Higher phenotypic plasticity does not confer higher salt resistance to <Emphasis Type="Italic">Robinia pseudoacacia</Emphasis> than <Emphasis Type="Italic">Amorpha fruticosa</Emphasis>

A greenhouse experiment was conducted in which two leguminous species commonly used in the Yellow River Delta for vegetation restoration, Robinia pseudoacacia and Amorpha fruticosa, were subjected to five salt treatments: 0, 50, 100, 150, and 200 mmol L^?1. We aimed to determine which of the two species would be better suited for growth in a saline environment, and whether the acclimation capacity to salinity resulted from an inherently higher phenotypic plasticity. The results showed that salinity affected most growth and biomass parameters but had no effects on most leaf traits and physiological parameters of the two species. Height, relative growth rate of crown area, root biomass, and leaf mass ratio of R. pseudoacacia were reduced by higher salinity, while A. fruticosa was not affected. Chlorophyll a-to-chlorophyll b ratio and total antioxidative capacity of A. fruticosa increased with higher salinity, whereas those of R. pseudoacacia remained unchanged. Root mass ratio and vitamin C concentration of both species were not affected by salinity, whereas vitamin C concentration of A. fruticosa was higher than that of R. pseudoacacia. The root-to-shoot ratio of A. fruticosa was higher than that of R. pseudoacacia in most salt treatments. Of all leaf traits, only leaf area differed between treatments. R. pseudoacacia generally exhibited a greater plasticity than A. fruticosa in response to salinity, but A. fruticosa was more resistant to the higher salinities than R. pseudoacacia, and was thus a better candidate for vegetation restoration in saline areas.     

Differences of skin morphology in Bos indicus,Bos taurus,and their crossbreds

Cutaneous evaporation is the main avenue by which cattle dissipate heat via the involvement of sweat glands and other skin components. The difference in skin morphology between B. indicus and B. taurus has been recognized, as well as differences in their ability to tolerate heat. The objective of this study was to compare skin morphology between B. indicus, B. taurus, and their crossbreds. Skin samples of Sahiwal (B. indicus) (n?=?10, reddish brown skin) and Holstein Friesian (HF) (B. taurus) (n?=?10, black and white skin) and crossbred of HF75% (n?=?10, black and white skin) and HF87.5 % (n?=?10, black and white skin) were biopsied for histological study, followed by measurement of skin components. The results indicated that breed significantly affected sweat gland morphology. The shape of the sweat gland, as indicated by the ratio of length/diameter, in Sahiwal was baggier in shape compared to HF (5.99 and 9.52) while values for crossbreds were intermediate (7.82, 8.45). The density and volume of sweat glands in Sahiwal (1,058 glands/cm²; 1.60 μ³?×?10^?6) were higher than in HF (920 glands/cm²; 0.51 μ³x10^?6) and crossbreds, both HF 75 % (709 glands/cm²; 0.68 μ³?×?10^?6) and HF 87.5 % (691 glands/cm²; 0.61 μ³?×?10^?6) respectively. However, capillary surface area was greater for HF (2.07 cm²) compared to Sahiwal (1.79 cm²); accordingly, the lower genetic fraction of HF in crossbred cattle showed less capillary surface area (1.83 and 1.9 cm² for HF75% and HF87.5 %) (P?<?0.01). Nerve density was not significantly different between Sahiwal and HF but was higher in the crossbred (P?<?0.01) cattle. Moreover, the effect of skin color (black and white) was evaluated and it was found that there was an interaction (P?<?0.01) between breed and skin color on the skin components. This study reveals that there are differences in skin morphology among B. indicus, B. taurus and their crossbreds, with these differences being more or less related to the genetic fraction of HF. This may imply that capability for cutaneous evaporative heat loss and tolerance to heat in crossbred cattle could be related to skin morphology.     

