Orientations of Mistaken Point Fronds Indicate Morphology Impacted Ability to Survive Turbulence

The Ediacaran fossils of the Mistaken Point E surface have provided crucial insight into early animal communities, including how they reproduced, the importance of Ediacaran height and what the most important factors were to their community dynamics. Here, we use this iconic community to investigate how morphological variation between eight taxa affected their ability to withstand different flow conditions. For each of Beothukis, Bradgatia, Charniodiscus procerus, Charniodiscus spinosus, Plumeropriscum, Primocandelabrum, Thectardis and Fractofusus we measured the orientation and length of their stems (if present) and their fronds. We statistically tested each taxon’s stem and frond orientation distributions to see whether they displayed a uniform or multimodal distribution. Where multimodal distributions were identified, the stem/frond length of each cohort was tested to identify if there were differences in size between different orientation groups. We find that Bradgatia and Thectardis show a bimodal felling direction, and infer that they were felled by the turbulent head of the felling flow. In contrast, the frondose rangeomorphs including Beothukis, Plumeropriscum, Primocandelabrum, and the arboreomorphs were felled in a single direction, indicating that they were upright in the water column, and were likely felled by the laminar tail of the felling flow. These differences in directionality suggests that an elongate habit, and particularly possession of a stem, lent greater resilience to frondose taxa against turbulent flows, suggesting that such taxa would have had improved survivability in conditions with higher background turbulence than taxa like Bradgatia and Thectardis, that lacked a stem and had a higher centre of mass, which may have fared better in quieter water conditions.

Effects of site, depth and sori origin on the growth and minerals composition of cultivated Saccharina latissima (Phaeophyceae) in the north of Norway

Interest in the cultivation of Saccharina latissima is increasing in the north of Norway. In the present study, S. latissima was cultivated at two sites (Kraknes and Rotsund), 90 km apart, in Troms, northern Norway (69–70°N). The effect of site, depth, and sori origin (Kraknes and Rotsund) on S. latissima growth, biofouling, minerals, and potentially toxic elements (PTEs) content was studied. Large variations in the frond length and wet weight were observed between sites. The site with lower seawater temperature, higher nutrient levels and no freshwater influence (Kraknes) had better growth and later outbreak of epibionts. Sori origin had a significant effect on the growth only at the Kraknes site with S. latissima produced from the Kraknes sori having longer frond length and higher wet weight. The iodine content was, in general, high and increased with cultivation depth. The arsenic and cadmium content varied between sites and was lower than the recommended maximum level for food supplements in EU regulations. The present study shows that growth, biofouling, minerals, and PTEs content vary profoundly within the same geographical region and between sori origin, it thereby underlines the importance of site selection and using traits with high growth rates for seeding and cultivation to achieve maximum biomass.

Orientations of Mistaken Point fronds indicate morphology impacted ability to survive turbulence

The Ediacaran organisms of the Mistaken Point E surface have provided crucial insight into early animal communities, including how they reproduced, the importance of Ediacaran height and what the most important factors were to their community dynamics. Here, we use this iconic community to investigate how morphological variation between eight taxa affected their ability to withstand different flow conditions. For each of Beothukis, Bradgatia, Charniodiscus procerus, Charniodiscus spinosus, Plumeropriscum, Primocandelabrum and Fractofusus we measured the orientation and length of their stems (if present) and their fronds. We statistically tested each taxon's stem and frond orientation distributions to see whether they displayed a uniform or multimodal distribution. Where multimodal distributions were identified, the stem/frond length of each cohort was tested to identify if there were differences in size between different orientation groups. We find that Bradgatia and Thectardis show a bimodal felling direction, and infer that they were felled by the turbulent head of the felling flow. In contrast, the frondose rangeomorphs including Beothukis, Plumeropriscum, Primocandelabrum, and the arboreomorphs were felled in a single direction, indicating that they were upright in the water column, and were likely felled by the laminar tail of the felling flow. These differences in directionality suggests that an elongate habit, and particularly possession of a stem, lent greater resilience to frondose taxa against turbulent flows, suggesting that such taxa would have had improved survivability in conditions with higher background turbulence than taxa like Bradgatia and Thectardis, which lacked a stem and which had a higher centre of mass, which may have fared better in quieter water conditions.

