Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Basic Disciplines of Agriculture submitted time 2017-11-10 Cooperative journals: 《中国生态农业学报》
Abstract：准确量化分析地气之间的物质和能量交换对于水资源管理和农业可持续发展是十分重要的。能量平衡闭合是评估观测数据准确性和分析地表能量平衡的一个重要的评价指数。本研究利用开路涡度相关系统和全要素自动气象站对华北平原典型冬小麦农田生态系统2013—2014 年度的能量通量及常规气象要素进行了连续观测, 分析了冬小麦农田各能量通量的日变化和年变化特征, 计算冬小麦在4 个生育时期(出苗期、越冬期、拔节期和灌浆期)的能量闭合和波文比。结果表明: 在日尺度上, 选取的4 个生育时期净辐射和各能量分量的日变化趋势均为单峰二次曲线, 净辐射、显热通量和潜热通量的峰值出现在12:00—13:00, 土壤热通量的峰值出现在14:00—15:00。在年尺度上, 净辐射和潜热通量的变化趋势较为一致, 均在越冬期达到最低值114.51 W·m2 和13.47 W·m2, 而在灌浆期达到最大值327.02 W·m2 和116.56 W·m2。选取的4 个生育时期的代表性观测日期能量闭合良好, 能量闭合率分别为0.49、0.77、0.81 和0.76。4 个生育时期内波文比值日变化趋势均呈倒“U”型, 出苗期波文比在14:00 达到最大值2.12; 越冬期、拔节期和灌浆期在10:00 左右达到最大值, 分别为1.48、0.31 和0.58。本文的定量化结果可为华北平原农田生态系统水热通量等研究提供依据。
Subjects: Biology >> Botany >> Applied botany submitted time 2021-07-20 Cooperative journals: 《广西植物》
Abstract： In order to investigate the geographical origin of domestication of Amomum tsaoko, two hundreds and seventy-two individuals were sampled to represent 20 populations of A. tsaoko, and sixty-two individuals of 5 populations of A. paratsao-ko were sampled as a related species materials. For acquiring genetic diversity informations, the sequence variations of their cpDNA were carried out. The results showed that we detected 7 haplotypes by the combined sequences, i.e. 3 haplotypes (H1, H2 and H3) were found in A. tsaoko populations, and 6 haplotypes (H1, H2, H3, H4, H5 and H7) were found in A. paratsao-ko populations. 2 haplotypes (H1 and H3) were shared by the two species. H1 was common haplotype, H2 was ancestral haplotype and H6 was specific haplotype to A. tsaoko, while H2, H4, H5 and H7 were specific to A. paratsao-ko. The genetic diversity of A. tsaoko was lower than that of A. paratsao-ko and mainly existed within populations. The genetic diversity of A. paratsao-ko mainly existed among different populations. The genetic diversity and the haplotype diversity (Hd) of the two populations (TC and YP) were all higher than other 18 populations of A. tsaoko. Further analyses indicated that the domesticated region of A. tsaoko would include Maguan, Xichou and Malipo, where at the front area of southeast Yunnan, and the area near Napo, Guangxi. Malipo would be the core domestication of A. tsaoko in the region, then the related area would expand to Xichou, Maguan, Pingbian and Napo. TC, YP and XH populations were proposed to protect their genetic diversity. The results of the two species were expected to provide genetic information and theoretical reference for protection and utilization of the germplasm resources.
