Can larch-Aralia elata agroforestry systems improve the soil chemical and microbial properties of larch plantations?

Agroforestry Systems - The conversion of secondary forests to larch plantations has resulted in soil degradation in Northeast China. Previous studies have proven that introducing native broadleaved...     

野生动物容纳量研究进展

环境容纳量是体现生物生存环境限制的重要指标,是合理调节种群数量的重要依据.该文以"野生动物容纳量""种群生存力分析"和"wildlife carrying capacity"为检索关键词,从CNKI和WOS中筛选出了59篇相关文献进行了总结分析.结果表明:野生动物容纳量的研究主要集中在营养容纳量和空间容纳量,其中以营养容纳量研究最为常见,在野生动物空间容纳量上还有探索空间;目前对鹿科动物容纳量的研究较多,对其余科属种的动物研究还不足;影响野生动物容纳量的主要因素有环境资源状况(数量、质量、波动)、动物个体在维持生存和生产过程中对营养物质的需求、生物对生境内资源的利用状况(数量、形式、效率和波动等)、生物种内及种间关系.考虑上述因素深入系统的研究还不够,动物栖息地容纳量具有动态性,一般选择冬季评估野生动物栖息地的容纳量,以有效判断环境容纳量的最低限值.为实施野生动物特别是珍稀物种栖息地精准管理,很有必要针对年际和年内水文差异开展野生动物动态容纳量研究.     

Mechanisms and management of acaricide resistance for Tetranychus urticae in agroecosystems

Journal of Pest Science - The two-spotted spider mite, Tetranychus urticae Koch, is a constant threat to sustainable production of numerous economically important crops globally. Management of T....     

几种药剂对烟苗白粉病防效初探及抗氧化代谢影响

为筛选防治烟草白粉病的高效低毒药剂.选择长势及白粉病发生一致的烤烟盆栽幼苗,设7个药剂处理和1个对照(清水、0.1％碳酸氢钠溶液、0.2％碳酸氢钠溶液、0.1％碳酸氢钠溶液+0.1％蒜溶液、0.2％碳酸氢钠溶液+0.1％蒜溶液碳酸氢钠、1％蛇床子素微乳剂、41.7％氟吡菌酰胺悬浮剂以及12.5％腈菌唑乳油),在0 d、7 d、14 d分别对叶片进行先取样再喷施,调查烟草白粉病施药前后发生情况,测量烤烟幼苗农艺性状,取样测定叶片中叶绿体色素、抗氧化代谢酶(SOD、Cu/Zn-SOD、CAT)、过氧化氢(H2 O2)和膜脂过氧化产物(MDA)含量等生理指标.结果表明,1％蛇床子素微乳剂对烟草幼苗白粉病相对防效为90.97％,病情指数0.80,对叶长、叶宽有显著促进作用,SOD活性显著高于CK,MDA含量显著低于CK,其综合防效最佳;41.7％氟吡菌酰胺悬浮剂相对防效达80.27％,病情指数1.53,SOD、CAT活性显著高于CK,H2 O2和MDA含量显著低于CK,综合防效次之;12.5％腈菌唑乳油相对防效为78.27％,病情指数为1.80,SOD、CAT活性显著高于CK,H2 O2含量显著低于CK,综合防效第3.因此,1％蛇床子素微乳剂,41.7％氟吡菌酰胺悬浮剂和12.5％腈菌唑乳油可作为防治烟草白粉病的候选药剂.     

不同促生剂对红花玉兰娇红2号苗木移栽生长的影响

娇红2号为红花玉兰系列新品种,具有极高观赏价值,但是红花玉兰娇红2号移栽后缓苗时间较长.为了缩短移栽缓苗期,促进苗木正常生长,尝试对红花玉兰娇红2号施用ABT-1号生根粉和EM菌剂,并分析其苗木生长发育过程,为揭示移栽后苗木生长响应规律及引种推广提供参考.以1年生红花玉兰娇红2号嫁接苗为试验材料,使用不同质量分数的ABT-1号生根粉和EM菌剂进行浸根、浇水试验.设置对照(CK)、A1、A2、A3、A4、B1、B2、B3、B4共9个处理,分别于5月、7月、9月进行生长指标和生理指标测定,分析各处理的苗木生长发育情况.结果 表明:各处理与对照相比,苗木根系生长恢复期缩短和结合体内保护酶系统的正向调节,促进了苗木正常生长;A3处理(ABT-1号生根粉)可缩短缓苗期2个月左右,用生根粉处理比EM菌剂处理的效果要好;A3处理(ABT-1号生根粉)能明显促进移栽苗木根系2-3级细根的分化吸收运输水分和营养,并通过提高净光合速率和调节自身保护酶系统活性,促进苗木恢复正常生长状态,缩短缓苗期2个月左右.     

