MOLECULAR BIOLOGY AND PHYSIOLOGY Fiber Initiation in 18 Cultivars and Experimental Lines of Three Gossypium Species

ABSTRACT A new technique was developed to study the cotton fiber initiation process and fiber initial densities. The goal was to provide an additional tool to cotton breeders and geneticists interested in fiber improvement. The objectives were to assess whether fiber initiation patterns reported for some Gossypium hirsutum L. and G. barbadense L. cultivars extend to a more diverse range of cultivars/lines; and to test if there is a relationship between fiber initials density, lint percentage, and fiber characteristics. This study was performed with 17 cultivars and experimental lines of G. hirsutum (upland cotton) and G. barbadense (Pima cotton) and one G. arboreum L. accession. The ovules were extracted from flowers at the day of anthesis and 1 and 2 d thereafter, stained with a fluorescent dye, DiOC 6 (3) (3,3′-dihexyloxacarbocyanine iodide), and observed under a light microscope. Staining cotton fiber initials with DiOC 6 (3) enabled the evaluation of a greater number of samples than the more time-consuming scanning electron microscopy protocols to assess the fiber initiation process. There were significant differences in fiber initial densities among cultivars and lines but these did not cluster into "upland" and "Pima" types as had been expected. Upland and Pima fiber initiation occurred at anthesis, whereas Sea Island Pima initiation was delayed a day. A delay in fiber initiation was also confirmed in fuzzless mutant lines. Fiber initial densities were not found to be useful predictors of lint percentage

RYE COVER CROP AS A SOURCE OF BIOMASS FEEDSTOCK: AN ECONOMIC PERSPECTIVE

ABSTRACT As more emphasis is placed on biopower and biofuels, the availability of biomass feedstock is taking center stage. The growth of the biomass feedstock market is further strengthened by the implementation of new regulations and federal programs. One option for biomass feedstock is the removal of cover crops, such as cereal rye. An experiment was initiated to compare three rye residue management techniques (residue retained, residue harvested or removed, and no rye cover control) and four nitrogen fertilizer treatments (0, 45, 90, 125 lb ac -1 ). Initial findings from this study show that the removal of rye cover crops for biomass feedstock is a viable option for producers, given the assumptions in the study. Further investigation is needed to determine the complete economic impact of removing rye cover crop for biomass feedstock

Assessment the flood hazard arising from land use change in a forested catchment in northern Iran

The provinces of northern Iran that border the Caspian Sea are forested and may be prone to increased risks of flooding due to deforestation and other land use changes, in addition to climate change effects. This research investigated changes in runoff from a small forested catchment in northern Iran for several land use change scenarios and the effects of higher rainfall and high antecedent soil moisture. Peak discharges and total runoff volumes from the catchment were estimated using the US Soil Conservation Service 'Curve Number' (SCS-CN) method and the SCS dimensionless unit hydrograph. This method was selected for reasons of data availability and operational simplicity for flood managers. A GIS was used to manipulate spatial data for use in the catchment runoff modelling. The results show that runoff is predicted to increase as a result of deforestation, which is dependent on the proportion of the catchment area affected. However, climate change presents a significant flood hazard even in the absence of deforestation. Other land use changes may reduce the peak discharges of all return period floods. Therefore a future ban on timber extraction, combined with agricultural utilisation of rangeland, could prove effective as 'nature-based' flood reduction measures throughout northern Iran

Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss. October 2015 - March 2016

The Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss (PHLIL) is a strategic, applied, research and education program aimed at improving food security by reducing post-harvest loss and food waste of seeds and durable staple crops, e.g., grains, oilseeds, and legumes. The Lab’s efforts are focused in four Feed the Future countries (Bangladesh, Ethiopia, Ghana, and Guatemala) and Afghanistan

Feed the Future: Reduction of Post-Harvest Loss Innovation Lab. October 2014 - September 2015

The Feed the Future Reduction of Post-Harvest Loss Innovation Lab is a strategic and applied, research and education program aimed at improving food security by reducing post-harvest loss and food waste of seeds and durable staple crops, e.g., grains, oilseeds, and legumes. The Lab’s efforts are focused in four Feed the Future countries (Bangladesh, Ethiopia, Ghana, and Guate-mala) and Afghanistan

Invasive annual grasses—Reenvisioning approaches in a changing climate

For nearly a century, invasive annual grasses have increasingly impacted terrestrial ecosystems across the western United States. Weather variability associated with climate change and increased atmospheric carbon dioxide (CO2) are making even more difficult the challenges of managing invasive annual grasses. As part of a special issue on climate change impacts on soil and water conservation, the topic of invasive annual grasses is being addressed by scientists at the USDA Agricultural Research Service to emphasize the need for additional research and future studies that build on current knowledge and account for (extreme) changes in abiotic and biotic conditions. Much research has focused on understanding the mechanisms underlying annual grass invasion, as well as assessing patterns and responses from a wide range of disturbances and management approaches. Weather extremes and the increasing occurrences of wildfire are contributing to the complexity of the problem. In broad terms, invasive annual grass management, including restoration, must be proactive to consider human values and ecosystem resiliency. Models capable of synthesizing vast amounts of diverse information are necessary for creating trajectories that could result in the establishment of perennial systems. Organization and collaboration are needed across the research community and with land managers to strategically develop and implement practices that limit invasive annual grasses. In the future, research will need to address invasive annual grasses in an adaptive integrated weed management (AIWM) framework that utilizes models and accounts for climate change that is resulting in altered/new approaches to management and restoration

Genome-Wide Association Studies of Grain Yield Components in Diverse Sorghum Germplasm

Citation: Boyles, R. E., Cooper, E. A., Myers, M. T., Brenton, Z., Rauh, B. L., Morris, G. P., & Kresovich, S. (2016). Genome-Wide Association Studies of Grain Yield Components in Diverse Sorghum Germplasm. Plant Genome, 9(2), 17. doi:10.3835/plantgenome2015.09.0091Grain yield and its primary determinants, grain number and weight, are important traits in cereal crops that have been well studied; however, the genetic basis of and interactions between these traits remain poorly understood. Characterization of grain yield per primary panicle (YPP), grain number per primary panicle (GNP), and 1000-grain weight (TGW) in sorghum [Sorghum bicolor (L.) Moench], a hardy C-4 cereal with a genome size of similar to 730 Mb, was implemented in a diversity panel containing 390 accessions. These accessions were genotyped to obtain 268,830 single-nucleotide polymorphisms (SNPs). Genome-wide association studies (GWAS) were performed to identify loci associated with each grain yield component and understand the genetic interactions between these traits. Genome-wide association studies identified associations across the genome with YPP, GNP, and TGW that were located within previously mapped sorghum QTL for panicle weight, grain yield, and seed size, respectively. There were no significant associations between GNP and TGW that were within 100 kb, much greater than the average linkage disequilibrium (LD) in sorghum. The identification of nonoverlapping loci for grain number and weight suggests these traits may be manipulated independently to increase the grain yield of sorghum. Following GWAS, genomic regions surrounding each associated SNP were mined for candidate genes. Previously published expression data indicated several TGW candidate genes, including an ethylene receptor homolog, were primarily expressed within developing seed tissues to support GWAS. Furthermore, maize (Zea mays L.) homologs of identified TGW candidates were differentially expressed within the seed between small- and large-kernel lines from a segregating maize population