and five interspecific hybrid accessions. A wide range of intra- and interspecific variation in ploidy level, genome size and chromosome number was observed. The ploidy levels of P. argentatum and P. incanum ranged from diploid to hexaploid. Chromosome number within these two species was also observed, 2n=36 to 2n=108 for P. argentatum and 2n=54 to 2n=90 for P. incanum.. Aneuploidy was observed in P. incanum P. hysterophorus, and five interspecific hybrids (2n=55, 56, 73, 74, 76, 2n=84). Diploid P. argentatum had a genome size of 1,624 Mb whereas the hexaploid P. argentatum had a genome of 4,812 Mb. P. incanum genome size ranged from 2,616 to 4,181 Mb, P. hysterophorus had 2,694 Mb and P. integrifolium had 5,756 Mb. The genome size of interspecific hybrids ranged from 2,523 to 4,225 Mb, and were categorized as triploid, tetraploid and pentaploid. Results of the present study provide useful foundation for future efforts to improve agronomic characteristics of guayule.

Technical Abstract: We have determined the genome size and ploidy level using flow cytometry and counted the chromosome number of 18 selected available germplasm of Parthenium, including selections from five species and five interspecific hybrid accessions. A wide range of intra- and interspecific variation in ploidy level, genome size and chromosome number was observed. The ploidy levels of P. argentatum and P. incanum ranged from diploid to hexaploid. Chromosome number within these two species was also observed, 2n=36 to 2n=108 for P. argentatum and 2n=54 to 2n=90 for P. incanum.. Aneuploidy was observed in P. incanum P. hysterophorus, and five interspecific hybrids (2n=55, 56, 73, 74, 76, 2n=84). Diploid P. argentatum had a genome size of 1,624 Mb whereas the hexaploid P. argentatum had a genome of 4,812 Mb. P. incanum genome size ranged from 2,616 to 4,181 Mb, P. hysterophorus had 2,694 Mb and P. integrifolium had 5,756 Mb. The genome size of interspecific hybrids ranged from 2,523 to 4,225 Mb, and were categorized as triploid, tetraploid and pentaploid. Results of the present study provide useful foundation for future efforts to improve agronomic characteristics of guayule.

Last Modified: 11/26/2014
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