Subjects: Materials Science >> Materials Science (General) submitted time 2017-04-10 Cooperative journals: 《材料研究学报》
Abstract：以 ZrCl4-BCl3-H2-Ar 作为化学气相沉积反应体系，在不同温度下化学气相沉积 ZrB2 涂层，用 X 射线衍射 和扫描电子显微镜(SEM)表征了涂层的微观形貌和晶粒择优生长。结果表明:在石墨基体表面 ZrB2 涂层的形 核模式为岛状生长，小岛不断生成和合并以及晶粒的生长使靠近石墨基体表面的涂层含有大量孔洞，并形成 细晶区。在1300~1600°C沉积的初期，ZrB2涂层中一次晶粒融合为二次晶粒，表现为方向的择优生长。 随着沉积的进行 ZrB2 涂层的形貌从二次晶粒生长为板块状晶粒，板块状晶粒进一步生长向金字塔形貌转变， 涂层内部生长为致密柱状晶，晶粒的择优取向从向转变;当金字塔形貌的晶粒棱边发生钝化时涂 层内部的晶粒向等轴晶转变，晶粒的择优取向由方向转变为方向。
Subjects: Biology >> Botany submitted time 2022-09-29 Cooperative journals: 《广西植物》
Abstract： To study the influencing factors on the quality of cultivated varieties of Radix Aconitum Vilmoriniani, a toxic medicinal material for traumatology in Yunnan Province, the chloroplast genomes of samples from ten different cultivation bases were sequenced by Illumina HiSeq 4000 high-throughput sequencing platform. Then the sequencing data were assembled and annotated followed by analysis of the characteristics of the chloroplast genomes by bioinformatics tools and construction of the phylogenetic tree. The results were as follows: (1) The full length of chloroplast genome of ten cultivated varieties from different regions was 155 744-155 937 bp, the large single-copy region (LSC) and small single-copy region (SSC) were 86 363-86 548 bp and 16 921-17 007 bp respectively, the size of the inverted repeat region (IR) was 26 170-26 236 bp. The total GC content of chloroplast genome of ten cultivated varieties was 38.1%, with obvious AT preference, and 131 genes were annotated, including 85 protein-coding genes, 37 tRNA genes and 8 rRNA genes. (2) These sequences identified 60-73 SSRs sites, and genome comparative analysis found that the length of chloroplast genome of ten cultivated varieties ranged from 155 744 to 155 937 bp with moderate expansion. Some variation hot spots were found, such as trnK-UUU-trnQ-UUG, trnY-GUA-trnE-UUC, trnC-GCA-trnT-GGU, ycf4-cemA, ycf1 and ndhF, etc. (3) Phylogenetic analysis based on the two datasets showed that JS-1-4, QJ-1-2, LX-1-3, LJ-3-2 were closely related to Aconitum vilmorinianum and LQ-1-3, GJ-1-3, NL-1-3, DC-2-2 were closely related to A. austroyunnanense. In the phylogenetic tree, which was constructed based on the chloroplast genomes, LJ-4-3 was closely related to A. delavayi and LJ-1-2 was closely related to A. duclouxii; while in the phylogenetic tree which was constructed based on the PCGs, LJ-4-3 was closely related to A. episcopale and LJ-1-2 was closely related to A. contortum. The results indicated that the hybrid origins of cultivation of Radix Aconitum Vilmoriniani included at least the two original plants: A. vilmorinianum and A. austroyunnanense, and other species of Aconitum even existed in individual cultivation bases. The mixed origins of cultivation may be one of the influencing factors on instability of the quality of Radix Aconitum Vilmoriniani.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-07-05 Cooperative journals: 《广西植物》
Abstract： Rhododendron capitatum and R. przewalskii are ornamental flowers and medicinal plants. The chloroplast genomes of R. capitatum and R. przewalskii have been sequenced using Illumina HiSeq 4000 platform to explore the evolution features and genetic structure. After assembly and annotation, the chloroplast genome structure of R. capitatum and R. przewalskii were analyzed and compared with that of other Rhododendron plants. The results were as follows: (1) The chloroplast genomes of R. capitatum and R. przewalskii exhibit a typical quadripartite structure, including a large single copy region (105 990, 109 191 bp), a small single copy region (2 617, 2 606 bp), and a pair of inverted repeat regions (45 825, 47 516 bp). And the two Rhododendron chloroplast genomes were 200 257 and 206 829 bp in length, respectively. (2) In addition, the 263 SSRs were detected in the chloroplast genome of R. capitatum and R. przewalskii, most of which had A/T base preference; the codons preferred ending in A/U. (3) The chloroplast genomes of Rhododendron species exhibit structure variation such as gene loss and genomic rearrangement. Our study enriches the genomic resources of Rhododendron plants and provides the theoretical basis for resource exploitation, genetic evolution, breeding, and phylogeny of R. capitatum and R. przewalskii.
