Comparative evolution of vegetative branching in sorghum.

Tillering and secondary branching are two plastic traits with high agronomic importance, especially in terms of the ability of plants to adapt to changing environments. We describe a quantitative trait analysis of tillering and secondary branching in two novel BC1F2 populations totaling 246 genotypes derived from backcrossing two Sorghum bicolor x S. halepense F1 plants to a tetraploidized S.

The Evolution of an Invasive Plant, L. ('Johnsongrass').

From noble beginnings as a prospective forage, polyploid ('Johnsongrass') is both an invasive species and one of the world's worst agricultural weeds. Formed by x hybridization, we show to have -enriched allele composition and striking mutations in 5,957 genes that differentiate it from representatives of its progenitor species and an outgroup. The spread of may have been facilitated by introgression from closely-related cultivated sorghum near genetic loci affecting rhizome development, seed size, and levels of lutein, a photochemical protectant and abscisic acid precursor.

Transmission Genetics of a × Backcross Populations.

Despite a "ploidy barrier," interspecific crosses to wild and/or cultivated sorghum (, 2n = 2x = 20) may have aided the spread across six continents of , also exemplifying risks of "transgene escape" from crops that could make weeds more difficult to control. Genetic maps of two BCF populations derived from crosses of (sorghum) and with totals of 722 and 795 single nucleotide polymorphism (SNP) markers span 37 and 35 linkage groups, with 2-6 for each of the 10 basic sorghum chromosomes due to fragments covering different chromosomal portions or independent segregation from different homologs. Segregation distortion favored alleles on chromosomes 2 (1.

Multi-Phase US Spread and Habitat Switching of a Post-Columbian Invasive, Sorghum halepense.

Johnsongrass (Sorghum halepense) is a striking example of a post-Columbian founder event. This natural experiment within ecological time-scales provides a unique opportunity for understanding patterns of continent-wide genetic diversity following range expansion. Microsatellite markers were used for population genetic analyses including leaf-optimized Neighbor-Joining tree, pairwise FST, mismatch analysis, principle coordinate analysis, Tajima's D, Fu's F and Bayesian clusterings of population structure.