Documented chromosome number determinations in some Physaria species (Brassicaceae)


  • Andrew M. Salywon Desert Botanical Garden
  • Jon P. Rebman San Diego Museum of Natural History
  • David A. Dierig Bridgestone Americas Inc.



meiotic chromosome number, Lesquerella, Physaria, Brassicaceae


The determination of the chromosome numbers of species of Physaria (Brassicaceae) are of interest as part of a breeding program to develop new industrial oilseeds and to further our knowledge of the genus in general. Polyploid plants could be useful in generating novel and improved breeding populations. We report 47 meiotic chromosome number determinations for 19 species of Physaria. The first chromosome number is reported for P. kingii subsp. kaibabensis as 2n = 5 II, and the first report of polyploidy in Physaria kingii susbsp. latifolia with a tetraploid determination of 2n = 10 II. A determination of 2n = 23 II is reported for Physaria mendocina, which was previously reported as 2n = ca. 50, which results in a new base number for the genus of x = 23.


BEEKS, R.M. 1955. Improvements in the squash technique for plant chromosomes. Aliso 3:131–133.
DIERIG, D.A., A.E. THOMPSON, J.P. REBMAN, R. KLEIMAN, & B.S. PHILLIPS. 1996. Collection and evaluation of new Lesquerella and Physaria germplasm. Industr. Crops Prod. 5:53–63.
DIERIG, D.A., P.M. TOMASI, A.M. SALYWON, & D.T. RAY. 2004. Improvement in hydroxy fatty acid seed oil content and other traits from interspecific hybrids of three Lesquerella species: Lesquerella fendleri, L. pallida, and L. lindheimeri. Euphytica 139:199–206.
LÖVE Á. 1984. Chromosome number reports LXXXIII. Taxon 33:351–354.
LYSAK, M.A., M.A. KOCH, J.M. BEAULIEU, A. MEISTER, & I.J. LEITCH. 2009. The dynamic upas and downs of genome size evolution in Brassicaceae. Mol. Biol. Evol. 26:85–98.
MANTON, I. 1932. Introduction to the genera cytology of the Cruciferae. Ann. Bot. 46:509–556.
MULLIGAN, G.A. 1966. Two new species of Physaria (Cruciferae) in Colorado. Canad. J. Bot. 44:1661–1665.
MULLIGAN, G.A. 1967a. Diploid and autotetraploid Physaria vitulifera (Cruciferae). Canad. J. Bot. 45:183–188.
MULLIGAN, G.A. 1967b. Cytotaxonomy of Physaria acutifolia, P. chambersii, and P. newberryi (Cruciferae). Canad. J. Bot. 45:1887–1898.
MULLIGAN, G.A. 1968. Physaria didymocarpa, P. brassicoides and P. floribunda (Cruciferae) and their close relatives. Canad. J. Bot. 46:735–740.
O’KANE, S. 2007. Physaria. In: Flora of North America Editorial Committee, eds. Flora of North America north of Mexico. Oxford University Press, New York, U.S.A., and Oxford, U.K. 7:616–665.
RICE ET AL. 2015. The Chromosome Counts Database (CCDB) – a community resource of plant chromosome numbers. New Phytol. 206(1):19–26.
ROLLINS, R.C. 1939a. The cruciferous genus Physaria. Rhodora 41:392–415.
ROLLINS, R.C. 1939b. Studies in the genus Lesquerella. Amer. J. Bot. 26:419–421.
ROLLINS, R.C. 1966. Chromosome numbers of Cruciferae. Contr. Gray Herb. 197:43–65.
ROLLINS, R.C. 1981. Studies in the genus Physaria (Cruciferae). Brittonia 33:332–341.
ROLLINS, R.C. & L. RÜDENBERG. 1971. Chromosome numbers of Cruciferae. II. Contr. Gray Herb. 201:117–133.
ROLLINS, R.C. & L. RÜDENBERG. 1977. Chromosome numbers of Cruciferae. III. Contr. Gray Herb. 207:101–116.
ROLLINS, R.C. & E.A. SHAW. 1973. The genus Lesquerella (Cruciferae) in North America. Harvard University Press, Cambridge, MA, U.S.A.
SALYWON, A.M., D.A. DIERIG, J.P. REBMAN, & D. JASSO DE RODRÍGUEZ. 2005. Evaluation of new Lesquerella and Physaria (Brassicaceae) oilseed germplasm. Amer. J. Bot. 92:53–62.
WEBER, W.A. & J.L. BREWBAKER. 1950. Physaria vitulifera, a tetrapolid species of Cruciferae. Univ. Colorado Stud., Ser. Biol. 1:24–28.



How to Cite

Salywon, A. M., Rebman, J. P., & Dierig, D. A. (2022). Documented chromosome number determinations in some Physaria species (Brassicaceae). Journal of the Botanical Research Institute of Texas, 16(2), 499–504.