作者机构:
[Wang Xiao-qing; Huang Guan-ming] Hunan Agr Univ, Coll Anim Sci & Technol, Changsha 410128, Peoples R China.;[Wu Qi-sheng; Guo Xiang; Ning Yue; Qi Jian-fei; Zeng Zhi-nan] Fisheries Res Inst Fujian, Xiamen 361013, Peoples R China.;[Zhu Li-yan] Fujian Anjoy Foods Holdings Co Ltd, Cent Lab, Xiamen 361028, Peoples R China.
通讯机构:
[Wang Xiao-qing] H;[Zeng Zhi-nan] F;Hunan Agr Univ, Coll Anim Sci & Technol, Changsha 410128, Peoples R China.;Fisheries Res Inst Fujian, Xiamen 361013, Peoples R China.
关键词:
近红外光谱;葡萄牙牡蛎;定量模型;相关系数
摘要:
葡萄牙牡蛎(Crassostrea angulata)是中国南方重要的海水养殖生物。 由于长期的人工育苗, 且未采取种质保护措施, 其种质资源不断衰退, 从而给牡蛎消费市场带来了不良影响, 急需开展葡萄牙牡蛎良种选育工作。 选育营养好、 口感佳的葡萄牙牡蛎, 需要对大量样本进行营养成分分析, 传统的实验室化学法耗时费力, 成本较高, 因此需寻求一种高效的葡萄牙牡蛎化学成分含量测定方法。 采用美国Thermo Fisher公司的傅里叶近红外光谱仪对6个产地的105份经过冷冻干燥和研磨处理的葡萄牙牡蛎样本(去除闭壳肌)进行光谱扫描, 通过采集的光谱数据与测定的化学真实值对比分析, 检测了近红外光谱技术(NIRS)对葡萄牙牡蛎中蛋白质、 糖原、 牛磺酸、 锌、 硒和钙6种成分含量预测的准确性。 利用TQ Analyst软件, 选用偏最小二乘法(PLS), 乘法散射校正(MSC)、 一阶求导、 Norris平滑等光谱预处理方法, 建立了6种成分的近红外定量模型, 并选取1/3总样品量的样本作为验证样本, 对模型进行了外部验证和交叉验证。 葡萄牙牡蛎的蛋白质、 糖原、 牛磺酸、 锌、 硒和钙6个模型的校正相关系数(RC)分别为0.985 3, 0.965 1, 0.950 4, 0.955 4, 0.920 0和0.925 2, 预测相关系数(RP)分别为0.985 1, 0.963 6, 0.944 1, 0.946 1, 0.919 0和0.924 1, 交叉验证相关系数(RCV)分别为0.981 7, 0.946 1, 0.900 5, 0.897 5, 0.875 3和0.829 2。 结果表明, 模型预测值与化学真实值有很高的相关度, 近红外光谱技术可以比较准确地预测葡萄牙牡蛎中蛋白质、 糖原、 牛磺酸、 锌、 硒、 钙的含量。 本实验样本采集时间跨度长, 产地分布范围广, 数量大, 具有较好的代表性, 样本经过冷冻干燥处理, 减少了水分对光谱质量的影响, 提高了模型的准确性及稳定性。 鉴于近红外光谱技术分析过程高效, 不使用化学试剂, 检测成本低, 该模型的建立对开展大规模葡萄牙牡蛎营养成分快速分析, 选育肉质性状佳的新品系具有重要意义。 Crassostrea angulata is the main variety of marine aquaculture in southern China. Due to long-term artificial breeding with no germplasm protection measures, its germplasm resources are declining, which has a negative impact on the oyster consumption market. Therefore, it is urgent to develop breeding of Crassostrea angulata (C. angulata). The selection for C. angulata with good nutrition and good flesh quality requires a large number of samples in the nutrient analysis. Traditional laboratory chemical method is time-consuming and costly, so we are looking for an efficient method for determining the chemical content of C. angulata. The spectroscopic scan was carried out using 105 frozen-dried and grinded C. angulata samples (removed the adductor muscle) from six regions with the Fouriernear-infrared spectrometer (Thermo Fisher, USA) in this study. By comparing the spectroscopic scan data to the chemical values, the accuracy of the content predictions of protein, glycogen, taurine, zinc, selenium and calcium in C. angulata obtained by near-infrared spectroscopy (NIRS) was studied. Using TQ Analyst (Thermo Fisher, USA) software, and selecting partial least squares (PLS), spectral preprocessing method like multiplication scattering correction (MSC), 1st derivative, and Norris derivative filter, the near-infrared models of the six components were established. And 1/3 of the total samples were selected as validation samples. The models were validated by external and cross validation. The correlation coefficients of calibration (RC) of the six models of protein, glycogen, taurine, zinc, selenium and calcium were 0.985 3, 0.965 1, 0.950 4, 0.955 4, 0.920 0 and 0.925 2, respectively. The correlation coefficients of prediction (RP) were 0.985 1, 0.963 6, 0.944 1, 0.946 1, 0.919 0 and 0.924 1, respectively. The correlation coefficients of cross validation (RCV) were 0.981 7, 0.946 1, 0.900 5, 0.897 5, 0.875 3 and 0.829 2, respectively. The results showed that the predicted values of the models had a high correlation with the chemical values, which indicated the NIRS could accurately predict the contents of protein, glycogen, taurine, zinc, selenium and calcium in C. angulata. The samples in this study had good representativeness. The collection time was long. The production area was wide and the quantity was large. The samples were frozen-dried, which reduced the influence of water on the spectral quality. Thus, the accuracy and stability of the models were improved. Spectroscopic scan and analysis based on NIRS was very efficient with no chemical reagents and low cost. The established quantitative model for 6 chemical compositions in C. angulata by NIRS would have a great significance for large-scale analysis of the nutritional compositions and for the selection of new strains with good flesh quality in C. angulata.