Litter- and soil carbohydrate-carbon stocks in 2-, 4- and 10-year-old improved fallows in eastern Zambia

This study evaluated the effects of tree species and sites on soil carbohydrates, litterfall, and litter chemistry in 2-, 4- and 10-year-old improved fallows at three sites in eastern Zambia. Between April 2002 and August 2003, litter was collected in 2-year-old tree fallows at Kalichero, Kalunga and Msekera for chemical analyses. Soil samples collected at 0–30 cm from all experiments were analysed for total soil organic carbon (SOC), but only those from 4- and 10-year-old fallows were analysed for carbohydrates. Soil arabinose- and mannose-C stocks, and carbohydrate-C percentages of SOC (7.7–20.6 %) significantly (P < 0.05) differed across tree species in 10-year-old coppicing fallows at Msekera. Converting M + F to improved fallows resulted in a decline in monosaccharide-C, carbohydrate-C stocks and carbohydrate-C percentage of SOC. There were significant (P < 0.05) variations in litterfall (0.7–2.3 t ha^?1 year^?1) and litter C contents (0.3–1.1 t ha^?1 year^?1) across 2-year-old coppicing tree fallows at Msekera. Litter production and C contents were significantly greater on sandy soils at Kalunga than on fine-textured soils at Msekera. Litter chemical contents (C, N, AUR and polyphenols) and ratios (C:N, P:N, AUR:N, and (AUR + P):N) for litter in fallows differed significantly (P < 0.05) across species and sites. In this study, the role of litter in carbon cycling in improved fallows depended on tree species and site conditions.     

Nitrous oxide emissions from two alpine meadows in the Qinghai–Tibetan Plateau

Nitrous oxide (N₂O) emission was measured in a Kobresia humilis meadow and a Potentilla fruticosa meadow in the Qinghai–Tibet Plateau from June 2003 to July 2006. Five treatments were setup in the two alpine meadows. Two bare soil treatments were setup in the K. humilis meadow (BSK) and in the P. fruticosa meadow (BSP) by removing the above- and belowground plant biomass. Three plant community treatments were setup with one in the K. humilis meadow (herbaceous community in the K. humilis meadow-HCK) and two in the P. fruticosa meadow (herbaceous community in the P. fruticosa meadow-HCP, and shrub community in the P. fruticosa meadow-SCP). Nitrous oxide emission from BSP was estimated to be 38.1?±?3.6 μg m^?2 h^?1, significantly higher than from BSK (30.2?±?2.8 μg m^?2 h^?1) during the whole experiment period. Rates from the two herbaceous blocks (HCK and HCP) were close to 39.5 μg m^?2 h^?1 during the whole experimental period whereas shrub community (SCP) showed significant high emission rates of N₂O. Annual rate of N₂O emission was estimated to be 356.7?±?8.3 and 295.0?±?11.6 mg m^?2 year^?1 from the alpine P. fruticosa meadow and from the alpine K. humilis meadow, respectively. These results suggest that alpine meadows in the Qinghai–Tibetan Plateau are an important source of N₂O, contributing an average of 0.3 Tg N₂O year^?1. We concluded that N₂O emission will decrease, due to a predicted vegetation shift from shrubs to grasses imposed by overgrazing.     

Sphingomonas ginsenosidivorax sp. nov., with the ability to transform ginsenosides

A Gram-negative, strictly aerobic, non-motile, non-spore-forming and rod-shaped bacterial strain designated KHI67^T was isolated from sediment of the Gapcheon River in South Korea and its taxonomic position was investigated by using a polyphasic approach. Strain KHI67^T was observed to grow optimally at 25–30 °C and at pH 7.0 on nutrient and R2A agar. On the basis of 16S rRNA gene sequence similarity, strain KHI67^T was shown to belong to the family Sphingomonadaceae and was related to Sphingomonas faeni MA-olki^T (97.6 % sequence similarity), Sphingomonas aerolata NW12^T (97.5 %) and Sphingomonas aurantiaca MA101b^T (97.3 %). The G + C content of the genomic DNA was determined to be 65.6 %. The major ubiquinone was found to be Q-10, the major polyamine was identified as homospermidine and the major fatty acids identified were summed feature 8 (comprising C_18:1 ω7c/ω6c; 37.0 %), C_16:0 (13.0 %), summed feature 3 (comprising C_16:1 ω7c/C_16:1 ω6c; 12.8 %) and C_14:0 2OH (9.3 %). DNA and chemotaxonomic data supported the affiliation of strain KHI67^T to the genus Sphingomonas. The DNA–DNA relatedness values between strain KHI67^T and its closest phylogenetic neighbours were below 15 %. Strain KHI67^T could be differentiated genotypically and phenotypically from the recognised species of the genus Sphingomonas. The isolate therefore represents a novel species, for which the name Sphingomonas ginsenosidivorax sp. nov. is proposed, with the type strain KHI67^T (=KACC 14951^T = JCM 17076^T = LMG 25801^T).     

