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.

Quantitative trait mapping of plant architecture in two BCF populations of Sorghum Bicolor × S. halepense and comparisons to two other sorghum populations.

Comparing populations derived, respectively, from polyploid Sorghum halepense and its progenitors improved knowledge of plant architecture and showed that S. halepense harbors genetic novelty of potential value for sorghum improvement Vegetative growth and the timing of the vegetative-to-reproductive transition are critical to a plant's fitness, directly and indirectly determining when and how a plant lives, grows and reproduces. We describe quantitative trait analysis of plant height and flowering time in the naturally occurring tetraploid Sorghum halepense, using two novel BCF populations totaling 246 genotypes derived from backcrossing two tetraploid Sorghum bicolor x S.

Genetic Analysis of Stem Diameter and Water Contents To Improve Sorghum Bioenergy Efficiency.

Biofuel made from agricultural products has the potential in contribute to a stable supply of fuel for growing energy demands. Some salient plant traits, such as stem diameter and water content, and their relationship to other important biomass-related traits are so far poorly understood. Here, we performed QTL mapping for three stem diameter and two water content traits in a BTx623 x IS3620c recombinant inbred line population of 399 genotypes, and validated the genomic regions identified using genome-wide association studies (GWAS) in a diversity panel of 354 accessions.

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.

Genotyping by Sequencing of 393 BTx623 × IS3620C Recombinant Inbred Lines Improves Sensitivity and Resolution of QTL Detection.

We describe a genetic map with a total of 381 bins of 616 genotyping by sequencing (GBS)-based SNP markers in a F-F recombinant inbred line (RIL) population of 393 individuals derived from crossing BTx623 to IS3620C, a guinea line substantially diverged from BTx623. Five segregation distorted regions were found with four showing enrichment for alleles, suggesting possible selection during formation of this RIL population. A quantitative trait locus (QTL) study with this number of individuals, tripled relative to prior studies of this cross, provided resources, validated previous findings, and demonstrated improved power to detect plant height and flowering time related QTL relative to other published studies.

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.

Genetic analysis of rhizomatousness and its relationship with vegetative branching of recombinant inbred lines of Sorghum bicolor × S. propinquum.

Premise Of The Study: Rhizomes, subterranean stems that grow horizontally, are a storage organ that is highly associated with overwintering and regrowth. This quantitative study aimed to discover genetic determinants of rhizomatousness, an important trait related to perenniality and invasiveness.

Methods: A population of 161 individuals of a recombinant inbred line (RIL) derived from morphologically distinct parents, Sorghum bicolor and Sorghum propinquum, which segregates for rhizomatousness, was phenotyped and genetically mapped.

Genetic analysis of inflorescence and plant height components in sorghum (Panicoidae) and comparative genetics with rice (Oryzoidae).

Background: Domestication has played an important role in shaping characteristics of the inflorescence and plant height in cultivated cereals. Taking advantage of meta-analysis of QTLs, phylogenetic analyses in 502 diverse sorghum accessions, GWAS in a sorghum association panel (n = 354) and comparative data, we provide insight into the genetic basis of the domestication traits in sorghum and rice.

Results: We performed genome-wide association studies (GWAS) on 6 traits related to inflorescence morphology and 6 traits related to plant height in sorghum, comparing the genomic regions implicated in these traits by GWAS and QTL mapping, respectively.

Comparative Genetics of Seed Size Traits in Divergent Cereal Lineages Represented by Sorghum (Panicoidae) and Rice (Oryzoidae).

Seed size is closely related to fitness of wild plants, and its modification has been a key recurring element in domestication of seed/grain crops. In sorghum, a genomic and morphological model for panicoid cereals, a rich history of research into the genetics of seed size is reflected by a total of 13 likelihood intervals determined by conventional QTL (linkage) mapping in 11 nonoverlapping regions of the genome. To complement QTL data and investigate whether the discovery of seed size QTL is approaching "saturation," we compared QTL data to GWAS for seed mass, seed length, and seed width studied in 354 accessions from a sorghum association panel (SAP) that have been genotyped at 265,487 SNPs.

Genetic analysis of vegetative branching in sorghum.

We identified quantitative trait loci influencing plant architecture that may be valuable in breeding of optimized genotypes for sustainable food and/or cellulosic biomass production, and advancing resilience to changing climates. We describe a 3-year study to identify quantitative trait loci (QTLs) for vegetative branching of sorghum in a recombinant inbred line population of 161 genotypes derived from two morphologically distinct parents, S. bicolor × S.

Alleles conferring improved fiber quality from EMS mutagenesis of elite cotton genotypes.

Genetic improvements for many fiber traits are obtained by mutagenesis of elite cottons, mitigating genetic uniformity in this inbred polyploid by contributing novel alleles important to ongoing crop improvement. The elite gene pool of cotton (Gossypium spp.) has less diversity than those of most other major crops, making identification of novel alleles important to ongoing crop improvement.

Seed shattering in a wild sorghum is conferred by a locus unrelated to domestication.

Suppression of seed shattering was a key step during crop domestication that we have previously suggested to be convergent among independent cereal lineages. Positional, association, expression, and mutant complementation data all implicate a WRKY transcription factor, SpWRKY, in conferring shattering to a wild sorghum relative, Sorghum propinquum. We hypothesize that SpWRKY functions in a manner analogous to Medicago and Arabidopsis homologs that regulate cell wall biosynthesis genes, with low expression toward the end of floral development derepressing downstream cell wall biosynthesis genes to allow deposition of lignin that initiates the abscission zone in the seed-pedicel junction.

Identification of bioconversion quantitative trait loci in the interspecific cross Sorghum bicolor × Sorghum propinquum.

For lignocellulosic bioenergy to be economically viable, genetic improvements must be made in feedstock quality including both biomass total yield and conversion efficiency. Toward this goal, multiple studies have considered candidate genes and discovered quantitative trait loci (QTL) associated with total biomass accumulation and/or grain production in bioenergy grass species including maize and sorghum. However, very little research has been focused on genes associated with increased biomass conversion efficiency.

Genetic analysis of recombinant inbred lines for Sorghum bicolor × Sorghum propinquum.

We describe a recombinant inbred line (RIL) population of 161 F5 genotypes for the widest euploid cross that can be made to cultivated sorghum (Sorghum bicolor) using conventional techniques, S. bicolor × Sorghum propinquum, that segregates for many traits related to plant architecture, growth and development, reproduction, and life history. The genetic map of the S.

Comparative physical mapping links conservation of microsynteny to chromosome structure and recombination in grasses.

Nearly finished sequences for model organisms provide a foundation from which to explore genomic diversity among other taxonomic groups. We explore genome-wide microsynteny patterns between the rice sequence and two sorghum physical maps that integrate genetic markers, bacterial artificial chromosome (BAC) fingerprints, and BAC hybridization data. The sorghum maps largely tile a genomic component containing 41% of BACs but 80% of single-copy genes that shows conserved microsynteny with rice and partially tile a nonsyntenic component containing 46% of BACs but only 13% of single-copy genes.