High fatty acid productivity from Scenedesmus obliquus in heterotrophic cultivation with glucose and soybean processing wastewater via nitrogen and phosphorus regulation.

In this study, the effects of nitrogen and phosphorus supply on biodiesel production from Scenedesmus obliquus with glucose as the carbon source were investigated. It was found that sufficient phosphorus could further improve biodiesel production under nitrogen starvation. S. obliquus was cultivated in soybean processing wastewater. The removal efficiencies of carbon oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) after 8-day cultivation were 72%, 95%, and 54%, respectively. Moreover, the fatty acid productivity after eight-day cultivation reached as high as 99.3 mg·L-1·d-1, which was 1.15 times higher than the highest efficiency using a glucose culture. This result was due to two naturally-formed stages occurring with sufficient phosphorus: nitrogen sufficiency stage for biomass and nitrogen starvation stage for lipid accumulation. It verified the conclusion of the roles of nitrogen and phosphorus obtained in the glucose culture and provided an economic and environmentally friendly choice for biodiesel production with efficient soybean wastewater treatment.

Clematisguniuensis (Ranunculaceae), a new species from Eastern China.

Clematisguniuensis sp. nov., a new narrowly endemic species of Clematis, is described and illustrated from the Huangshan Mountains of Eastern China. A description of C.guniuensis is presented along with illustrations, photographs and diagnostic differences between the new species and its putative close allies.

Selenium (Se) Does Not Reduce Cadmium (Cd) Uptake and Translocation in Rice (Oryza sativa L.) in Naturally Occurred Se-Rich Paddy Fields with a High Geological Background of Cd.

This study examined the selenium (Se) and cadmium (Cd) uptake by rice from soil and analyzed the relationship between Se and Cd in naturally occurred Se-rich paddy fields with a high geological background of Cd. Significant correlations were observed between soil Se and plant biomass Se, but not between soil Cd and plant biomass Cd. High concentrations of Cd were detected in rice plants and particularly in rice grains, suggesting potential health risks to human. Contrary to results from other previous studies, our results showed that high soil Se did not reduce Cd uptake by rice, although it decreased the availability of Cd in soil. Rather, soil Se and internal Se pool in rice were positively correlated to the transfer of Cd from root to straw. The effect of Se on the uptake and translocation of Cd in rice in field is therefore different from those in pot experiments.

Development of microsatellite markers for a Chinese endemic plant, Torreya yunnanensis (Taxaceae).

PREMISE OF THE STUDY: Microsatellite markers were developed in Torreya yunnanensis (Taxaceae) to investigate the genetic diversity, phylogeography, and population structure of the species. METHODS AND RESULTS: Sixteen primer sets were identified using Illumina 2 × 100-bp paired-end sequencing and bioinformatic screening. Most primers also amplified in T. fargesii, T. grandis, T. jackii, and T. nucifera. CONCLUSIONS: These results indicate the utility of these microsatellite markers in T. yunnanensis for future studies of molecular ecology as well as their applicability across the genus.

Two new species of Primulina (Gesneriaceae) from limestone karsts of China.

The limestone karst area of South China is a major biodiversity hotspot of global terrestrial biomes. During extensive field work on the Guangxi limestone formations, two unknown species of Gesneriaceae were collected. After conducting a comprehensive study of the literature and herbarium specimens, Primulina davidioides and P. hiemalis are recognized as two species new to science, and described and illustrated here. P. davidioides is morphologically close to P. lunglinensis based on the shape of the leaf and flower, but it can be easily distinguished by the shape of the bracts, corolla and stigma, indumentum of peduncles, pedicels and pistil and number of staminodes. P. hiemalis is closely relate to P. luzhaiensis in vegetative appearance, but differs in the shape of the calyx and stigma, number of bracts and staminodes, indumentum of the leaf blade and peduncle, and position of stamens in the corolla tube. Considering that not enough is known about their populations, it is proposed that their conservation statuses should currently be classed as data deficient (DD) according to the IUCN Red List Category and Criteria.

[Residue and Degradation of Roxarsone in the System of Soil-Vegetable].

The field experiment was developed for simulating the residues, transformation and degradation in soil-vegetable system of Roxarsone contained in organic fertilizer. Under the treatment, the yield of Brassica chinensis decreased in low Roxarsone concentration with a decline by 15% to 32% compared with the control group; there had an accumulating role of vegetables to arsenic, and the root was the main part; total content of arsenic in the soil was positively correlated with the dose of the applied Roxarsone; total arsenic in soil first increased and then decreased with the planting time prolonged and peaked at 12.94 mg x kg(-1), while the level of inorganic arsenic in the soil stabilized after 30 d, which accounting for 66.75% to 98.56% of the total arsenic; there existed a positively significant correlation of total arsenic content between the Brassica chinensis and the soil as well as the arsenic enrichment factor of vegetables; the degradation rate of Roxarsone in soil was slow, there was still some Roxarsone remained in soil after 45 d when added the organic fertilizer which containing Roxarsone with the dose higher than 5 000 kg x hm(-2); Roxarsone could significantly increase the number of bacteria in the soil, and low concentration showed an inhibited role in the growth of fungi and actinomyces, while high concentration of Roxarsone promoted the growth.

