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Zhang Y.-Q.,Southwest University | Wen M.-X.,Zhejiang Citrus Research Institute | Li X.-P.,Southwest University | Shi X.-J.,Southwest University
Journal of the Science of Food and Agriculture | Year: 2014

BACKGROUND: Phosphorus (P) loss from cropland is accelerating the eutrophication of waters around the world such as the Three Gorges Reservoir (TGR) in China. We investigated whether purple paddy soil under long-term P applications was a major source of P efflux to the TGR. RESULTS: Substantial surplus P in the plough layer (0-20cm) was evident after 15-year P applications. Available P (Olsen-P) in the plough layer ranged from 1.9 to 42.4mgkg-1 and some of which will exceed the threshold of 30mgkg-1 for environmental concern within 7years of P application (inorganic NPK with or without organic fertiliser). Between 30 and 70% of Olsen-P was leached out of the 0-30cm soil layer. Surplus P resulted in high P concentrations in the surface water during the rice cropping season, and these concentrations exceeded those in most waters of the TGR and exceeded the critical level for eutrophication (0.1mgL-1) during the first 10days after rice planting. Furthermore, total P in run-off due to rainfall events exceeded the level for eutrophication, with a total loss of 43.2-147.9g P ha-1 depending on the fertilisation. CONCLUSION: Current agronomic P management in purple paddy soil is environmentally unsustainable in terms of the adverse impact on surface water quality. Integrated P management practices are urgently required to optimise crop yield while minimising P loss in order to protect surface water quality in the TGR region. © 2013 Society of Chemical Industry.

Yu X.,Tongji University | Huang Z.,Zhejiang Citrus Research Institute | Liu W.,Tongji University | Shi S.,Tongji University | And 2 more authors.
Organic and Biomolecular Chemistry | Year: 2015

Palladium-catalyzed heteroarylation of 1-substituted 1,2,3-triazoles with furans and thiophenes has been developed in the presence of pyridine and Ag2CO3. The procedure is suitable for the regioselective preparation of 1,5-disubstituted 1,2,3-triazoles through conventional heating at reaction temperatures of 90-100°C for 18 h. © The Royal Society of Chemistry 2015.

Hou X.,Zhejiang University | Huang F.,Zhejiang University | Zhang T.-Y.,Zhejiang University | Xu J.-G.,Zhejiang Citrus Research Institute | And 2 more authors.
Journal of Integrative Agriculture | Year: 2014

Two scab diseases are currently recognized on citrus: citrus scab, caused by Elsinoë fawcettii, and sweet orange scab, caused by E. australis. Although these pathogens are economically important, there is no molecular data on these species in China. Here we use internal transcribed spacer sequence data to report on host-specificity and genetic relationships among 46 isolates collected from the main citrus varieties grown across China. All strains isolated were E. fawcettii. Based on pathogenicity testing on 9 different citrus species, isolates were divided into 11 pathotypes (SM, FBHR, SJCR, SPOJCR, SR, SOJG, SPOJC, SRGC, Lemon and two unnamed pathotypes). SM is a new pathotype, and two isolates did not fit into any of the known pathotypes of E. fawcettii. Inter-simple sequence repeat (ISSR-PCR) assays separated the E. fawcettii isolates into 10 subgroups; the groupings basically corresponded to the pathogenicity test. © 2014 Chinese Academy of Agricultural Sciences.

Jin H.,Tongji University | Huang Z.D.,Zhejiang Citrus Research Institute | Kuang C.X.,Tongji University | Wang X.K.,Tongji University
Chinese Chemical Letters | Year: 2011

An efficient and mild protocol for bromination of aryl azides with N-bromosuccinimide (NBS) under FeCl 3 catalysis in 1,2-dichloroethane was developed. It is proved to be an efficient method for obtaining brominated aryl azides. © 2010 Chun Xiang Kuang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Wen M.,Zhejiang Citrus Research Institute | Wen M.,Southwest University | Shi X.,Southwest University
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2013

Calcium (Ca), as an important nutrition, can regulate the physiological metabolic process and is closely related to fruit quality, the shelf life of fruit and physiological diseases during storage time. It is meaningful to study the relation of Ca nutrition and fruit quality and senescence for producing fruit with high quality, alleviating economic loss from rotten fruit and prolonging the fruit storage time. At present, there were some reports about Ca nutrition and fruit quality but many reported the effect of Ca on storage property of fruit by studying the respiration intensity and electric conductivity of fruits supplementing Ca solution on fruit during maturing stage or harvest time, few reported the effect of Ca on the inherent quality and the shelf life of fruits supplying Ca nutrition during fruit growing period. In order to make clear the effect of Ca nutrition sprayed on citrus trees in different growing periods on citrus fruit quality and senescence during storage time and propose comprehensive management measures for Ca nutrition of citrus orchards, the effect of Ca on fruit quality including vitamin C, total sugar, acid, total soluble solid (TSS), some enzymes and materials related to fruit senescence including peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), polygalacturonase (PG), cellulose (CX), malonaldehyde (MDA), protopectin (PP) and soluble pectin (SP) were studied in this paper. The effects of Ca on quality and enzyme activities of citrus fruits were studied by spraying calcium nitrate in different growth periods on Beibei-447 Jincheng orange (Citrus sinensis Osbeck, Beibei-447 orange). The results showed that Ca mass fraction in citrus fruits increased significantly, the oxygenolysis of vitamin C was restrained, total soluble solid (TSS), the ratio of sugar and acid increased and the fruit quality were maintained during storage by spraying Ca on citrus trees in different growth periods. The activities of polygalacturonase (PG), cellulase (CX) and peroxidase (POD) of different Ca treatments decreased but those of superoxide dismutase (SOD), catalase (CAT) increased because of high Ca mass fraction in fruits. The structure of cell was protected and lipid peroxidation was alleviated so that the mass fraction of malonaldehyde (MDA) and soluble pectin decreased, the senescence of fruit was postponed and the fruit was eventually kept in good during storage. The best effect on prolonging storage time of citrus fruit was to spray Ca on citrus trees in young fruit period, then spraying Ca on citrus trees in fruit rapid growth period and the worst was in fruit mature period. Spraying Ca on citrus trees in young fruit period and fruit rapid growth period were important measures to keep citrus fruit in good quality during storage.

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