Latitudinal, seasonal and depth-dependent variation in growth, chemical composition and biofouling of cultivated Saccharina latissima (Phaeophyceae) along the Norwegian coast

The Norwegian coastline covers more than 10° in latitude and provides a range in abiotic and biotic conditions for seaweed farming. In this study, we compared the effects of cultivation depth and season on the increase in biomass (frond length and biomass yield), chemical composition (protein, tissue nitrogen, intracellular nitrate and ash content) and biofouling (total cover and species composition) of cultivated Saccharina latissima at nine locations along a latitudinal gradient from 58 to 69° N. The effects of light and temperature on frond length and biofouling were evaluated along with their relevance for selecting optimal cultivation sites. Growth was greater at 1–2 m than at 8–9 m depth and showed large differences among locations, mainly in relation to local salinity levels. Maximum frond lengths varied between 15 and 100 cm, and maximum biomass yields between 0.2 and 14 kg m−2. Timing of maximum frond length and biomass yield varied with latitude, peaking 5 and 8 weeks later in the northern location (69° N) than in the central (63° N) and southern (58° N) locations, respectively. The nitrogen-to-protein conversion factor (averaged across all locations and depths) was 3.8, while protein content varied from 22 to 109 mg g−1 DW, with seasonality and latitude having the largest effect. The onset of biofouling also followed a latitudinal pattern, with a delayed onset in northern locations and at freshwater-influenced sites. The dominant epibiont was the bryozoan Membranipora membranacea. Our results demonstrate the feasibility of S. latissima cultivation along a wide latitudinal gradient in North Atlantic waters and underscore the importance of careful site selection for seaweed aquaculture.

Effect of seeding methods and hatchery periods on sea cultivation of Saccharina latissima (Phaeophyceae): a Norwegian case study

To reach the goal of an industrialised macroalgae industry in Norway and other high-cost countries in the near future, a standardised seedling production method to improve quality control and predictability of cultivated biomass is essential. A total of 11 different treatments for seeding twine or rope with meiospores, gametophytes or juvenile sporophytes from the kelp Saccharina latissima were measured for growth (frond length, frond area, biomass yield and density) and protein content after 80 and 120 days at sea. Meiospore- and gametophyte-seeded twines were pre-cultivated in the hatchery for 14–42 days prior to deployment, while juvenile sporophytes of different ages were seeded on ropes directly on the day of deployment using a commercial binder to attach the seedlings. The results showed that seeding with meiospores pre-cultivated in the hatchery for 42 days (S42) before deployment gave significantly longer fronds (77.0 ± 6.7 cm) and a higher biomass yield (7.2 ± 0.1 kg m−1) at sea compared to other treatments. The poorest growth was measured for the direct-seeded sporophytes pre-cultivated in free-floating cultures for 35 days prior to deployment (D35; 34.4 ± 2.4 cm frond length and 1.6 ± 0.4 kg m−1). Image analysis was used to measure the coverage of the twine substrate before deployment, and a correlation was found between substrate coverage and frond length at sea, indicating that this can be used as a tool for quantity and quality control during the hatchery phase and before deployment. The protein content did not reveal any large differences between the treatments after 120 days of cultivation.

El complejo Dryopteris patula (Dryopteridaceae) en México: análisis morfométricos

We studied collections from four species of the <em>Dryopteris patula</em> complex <em>(D. cinnamomea, D. patula, D. rosea, and D. rossii)</em> to identify the morphological characters that distinguish them from one another. <em>D. maxonii</em> and <em>D. wallichiana</em> were included as comparative species to evaluate characters that distinguish species within the complex. Quantitative characters were examined through principal component and canonical discriminant analyses, and both qualitative and quantitative characters were used to obtain phenograms. Multivariate analyses determined that basal pinna length, stipe scale length, number of pinna pairs, and frond length are the variables that discriminate among <em>D. rossii</em> and the other species of the complex. The phenogram showed two groups. One included <em>D. maxonii</em> and <em>D. wallichiana</em>, while the second grouped the four species of the complex. These species were distinguished by the shape and margin of their rhizome scales, color of stipe, and shape of the blade. A combination of morphological characters supports the recognition of the four species as valid. An identification key is given and a taxonomic treatment is presented for each of the taxa.

