滇中冷凉山区不同播期反季花椰菜产量效益分析

为摸索滇中高海拔冷凉山区反季节栽培花椰菜的最佳播期以集成高效栽培技术推广应用,于2017—2018年选择海拔2250 m的云南省峨山县塔甸镇大西村地块进行9个播期的2年随机区组试验。结果表明,花椰菜生育期随播期推迟而延长,而花球采收期除播期7月10日外随播期推迟而逐渐增长;花椰菜株高、外叶数、开展度、球高、球径和单球重等农艺性状有随播期延迟呈现先逐渐减小而后又逐渐增大的趋势;莲座期黑腐病和霜霉病的病情指数随着播期的延迟呈现先逐渐升高而后又逐渐下降的趋势;花椰菜小区产量随着播期的延迟呈现先逐渐下降而后又逐渐提高的趋势,播期4月20日和4月30日与其余7个播期产量之间的差异达极显著水平。综合花椰菜在冷凉山区反季节栽培的生产实际和各播期产量产值及商品性表现,推荐滇中高海拔冷凉山区反季节栽培花椰菜的最佳播期为4月20—30日。     

Effects of music stimulus on behavior response,cortisol level,and horizontal immunity of growing pigs

An enriched environment is widely used to improve domestic animals’ welfare and promote their natural behaviors. Music can reduce abnormal behavior in humans, nonhuman primates, and rodents. However, little is known about the effects of music on pigs. This study aims to explore the effects of repeated music stimulation on the behavior, physiology, and immunity of growing pigs. A total of 72 hybrid piglets (Large White × Duroc × Minpig) were randomly divided into three groups, including music (Mozart K.448, 60 to 70 dB), noise (recorded mechanical noise, 80 to 85 dB), and control (natural background sound, <40 dB), and 6 h sound stimulation was given per day (1000 to 1600 hours) from 40 to 100 d of age. The behavioral activities of the pigs were observed during the music stimulation, and their serum cortisol, salivary cortisol, and serum immune indices were also measured. Compared with the control group, the music group and noise group increased activity but decreased lying of pigs (P < 0.05). A significant increase in tail-wagging, playing, and exploring behaviors of pigs was found in the music group (P < 0.05), and the noise significantly increased the aggressive behavior of the pigs (P < 0.05). Tail-wagging, playing, exploring, manipulating, and aggressive behaviors decreased over time. Short-term (8 d) music stimulus had a lower cortisol level than that of the noise and control groups (P < 0.05), whereas long-term (60 d) music stimulus increased immunoglobulin G (IgG), interleukin-2 (IL-2), and interferon-gamma (IFN-γ) levels (P < 0.05) and decreased interleukin-4 (IL-4) level (P < 0.05). Long-term noise stimulus significantly reduced the level of IgG (P < 0.05) but did not affect the level of IL-2, IL-4, and IFN-γ levels (P > 0.05). In conclusion, short-term music stimulus (8 d) reduced the stress response, whereas long-term music stimulus (60 d) enhanced the immune responses. In addition, the noise increased the aggressive behavior, and long-term noise reduced the immunity of the growing pigs.     

甜菜BvGSTU9基因的生物信息学及在镉胁迫下的表达分析

为了进一步研究甜菜谷胱甘肽转移酶BvGSTU9 (LOC104894060)在重金属胁迫过程中的功能。本研究以‘780016B/12优’为实验材料,对该基因序列特征、结构、功能进行预测分析,并利用qPCR检测该基因在不同浓度镉胁迫下的表达量变化。结果显示甜菜BvGSTU9基因全长925 bp,开放阅读框675 bp,编码了由224个氨基酸组成的不稳定膜外蛋白。BvGSTU9与菠菜、藜麦的氨基酸序列相似性较高,与系统发育进化树分析结果基本相符。二级和三级结构预测表明该基因主要由α-螺旋、β-折叠、延伸链及无规则卷曲组成。qPCR显示BvGSTU9基因在不同浓度的镉胁迫下均受到不同程度的诱导,因此可以推断甜菜BvGSTU9基因无论从结构还是功能上,与镉逆境胁迫存在着一定的应答关系。研究结果也为甜菜耐重金属镉机制研究提供参考依据。     

Do cover crops change the lability of phosphorus in a clayey subtropical soil under different phosphate fertilizers?

