Genomic Variation Shaped by Environmental and Geographical Factors in Prairie Cordgrass Natural Populations Collected across Its Native Range in the USA.

Prairie cordgrass ( Link) is a native perennial warm-season (C4) grass common in North American prairies. With its high biomass yield and abiotic stress tolerance, there is a high potential of developing prairie cordgrass for conservation practices and as a dedicated bioenergy crop for sustainable cellulosic biofuel production. However, as with many other undomesticated grass species, little information is known about the genetic diversity or population structure of prairie cordgrass natural populations as compared to their ecotypic and geographic adaptation in North America.

Determination of genome size variations among different date palm cultivars ( L.) by flow cytometry.

Date palm is an important fruit crop and member of palm family, reported with varied ploidy levels, i.e., 14 (2 = 28) to 18 (2 = 36) pairs of chromosomes and genomic size due to the limited work done on its cytological aspect.

Assessment of the potential for gene flow from transgenic maize (Zea mays L.) to eastern gamagrass (Tripsacum dactyloides L.).

Eastern gamagrass (Tripsacum dactyloides L.) belongs to the same tribe of the Poaceae family as maize (Zea mays L.) and grows naturally in the same region where maize is commercially produced in the USA.

Meiotic pairing as an indicator of genome composition in polyploid prairie cordgrass (Spartina pectinata Link).

The existence of neopolyploidy in prairie cordgrass (Spartina pectinata Link) has been documented. The neohexaploid was discovered coexisting with tetraploids in central Illinois, and has been reported to exhibit competitiveness in the natural environment. It is hypothesized that the natural tetraploid cytotype produced the hexaploid cytotype via production of unreduced gametes.

Transcriptome Analysis of Spartina pectinata in Response to Freezing Stress.

Prairie cordgrass (Spartina pectinata), a perennial C4 grass native to the North American prairie, has several distinctive characteristics that potentially make it a model crop for production in stressful environments. However, little is known about the transcriptome dynamics of prairie cordgrass despite its unique freezing stress tolerance. Therefore, the purpose of this work was to explore the transcriptome dynamics of prairie cordgrass in response to freezing stress at -5°C for 5 min and 30 min.

Validating DNA Polymorphisms Using KASP Assay in Prairie Cordgrass (Spartina pectinata Link) Populations in the U.S.

Single nucleotide polymorphisms (SNPs) are one of the most abundant DNA variants found in plant genomes and are highly efficient when comparing genome and transcriptome sequences. SNP marker analysis can be used to analyze genetic diversity, create genetic maps, and utilize marker-assisted selection breeding in many crop species. In order to utilize these technologies, one must first identify and validate putative SNPs.

Insight into genomic changes accompanying divergence: genetic linkage maps and synteny of Lucania goodei and L. parva reveal a Robertsonian fusion.

Linkage maps are important tools in evolutionary genetics and in studies of speciation. We performed a karyotyping study and constructed high-density linkage maps for two closely related killifish species, Lucania parva and L. goodei, that differ in salinity tolerance and still hybridize in their contact zone in Florida.

Effects of community- and neighborhood-scale spatial patterns on semi-arid perennial grassland community dynamics.

Although plant spatial patterns strongly influence community-structuring processes, few empirical studies have addressed pattern effects on perennial community dynamics. We tested the effects of community- and neighborhood-scale patterns in experimental semi-arid grassland communities comprising the stronger competitor crested wheatgrass (Agropyron cristatum) and the weaker competitor Snake River wheatgrass (Elymus wawawaiensis). Treatments consisted of community-scale patterns (Poisson random, regular, and aggregated) and neighborhood-scale patterns (Poisson random, small, and large aggregations) applied to 6.

Discovery of natural Miscanthus (Poaceae) triploid plants in sympatric populations of Miscanthus sacchariflorus and Miscanthus sinensis in southern Japan.

Premise Of The Study: Looming petroleum shortages and projected negative impacts of human-induced climate change may be partly alleviated by the development and use of bioenergy feedstock crops. Miscanthus ×giganteus, a highly productive sterile triploid hybrid grass that was discovered in Japan several decades ago, has considerable potential as an alternative source of energy. Given the risks, however, involved in the reliance upon production of one clone of this hybrid, which is a natural cross between Miscanthus sacchariflorus and Miscanthus sinensis, for lignocellulosic bioenergy production, natural occurrences of triploidy were investigated in sympatric populations of tetraploid M.

Out of the swamp: unidirectional hybridization with weedy species may explain the prevalence of Amaranthus tuberculatus as a weed.