Salt tolerance of a cash crop halophyte Suaeda fruticosa: biochemical responses to salt and exogenous chemical treatments

Suaeda fruticosa Forssk is a leaf succulent obligate halophyte that produces numerous seeds under saline conditions. Seeds are a good source of high quality edible oil and leaves are capable of removing substantial amount of salt from the saline soil besides many other economic usages. Little is known about the biochemical basis of salt tolerance in this species. We studied some biochemical responses of S. fruticosa to different exogenous treatments under non-saline (0 mM), moderate (300 mM) or high (600 mM) NaCl levels. Eight-week-old seedlings were sprayed twice a week with distilled water, hydrogen peroxide (H₂O₂, 100 μM), glycine betaine (GB, 10 mM), or ascorbic acid (AsA, 20 mM) for 30 days. At moderate (300 mM) NaCl, leaf Na⁺, Ca²⁺ and osmolality increased, along with unchanged ROS and antioxidant enzyme activities, possibly causing a better plant growth. Plants grew slowly at 600 mM NaCl to avoid leaf Na⁺ buildup relative to those at 300 mM NaCl. Exogenous application of distilled water and H₂O₂ improved ROS scavenging mechanisms, although growth was unaffected. ASA and GB alleviated salt-induced growth inhibition at 600 mM NaCl through enhancing the antioxidant defense system and osmotic and ion homeostasis, respectively.     

Micropropagation of <Emphasis Type="Italic">Asparagus macrorrhizus</Emphasis>, a Spanish endemic species in extreme extinction risk

Asparagus macrorrhizus: is a new species, which has been recently described. It is limited to the area surrounding the “Mar Menor” lagoon, in Murcia (Spain), and is the only “Critically Endangered” species of the genus Asparagus. Despite being protected, the number of plants has decreased in the last years due to the urbanization of its natural habitat. This species is a valuable genetic resource for asparagus breeding because of its special characteristics. So, the development of a micropropagation protocol is crucial to its conservation and use in breeding programs. The micropropagation protocol from asparagus rhizome buds previously developed by our research group has been adapted for A. macrorrhizus. Rhizome buds of A. macrorrhizus were extracted, disinfected, and then cultured on Asparagus Rhizome Bud Medium (ARBM) consisting of MS medium supplemented with 0.3 mg l^??1 NAA, 0.1 mg l^??1 KIN, 2 mg l^??1 ancymidol and 6% sucrose. A percentage of 69.7?±?8.0% of the rhizome buds developed shoots, but only 17.4?±?7.9% of them rooted. To increase this low rooting rate, the shoots were cultured on Macrorrhizus Rooting Media (MRM) supplemented with three different concentrations of IBA. The highest rooting rate (55.0?±?7.9%) was reached when shoots were incubated in MRM-2 consisting of MS medium supplemented with 2 mg l^??1 IBA and 4% sucrose. The acclimatization rate of the micropropagated plantlets was 90%. The method developed in this study allows the micropropagation of A. macrorrhizus, offering a new option to preserve this almost extinct species.     