Subjects: Mechanics >> Basic Mechanics submitted time 2023-04-24 Cooperative journals: 《应用力学学报》
Abstract： In water transportation projects,due to the constraints of topography and geology,bifurcated pipelines have been widely promoted and applied.The leakage of bifurcated water pipelines is an important issue of great concern to scholars at home and abroad,and the transient flow method is one of the most efficient,accurate and fast leak detection methods at present.Based on this,this paper constructs a transient flow model of water pipeline with bifurcation structure,and explores the influence of different factors on the pressure change at the end of the valve.The factors affecting the pressure change at the end of the valve were investigated.The results show that the difference of pressure curve increases with the increase of the length of bifurcation pipe,the attenuation rate of pressure curve decreases with the increase of valve closing time,and the leakage has little influence on the variation period of pressure curve.The leakage position is different,the shape of the pressure curve at the amplitude is different.When the leakage position is in the upper half of the pipeline,the curve will be convex at the amplitude,and when it is in the lower half of the pipeline,the curve will be concave at the amplitude trend.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-12-26 Cooperative journals: 《广西植物》
Abstract： To explore expression level of alkaloid and its synthetase gene in Isatis indigotica upon Plasmodiophora brassicae Woronin exposure. Our study verified grade of disease severity according to morphology. Moreover, histological, physiological, biochemical parameters have been collected together with transcriptomics and metabolomic analysis in Isatis indigotica after infection at time scale 0, 7, 14, 21 d. Results showed that: (1) After infect with P. brassicae, I. indigotica showed club roots grade in 0, 1, 3, and 5 respectively at 7, 14, 21 d, notably, cortical invasion occurred on 7 d. (2) Our study revealed when P. brassicae exposes lasting 14 d later, the level of soluble protein and malondialdehyde, along with superoxide dismutase, peroxidase, polyphenol oxidase and catalase activity in I. indigotica increased significantly compared to control group at time depended manner. (3) A total of 161 alkaloids were detected in metabolomics, among those alkaloids, indoles were noticed as the most abundant form. There were 16, 17 and 39 discriminating metabolites have been spotted after infected with P. brassicae at 7, 14, 21 d, the most discriminating metabolites enriched at alkaloid and amino acid metabolism pathways. (4) Transcriptome analysis showed that there were 2 439, 256 and 6 437 genes expression alteration at 7, 14, 21 d compared to control, those differentially expressed genes enriched at 11 alkaloids related metabolism pathways. Markedly, expression level of 9 genes (encoding for enzymes thebaine synthase, tyrosine aminotransferase, indole-3-pyruvate monooxygenase and aldehyde dehydrogenase) were increased after infection at 7, 14, 21 d. Our results revealed the interaction between P. brassicae and I. indigotica. The effects of P. brassicae on indole alkaloids and enzymic genes expression laid ground for studying genes mediate club root resistance and alkaloid secondary metabolic pathways in I. indigotica.
