Proso Millet (Panicum miliaceum L.) as Alternative Source of Starch and Phenolic Compounds: A Study on Twenty-Five Worldwide Accessions.

Proso millet has been proposed as an effective anti-diabetic food thanks to the combined action of polyphenols and starch. This study aimed to characterize the chemical composition of twenty-five accessions, in order to enhance this cereal as an alternative to available starch for food applications or to propose new food ingredients with health benefits. Proso millet contained a high percentage of starch, reaching values of 58.51%. The amylose content showed high variability, with values ranging from 1.36 to 42.70%, and significantly higher values were recorded for the white accessions than for the colored ones. High-resistant starch content (13.41-26.07%) was also found. The HPLC-MS analysis showed the same phenolic pattern in all the samples. Cinnamic acids are the most abundant compounds and significant differences in their total content were found (0.69 to 1.35 mg/g DW), while flavonoids were only detected in trace amounts. Statistical results showed significantly higher antiradical activity in the colored accessions than in the white ones.

Genome wide association study of agronomic and seed traits in a world collection of proso millet (Panicum miliaceum L.).

BACKGROUND: The climate crisis threatens sustainability of crop production worldwide. Crop diversification may enhance food security while reducing the negative impacts of climate change. Proso millet (Panicum milaceum L.) is a minor cereal crop which holds potential for diversification and adaptation to different environmental conditions. In this study, we assembled a world collection of proso millet consisting of 88 varieties and landraces to investigate its genomic and phenotypic diversity for seed traits, and to identify marker-trait associations (MTA). RESULTS: Sequencing of restriction-site associated DNA fragments yielded 494 million reads and 2,412 high quality single nucleotide polymorphisms (SNPs). SNPs were used to study the diversity in the collection and perform a genome wide association study (GWAS). A genotypic diversity analysis separated accessions originating in Western Europe, Eastern Asia and Americas from accessions sampled in Southern Asia, Western Asia, and Africa. A Bayesian structure analysis reported four cryptic genetic groups, showing that landraces accessions had a significant level of admixture and that most of the improved proso millet materials clustered separately from landraces. The collection was highly diverse for seed traits, with color varying from white to dark brown and width spanning from 1.8 to 2.6 mm. A GWAS study for seed morphology traits identified 10 MTAs. In addition, we identified three MTAs for agronomic traits that were previously measured on the collection. CONCLUSION: Using genomics and automated seed phenotyping, we elucidated phylogenetic relationships and seed diversity in a global millet collection. Overall, we identified 13 MTAs for key agronomic and seed traits indicating the presence of alleles with potential for application in proso breeding programs.

Steryl ferulates composition in twenty-two millet samples: Do "microwave popping" and fermentation affect their content?

Climate change has led to rediscovery of minor drought tolerant grains such as millet. Among its bioactive molecules, steryl ferulates have been poorly explored. Steryl ferulates composition of was investigated by high performance liquid chromatography-diode array detector-tandem mass spectrometry and high resolution tandem mass spectrometry in twenty-two millet samples and also in some fermented and microwave heated samples. Six compounds were found in Panicum, Pennisetum, Eleusine and Setaria genera, with a prevalence of campestanyl and sitostanyl ferulate. The lowest steryl ferulates content was found in Panicum, with values ranging from 2.98 ± 0.04 µg/g to 8.72 ± 0.41 µg/g. Foxtail millet and finger millet showed the highest amount with 46.07 ± 5.20 µg/g and 85.29 ± 4.30 µg/g, respectively. As for pearl millet, microwave heating and fermentation increased steryl ferulates by two (33.77 ± 0.88 µg/g) and five (75.83 ± 1.25 µg/g) times, with respect to the untreated sample. Microwave heating and fermentation could be used to increase steryl ferulates in millet.

Terpene Profiles Composition and Micromorphological Analysis on Two Wild Populations of Helichrysum spp. from the Tuscan Archipelago (Central Italy).

