Spatio-temporal dynamic of suitable areas for species conservation in West Africa: eight economically important wild palms under present and future climates

Sustainable conservation of tropical resources required understanding of their distribution for effective assessment and definition of conservation priorities. In tropical areas, wild palms are highly valued keystone resources with growing demand for both subsistence uses and commercial trade. Here we focused on eight such species (Borassus aethiopum Mart., Eremospatha macrocarpa (G.Mann & H.Wendl.) H.Wendl., Hyphaene thebaica Mart., Laccosperma opacum (G.Mann & H.Wendl.) Drude, Phoenix reclinata Jacq., Raphia hookeri G.Mann & H.Wendl., Raphia sudanica A. Chev., and Raphia vinifera P.Beauv.). This study tested (i) how those palms distributions may be affected under future climate scenarios, and (ii) if species are effectively conserved currently and under future forecasts for their native distributional areas. Finally, we defined spatial priorities for the species’ conservation. Available bioclimatic and soil data layers were used for the modelling with maximum entropy approaches, and resulting maps were overlaid on the existing protected areas network. Results showed that much of the distribution of the species will remain largely stable, albeit with some expansion and retraction in some species; relationships with protected areas networks suggest that protected portions of species distributions will also remain stable. The areas identified as highest conservation priority differ between models even though the highest-priority areas holding most palm species are located along the coast (from Guinea to Nigeria). Further development of these analyses could aid in forming a more complete picture of the distributions and populations of the species, which in turn could aid in developing effective conservation strategies for this botanically important family.     

Identification of potential areas for wild palm cultivation in the Republic of Benin through remote sensing and ecological niche modeling

Wild palms contribute significantly to food security and local economy in tropical areas, and particularly in sub-Saharan Africa. In light of this importance, eight palm species were explored [Borassus aethiopum (L.) Mart, Eremospatha macrocarpa (G. Mann et H. Wendl.) H. Wendl., Laccosperma opacum (G. Mann et H. Wendl.) Drude, Hyphaene thebaica (L.) Mart, Phoenix reclinata Jacq., Raphia hookeri G. Mann et H. Wendl., R. sudanica A. Chev., and R. vinifera P. Beauv.] as targets for conservation, domestication, and cultivation in Benin. Cultivation potential was evaluated in a coarse-resolution, first-pass effort using ecological niche models to relate known occurrences of each species to vegetation indices (VEG), gross primary productivity (GPP), and soil characteristics (SOIL), and model outputs were related to human distribution and land-use patterns. Results showed that wild palms responded differentially to different suites of environmental factors: some species showed best model performance with VEG + GPP + SOIL, others with GPP + SOIL or VEG + GPP, or with a single factor. Two species had broad potential distributions across the country; others had potential areas in the north (2 species) or the south (4 species). Raphia hookeri and R. vinifera showed greatest overlap in terms of ecology and distribution, whereas L. opacum and R. sudanica had the lowest similarity. These models constitute initial steps toward a sustainable scheme for planning exploration of the possibility of cultivation of these species.     

Lipase Activity and Lipid Metabolism During Oat Malting

Experiments were conducted to determine the relationship, if any, between lipase activity and the metabolism of lipids during malting (germination) of oat (Avena sativa L.) seed. During the course of malting, concentration of the free fatty acid fraction increased markedly at the expense of the neutral lipid fraction (predominantly triacylglycerides), while the initially high lipase activity (most of which is located in the surface layers of the grains) decreased by ≈40%. The fatty acid compositions of total and neutral lipid fractions were stable during malting, but there were marked changes in the free fatty acid and phospholipid fractions. In a comparison among 12 hulled and hull-less genotypes, there were no significant regressions between the quantitative changes in lipid fractions and lipase activities. Brief treatments with chemicals or hot H₂O that partially or completely inhibited lipase activity had various effects on subsequent quantitative changes in lipid fractions, but these changes were not consistent with the inhibitions in lipase activity observed. It was concluded that the degradation in triacylglycerides and increase in free fatty acids observed during oat malting were not controlled by the level of total lipase activity. Rather, it was suggested that oat may have another lipase present in the cells where the oil bodies are located that hydrolyzes triacylglycerides from the oil bodies during germination. Further research is needed to substantiate this hypothesis.     