Subjects: Biology >> Botany submitted time 2022-11-24 Cooperative journals: 《广西植物》
Abstract：
Psammosilene tunicoides is an important ethnic medicine in Southwest China and the main raw material for Chinese patent medicines such as Yunnan Baiyao. The purpose of this study was to isolate and identify the pathogenic fungus of root rot of P. tunicoides in Yunnan, and to provide a theoretical basis for the diagnosis and prevention of root rot of P. tunicoides. In this study, the disease-health junction of the root tissue of diseased plant was isolated and purified by pure culture method to obtain the main pathogenic microorganisms of P. tunicoides. Isolated pathogenic microorganisms were analyzed the pathogenicity according to Koch’s Postulates, and then were identified by morphological observation, rDNA-ITS and TEF-1α sequence analysis and phylogenetic tree construction. The results were as follows: (1) A total of 85 strains of fungi were obtained, among which PSD-1, PSD-2, and PSD-3 of Fusarium fungi caused P. tunicoides root rot; (2) These three strains were re-inoculated into the P. tunicoides, which produced similar disease symptoms occurred with field plants, and the disease incidence after inoculation with pathogenic fungi were 60%, 61.7%, and 71.7%, respectively; (3) Combined with morphological observation and gene sequence analysis, the three strains were identified as Fusarium oxysporum. This study firstly found that the F. oxysporum was one of the main pathogenic fungi causing root rot of P. tunicoides. The results of this study lay a foundation for the in-depth exploration of the endophytic flora with biological control of root rot and its mechanism, and serve as a theoretical basis for the follow-up prevention and control of the disease.
Subjects: Biology >> Zoology submitted time 2017-10-23 Cooperative journals: 《动物营养学报》
Abstract：近年来，牛奶质量安全问题频发，已严重威胁到公共健康。因此，牛奶质量安全成为国际关注的重点。当牛奶中残留兽药时，会对消费者造成不良的影响。本文从牛奶中兽药检测技术的原理和优缺点出发，对牛奶中兽药残留的检测技术进行了较全面的综述，并对牛奶中兽药残留检测技术在未来的发展方向作了展望。
Subjects: Biology >> Zoology submitted time 2017-10-11 Cooperative journals: 《动物营养学报》
Abstract：农作物秸秆作为一种资源丰富、来源广泛的生物质资源，在畜牧业和生物能源产业应用潜力巨大。但由于其复杂的化学组成以及抗性结构，使其不能直接高效地通过生物转化所利用。通过预处理可以降低秸秆纤维素的结晶度，提高秸秆的利用率。然而预处理过程不可避免地使秸秆在高温或化学催化作用下过度降解，并伴随着副产物的产生，对后续微生物发酵有抑制作用。本文综述了秸秆的稀酸、碱、蒸汽爆破以及生物预处理技术的研究进展，并对预处理副产物呋喃类衍生物、弱酸类和酚类化合物的产生与抑制机理作一综述。
Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究饲粮中添加不同水平苜蓿黄酮对28~70日龄扬州鹅生长性能、器官发育和血清生化指标的影响。选取240只21日龄健康、体重相近的扬州鹅公鹅，随机分为4个组，每组6个重复，每个重复10只鹅。对照组饲喂基础饲粮，试验组（Ⅰ、Ⅱ、Ⅲ组）分别饲喂添加150、300和450 mg/kg苜蓿黄酮的试验饲粮。预试期7 d，正试期42 d。结果表明：1）Ⅱ组的末重和平均日采食量显著高于其他3组（P0.05）。2）对照组和各试验组间的宰前活重、屠体重、屠宰率、半净膛重、半净膛率、全净膛重、全净膛率、腿肌重和腿肌率差异不显著（P>0.05）；各试验组的胸肌重和胸肌率均显著高于对照组（P0.05）；各试验组的脾脏重显著高于对照组（P0.05）；Ⅱ组和Ⅲ组的血清谷丙转氨酶（ALT）和谷草转氨酶（AST）活性高于Ⅰ组和对照组，但差异不显著（P>0.05）；Ⅰ组和Ⅱ组血清碱性磷酸酶（ALP）活性高于对照组和Ⅲ组，但差异不显著（P>0.05）。综上所述，苜蓿黄酮的添加能够提高扬州鹅的生长性能、器官发育和血清生化指标，其中添加300 mg/kg苜蓿黄酮的效果最好。
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