Hipp, A. L., P. E. Rothrock, R. Whitkus, and J. A. Weber. 2010. Chromosomes tell half of the story: the correlation between karyotype rearrangements and genetic diversity in sedges, a group with holocentric chromosomes. Molecular Ecology 19: 3124-3138.  abstract  PDF

Anacker, B. L., N. E. Rank, D. Huberli, M. Garbelotto, S. Gordon, T. Harnik, R. Whitkus, and R. Meentemeyer. 2008. Susceptibility to Phytophthora ramorum in a key infectious host: landscape variation in host genotype, host phenotype, and environmental factors. New Phytologist 177: 756-766.  abstract  PDF

Roalson, E. H., A, G. McCubbin, and R. Whitkus. 2007. Chromosome evolution in the Cyperales. Aliso 23:62-71.

Lowrey, T. K., R. Whitkus, and W. R. Sykes.  2005. A new species of Tetramolopium (Asteraceae) from Mitiaro, Cook Islands: Biogeography, phylogenetic relationships, and dispersal.  Systematic Botany 30: 448-455. BioOne Article

Lukaszewski, A. J., K. Rybka, V. Korzun, S. V. Malyshev, B. Lapinski, and R. Whitkus.  2004.  Genetic and physical mapping of homoeologous recombination points involving wheat chromosomes 2B and rye chromosome 2R.  Genome 47: 36-45.  abstract

Ehdaie, B., R. Whitkus and J. G. Waines.  2003.  Root biomass, water-use efficiency and performance of wheat-rye translocations of chromosomes 1 and 2 in spring bread wheat ‘Pavon’.  Crop Science 43: 710-717.  abstract

Georgiady, M. S., R. Whitkus and E. M. Lord.  2002. Genetic analysis of traits distinguishing outcrossing and self-pollinating forms of currant tomato, Lycopersicon pimpinellifolium (Jusl.) Mill.  Genetics 161: 333-344.  abstract  PDF

Whitkus, R., H. Doan, and T. K. Lowrey. 2000. Genetics of adaptive radiation in Hawaiian species of Tetramolopium (Asteraceae). III. Evolutionary genetics of sex expression. Heredity 85: 37-42.    abstract

Okada, M., T. K. Lowrey, and R. Whitkus. 2000. Quantitative morphological variation in Tetramolopium (Asteraceae) in Hawaii and the Cook Islands. Plant Systematics and Evolution 221:1-13.    abstract

Brunell, M. S., A. Lukaszewski, and R. Whitkus. 1999. Development of arm specific RAPD markers for rye chromosome 2R in wheat. Crop Science 39:1702-1706.   abstract

Heaton, H. J., R. Whitkus, and A. Gómez-Pompa. 1999. Extreme ecological and phenotypic differences in the tropical tree chicozapote (Manilkara zapota (L.) van Royen) are not matched by genetic divergence: A RAPD analysis. Molecular Ecology 8: 627-632.

Brunell, M. S. and R. Whitkus. 1999. Analysis of cross-compatibility in Eriastrum densifolium (Polemoniaceae). Plant Systematics and Evolution 215: 241-254.   abstract

Brunell, M. S. and R. Whitkus. 1998. Assessment of morphological variation in Eriastrum densifolium (Polemoniaceae): Implications for subspecific delimitation and conservation. Systematic Botany 23: 351-368.  

Whitkus, R. 1998. Genetics of adaptive radiation in Hawaiian and Cook Islands species of Tetramolopium (Asteraceae). II. Genetic linkage map and its implications for interspecific breeding barriers. Genetics 150: 1209-1216.   abstract  PDF

Whitkus, R., M. De la Cruz, L. Mota-Bravo, and A. Gómez-Pompa. 1998. Genetic diversity and relationships of cacao (Theobroma cacao L.) in southern Mexico. Theoretical and Applied Genetics 96: 621-627.   abstract  PDF

Brunell, M. S. and R. Whitkus. 1997. RAPD marker variation in Eriastrum densifolium (Polemoniaceae): Implications for subspecific delimitation and conservation. Systematic Botany 22: 543-553.

