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Soil salinization and alkalization frequently co-occur in nature, but little is known about the mixed effects of salt-alkaline stresses on plants. An experiment with mixed salts (NaCl, Na(2)SO(4), NaHCO(3) and Na(2)CO(3)) and 30 salt-alkaline combinations (salinity 24-120 mmol/L and pH 7.03-10.32) treating Medicago sativa seedlings was conducted. The results demonstrated that salinity and alkalinity significantly affected total biomass and biomass components of seedlings. There were interactive effects of salt composition and concentration on biomass (P

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The future of wild tigers is dire, and the Global Tiger Initiative's (GTI) goal of doubling tiger population size by the next year of the tiger in 2022 will be challenging. The GTI has identified 20 tiger conservation landscapes (TCL) within which recovery actions will be needed to achieve these goals. The Amur tiger conservation landscape offers the best hope for tiger recovery in China where all other subspecies have most likely become extirpated. To prioritize recovery planning within this TCL, we used tiger occurrence data from adjacent areas of the Russian Far East to develop two empirical models of potential habitat that were then averaged with an expert-based habitat suitability model to identify potential tiger habitat in the Changbaishan ecosystem in Northeast China. We assessed the connectivity of tiger habitat patches using least-cost path analysis calibrated against known tiger movements in the Russian Far East to identify priority tiger conservation areas (TCAs). Using a habitat-based population estimation approach, we predicted that a potential of 98 (83-112) adult tigers could occupy all TCAs in the Changbaishan ecosystem. By combining information about habitat quality, connectivity and potential population size, we identified the three best TCAs totaling over 25 000 km 2 of potential habitat that could hold 79 (63-82) adult tigers. Strong recovery actions are needed to restore potential tiger habitat to promote recovery of Amur tigers in China, including restoring ungulate populations, increasing tiger survival through improved anti-poaching activities, landuse planning that reduces human access and agricultural lands in and adjacent to key TCAs, and maintaining connectivity both within and across international boundaries. Our approach will be useful in other TCLs to prioritize recovery actions to restore worldwide tiger populations.Restoring tiger conservation landscapes M. Hebblewhite et al. 580Animal Conservation 15 (2012) 579-592

Summary The progress of bio‐hydrogen technology has led to the development of new energy technologies and is significant for the sustainable use of energy. After summarizing current research results, this study discusses that the key to increasing the hydrogen production rate is to improve the activity of hydrogen producing bacteria under the conditions of anaerobic fermentation. Using waste to prepare hydrogen producing bacteria is the developmental trend. The primary factors influencing bio‐hydrogen production from plant straw fermentation are also pointed out, indicating the method to improve the hydrogen production rate from plant straw. In addition, application of artificial intelligence technology to a bio‐hydrogen production reactor is helpful to achieve automatic control of continuous bio‐hydrogen production and improve the rate of hydrogen production.

Citric acid plays an important role in fresh fruit flavor and its adaptability to post-harvest storage conditions. In order to explore organic acid regulatory mechanisms in post-harvest citrus fruit, systematic biological analyses were conducted on stored Hirado Buntan Pummelo (HBP; Citrus grandis) fruits. Highperformance capillary electrophoresis, subcellular organelle expression microarray, real-time quantitative reverse transcription polymerase chain reaction, gas chromatography mass spectrometry (GC-MS), and conventional physiological and biochemical analyses were undertaken. The results showed that the concentration of organic acids in HBP underwent a regular fluctuation. GC-MS-based metabolic profiling indicated that succinic acid, g-aminobutyric acid (GABA), and glutamine contents increased, but 2-oxoglutaric acid content declined, which further confirmed that the GABA shunt may have some regulatory roles in organic acid catabolism processes. In addition, the concentration of organic acids was significantly correlated with senescence-related physiological processes, such as hydrogen peroxide content as well as superoxide dismutase and peroxidase activities, which showed that organic acids could be regarded as important parameters for measuring citrus fruit post-harvest senescence processes.Keywords: Citrus; gene expression; metabolite; organic acids; post-harvest storage.

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Organic acids are a major index of fresh fruit marketing properties. However, the genetic effects on the organic acid level in postharvest citrus fruit still remain unknown. Here, we used the fruits of about 40 lines in a hybrid population (high-acid "HB Pumelo" × low-acid "Fairchild") to analyze the organic acid metabolism of postharvest citrus fruit. A transgressive content of titratable acid (TA) was observed, which was attributed to citrate accumulation. High- and low-acid fruits (No. 130, 168 and No. 080, 181, respectively) were chosen for further study. Gene expression analysis on citrate metabolism showed that the high accumulation of citrate could be attributed to the low activity of γ-aminobutyric acid (GABA) shunt, and was partially due to the block of tricarboxylic acid (TCA) cycle by low mitochondrial aconitase (m-ACO) expression. TA level was significantly negatively correlated with weight loss in fruits during postharvest storage, implying a close relationship between organic acid and water metabolism.