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  • Author or Editor: Xie Shen x
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Rice straw represents a significant energy source for ruminant animals, and fibers and lignin contents of rice straw are negatively related to intake potential of forages. For improvement of the digestibility of rice straw, it is necessary to understand the genetic basis of the related traits. In present study, mapping of quantitative trait loci (QTL) for acid detergent fiber (ADF), neutral detergent fiber (NDF), and acid detergent lignin (ADL) was carried out using a doubled haploid (DH) population derived from a cross between indica variety Zai-Ye-Qing 8 (ZYQ8) and japonica variety Jing-Xi 17 (JX17). The results indicated that all three parameters were continuously distributed among the DH lines, but many DH lines showed transgressive segregation for all the three traits. A total of three main-effect QTLs were identified for ADF and ADL, two of which, qADF-9 and qADL-9, shared the same region on chromosome 9. These two main-effect QTLs explained more than 20% of the total phenotypic variations, whereas the other QTL, qADF-5, explained 12.8% of the total phenotypic variation for ADF. In addition, another two epistatic QTLs, qADF-2 and qADF-3 could explain 17.6% of the total variations. Thus, we concluded that both main-effects and epistatic QTLs were important in controlling the genetic basis of ADF.

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The aim of this study was to compare the antioxidant activity of crude extracts of differing polarities of the fruits of Chaenomeles speciosa (Sweet) Nakai. The antioxidant compositions of the extracts were analyzed qualitatively and quantitatively, respectively. The 75% ethanol extract of the dried fruits was fractionated by sequential extraction using petroleum ether, ethyl acetate, and n-butyl alcohol. The antioxidant effectiveness of the components of differing polarities was examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging method and compared with two reference substances: ascorbic acid and butylated hydroxytoluene (BHT). The total phenolic content of the extracts was analyzed using the Folin–Ciocalteu method and expressed as gallic acid equivalents. The active compounds were analyzed by thin-layer chromatography (TLC)–bioautography and ultra-performance liquid chromatography (UPLC). The order of antioxidant capacities of various solvent extracts from the fruit of C. speciosa was found to be ethyl acetate ≥ n-butyl alcohol > petroleum ether. The ethyl acetate extract was more active than the reference substances ascorbic acid and BHT. The radical-scavenging capacity of the extracts decreased as the total phenolic content decreased. TLC–bioautography revealed that the ethyl acetate extract contained many antioxidant spots that can remove DPPH radical, and protocatechuic acid and chlorogenic acid were the major antioxidant components. UPLC analysis confirmed that protocatechuic acid and chlorogenic acid were mainly distributed in the ethyl acetate fraction. The study demonstrated that the ethyl acetate extract had excellent antioxidant capacity. The total phenolic, protocatechuic acid, and chlorogenic acid contents of this extract were higher than those of the other two solvent extracts. These results showed that the ethyl acetate extract from the fruit of C. speciosa could be considered as a potential source of natural antioxidant agent.

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Abstract  

The uptake of rare earth elements (REE) by Euglena gracilis cells has been investigated in Fudan University. The remarkable ability to transport REEs to these cell’s compartments had been observed. X-ray absorption fine structure experiments (XAFS) of cerium in Euglena gracilis were performed at Beijing Synchrotron Radiation Facility (BSRF) to directly determine the cerium valence state and coordination structure in situ. Extended X-ray absorption fine structure (EXAFS) derived calculation showed that cerium was surrounded by 8 N atoms with bond length of 0.258 nm. Combining with other measurements, it may indicate that most likely REEs are mainly located in chlorophyll molecules.

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