摘要:
Abstract Diatoms are a type of photosynthetic phytoplankton that can acclimate to the light level of their environment. Diatoms from different habitats exhibit different photoacclimation characteristics; those from relatively low-light intensity habitats present relatively high photosynthetic activity, high light-harvesting pigment (Chla) content, and low xanthophyll content. Conversely, diatoms from high-light intensity environments have lower photosynthetic activity, less Chla content, and efficient xanthophyll cycling. Hence, diatoms can maintain high growth and photosynthetic activity within a wide range of light intensities. Whether the mechanisms of such adaptability are a consequence of biological photoacclimation to different light intensities or interspecific differences is unknown. Here, we show that differences in photoacclimation ability are more significant than species differences. We found similar species compositions in low- and high-light habitats of the Hanjiang River, China; however, there were remarkable differences in rapid light-response curve parameters. The photoacclimation of algae and trends in their photosynthetic activity can be estimated by rapid detection techniques. We isolated three diatom species common to both habitats and grew them under various light intensities, finding that they have an excellent ability to acclimate to local light conditions. Diatoms can use physiological strategies to handle light fluctuations, but only for short periods. Our results provide a theoretical basis for controlling algal blooms through light management. With knowledge of the photoacclimation characteristics of diatoms and according to the availability of local water conservancy facilities, it is possible to use light management to control diatom blooms more efficiently than with conventional techniques, thereby reducing water usage.
摘要:
Abstract The mitochondrial genome of one potamidae species Neilupotamon papileonaceum was sequenced and annotated. The mitogenome is 16,273 bp in length, containing 37 typical genes. The A + T content of the whole mitogenome is 68.9%. Most of the PCGs started with ATG and stopped with TAT, except for ATP8 and ND6 stopped with TGA, COX1, COX2, ND5, ND4, and ND4L used incomplete T as stop codon. The phylogeny tree is monophyletic among 15 related species. The relationships of N. papileonaceum, Sinopotamon yaanense, and Longpotamon yangtsekiense were closer than others. This study further enriched mitogenome database of the tribe Typhlocybini.
摘要:
Monitoring the ecological status of drinking water reservoirs is very important for assessing risks to the safety of drinking water supplies. Because of the huge number of potential organic and inorganic contaminants in water, we focused our study on common water quality variables and three ecological indices. In this study, we used the modified Carlson trophic status index, Shannon diversity index, and the phytoplankton functional group index to assess the changing ecological status of Zhushuqiao Reservoir, a drinking water source in central China. Stratified water sampling for abiotic and biotic variables was conducted bimonthly from April 2016 to February 2017. All three indices indicated that upper reservoir water quality and ecological condition were worse than those in the lower reservoir. Also, the dominant phytoplankton species in the upper reservoir differed significantly from those in the lower reservoir. The reservoir was eutrophic from June to October, especially in June. During the other months, it was mesotrophic, with the best water quality in winter. Water temperature was the main driver of seasonal changes in both biotic and abiotic indicators, although hydrological condition also affected water quality. Total phosphorus (TP) was the limiting factor for phytoplankton, but phytoplankton biomass increased greatly when both TP and total nitrogen increased. Each index had weaknesses; but applying all three together yielded a comprehensive ecological assessment of Zhushuqiao Reservoir and could do so for other similar reservoirs.
摘要:
Genetic diversity is an important component of biodiversity and investigating and protecting the wild genetic diversity of species has always been an important research topic in conservation biology. Due to habitat destruction and over catching, wild Chinese soft-shell turtles (Pelodiscus spp.) have been severely damaged, resulting in the species being listed on the IUCN Red List of Threatened Species in 2000. However, only few studies with contradictory results on the genetic diversity of Pelodiscus turtles have been reported. To investigate the genetic diversity and population structure of Pelodiscus turtles, 123 specimens were collected from five localities in East Asia, and their genetic variation was analyzed on the basis of a 922-bp partial sequence of the mitochondrial cytb gene. Forty-nine polymorphic sites were detected, revealing 56 haplotypes. A pattern of high haplotype diversity (Hd = 0.994) and nucleotide diversity (pi = 0.01655) was found in the examined range. A maximum likelihood phylogenetic tree and median-joining network analyses indicated that the Pelodiscus turtles divided in four populations throughout East Asia, and the Pelodiscus turtles probably originate from the Yangtze River and was introduced to Yellow River, Taiwan, and Japan through Xijiang River. These results served a helpful resource for conservation of Pelodiscus turtles.