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Application of Drone and WorldView-4 Satellite Data in Mapping and Monitoring Grazing Land Cover and Pasture Quality: Pre- and Post-Flooding
Get PDFFrequent flooding worldwide, especially in grazing environments, requires mapping and monitoring grazing land cover and pasture quality to support land management. Although drones, satellite, and machine learning technologies can be used to map land cover and pasture quality, there have been limited applications in grazing land environments, especially monitoring land cover change and pasture quality pre- and post-flood events. The use of high spatial resolution drone and satellite data such as WorldView-4 can provide effective mapping and monitoring in grazing land environments. The aim of this study was to utilize high spatial resolution drone and WorldView-4 satellite data to map and monitor grazing land cover change and pasture quality pre-and post-flooding. The grazing land cover was mapped pre-flooding using WorldView-4 satellite data and post-flooding using real-time drone data. The machine learning Random Forest classification algorithm was used to delineate land cover types and the normalized difference vegetation index (NDVI) was used to monitor pasture quality. This study found a seven percent (7%) increase in pasture cover and a one hundred percent (100%) increase in pasture quality post-flooding. The drone and WorldView-4 satellite data were useful to detect grazing land cover change at a finer scale
Distribution and conservation status of Camellia longzhouensis (Theaceae), a critically endangered plant species endemic to southern China
Get PDFCamellia longzhouensis (Theaceae) is an endemic evergreen shrub or small tree with a distribution restricted to South China. It is listed as Grade-II in the National Key Protected Wild Plants List. In this study, we surveyed its distribution, examined its population structure, identified factors affecting its survival, and reassessed its extinction risk. We found that C. longzhouensis was only distributed in the Nonggang National Nature Reserve and the surrounding area. Its individuals only grew under the secondary forest canopy in the karst mountain. A total of 58 individuals of C. longzhouensis in three sub-populations were found. Soil fertility and understory light availability were the main habitat factors influencing the survival of C. longzhouensis. Anthropogenic disturbances and reproductive obstacles have caused a low seed-setting rate, poor seedling survival, and a lack of adult plants of C. longzhouensis in the natural habitat. The population structure of C. longzhouensis is spindle-shaped, indicating poor natural regeneration and inhibited seedling recruitment. Cleistanthus petelotii had a significant positive interspecific interaction with C. longzhouensis in the community. Based on the information obtained here and IUCN criterion C2ai, we recommend that C. longzhouensis be categorized in the International Union for Conservation of Nature (IUCN) Red List as Critically Endangered. We also developed a comprehensive protection strategy, consisting of in situ conservation, ex situ conservation, reintroduction, and commercial utilization. This strategy can be readily applied to protect other endangered plants with economic value in karst poor regions
Assessing seaweed extract as a biostimulant on the yield of organic leafy greens in Tennessee
Get PDFBiostimulants are a better alternative to expensive organic fertilizers used in certified organic crop production. Seaweed extracts (Stimplex®), derived from brown algae (Ascophyllum nodosum) present in marine water, can be used as a “biostimulant” in agriculture to enhance plant yield and improve plant growth. The aim of this study was to elucidate the effect of Stimplex® on the yield of leafy green vegetables produced in an organic farming system. A Stimplex® greenhouse trial was conducted in fall 2015 and spring 2016 at the Tennessee State University organic research farm. Six leafy greens –lettuce, mustard, kale, Swiss chard, amaranths and collards– were foliar sprayed with Stimplex® (treated) bi-weekly for six weeks at the recommended dose of 3.2 ml/L (0.4 oz/gal of water), and six were untreated (control). Seedlings were raised in the greenhouse from organic seeds in pots, and organic management practices were followed per National Organic Program standards throughout the study. For each leafy green, a total of five treated potted plants and five untreated potted plants were used in three replications. Results showed that plants treated with Stimplex® were more vigorous, healthier and increased yield over untreated plants, except for amaranths. The percentage increase in plant yield of all crops was between 11% and 35%. The highest and lowest increase in plant yield was observed in the mustard greens (35.8 %) and Swiss chard (11.0%). Results suggest Stimplex® stimulates higher yields in leafy greens
Recent Advances in the Application of CRISPR/Cas9 Gene Editing System in Poultry Species
Get PDFCRISPR/Cas9 system genome editing is revolutionizing genetics research in a wide spectrum of animal models in the genetic era. Among these animals, is the poultry species. CRISPR technology is the newest and most advanced gene-editing tool that allows researchers to modify and alter gene functions for transcriptional regulation, gene targeting, epigenetic modification, gene therapy, and drug delivery in the animal genome. The applicability of the CRISPR/Cas9 system in gene editing and modification of genomes in the avian species is still emerging. Up to date, substantial progress in using CRISPR/Cas9 technology has been made in only two poultry species (chicken and quail), with chicken taking the lead. There have been major recent advances in the modification of the avian genome through their germ cell lineages. In the poultry industry, breeders and producers can utilize CRISPR-mediated approaches to enhance the many required genetic variations towards the poultry population that are absent in a given poultry flock. Thus, CRISPR allows the benefit of accessing genetic characteristics that cannot otherwise be used for poultry production. Therefore CRISPR/Cas9 becomes a very powerful and robust tool for editing genes that allow for the introduction or regulation of genetic information in poultry genomes. However, the CRISPR/Cas9 technology has several limitations that need to be addressed to enhance its use in the poultry industry. This review evaluates and provides a summary of recent advances in applying CRISPR/Cas9 gene editing technology in poultry research and explores its potential use in advancing poultry breeding and production with a major focus on chicken and quail. This could aid future advancements in the use of CRISPR technology to improve poultry production
Sources of Resistance to Common Bacterial Blight and Charcoal Rot Disease for the Production of Mesoamerican Common Beans in the Southern United States
Get PDFThe gene pool of Mesoamerican common beans (Phaseolus vulgaris L.) includes genotypes in the small-to-medium-size seeded dry beans, as well as some snap beans from hotter environments adapted to the Southeastern United States. However, the warm and humid climate of the Southeastern United States is conducive to diseases such as Common Bacterial Blight (CBB) and Charcoal Rot (CR). The pathogens for these two diseases can survive long periods in infested soil or on seeds and are difficult to control through pesticides. Hence, field-level resistance would be the best management strategy for these diseases. The goals of this study were (1) to evaluate field-level resistance from the various commercial classes and subgroups represented in the Mesoamerican gene pool as sources for breeding beans for the region and (2) to evaluate genome-wide marker × trait associations (GWAS) using genetic markers for the genotypes. A total of 300 genotypes from the Mesoamerican Diversity Panel (MDP) were evaluated for CBB and CR in field experiments for three years. CBB resistance was also tested with a field isolate in controlled greenhouse conditions. The analysis of variance revealed the presence of variability in the MDP for the evaluated traits. We also identified adapted common bean genotypes that could be used directly in Southeastern production or that could be good parents in breeding programs for CBB and CR resistance. The GWAS detected 14 significant Single-Nucleotide Polymorphism (SNP) markers associated with CBB resistance distributed on five chromosomes, namely Pv02, Pv04, Pv08, Pv10, and Pv11, but no loci for resistance to CR. A total of 89 candidate genes were identified in close vicinity (±100 kb) to the significant CBB markers, some of which could be directly or indirectly involved in plant defense to diseases. These results provide a basis to further understand the complex inheritance of CBB resistance in Mesoamerican common beans and show that this biotic stress is unrelated to CR resistance, which was evident during a drought period. Genotypes with good yield potential for the Southeastern U.S. growing conditions were found with resistant to infection by the two diseases, as well as adaptation to the hot and humid conditions punctuated by droughts found in this region