Glutathione S-transferase genetic polymorphisms (GSTM1, GSTT1 and GSTO2) in three Iranian populations

Genetic polymorphisms in genes encoding glutathione S-transferases M1 (GSTM1; a member of class mu), T1 (GSTT1; a member of class theta) and O2 (GSTO2; a member of class omega) have been defined previously. Studies have revealed that there were significant differences between populations for allelic frequencies of GSTT1, GSTM1 and GSTO2 N412D polymorphisms. To get more insight into the genetic structure of Iranian populations the present study was done on Iranian Georgians living in Frydoonshahr (Isfahan province) and two Persian populations who living in Shiraz (Fars province) and Frydoonshahr. Study subjects consisted of 401 unrelated healthy individuals. From these 121 were Georgians. The remaining subjects were Persians from either Frydoonshahr (n = 34) or Shiraz (n = 246). The genetic polymorphism of GSTT1, GSTM1 and GSTO2 N412D was detected by PCR-based method. The frequency of GSTT1 null genotype in Georgian and Persians of Frydoonshahr and Shiraz was 15.7, 35.2 and 24.8%, respectively. There was significant difference between these populations for the distributions of the GSTT1 genotypes (χ² = 7.00, df = 2, P = 0.030). No significant difference was observed between these populations for polymorphisms of GSTM1 (χ² = 1.682, df = 2, P = 0.431) and GSTO N142D (χ² = 4.622, df = 4, P = 0.328). The prevalence of GSTT1 null genotype in Iranian Georgians showed significant difference with Persians and other Asian countries, but it seems to be similar with the frequency which was reported from European populations.     

Flavobacterium kyungheensis sp. nov., isolated from soil of a ginseng field

A Gram-staining negative, strictly aerobic, motile by gliding, non-spore-forming, pale yellow pigmented and rod-shaped bacterium designated strain THG-107^T was isolated from soil of a ginseng field on Ganghwa Island in the Republic of Korea and its taxonomic position was investigated by using a polyphasic study. Growth of strain THG-107^T was found to occur at 4–37 °C (optimum, 20–30 °C), at pH 5.5–10 (optimum, pH 7.0) and in the presence of 0–1 % (w/v) NaCl (optimum, absence) on R2A agar. On the basis of 16S rRNA gene sequence similarity, strain THG-107^T was shown to belong to the family Flavobacteriaceae and was related to Flavobacterium denitrificans ED5^T (99.1 % similarity). The G+C content of the genomic DNA was determined to be 34.2 mol%. These results are consistent with characteristics of members of the genus Flavobacterium. The only isoprenoid quinone detected in strain THG-107^T was menaquinone-6 (MK-6) and the major polyamine was identified as homospermidine (82.9 %). The major polar lipid detected was phosphatidylethanolamine and the major cellular fatty acids were identified as iso-C_15:0 (26.3 %), iso-C_17:0 3OH (12.6 %) and summed feature 3 (comprising C_16:1 ω7c and/or C_16:1 ω6c; 11.6 %). Flexirubin-type pigments were found to be present. Strain THG-107^T has β-glucosidase activity to convert ginsenosides Rb₁ and Rd into Gyp17 and F₂. DNA-DNA hybridization with F. denitrificans ED5^T was 52 %. Strain THG-107^T could be distinguished from F. denitrificans ED5^T and the other species of the genus Flavobacterium by its phylogenetic and genetic distinctiveness and by several phenotypic properties. Therefore, strain THG-107^T is considered to represent a novel species in the genus Flavobacterium, for which the name Flavobacterium kyungheensis sp. nov. is proposed (type strain THG-107^T = KACC 16219^T = LMG 26575^T).     

Meta-analysis of maize yield response to woody and herbaceous legumes in sub-Saharan Africa

