PHYSICAL DORMANCY IN SEEDS, WITH SPECIAL REFERENCE TO GERANIACEAE: MORPHO-ANATOMY, DEVELOPMENT, PHYSIOLOGY, BIOMECHANICS AND CLASSIFICATION OF WATER-GAP COMPLEXES

The primary aims of this dissertation were to (1) identify and characterize the water-gap complex in seeds of Geraniaceae, (2) investigate its role in physical dormancy (PY) break and (3) develop a new classification system for water-gap complexes in seeds of angiosperms. The winter annuals Geranium carolinianum and G. dissectum were selected as the main representative species for the study, and seeds of an additional 29 species from the Geraniaceae were used to compare the water-gap complex within the family. A new classification system for water-gap complexes in species with PY was developed by comparing the morpho-anatomical features of PY seeds and fruits of 16 families. The water-gap complex of G. carolinianum was identified as a micropyle-hinged valve gap complex, and only a slight morpho-anatomical variation was observed within the family. Ontogenetic studies of the seed coat of G. carolinianum revealed that the water-gap region of Geraniaceae develops as an entity of the micropyle. The timing of seed germination with the onset of autumn can be explained by PY-breaking processes involving (a) two-temperature-dependent steps in G. carolinianum, and (b) one or two moisture-dependent step(s) along with the inability to germinate under high temperatures in G. dissectum. Step-I and step-II in PY-breaking of G. carolinianum are controlled by chemical and physical processes, respectively. This study indicates the feasibility of applying the developed thermal time model to predict or manipulate sensitivity induction in seeds with two-step PY-breaking processes. The model is the first and the most detailed one yet developed for sensitivity induction in PY-break. Based on the morpho-anatomical features, three basic water-gap complexes (types I, II and III) were identified in species with PY in 16 families. Depending on the number of openings involved in initial imbibition, the water-gap complexes were subdivided into simple and compound. The new classification system enables the understanding of relationships between water-gap complexes of taxonomically unrelated species with PY

Seaweeds as a Source of Functional Proteins

International audienceProtein is one of the major macronutrients essential in human nutrition. Protein sources especially animal sourced proteins are expensive, thus much work has been carried out to explore alternative protein sources. Seaweeds, or macroalgae, are emerging as one of the alternative protein sources. They are rich in protein with an excellent amino acid profile comparable to the other conventional protein sources. Seaweed protein contains bioactive components, such as free amino acids, peptides, lectins, and phycobiliproteins, including phycoerythrin and phycocyanin, among others. Seaweed proteins have been proved for their antihypertensive, antidiabetic, antioxidant, anti-inflammatory, antitumoral, antiviral, antimicrobial, and many other beneficial functional properties. Therefore, seaweed proteins can be a natural alternative source for functional food development. This paper discusses the compositional and nutritional aspects of seaweed protein, protein extraction techniques, functional properties of various seaweed proteins, as well as their safety for new product development and functional food applications