Significant variation occurred across all species and compounds examined. Total fatty acids (TFA) were generally higher in the fronds, with highest levels and largest variability www.selleckchem.com/products/INCB18424.html observed in Ascophyllum nodosum (1.5% of DW in the base, 6.3% of DW in frond tips). Percentages of the omega-3 fatty acids 18:4 n-3 and 20:5 n-3 were generally higher in more distal parts, while 20:4 n-6 exhibited a contrasting pattern, with higher levels in basal structures and holdfasts. Trends for pigments were similar to those for fatty acids in Laminariales. In the Fucales, highest levels were detected in the mid-fronds, with lower concentrations in meristematic areas. Highest levels
and greatest MK1775 variability in pigments (e.g. chlorophyll a) was observed in Fucus serratus (1.07 mg·g-1 DW in the base, 3.04 mg·g-1 DW in the mid frond). Intra-thallus variability was attributed to physiological functions of the respective thallus sections, e.g. photosynthetic activity, meristematic tissue and to variations in physical attributes of the structures investigated. Regarding potential commercial nutritional
applications, fronds appeared to represent most suitable source materials, due to higher levels of pigments, poly-unsaturated fatty acids and more preferable omega-3/omega-6 ratios. This article is protected by copyright. All rights reserved. “
“The impact of abiotic factors on kelp sporophyte reproduction has rarely been investigated. 上海皓元医药股份有限公司 Laminaria digitata (Hudson) J.V. Lamouroux is one of the few summer fertile Laminaria species worldwide and reproduction is subjected to relatively high water temperatures. We investigated the impact of prevailing
summer temperatures (~18°C in August) on the induction of sporangia, meiospore release, and germination at the island of Helgoland (North Sea). At Helgoland, fertile sporophytes are found between April and December with a maximum in late summer. While released meiospore numbers were constant between June and October, germination rates decreased significantly in summer. Short-term exposure of mature sori to 17°C–22°C induced a significantly higher meiospore release indicating enhancement of sporulation by elevated temperatures. Induction of sporangia on vegetative blade disks was not possible at 20°C, and fertility was only 20% at 18°C–19°C, but it was 100% in cool temperatures of 1°C–10°C. It was shown for the first time in a kelp species that “sporogenesis” is the life-cycle process with the narrowest temperature window compared to growth or survival of the sporophyte or reproduction, growth, and survival of the gametophyte. We incorporated several parameters (induction time, fertile area, and relative fertility) into a “Reproductive efficiency index.” This indicates that sporogenesis of L. digitata is a cold-adapted process with an optimum at (5)–10°C.