Two wild populations of Helichrysum (Mill.) located at Elba Island (Tuscan Archipelago, Central Italy) were morphologically and phytochemically analyzed to taxonomically identify H. litoreum (population A) and H. italicum subsp. italicum (population B). Micromorphological and histochemical analyses were performed on the indumentum using Scanning Electron Microscope (SEM) and Light Microscope (LM). Morphometric analyses on vegetative and reproductive traits were also conducted. Finally, a chemotaxonomic analysis was carried out on the terpene profile of flowers, leaves and bark tissues using gas chromatography (GC-MS). Results suggested that morphological discriminant traits were mainly in leaves and cypselae glandular tissues. Phytochemical analysis indicated that a high relative content of α-pinene and ß-caryophyllene were the main markers for population A, while a high relative content of neryl-acetate, α-curcumene, isoitalicene and italicene, especially in the terpene profile of bark tissue, were the main compounds for discriminating population B. The analysis suggested that the wild population A could be mainly ascribed to H. litoreum, whilst population B is defined by H. italicum.

The influence of tuber mineral element composition as a function of geographical location on acrylamide formation in different Italian potato genotypes.

BACKGROUND: The present study was aimed at examining the effect of tuber mineral composition, distinctive for geographical location, on the expression of acrylamide precursors in three potato genotypes (Arinda, Rossa di Cetica and Sieglinde) in three Italian potato cultivation regions (Puglia, Sicily and Tuscany). RESULTS: Sucrose and amino acids were not correlated with acrylamide formation. In contrast, reducing sugars, limiting with respect to the principal amino acid precursor asparagine, were positively correlated with acrylamide. From analysis of variance, both acrylamide and reducing sugars were not significant for variety but highly significant for location, with higher levels occurring in all three varieties cultivated in Tuscany, followed by Sicily and Puglia respectively. Reducing sugars were negatively correlated with K and Ca and positively correlated with Zn and Cu. Neither N nor P was correlated with reducing sugar content. Path analysis, a statistical technique distinguishing causation and correlation between variables, was implemented to provide additional insight on the interactions between mineral elements and reducing sugars under open field conditions. The variation in reducing sugars in all three varieties was shown to be attributable to Zn. CONCLUSION: Cultivation location has a significant impact on the composition of tuber mineral elements and, as a result, on genotype in the expression of reducing sugars. The negative correlation between Zn and K and the variation in reducing sugar content attributed to the element Zn, which is particularly available in acid soils, are important factors warranting future research aimed at reducing acrylamide formation from an agronomic perspective.

Serpentine soils affect heavy metal tolerance but not genetic diversity in a common Mediterranean ant.

Natural habitats with serpentine soils are rich in heavy metal ions, which may significantly affect ecological communities. Exposure to metal pollutants results, for instance, in a reduction of population genetic diversity and a diffused higher tolerance towards heavy metals. In this study, we investigated whether chronic exposure to metals in serpentine soils affect accumulation patterns, tolerance towards metal pollutants, and genetic diversity in ants. In particular, we studied colonies of the common Mediterranean ant, Crematogaster scutellaris, along a contamination gradient consisting of two differently contaminated forests and a reference soil with no geogenic contamination. We first evaluated the metal content in both soil and ants' body. Then, we tested for tolerance towards metal pollutants by evaluating the mortality of ants fed with nickel (Ni) solutions of increasing concentrations. Finally, differences in genetic diversity among ants from different areas were assessed using eight microsatellite loci. Interestingly, a higher tolerance to nickel solutions was found in ants sampled in sites with intermediate levels of heavy metals. This may occur, because ants inhabiting strongly contaminated areas tend to accumulate higher amounts of contaminants. Additional ingestion of toxicants beyond the saturation threshold would lead to death. There was no difference in the genetic diversity among ant colonies sampled in different sites. This was probably the result of queen mediated gene flow during nuptial flights across uncontaminated and contaminated areas of limited geographical extent.