Fate of Dwarf Bunt Fungus Teliospores During Milling of Wheat into Flour

Wheat contaminated with teliospores of Tilletia controversa Kühn (TCK) was mixed with uncontaminated wheat and processed through the Kansas State University pilot mill. Two 50-bu lots of the contaminated mixture were cleaned, tempered, and milled. Approximately 500 samples of wheat, cleanings, and mill fractions were collected and examined for the presence of intact and broken TCK teliospores. Whole wheat samples (50 g) were washed, sieved through a 60-μm nylon sieve, and pelleted by centrifugation. Contents of the pellet were examined microscopically for the presence of TCK spores. The procedure was modified as needed to accommodate cleanings and mill fractions. Levels of spore contamination in whole wheat samples decreased at each step during the handling process, and large numbers of spores were found in materials that were sieved or aspirated from the grain. Very few spores were found in bran, germ, and shorts; none were detected in red dog or straight-grade flour. The results showed that a high percentage of spores can be removed from wheat by mechanical cleaning but that it is not feasible to remove all of them.     

Using Multivariate Techniques to Predict Wheat Flour Dough and Noodle Characteristics from Size‐Exclusion HPLC and RVA Data

Flour proteins of hard and soft winter wheats grown in Oregon were characterized by size‐exclusion HPLC (SE‐HPLC). Flour pasting characteristics were assessed by a Rapid Visco Analyser (RVA). Principle component scores (PCS) were calculated from both RVA data and from absorbance area and % absorbance values from SE‐HPLC. The PCS and cross‐products, ratios, and squares were used to derive wheat classification and quality prediction models. A classification model calculated from PCS of SE‐HPLC data could reliably separate these hard and soft wheats. The prediction models for mixing and noodle characteristics showed better performance when calculated from PCS values of both SEHPLC and RVA data than from SE‐HPLC data only. The R² values of prediction models for mixograph absorption, peak time, and tolerance were 0.827, 0.813, and 0.851, respectively. Prediction models for noodle hardness, cohesiveness, chewiness, and resilience immediately after cooking had R² values of 0.928, 0.928, 0.896, and 0.855, respectively. These results suggest that multivariate methods could be used to develop reliable prediction models for dough mixing and noodle characteristics using just SE‐HPLC and RVA data.     

Identification of Wheat Lines Possessing the 1AL.1RS or 1BL.1RS Wheat-Rye Translocation by Near-Infrared Reflectance Spectroscopy

Wheat-rye chromosomal translocations, particularly those involving the short arm of rye chromosome 1R, have been used during the past 25 years to instill resistance to plant pathogens and insects and improve the hardiness, adaptation, and yield of wheat. Unfortunately, the presence of the 1AL.1RS or 1BL.1RS rye translocations in wheat has been shown to impart inferior dough handling and baking characteristics. Although numerous analytical techniques (e.g., HPLC, monoclonal antibody tests, high-performance capillary electrophoresis) have been developed for detecting these translocations, the complexity of the analytical procedures restricts their use to research and analytical laboratories. The purpose of this study was to examine the potential of diffuse reflectance near-infrared spectroscopy, a well-accepted technique in the grain industry, for detecting 1RS-containing genotypes. This research used three independent groups of wheat samples, ranging in genetic diversity from sister lines derived from 1RS breeding populations to commercial cultivars. Based on the diffuse reflectance spectra (1,100–2,500 nm) of flour, partial least squares (PLS) models, through cross-validation, exhibited misclassification rates as low as 0%, particularly for commercial cultivars. Misclassification rates for corresponding, but separate, test sets were as low as 1%. When the same modeling procedure was applied to samples of more closely related genetic backgrounds, cross-validation misclassification rates rose to 15–20%. Most problematic were samples that were heterogeneous for 1RS such as the cultivar Rawhide. Incorporating heterogeneous samples into a calibration equation improved the classification accuracy of these samples but diminished the prediction accuracy of nonheterogeneous samples.     

Relationships Between Small-Scale Wheat Quality Assays and Commercial Test Bakes

Typical commercial bakeries in the United States are highly mechanized, mass-production facilities. U.S. hard wheat breeding programs use small-scale physical dough testing and pup loaf bake procedures to identify and select improved quality genotypes. The accuracy of such approaches in the prediction of commercial-scale quality performance is poorly understood. Samples from six hard red winter wheat cultivars grown in 11 locations over three harvest years were used to correlate grain hardness, small-scale test bakes, mixograph variables, and various measures of flour protein composition with quality assessments from commercial test laboratories. Samples were milled on both pilot- and small-scale mills. Protein content and 100-g pup loaf volume were more often significantly correlated with commercial test bake variables than all other small-scale variables. Stepwise multiple regression models explained, on average, ≈40% of the variation in commercial test bake procedures. Mixograph properties, pup loaf volumes and absorption, and flour protein content were the most frequent variables identified in model development. Pup loaf bake results on pilot- and small-scale milled flours were highly correlated. Differences in milling technology do not appear to be a significant source of error in relating small-scale test bakes to commercial quality.