水产科学实验原始数据处理的自动化技术

应用 Microsoft Excel软件建立了对原始数据进行不同处理的工作表,通过工作表中的名称、公式、填充、链接、宏等技术,完成原始数据处理的自动化过程。     

A novel 31-bp indel in the paired box 7 (PAX7) gene is associated with chicken performance traits

1. A novel 31-bp indel polymorphism in intron 3 of the chicken paired box 7 (PAX7) gene was identified and genotyped in an F₂ resource population of Gushi chicken crossed with Anka broiler to analyse its associations with chicken growth, carcass and meat quality traits.

2. Results showed that the 31-bp indel was significantly associated with body weight at 4, 6, 8, 10, 12 weeks of age and body size indices including shank length, shank girth, body slanting length at 8 and 12 weeks of age. Significant associations were found for carcass weight, semi-evisceration weight, evisceration weight, breast muscle fibre diameter, leg muscle fibre diameter, breast muscle fibre density, while no significant association with leg muscle fibre density was observed.

3. It was concluded that the 31-bp indel in intron 3 of the PAX7 gene was associated with chicken growth, carcass and meat quality traits where the 31-bp deletion had a negative effect on chicken growth and carcass traits and positive effect on meat quality traits.     

Up-regulated expression of PD-1 and its ligands during acute Classical Swine Fever virus infection in swine

In order to investigate the relationship between the PD-1 pathway and impairment of immune responses with the CSFV infection, the mRNA expression of PD-1 and its ligands were evaluated by quantitative polymerase chain reaction (qPCR) during artificial CSFV infection. Simultaneously, expression of IL-2 and IL-10 mRNA were detected. The T cell proliferation and CSFV load in plasma were also measured. Results showed that the expression of PD-1 and its ligands mRNA were significantly increased (p < 0.01) in PBMC from 3 to 7 days post infection (dpi). Meanwhile the level of IL-10 was up-regulated (p < 0.01). The IL-2 mRNA was not obviously changed but it is significantly increased from 14 dpi. The T cell proliferation was notably decreased at 7 dpi. The CSFV load was also increased in plasma. Overall, our results suggest that the expression of PD-1 and its ligands were up-regulated and probably correlated with immune inhibition during acute CSFV infection.     

Apoptosis‐Like Events and In Vitro Fertilization Capacity of Sex‐Sorted Bovine Sperm

This study utilized three staining assays (Annexin V, mitochondrial membrane potential (JC‐1) and TUNEL) for flow cytometric analysis of apoptosis in sex‐sorted sperm from four different bulls (A, B, C and D). Correlations between sperm quality and IVF efficiency were then assessed to determine which assay provided the best prediction of IVF efficiency. The results of the Annexin V assays, as well as measures of viable sperm, early apoptosis, necrotic sperm and mitochondrial membrane potential (?ψm) showed that the sex‐sorted sperm collected from bull A significantly differed from those of the other three bulls (p < 0.05). In addition, the levels of DNA fragmentation in sex‐sorted sperm from bull A were significantly lower than those from bulls B and C (p < 0.05). The percentage of cells reaching the cleavage and blastocyst stages in sex‐sorted sperm from bull A were significantly greater than those from the other bulls (p < 0.05). A significant positive correlation was observed between viable sperm and the percentage of cells at the cleavage or blastocyst stages (p < 0.05). In contrast, a negative correlation was found between early apoptotic sperm and the percentage of cells at the cleavage or blastocyst stages (p < 0.05). In conclusion, these results indicated that the Annexin V assay was the most reliable technique for the prediction of the IVF success of sex‐sorted bovine sperm.     

Salix tetradenia Hand.‐Mazz: a new natural plant host of ‘Candidatus phytoplasma’

This article reports Salix tetradenia Hand.‐Mazz as a new host of Candidatus phytoplasma and demonstrates its association with witches' broom disease on S. tetradenia plants. Plants exhibited typical visual symptoms of phytoplasma with virescence, abnormality of flowers and witches' broom, and phytoplasma bodies were observed by transmission electron microscopy. Products of 1.2 kb were amplified by nested PCR using phytoplasma universal primer pairs R16F2n/R16R2, but no amplification products were obtained from symptomless plants. The sequence analysis of three 16S rDNA isolates showed 99.84%, 99.68% and 99.76% identify, respectively, with the homologous gene (nc_005303) of member of ‘Candidatus phytoplasma asteris’ (16SrI) group. Phylogenetic and virtual computer‐simulated restriction fragment length polymorphism analysis of the 16S rRNA, tuf and rp gene sequences confirmed that this phytoplasma clustered in the 16SrI‐B subgroup. These results indicated that the diseased S. tetradenia plants were infected by a phytoplasma of the 16SrI group. This is the first report on the occurrence of phytoplasma disease on S. tetradenia worldwide.