A number of studies have tested the effect of woody and herbaceous legumes on soil fertility and maize yields in sub-Saharan Africa. However, their effects on maize productivity are much debated because results have been variable. A meta-analysis was conducted with the aim of evaluating the evidence in support of yield benefits from woody and herbaceous green manure legumes. A total of 94 peer-reviewed publications from West, East and southern Africa qualified for inclusion in the analysis. Maize yield from herbaceous green manure legumes (54 publications), non-coppicing legumes (48 publications), coppicing woody legumes (10 publications), natural fallows (29 publications), and fully fertilized monoculture maize (52 publications) were compared. Mixed linear modelling using yield differences (D) and response ratios (RR) indicated that the response to legumes is positive. The mean yield increase (D) over unfertilized maize was highest (2.3 t ha^?1) and least variable (CV?=?70%) in fully fertilized maize, while it was lowest (0.3 t ha^?1) and most variable (CV?=?229%) in natural fallows. The increase in yield over unfertilized maize was 1.6 t ha^?1 with coppicing woody legumes, 1.3 t ha^?1 with non-coppicing woody legumes and 0.8 t ha^-1 with herbaceous green manure legumes. Doubling and tripling of yields relative to the control (RR > 2) was recorded in coppicing species (67% of the cases), non-coppicing legumes (45% of the cases), herbaceous green manure legumes (16% of the cases) and natural fallows (19% of the cases). However, doubling or tripling of yields occurred only in low and medium potential sites. Amending post-fallow plots with 50% of the recommended fertilizer dose further increased yields by over 25% indicating that legume rotations may play an important role in reducing fertilizer requirements. Except with the natural fallow, the 95% confidence intervals of D and RR were higher than 1 and 0, respectively indicating significant and positive response to treatments. Therefore, it is concluded that the global maize yield response to legumes is significantly positive and higher than unfertilized maize and natural vegetation fallows.     

Common genetic variants associated with lipid profiles in a Chinese pediatric population

Genome-wide association (GWA) studies have identified many candidate genes that are associated with blood lipid and lipoprotein concentrations. In this study, we want to know whether the results from European for lipid-related single-nucleotide polymorphisms (SNPs) are generalizable to Chinese children. We genotyped seven SNPs in Chinese school-age children (n = 3,503) and assessed the associations of these SNPs with lipids profiles and dyslipidemia. After false discovery rate correction, of the seven SNPs, six (rs2144300, p ~ 9.30 × 10^?3; rs1260333, p ~ 6.20 × 10^?11; rs1260326, p ~ 8.73 × 10^?11; rs10105606, p ~ 0.010; rs1748195, p ~ 0.016 and rs964184, p ~ 2.33 × 10^?13) showed strong association with triglycerides. Three SNPs (rs1260333, p ~ 3.30 × 10^?3; rs1260326, p ~ 4.39 × 10^?3 and rs2954029, p ~ 6.36 × 10^?4) showed strong association with total cholesterol. Two SNPs (rs10105606, p ~ 6.66 × 10^?4 and rs1748195, p ~ 2.55 × 10^?3) showed strong association with high density lipoprotein cholesterol. Four SNPs (rs1260333, p ~ 0.017; rs1260326, p ~ 0.013; rs2954029, p ~ 1.09 × 10^?3 and rs964184, p ~ 5.51 × 10^?3) showed strong association with low density lipoprotein cholesterol. There were significant associations between rs1260333 (OR is 0.82, 95 % CI 0.74–0.92, p ~ 3.96 × 10^?4), rs1260326 (OR is 0.82, 95 % CI 0.74–0.92, p ~ 5.31 × 10^?4), and rs964184 (OR is 1.36, 95 % CI 1.20–1.55, p ~ 1.89 × 10^?6) and dyslipidemia. These SNPs generated strong combined effects on lipid profiles and dyslipidemia. Our study demonstrates that SNPs associated with lipids from European GWA studies also play roles in Chinese children, which broadened the understanding of lipids metabolism.     

Growth, regeneration and shade tolerance of the Wild Service Tree (Sorbus torminalis (L.) Crantz) in aged oak coppice forests

Sorbus torminalis L. (Crantz) is a rare species in Central European forests with very limited quantitative information on its regeneration and growth dynamics. Since coppicing is no longer practiced in the most parts of Central Europe, it is unclear whether S. torminalis, which has usually a shorter end height than companion species, can persist in high forest systems. Here, we quantified species frequency on three 1 ha sample plots of former oak coppice forest. To determine whether S. torminalis regenerated continuously and how it might compete with oaks, the age of 80 trees was determined, and diameter and height growth were reconstructed for the 20 largest trees by stem analysis. To assess its shade tolerance, photosynthesis was measured for leaves located in high and low light conditions. Dendrochronological data demonstrated that, over the last 80 years, continuous recruitment of S. torminalis occurred. Growth patterns and photosynthesis measurements suggest that S. torminalis is a highly shade-tolerant species. We conclude that abandonment of coppicing in these forests does not threaten the status of S. torminalis, which can persist beneath the canopy of oaks.     