Peculiarities of growth and lipoxygenase activity of wild fern Dryopteris filix-mas (L.) Schott

<p>We studied the peculiarities of growth, localization and dynamics of lipoxygenase activity in sporophyte organs of wild fern <em>Dryopteris filix-mas </em>(L.) Schott at various stages: intensive growth; sori ripening; spore release; summer vegetation, and vegetation termination. Morphometric analysis showed that the weight of one plant during sporophyte ontogenesis varied from 130 to 150 g. Frond length varied from 11 to 85 cm. Diameter of the overground part of rhizome was 9-10 cm. In the stage of spore release and during the summer vegetation we mentioned 7 fronds on plant, and in the phase of vegetation termination – 18. The plants had the biggest weight in phase of spore release. Following spore release and at the beginning of vegetation termination, the frond weight diminished almost by two times. An intensive elongation of fronds was observed prior to the start of spore release. When fronds unfold and grow the number of segments of the first order increase from 39 to 47 pairs. Frond length in the stage of summer vegetation increased from 4.3 to 11.2 cm (9 pairs), and then it gradually decreased from 10.2 to 0.1 cm (39 pairs) that resulted in the formation of a lanceolate lamina. In the stage of vegetation termination, the fern had 18 fronds, 12 of which remained green, while the rest dried and turned greyish-brown. The frond lamina contained 47 pairs of segments of the first order whose length increased from 4.5 to 10.5 cm, and then it diminished from 9.5 to 0.05 cm. The rhizome weight was in the range of 110.2–115.7 g in all the stages except vegetation termination. The morphological analysis showed that plants had successfully passed all developmental phases, reached their normal dimensions, had a mass spore formation, no external signs of suppression and damages, and this was generally consistent with the highest level of life state assessment. Localization and dynamics of lipoxygenase (LOX) activity in organs of the sporophyte of <em>D. filix-mas </em>have been studied. We registered that fronds contained 13-LOX with рН_opt.values of 7.2, rhizomes – 9-LOX (рН_opt.6.5). Peculiarities that were mentioned in localization and dynamics of LOX isoforms catalytic activity in the fern organs at various phases of development suggest that the enzyme might be involved in the regulation of lipid metabolism of growth processes that ensure plant adaptation to the environment. </p><p> </p>

Effects of shading, irrigation and mycorrhizal inoculation on growth and development of oil palm Elaeis guineensis Jacq. (Magnoliophyta: Arecaceae) seedlings in the nursery

Experiments were conducted to examine the growth and development of oil palm Elaeis guineensis Jacq. (Magnoliophyta: Arecaceae) seedlings subjected to shading, irrigation regimes and mycorrhizal inoculation in the dry season. Treatments were 2 x 2 x 2 factorial combination consisting of shade and no-shade (open sun), 7 and 14 day irrigation intervals and mycorrhizal inoculation or non-inoculation. Seedlings that were grown under shade and irrigated weekly produced highest number and length of fronds, and shoot, leaf and frond weights in addition to taller plants compared to open sun (unshaded) seedlings. Across irrigation treatments, unshaded seedlings had lower weights of leaf, frond and shoot biomass. The effects of shade treatments were significant on plant height and frond length from 2 to 20 weeks after planting. The seedlings irrigated fortnightly produced longer roots compared with the unshaded and weekly irrigated. Fortnight irrigation enhanced root development compared with weekly irrigation. Shading and weekly irrigation significantly enhanced soil moisture contents and seedling water use efficiency compared with the unshaded. Shaded seedlings irrigated weekly used larger amount of water compared with fortnight irrigation. Significant interactions were obtained between shade and irrigation regimes for most of the growth parameters measured. Mycorrhizal inoculation, shaded and weekly irrigated seedlings were more vigorous compared with the unshaded and non-inoculated.