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Genome evolution in the genus Sorghum (Poaceae).
Ann Bot. 2005 Jan; 95(1):219-27.AB

Abstract

BACKGROUND AND AIMS

The roles of variation in DNA content in plant evolution and adaptation remain a major biological enigma. Chromosome number and 2C DNA content were determined for 21 of the 25 species of the genus Sorghum and analysed from a phylogenetic perspective.

METHODS

DNA content was determined by flow cytometry. A Sorghum phylogeny was constructed based on combined nuclear ITS and chloroplast ndhF DNA sequences.

KEY RESULTS

Chromosome counts (2n = 10, 20, 30, 40) were, with few exceptions, concordant with published numbers. New chromosome numbers were obtained for S. amplum (2n = 30) and S. leiocladum (2n = 10). 2C DNA content varies 8.1-fold (1.27-10.30 pg) among the 21 Sorghum species. 2C DNA content varies 3.6-fold from 1.27 pg to 4.60 pg among the 2n = 10 species and 5.8-fold (1.52-8.79 pg) among the 2n = 20 species. The x = 5 genome size varies over an 8.8-fold range from 0.26 pg to 2.30 pg. The mean 2C DNA content of perennial species (6.20 pg) is significantly greater than the mean (2.92 pg) of the annuals. Among the 21 species studied, the mean x = 5 genome size of annuals (1.15 pg) and of perennials (1.29 pg) is not significantly different. Statistical analysis of Australian species showed: (a) mean 2C DNA content of annual (2.89 pg) and perennial (7.73 pg) species is significantly different; (b) mean x = 5 genome size of perennials (1.66 pg) is significantly greater than that of the annuals (1.09 pg); (c) the mean maximum latitude at which perennial species grow (-25.4 degrees) is significantly greater than the mean maximum latitude (-17.6) at which annual species grow.

CONCLUSIONS

The DNA sequence phylogeny splits Sorghum into two lineages, one comprising the 2n = 10 species with large genomes and their polyploid relatives, and the other with the 2n = 20, 40 species with relatively small genomes. An apparent phylogenetic reduction in genome size has occurred in the 2n = 10 lineage. Genome size evolution in the genus Sorghum apparently did not involve a 'one way ticket to genomic obesity' as has been proposed for the grasses.

Authors+Show Affiliations

Department of Soil and Crop Sciences, Texas Agricultural Experiment Station, Texas A&M University, College Station, TX 77843-2474, USA. hj-price@tamu.eduNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

15596469

Citation

Price, H James, et al. "Genome Evolution in the Genus Sorghum (Poaceae)." Annals of Botany, vol. 95, no. 1, 2005, pp. 219-27.
Price HJ, Dillon SL, Hodnett G, et al. Genome evolution in the genus Sorghum (Poaceae). Ann Bot. 2005;95(1):219-27.
Price, H. J., Dillon, S. L., Hodnett, G., Rooney, W. L., Ross, L., & Johnston, J. S. (2005). Genome evolution in the genus Sorghum (Poaceae). Annals of Botany, 95(1), 219-27.
Price HJ, et al. Genome Evolution in the Genus Sorghum (Poaceae). Ann Bot. 2005;95(1):219-27. PubMed PMID: 15596469.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Genome evolution in the genus Sorghum (Poaceae). AU - Price,H James, AU - Dillon,Sally L, AU - Hodnett,George, AU - Rooney,William L, AU - Ross,Larry, AU - Johnston,J Spencer, PY - 2004/12/15/pubmed PY - 2005/5/14/medline PY - 2004/12/15/entrez SP - 219 EP - 27 JF - Annals of botany JO - Ann. Bot. VL - 95 IS - 1 N2 - BACKGROUND AND AIMS: The roles of variation in DNA content in plant evolution and adaptation remain a major biological enigma. Chromosome number and 2C DNA content were determined for 21 of the 25 species of the genus Sorghum and analysed from a phylogenetic perspective. METHODS: DNA content was determined by flow cytometry. A Sorghum phylogeny was constructed based on combined nuclear ITS and chloroplast ndhF DNA sequences. KEY RESULTS: Chromosome counts (2n = 10, 20, 30, 40) were, with few exceptions, concordant with published numbers. New chromosome numbers were obtained for S. amplum (2n = 30) and S. leiocladum (2n = 10). 2C DNA content varies 8.1-fold (1.27-10.30 pg) among the 21 Sorghum species. 2C DNA content varies 3.6-fold from 1.27 pg to 4.60 pg among the 2n = 10 species and 5.8-fold (1.52-8.79 pg) among the 2n = 20 species. The x = 5 genome size varies over an 8.8-fold range from 0.26 pg to 2.30 pg. The mean 2C DNA content of perennial species (6.20 pg) is significantly greater than the mean (2.92 pg) of the annuals. Among the 21 species studied, the mean x = 5 genome size of annuals (1.15 pg) and of perennials (1.29 pg) is not significantly different. Statistical analysis of Australian species showed: (a) mean 2C DNA content of annual (2.89 pg) and perennial (7.73 pg) species is significantly different; (b) mean x = 5 genome size of perennials (1.66 pg) is significantly greater than that of the annuals (1.09 pg); (c) the mean maximum latitude at which perennial species grow (-25.4 degrees) is significantly greater than the mean maximum latitude (-17.6) at which annual species grow. CONCLUSIONS: The DNA sequence phylogeny splits Sorghum into two lineages, one comprising the 2n = 10 species with large genomes and their polyploid relatives, and the other with the 2n = 20, 40 species with relatively small genomes. An apparent phylogenetic reduction in genome size has occurred in the 2n = 10 lineage. Genome size evolution in the genus Sorghum apparently did not involve a 'one way ticket to genomic obesity' as has been proposed for the grasses. SN - 0305-7364 UR - https://www.unboundmedicine.com/medline/citation/15596469/Genome_evolution_in_the_genus_Sorghum__Poaceae__ L2 - https://academic.oup.com/aob/article-lookup/doi/10.1093/aob/mci015 DB - PRIME DP - Unbound Medicine ER -