Okada, M., R. Whitkus, and T. K. Lowrey. 1997. Genetics of adaptive radiation in Hawaiian and Cook Islands species of Tetramolopium (Asteraceae: Astereae): I. Nuclear RFLP marker diversity. American Journal of Botany 84: 1236-1246.   abstract   PDF

de la Cruz, M., L. Mota-Bravo, A. Gómez-Pompa, and R. Whitkus. 1996. Cacao: su domesticacíon. Investigacion y Ciencia (Spanish edition of Scientific American) 237: 38-39.

Ellstrand, N. C., R. Whitkus, and L. H. Rieseberg. 1996. Distribution of spontaneous plant hybrids. Proceeding of the National Academy of Sciences, USA 93: 5090-5093.   abstract  PDF

de la Cruz, M., R. Whitkus, and L. Mota-Bravo. 1995. Tropical tree DNA isolation and amplification. Molecular Ecology 4: 787-789.  

de la Cruz, M., R. Whitkus, A. Gómez-Pompa, and L. Mota-Bravo. 1995. Origins of cacao cultivation. Nature 375: 542-543.

Pereira, M. G., M. Lee, P. Bramel-Cox, W. Woodman, J. Doebley, and R. Whitkus. 1994. Construction of an RFLP map in sorghum and comparative mapping in maize. Genome 37: 236-243.

Whitkus, R., J. Doebley, and J. F. Wendel. 1994. Nuclear DNA markers in systematics and evolution, p. 116-141. In Phillips, R. L. And I. K. Vasil (eds.), DNA-Based Markers in Plants. Kluwer Acad. Publ., The Netherlands.

Whitkus, R., J. Doebley, and M. Lee. 1992. Comparative genome mapping of sorghum and maize. Genetics 132: 1119-1130.   abstract   PDF

Whitkus, R. 1992. Allozyme variation within the Carex pachystachya complex (Cyperaceae). Systematic Botany 17: 16-24.

Whitkus, R. 1991. Chromosome counts of Carex section Ovales. Botanical Gazette 152: 224-230.

Les, D. H., R. Whitkus, F. A. Bryan, and L. E. Tyrrell. 1989. Biochemical basis of floral color polymorphism in a heterocyanic population of Trillium sessile (Liliaceae). American Journal of Botany 76: 23-29.

Crawford, D. J., B. J. Post, and R. Whitkus. 1988. Allozyme variation within and between populations of Coreopsis latifolia (Asteraceae). Plant Species Biology 3: 1-5.

Crawford, D. J. and R. Whitkus. 1988. Allozyme divergence and mode of speciation for Coreopsis gigantea and C. maritima (Compositae). Systematic Botany 13: 256-264.

Whitkus, R. 1988. Modified version of GENESTAT. A program for computing genetic statistics from allelic frequency data. Plant Genetics Newsletter 4: 10.

Whitkus, R. 1988. Experimental hybridizations among chromosome races of Carex pachystachya and the related species C. malcoviana and C. preslii (Cyperaceae). Systematic Botany 13: 156-153.

Whitkus, R., F. A. Bryan, D. H. Less, and L. E. Tyrrell. 1987. Genetic structure in a heterocyanic population of Trillium sessile (Liliaceae). Plant Species Biology 2: 67-73.

Wolf, S. J. and R. Whitkus. 1987. A numerical analysis of flavonoid variation in Arnica subgenus Austromontana (Asteraceae). American Journal of Botany 74: 1577-1584.

Crawford, D., J., R. Whitkus, and T. F. Stuessy. 1987. Plant evolution and speciation on oceanic islands, pp. 183-199. In Urbanska, K. M. (ed.), Differentiation Patterns in Higher Plants. Acad. Press, London.

Whitkus, R. 1985. A FORTRAN program for computing genetic statistics from allelic frequency data. Journal of Heredity 76: 152.

Whitkus, R. and J. G. Packer. 1984. A contribution to the taxonomy of the Carex macloviana D’Urv. aggregate (Cyperaceae) in western Canada and Alaska. Canadian Journal of Botany 62: 1592-1607.

Packer, J. G. And R. Whitkus. 1982. In Love, A. (ed.), IOPB chromosome Number Reports LLXV. Taxon 31: 363-364.

Whitkus, R. 1981. Chromosome numbers of some northern New Jersey carices. Rhodora 83: 461-464.