[Characteristics of arsenic content in the livestock farms' surrounding environment in Shanghai suburbs].

In the suburbs of Shanghai, selected five large farms and surface water, feed, soil and vegetable samples were collected, and then total and inorganic arsenic were detected to survey the current arsenic level of the livestock farms in Shanghai suburban, as well as the usage situation of organic arsenic as feed additives. The results showed that the total arsenic content in water samples ranged from 0. 00 microgL-1 to 23.00 microg L-1 , below the first standard of surface water quality (50 microg L-1 ) ; total arsenic in feed was among 0.40-12.13 mgkg-1 , in which inorganic arsenic was 10.0% -80.0% ; total arsenic in spot-checking feed samples was 0. 16-21.39 mg kg-1 and inorganic arsenic was 0. 003-10. 67 mgkg-1 , and samples exceeding the limits of arsenic in feed accounted for 16. 7% ; total arsenic content in soils ranged from 8.08-18.50 mgkg-1 , in which 22. 2% samples were higher than the first standard of soil environmental quality, and inorganic arsenic accounted for 44. 2% -78. 9% of total arsenic; vegetables' total arsenic was 0. 003-0. 093 mg kg-1, not higher than the maximal residue limit of 0. 50 mg kg -1 on the current national standard; there were some differences in different parts of the same species vegetables on arsenic content: arsenic content in roots were higher than that in the aboveground part, and the bioconcentration factors showed a significantly positive correlation with the arsenic content in vegetables and a negative correlation with the arsenic content in rhizosphere.

[Effects of intercropping Sedum plumbizincicola in wheat growth season under wheat-rice rotation on the crops growth and their heavy metals uptake from different soil types].

A pot experiment with heavy metals- contaminated black soil from Heilongjiang Province, alluvial soil from Henan Province, and paddy soil from Zhejiang Province was conducted to study the effects of intercropping Sedum plumbizincicola in wheat growth season under wheat (Triticum aestivum) - rice (Oryza sativa) rotation on the growth of the crops and their heavy metals uptake, aimed to explore the feasibility of simultaneous grain production and heavy metals-contaminated soil phytoremediation in main food crop production areas of this country. Comparing with monoculture T. aestivum, intercropping S. plumbizincicola increased the soil NaNO3 -extractable Zn and Cd significantly, with the increment of extractable Zn in test paddy soil, alluvial soil, and black soil being 55%, 32% and 110%, and that of extractable Cd in test paddy soil and black soil being 38% and 110%, respectively. The heavy metals concentration in T. aestivum shoots under intercropping S. plumbizincicola was 0.1-0.9 times higher than that under monoculture T. aestivum, but the intercropping had little effects on the rice growth and its heavy metals uptake. Though the Cd concentration in rice grain after S. plumbizincicola planting was still higher than 0.2 mg kg(-1) (the limit of Cd in food standard), it presented a decreasing trend, as compared with that after monoculture T. aestivum. Therefore, intercropping S. plumbizincicola in wheat growth season under wheat-rice rota- tion could benefit the phytoremediation of heavy metals-contaminated soil, and decrease the food-chain risk of rotated rice.

[Subcellular distribution and chemical forms of Cd and Zn in Sedum jinianum].

With water culture and by using differential centrifugation technique and sequential extraction, the subcellular distribution and chemical forms of Cd and Zn in the root, stem and leaf of Sedum jinianum were studied. In treatment 10 micromol Cd x L(-1), most of Cd in S. jinianum was in the soluble fraction of cell; while in treatment 100 miromol Cd x L(-1), the Cd in root was mainly deposited on cell wall, the Cd in stem was mainly on cell wall and in soluble fraction, and over 90% of Cd in leaf were in soluble fraction. In treatment 100 micromol Cd x L(-1), the proportion of Cd on the cell walls of root, stem and leaf increased, while that in soluble fraction decreased. In treatments 1 and 800 micromol Zn x L(-1), the Zn in root, stem and leaf mainly presented in soluble fraction; while in treatments with the Zn level between 1.0 and 800 micromol x L(-1), there were no differences in the proportions of Zn in the soluble fraction and on the cell walls of root, stem and leaf. Very low proportions of Cd and Zn were found in cell organelle. The Cd in the root, stem and leaf was predominated with NaCl- and water-extractable forms, while Zn in the plants were existed in numerous chemical forms.