Age and growth characteristics of the Starry Skate,Raja stellulata,with a description of life history and habitat trends of the central California,U.S.A., skate assemblage

Skates are prevalent in fisheries worldwide, but rarely are they identified to species. This is of conservation and management concern since skates exhibit a broad range of life history characteristics. The present study investigated the age and growth of the Starry Skate, Raja stellulata, and compared it to other regional skates inhabiting the U.S. West Coast. Age and growth parameters were determined using two vertebral preparation techniques: gross sectioning and histological sectioning. Gross section age estimates ranged from zero to 11 years and growth was described by the two parameter von Bertalanffy growth function (2 VBGF; L _∞ ?=?915 mm total length (TL) and k?=?0.13 year^-1; n?=?189). Histological section age estimates ranged from zero to 15 years and growth was also described by the 2 VBGF (L _∞ ?=?1092 mm TL, k?=?0.06 year^-1; n?=?68). Histological section results reflect a more conservative life history, specifically a lower von Bertalanffy growth coefficient, but had slightly biased results and a smaller sample size than the gross section results. An age and depth trend was found within the central California skate assemblage, in which habitat depth and maximum age were positively correlated.     

Large multiethnic Candidate Gene Study for C-reactive protein levels: identification of a novel association at CD36 in African Americans

C-reactive protein (CRP) is a heritable biomarker of systemic inflammation and a predictor of cardiovascular disease (CVD). Large-scale genetic association studies for CRP have largely focused on individuals of European descent. We sought to uncover novel genetic variants for CRP in a multiethnic sample using the ITMAT Broad-CARe (IBC) array, a custom 50,000 SNP gene-centric array having dense coverage of over 2,000 candidate CVD genes. We performed analyses on 7,570 African Americans (AA) from the Candidate gene Association Resource (CARe) study and race-combined meta-analyses that included 29,939 additional individuals of European descent from CARe, the Women’s Health Initiative (WHI) and KORA studies. We observed array-wide significance (p < 2.2 × 10^?6) for four loci in AA, three of which have been reported previously in individuals of European descent (IL6R, p = 2.0 × 10^?6; CRP, p = 4.2 × 10^?71; APOE, p = 1.6 × 10^?6). The fourth significant locus, CD36 (p = 1.6 × 10^?6), was observed at a functional variant (rs3211938) that is extremely rare in individuals of European descent. We replicated the CD36 finding (p = 1.8 × 10^?5) in an independent sample of 8,041 AA women from WHI; a meta-analysis combining the CARe and WHI AA results at rs3211938 reached genome-wide significance (p = 1.5 × 10^?10). In the race-combined meta-analyses, 13 loci reached significance, including ten (CRP, TOMM40/APOE/APOC1, HNF1A, LEPR, GCKR, IL6R, IL1RN, NLRP3, HNF4A and BAZ1B/BCL7B) previously associated with CRP, and one (ARNTL) previously reported to be nominally associated with CRP. Two novel loci were also detected (RPS6KB1, p = 2.0 × 10^?6; CD36, p = 1.4 × 10^?6). These results highlight both shared and unique genetic risk factors for CRP in AA compared to populations of European descent.     

