Mycorrhiza-plant colonization patterns on a subalpine glacier forefront as a model system of primary succession

Lyman glacier in the North Cascades Mountains of Washington has a subalpine forefront characterized by a well-developed terminal moraine, inconspicuous successional moraines, fluting, and outwash. These deposits were depleted of symbiotic fungi when first exposed but colonized by them over time after exposure. Four major groups of plant species in this system are (1) mycorrhiza-independent or facultative mycotrophic, (2) dependent on arbuscular mycorrhizae (AM) (3) dependent on ericoid mycorrhiza (ERM) or ectomycorrhizae (EM), and (4) colonized by dark-septate (DS) endophytes. We hypothesized that availability of mycorrhizal propagules was related to the success of mycorrhiza-dependent plants in colonizing new substrates in naturally evolved ecosystems. To test this hypothesis roots samples of 66 plant species were examined for mycorrhizal colonization. The plants were sampled from communities at increasing distances from the glacier terminus to compare the newest communities with successively older ones. Long established, secondary successional dry meadow communities adjacent to the glacier forefront, and nearby high alpine communities were sampled for comparison. DS were common on most plant species on the forefront. Nonmycorrhizal plants predominated in the earlier successional sites, whereas the proportion of mycorrhizal plants generally increased with age of community. AM were present, mostly at low levels, and nearly absent in two sites of the forefront. ERM were present in all species of Ericaceae sampled, and EM in all species of Pinaceae and Salicaceae. Roots of plants in the long established meadow and heath communities adjacent to the forefront and the high alpine community all had one or another of the colonization types, with DS and AM predominating.     

Culture studies on some Florida species of Caulerpa: Morphological responses to reduced illumination

The morphological development of three species of Caulerpa, C. sertularioides, C. paspaloides and C. racemosa has been studied in low light culture. The resulting morphologies are described and contrasted with the typical morphologies. Culture forms in all cases were unlike the field forms but each had affinities with other taxa described in the literature. The most important generalized response was a change in the symmetry of the assimilators from radial to bilateral. This response supports an earlier morphologically based theory on the evolutionary relationships among the species of Caulerpa.     

Occurrence of Amoebophrya spp. infection in planktonic dinoflagellates in Changjiang (Yangtze River) Estuary,China

The parasitic dinoflagellates in the genus of Amoebophrya can infect broad ranges of planktonic dinoflagellates, and transform algal biomass into organic matter that can be recycled within the planktonic community. The ecological significance of Amoebophrya spp. during harmful algal bloom (HAB) events was gradually recognized along with revelation of its host specificity and diversity in picoplankton communities. The eutrophicated coastal waters of China are frequently affected by HABs, particularly in Changjiang (Yangtze River) estuary and the adjacent East China Sea; while, no research has been conducted to explore the ecological roles of parasitism during HAB events and the related dinoflagellate bloom dynamics. For the first time, we confirmed the presence of Amoebophrya infections in the planktonic community of this region; six species of dinoflagellates were infected, including Ceratium tripos, Scrippsiella trochoidea, Gonyaulax spinifera, Gymnodinium sp., Gonyaulax sp. and an Alexandrium sp. Molecular sequences retrieved from environmental water samples revealed high genetic diversity of Amoebophryidae-like organisms in the water column. Amoebophrya-infected dinoflagellates were only observed in high salinity (>20) stations suggesting that salinity may be a factor limiting the distribution of Amoebophyra infections in natural environment. Whereas, no evidence of Amoebophrya infection was observed in the bloom-forming species Karenia mikimotoi, suggesting that K. mikimotoi in this region was likely free of Amoebophridae infection.     

Karyological studies of three species of Cladophora (Cladophorales,Chlorophyta) from Bermuda

Abstract

Chromosome numbers for three species of Cladophora from Bermuda are presented. C. laetevirens (Dillw.) Kuetz., C. prolifera (Roth) Kuetz., and C. conferta Crouan frat. ex Schramm & Maze were found to have similar karyotypes with 1 N = 2 X = 12 chromosomes belonging to size class III (0.8–2.2 μm). Correlations between each species' karyotype and its morphology and phytogeographic affinity are discussed. Estimates of the basic genome (1 X) for these and other Cladophora species indicate that nuclear DNA content, which shows a threefold variation in the genus, occurs in discontinuous increments. These findings are discussed in relation to reports of large scale, discontinuous DNA variation in vascular plant genera.     

