Allotetraploid cotton species (Gossypium) belong to a 1–2 million year old lineage that reunited diploid genomes that diverged from each other 5–10 million years ago. To characterize genome evolution in the diploids and allotetraploids, comparative RFLP mapping was used to construct genetic maps for the allotetraploids (AD genome; n = 26) and diploids (A and D genomes; n = 13). Comparisons amon...

Colchicine has been used to induce chromosome doubling in plant species. Diploid cotton species have inherited desirable genes that are resistant to biotic and abiotic stresses and also possesses useful fiber quality traits, such as higher fiber length and strength. To transfer these desirable traits to the most extensively cultivated tetraploid cotton species through hybridization, it is a pre...

Reniform nematode (Rotylenchulus reniformis) has become a major pest of cotton in the mid-south area of the United States. Resistance genes, Ren1 and Ren2 from Gossypium longicalyx and Gossypium aridum, respectively, have been identified and introduced into Upland cotton (Gossypium hirsutum). We developed an F2 population of 184 progeny plants by crossing Ren2 -containing plants with a LONREN-2...

Transposable elements, particularly LTR-retrotransposons, comprise the primary vehicle for genome size expansion in plants, while DNA removal through illegitimate recombination and intrastrand homologous recombination serve as the most important counteracting forces to plant genomic obesity. Despite extensive research, the relative impact of these opposing forces and hence the directionality of...

Thirty volunteer subjects were exposed to controlled amounts of respirable dust generated by the carding of cotton in an experimental cardroom. Eighteen exposures each lasting six hours were performed while carding unwashed and washed cottons from the three major growing regions of the United States. Elutriated dust was analysed gravimetrically and was comparable (0.59 mg/m3 +/- 0.04) for all e...

Levels of genetic diversity within and among populations and species are shaped by both external (population-level) and internal (genomic and genic) evolutionary forces. To address the effect of internal pressures, we estimated nucleotide diversity for a pair of homoeologous Adh loci in an allotetraploid species, Gossypium hirsutum. These data represent the first such estimates for a pair of ho...

We assessed the effects of red imported fire ants (Solenopsis invicta; hereafter fire ant) on the foraging of hispid cotton rats (Sigmodon hispidus). We used a manipulative experiment, placing resource patches with a known amount of millet seed within areas with reduced (RIFA [-]) or ambient (RIFA [+]) numbers of fire ants. We measured giving up densities (the amount of food left within each pa...

The formation of allopolyploid cotton precipitated a rapid diversification and colonization of dry coastal American tropical and subtropical regions. Previous phylogenetic analyses, combined with molecular divergence analyses, have offered a temporal framework for this radiation, but provide only weak support for some of the resolved branches. Moreover, these earlier analyses did not include th...

Bollgard cotton (Gossypium hirsutum L.) containing the CryIAc endotoxin of Bacillus thuringiensis Berliner became commercially available to cotton producers in 1996. Bollgard cultivars since that time have provided excellent control of the tobacco budworm, Heliothis virescens F., for growers in Arkansas. Control of bollworm, Helicoverpa zea (Boddie), and other lepidopterous pests has been less ...