*Amaranthus tuberculatus represents one of the most dramatic cases of weed invasion documented in the midwestern USA. The species is infamous for evolving resistance to multiple herbicides, and predicting whether these resistances may be transferred to widespread weeds of the Amaranthus hybridus aggregate is a matter of epidemiological concern. Here, we explore the patterns of genetic exchange between Amaranthus tuberculatus and A.

Genome size and nucleotypic variation in Malus germplasm.

The genus Malus has anywhere between 25 and 33 species along with several subspecies. Malus species as well as clones within the same species have varying ploidy levels, as these are more than likely collected from different trees and (or) from different locations. In recent years, large numbers of Malus germplasm accessions have been collected and maintained at the United States National Germplasm Clonal Repository; however, genome sizes of this material have not yet been determined.

Saw palmetto extract induces nuclear heterogeneity in mice.

Saw palmetto (SW), a phytotherapeutic compound used in the treatment of prostate disease, was examined for potential nuclear effects. SW extract was incorporated into a complete casein-based semisynthetic rodent chow at 0%, 0.1% and 1% SW.

PRINS-labeled knobs are not associated with increased chromosomal stickiness in the maize st1 mutant.

In maize, the st1 mutant has been observed to result in chromosomes that stick together during both mitotic and meiotic anaphase. These sticky chromosomes result in abnormal chromosome separation at anaphase. Although the mechanism producing the st1 mutant phenotype is unknown, delayed replication of knob heterochromatin has been implicated in similar phenomena that result in sticky chromosomes.

Aquatic herbicides and herbicide contaminants: In vitro cytotoxicity and cell-cycle analysis.

Concerns have arisen about the possible effects of herbicide contamination in aquatic ecosystems. Crop herbicides are introduced into the aquatic environment both inadvertently through runoff events and intentionally through the use of those registered for use in waterways. Acetochlor and atrazine are two agricultural crop herbicides that have often been reported to contaminate waters.

Variation in nuclear DNA content in Malus species and cultivated apples.

The nuclear DNA content for a group of 40 Malus species and hybrids has been estimated using flow cytometry. Estimates of nuclear DNA content for this germplasm collection range from 1.45 pg for Malus fusca (diploid) to 2.

Differential metamorphosis alters the endocrine response in anuran larvae exposed to T3 and atrazine.

Pesticide chemical contamination is one of the suspected contributors of the amphibian population decline. The herbicide atrazine is one of the major surface water contaminants in the U.S.

A multipronged approach to addressing the organ shortage.

Organ donation rates continue to lag behind the number of patients waiting for an organ transplant. The Alabama Organ Center, the organ procurement organization for the state of Alabama, is using a multipronged approach to address the organ shortage. The plan includes clinical options, public education, and professional education.

Localization of repetitive DNA sequences on in vitro Xenopus laevis chromosomes by primed in situ labeling (PRINS).

Xenopus laevis is an important reference model organism used in many vertebrate studies. Gene mapping in X. laevis, in comparison to other reference organisms, is in its early stages.

Developmental impact of atrazine on metamorphing Xenopus laevis as revealed by nuclear analysis and morphology.

Atrazine is one of the major surface water contaminants in the midwestern United States. Speculations have arisen on the potential effects of atrazine contamination to anuran larvae developing in these surface waters. In this study, Xenopus laevis tadpoles were exposed to environmentally relevant concentrations of atrazine.

Fertility, segregation at a herbicide-resistance locus, and genome structure in BC hybrids from two important weedy Amaranthus species.

Field studies have established high potential for hybridization between two important and often coexisting weedy species, Amaranthus hybridus and Amaranthus tuberculatus. Prezygotic reproductive barriers between these species are believed to be limited to pollen competition and availability. A greenhouse study showed that a herbicide-resistance gene (ALS) from A.

Metamorphosis in Xenopus laevis is not associated with large-scale nuclear DNA content variation.

Amphibian metamorphosis is a complex process that has been speculated to involve DNA amplification and chromatin rearrangement. While recent studies have concentrated on chromatin rearrangement, only a few studies have dealt with variation in the amount of DNA during amphibian metamorphosis. In this study, nuclei were isolated from Xenopus laevis at various developmental stages.

Amaranthus hybridus can be pollinated frequently by A. tuberculatus under field conditions.

Recent studies have confirmed that weedy Amaranthus species are capable of interspecific hybridization, and such hybridization may foster the evolution of herbicide resistance. However, the extent to which hybridization among these species occurs in nature is unknown. The purpose of this study was to determine the frequency under field conditions at which A.

In vivo genotoxicity of atrazine to anuran larvae.

Atrazine has been an environmental contaminant for more than two decades. While there can be little dispute as to the presence of atrazine in non-target watersheds, the debate has centered on the consequences of this contamination. The purpose of this study was to determine if atrazine is genotoxic to developing anurans.