Ulva lactuca and U. flexuosa (Chlorophyta,Ulvophyceae) cultivation in Brazilian tropical waters: recruitment,growth, and ulvan yield

Ulva spp. are used in a wide range of commercial applications, including bioremediation, food, bioenergy, pharmaceuticals, and agriculture. The sulfated polysaccharide ulvan obtained from Ulva spp. is of interest for triggering plant defenses against disease. However, the cultivation of Ulva spp. is still in its infancy. This study verified the feasibility of cultivating Ulva lactuca and Ulva flexuosa at two sites on the tropical Brazilian coast. We investigated the following: (a) methods to induce sporulation, (b) comparison of seeding ropes inoculated in vitro versus seeding at sea over 40 days, (c) production and harvest cycles at 15 and 30 days, (d) growth productivity of U. flexuosa at sea and in outdoor tanks, and (e) comparison of ulvan yields from biomass cultivated in tanks and the sea. High nutrient treatment was the most efficient method to induce sporulation (7,540?±?3,133 spores m^?1). Sea-based cultivation of U. flexuosa was only successful at one site. Seeding of ropes in vitro was more efficient than seeding at sea (0.31?±?0.20 g m^?2 day^?1), and 15-day harvest cycles were most efficient (20.1?±?1.8 % day^?1; 0.46?±?0.11 g m^?2 day^?1). Despite differences in plant growth in tanks (27.9?±?4.4 % day^?1) and at sea (20.1?±?1.8 % day^?1), the dry biomass and ulvan yields (17.7?±?5.0 %) did not differ between these systems. Cultivation of U. flexuosa was feasible at sea using in vitro seeding with a production cycle of 15 days in Brazilian tropical waters and tanks with high irradiance and enriched seawater.     

Combating aggressive macrophyte encroachment on a typical Yangtze River lake: lessons from a long-term remote sensing study of vegetation

Overabundant growth of emergent lacustrine plants can cause biodiversity, ecosystem service and economic loss. The two-basined Wuchang Lake is a typical small shallow lake within the Yangtze River floodplain. Expansion of the emergent macrophyte Zizania latifolia at Wuchang Lower Lake (to 49 km² in area, c. 87.0% of Lower Lake) has increasingly denied the local community open water for fishing since the 1980s. To better understand the causes of these changes and potential remediation, we used annual Landsat imagery from 1975 to 2012 to determine the patterns of expansion between years as well as the effects of water levels in different seasons and trophic status on the annual extent of macrophytes in the Lower Lake. These analyses showed that: (1) Z. latifolia progressively covered the Lower Lake, while remaining confined to one inlet in the Upper Lake; (2) despite the generally increasing trend, there were obvious annual variations in area of Z. latifolia; (3) variation of water level in spring contributed to between-year variation in area and was significantly negatively correlated with expansion in Z. latifolia. Based on these results, to reduce the expansion in Z. latifolia, we recommend maintaining spring Lower Lake water levels above at least at 11.6 m and better at 12 m, cutting shoots in June and July, with subsequent shoot removal in autumn.     

N2 fixing alder (Alnus viridis spp. fruticosa) effects on soil properties across a secondary successional chronosequence in interior Alaska

Green alder (Alnus viridis ssp. fruticosa) is a dominant understory shrub during secondary successional development of upland forests throughout interior Alaska, where it contributes substantially to the nitrogen (N) economy through atmospheric N₂ fixation. Across a replicated 200+ year old vegetation chronosequence, we tested the hypotheses that green alder has strong effects on soil chemical properties, and that ecosystem-level N inputs via N₂ fixation decrease with secondary successional stand development. Across early-, mid-, and late-successional stands, alder created islands of elevated soil N and carbon (C), depleted soil phosphorus (P), and more acidic soils. These effects translated to the stand-level in response to alder stem density. Although neither N₂ fixation nor nodule biomass differed among stand types, increases in alder densities with successional time translated to increasing N inputs. Estimates of annual N inputs by A. viridis averaged across the upland chronosequence (6.6 ± 1.2 kg N ha^?1 year^?1) are substantially less than inputs during early succession by Alnus tenuifolia growing along Alaskan floodplains. However, late-succession upland forests, where densities of A. viridis are highest, may persist for centuries, depending on fire return interval. This pattern of prolonged N inputs to late successional forests contradicts established theory predicting declines in N₂-fixation rates and N₂-fixer abundance as stands age.     

