Ipomoea batatas (L.) Lam.: a rich source of lipophilic phytochemicals

The lipophilic extracts from the storage root of 13 cultivars of sweet potato (Ipomoea batatas (L.) Lam.) were evaluated by gas chromatography-mass spectrometry with the aim to valorize them and offer information on their nutritional properties and potential health benefits. The amount of lipophilic extractives ranged from 0.87 to 1.32% dry weight. Fatty acids and sterols were the major families of compounds identified. The most abundant saturated and unsaturated fatty acids were hexadecanoic acid (182-428 mg/kg) and octadeca-9,12-dienoic acid (133-554 mg/kg), respectively. β-Sitosterol was the principal phytosterol, representing 55.2-77.6% of this family, followed by campesterol. Long-chain aliphatic alcohols and α-tocopherol were also detected but in smaller amounts. The results suggest that sweet potato should be considered as an important dietary source of lipophilic phytochemicals.info:eu-repo/semantics/publishedVersio

Beach profile model with size-selective sediment transport. I: Laboratory experiment and sensitivity study

The response of physical models of beach profiles to random breaking waves was studied to investigate size-selective sediment transport and cross-shore profile evolution. Three types of beach profiles with different sediment mixtures were considered and subjected to waves until profiles reached equilibrium. Size-selective sediment transport was evident in the experiments, with the mean sediment size varying up to 20% along the beach profiles. Consistent coarsening and fining of the surface sediment in the experiments revealed size-selective sediment transport governed by cross-shore variations in energy dissipation, affecting important beach profile features such as sandbar structures and offshore and foreshore slopes. The theoretical basis of the transport phenomenon was described by analyzing the relationship between the transport processes and essential wave and hydrodynamic parameters obtained using a new set of numerical models. The results showed that beach profile changes and associated sediment grain sorting are most sensitive to instantaneous total water velocity and local energy flux under propagating waves. © 2014 American Society of Civil Engineers

Change in nuclear DNA content and pollen size with polyploidisation in the sweet potato (Ipomoea batatas, Convolvulaceae) complex

International audienceGenome size evolution, and its relationships with pollen grain size, has been investigated in the sweet potato (Ipomoea batatas), an economically important crop, and closely related diploid and tetraploid species, assessing the nuclear DNA content of 22 accessions from five Ipomoea species, 10 sweet potato varieties and two outgroup taxa. Nuclear DNA amounts were determined by flow cytometry. Pollen grains have been studied at scanning and transmission electron microscopy. 2C DNA content of hexaploid I. batatas ranged over 3.12-3.29 pg, mean monoploid genome size being 0.539 pg (527 Mbp) much as for the related diploid accessions. In tetraploid species I. trifida and I. tabascana, 2C DNA content was respectively 2.07 and 2.03 pg. In the diploid species closely related to sweet potato e.g. I. ×leucantha, I. tiliacea, I. trifida, I. triloba, 2C DNA content was 1.01-1.12 pg. However, two diploid outgroup species, I. setosa and I. purpurea, were clearly different from the other diploid species with 2C of 1.47-1.49 pg; they also have larger chromosomes. The I. batatas genome presents 60.0% of AT bases. DNA content and ploidy level were positively correlated within this complex. In I. batatas and the more closely related species I. trifida, genome size and ploidy levels were correlated with pollen size. Our results allow us proposing alternative or complementary hypotheses to the one currently proposed for the formation of hexaploid Ipomoea batatas. This article is protected by copyright. All rights reserved