Exploration and determination of algal role as Bioindicator to evaluate water quality – Probing fresh water algae

ObjectivesTo explore the algal floral diversity and its role to determine water quality.MethodsThe regular monthly collection of algal and water samples was made during 2018. Unicellular algae were preserved in 2 to 3% formalin while macroalgae in 4% formalin. Microphotographs of algae were taken at the biotechnological Lab of PCSIR Lahore, Pakistan. Palmer pollution index was used to determine water quality.ResultsThe study identified 201 algal species distributed among 57 genera, 42 families, 25 orders, 10 classes and 7 divisions. The total score of Algal Genus Pollution Index of Banjosa Lake, Ali Sojal Dam, Dothan Dam, Drake Dam and Rawalakot Nullah (city) were 14, 9, 10, 18 and 25 respectively. It was revealed that Banjosa Lake has probable organic pollution, Ali Sojal Dam and Dothan Dam showed lack of organic pollution, Drake Dam indicated moderate pollution while Rawalakot Nullah (City) indicated confirm high organic pollution.ConclusionWe strongly recommend the conservation and managed status of algal species for sustainable resource of algal- derived products in future. It was revealed that the water quality of Banjosa Lake, Drak Dam and Rawalakot Nullah was affected from anthropogenic activities and needs to be managed.     

Intrinsic autotrophic biomass yield and productivity in algae: experimental methods for strain selection

Using an analogy with fed-batch heterotrophic growth, the algal photoautotrophic yield Φ(DW) (in grams of dry weight biomass synthesized per micromole of absorbed photons) was derived from the algae batch growth behavior in nutrient-replete medium. At known levels of incident light, the yield Φ(DW) enables the estimate of a maximum productivity, and is therefore critical to compare and select algal cultures and growth conditions for large-scale production. The algal culture maximum growth rate was shown to be an unreliable indicator of autotrophic biomass yield. The developed carbonate addition method (carbonate addition, neutralization, and sealing) alleviated carbon limitations otherwise seen in aerated batch cultures, leading to two to five fold higher yield estimates. The fully defined FLX growth medium with variable ionic strengths (FLX1-100) supported excellent growth in most cultures tested. The chosen experimental methods and versatile FLX medium proved well-suited for small sample volumes and a high number of samples.     

Algal turf scrubber (ATS) floways on the Great Wicomico River,Chesapeake Bay: productivity,algal community structure,substrate and chemistry1

Two Algal Turf Scrubber (ATS) units were deployed on the Great Wicomico River (GWR) for 22 months to examine the role of substrate in increasing algal productivity and nutrient removal. The yearly mean productivity of flat ATS screens was 15.4 g · m^?2 · d^?1. This was elevated to 39.6 g · m^?2 · d^?1 with a three‐dimensional (3‐D) screen, and to 47.7 g · m^?2 · d^?1 by avoiding high summer harvest temperatures. These methods enhanced nutrient removal (N, P) in algal biomass by 3.5 times. Eighty‐six algal taxa (Ochrophyta [diatoms], Chlorophyta [green algae], and Cyan‐obacteria [blue–green algae]) self‐seeded from the GWR and demonstrated yearly cycling. Silica (SiO₂) content of the algal biomass ranged from 30% to 50% of total biomass; phosphorus, nitrogen, and carbon content of the total algal biomass ranged from 0.15% to 0.21%, 2.13% to 2.89%, and 20.0% to 25.7%, respectively. Carbohydrate content (at 10%–25% of AFDM) was dominated by glucose. Lipids (fatty acid methyl ester; FAMEs) ranged widely from 0.5% to 9% AFDM, with Omega‐3 fatty acids a consistent component. Mathematical modeling of algal produ‐ctivity as a function of temperature, light, and substrate showed a proportionality of 4:3:3, resp‐ectively. Under landscape ATS operation, substrate manipulation provides a considerable opportunity to increase ATS productivity, water quality amelioration, and biomass coproduction for fertilizers, fermentation energy, and omega‐3 products. Based on the 3‐D prod‐uctivity and algal chemical composition demonstrated, ATS systems used for nonpoint source water treat‐ment can produce ethanol (butanol) at 5.8× per unit area of corn, and biodiesel at 12.0× per unit area of soy beans (agricultural production US).     

Wastewater treatment high rate algal ponds for biofuel production

While research and development of algal biofuels are currently receiving much interest and funding, they are still not commercially viable at today’s fossil fuel prices. However, a niche opportunity may exist where algae are grown as a by-product of high rate algal ponds (HRAPs) operated for wastewater treatment. In addition to significantly better economics, algal biofuel production from wastewater treatment HRAPs has a much smaller environmental footprint compared to commercial algal production HRAPs which consume freshwater and fertilisers. In this paper the critical parameters that limit algal cultivation, production and harvest are reviewed and practical options that may enhance the net harvestable algal production from wastewater treatment HRAPs including CO₂ addition, species control, control of grazers and parasites and bioflocculation are discussed.