Vertical distribution of ammonia-oxidizing archaea (AOA) in the hyporheic zone of a eutrophic river in North China

Nitrification plays a significant role in the global nitrogen cycle, and this concept has been challenged with the discovery of ammonia-oxidizing archaea (AOA) in the environment. In this paper, the vertical variations of the diversity and abundance of AOA in the hyporheic zone of the Fuyang River in North China were investigated by molecular techniques, including clone libraries, phylogenetic analysis and real-time polymerase chain reaction. The archaeal amoA gene was detected in all sediments along the profile, and all AOA fell within marine group 1.1a and soil group1.1b of the Thaumarchaeota phylum, with the latter being the dominant type. The diversity of AOA decreased with the sediment depth, and there was a shift in AOA community between top-sediments (0–5 cm) and sub-sediments (5–70 cm). The abundance of the archaeal amoA gene (1.48 × 10⁷ to 5.50 × 10⁷ copies g^?1 dry sediment) was higher than that of the bacterial amoA gene (4.01 × 10⁴ to 1.75 × 10⁵ copies g^?1 dry sediment) in sub-sediments, resulting in a log₁₀ ratio of AOA to ammonia-oxidizing bacteria (AOB) from 2.27 to 2.69, whereas AOB outnumbered AOA in top-sediments with a low log₁₀ ratio of (?0.24). The variations in the AOA community were primarily attributed to the combined effect of the nutrients (ammonium-N, nitrate-N and total organic carbon) and oxygen in sediments. Ammonium-N was the major factor influencing the relative abundance of AOA and AOB, although other factors, such as total organic carbon, were involved. This study helps elucidate the roles of AOA and AOB in the nitrogen cycling of hyporheic zone.     

Percentage cover,biomass, distribution,and potential habitat mapping of natural macroalgae,based on high-resolution satellite data and in situ monitoring,at Libukang Island,Malasoro Bay,Indonesia

In this study, we combined remote sensing data and in situ observations to explore the potential habitats of macroalgae at Libukang Island, Indonesia. High-resolution satellite images from the GeoEye-1 were used to estimate and to map the geomorphological structures together with macroalgal species in the study area. Seasonal variations of percentage cover and biomass of macroalgae associated with substrates were investigated in May and November 2014, and June 2015, using quadrats as sampling unit. A total of nine common genera were found in the study area with three dominant genera: Sargassum, Padina, and Turbinaria. Most of macroalgae was observed in the eastern part of the Island, on several substrate types and particular oceanographic conditions (wave and current). Mean biomasses of Sargassum and Padina were high in May (1189.6 ± 455 and 166.7 ± 15.4 g DW.m^?2, respectively), while the biomass of Turbinaria was high in November (3245 ± 599.8 g DW.m^?2). The map accuracy of image classification for all typology substrates was 74.19%. Overall, approximately 62.3% of the total study area can be considered as potential for natural macroalgae habitats. Spectral response characteristic of shallow water substrates at study area based on GeoEye-1 is also presented. The results of this study exhibit a potential utilization of natural macroalgae in the study area, and provide information for a possible diversification of the use of macroalgae in Indonesia. The method could be useful for habitat management and future biomonitoring in the study area or other similar areas in Indonesia.     

Formation,regeneration, and transformation of protoplasts of Streptomyces diastatochromogenes 1628

Toyocamycin exhibits effective biological activities for use against plant pathogenic fungi thanks to its structural similarity to nucleoside. It has been recognized as a promising agricultural antibiotic utilized in controlling the occurrence of plant diseases. In our previous study, a strain that was isolated was identified and designated as Streptomyces diastatochromogenes whose major secondary metabolite was toyocamycin, but the production was largely limited. Protoplast transformation is a useful technique in the improvement of streptomycete. In this study, we optimized some key factors necessary for protoplast formation, regeneration, and transformation of S. diastatochromogenes. When mycelium was cultivated in CP medium with 1 % glycine, harvested at 48 h old, and then treated with 3 mg lysozyme/mL in P buffer for 1 h, the greatest regeneration frequency (42.5 %) of protoplasts was obtained. By using 1?×?10⁹/mL protoplasts with polyethylene glycol 1000 at a concentration of 30 % (w/v), the best performance of protoplast transformation efficiency was 4.8?×?10³/μg DNA transformants.