Plants have developed different mechanisms to absorb and solubilize phosphorus (P) in the soil, especially in environments with low P availability. This study evaluated the effects of different winter cover crops on soil P availability in a clayey subtropical (Hapludox) soil receiving soluble P fertilizer and a rock phosphate applied to the summer crop, under no‐tillage. The experiment was carried out over 3 yrs (2009–2011) with five different cover crop species: common vetch, fodder radish, ryegrass, black oat, white clover and fallow as control. The soil was sampled after the third year of cover crop cultivation and analysed for inorganic and organic P forms according to the well‐established Hedley fractionation procedure. Phosphate fertilizers promoted accumulation of both labile and nonlabile P pools in soil in the near surface layer, especially under rock phosphate. Fertilizer applications were not able to change P fractions in deeper layers, emphasizing that the Brazilian clayey soils are a sink of P from fertilizer and its mobility is almost nil. Although the cover crops recycled a great amount of P in tissue, in a short‐term evaluation (3 yrs) they only changed the content of moderately labile P in soil, indicating that long‐term studies are needed for more conclusive results.     

正交设计优化青蒿SRAP-PCR反应体系及引物筛选

为了建立青蒿的SRAP最佳扩增体系,并筛选出SRAP多态性引物,本研究以青蒿叶片DNA为模板,采用正交试验设计,以Mg^2+、dNTP Mix、Taq DNA聚合酶、引物和DNA模板5种因素5个水平,对青蒿SRAP反应体系进行研究。结果表明,青蒿SRAP-PCR最佳反应体系为:引物0.6μmol/L、Mg^2+2.0 mmol/L、模板DNA 5.1 ng、Taq DNA聚合酶2.0 U、dNTPs 0.25 mmol/L,总体积为25μL。各因素对扩增反应均有不同影响,其中引物浓度的影响最大,dNTPs的影响最小。运用该体系对不同种质资源的青蒿进行验证,证明该体系稳定可靠,并在30个引物组合中筛选出了25对扩增条带清晰,多态性丰富的引物组合。这一结论为今后利用SRAP标记技术进行青蒿分子遗传学研究提供了科学依据。     

亏缺灌溉对南疆棉花生长和水分利用的影响

针对南疆地区水资源短缺、作物水分利用效率低等问题,以棉花为试验材料进行田间小区试验,在棉花现蕾期、开花期以及结铃期分别设置3个亏缺灌溉水平(W₁:50%ET_c,W₂:65%ET_c,W₃:80%ET_c,ET_c为作物蒸发蒸腾量),以全生育期100%ET_c灌溉处理为对照(CK),研究膜下滴灌条件下,不同生育期亏缺灌溉对棉花生长、产量、氮素吸收和水分利用效率的影响.结果表明:现蕾期亏水对棉花株高、叶面积指数、地上干物质生长、氮素吸收和产量有不同程度的抑制效应,但复水后补偿效应显著,其中轻度亏水(W₃)在籽棉产量减少3.48%的条件下,WUE高达1.57 kg/m³,显著高于CK的1.48 kg/m³;开花期亏水,棉花的各项生长指标均有显著降低,复水后补偿效应不显著,不利于棉花生长发育;结铃期亏水对棉花地上干物质累积、氮素吸收和产量均有显著的抑制效应,但在W₂和W₃水平下,WUE均达1.51 kg/m³.综合考虑在保证棉花产量的同时达到节水增产的目的,可在棉花蕾期进行80%ET_c灌水,其他生育阶段实施充分灌溉,来控制营养生长,促进生殖生长,获得更高的水分利用效率.     

施用锌肥和遮阴互作对花生生长发育、抗病性及产量的影响

采用大田裂区试验，研究了施用锌肥和不同遮阴程度互作对花生生长发育、抗病性及产量的影响。结果表明，与不施锌肥相比，施用锌肥能提高花生不同部位锌含量、增加叶片SPAD值，提高花生叶片中可溶性糖、蛋白质和生长素含量，减少花生病害的发生，平均降低7.1个百分点，花生产量平均增加19.4%。相同施锌水平下，随着遮阴程度的增加，花生不同部位锌的含量和不同生育期叶片SPAD值以及花生叶片中可溶性糖、蛋白质和生长素含量呈增加趋势，花生的发病率比不遮阴对照增加4.8、10.2个百分点，花生产量平均降低16.5%、10.0%。在30%、70%的遮阴条件下，施用锌肥的花生产量比不施锌的分别提高21.1%、25.0%。本试验条件下，施用七水硫酸锌30 kg/hm2，使花生具有较强的抗低温寡照能力及抗病性能，增产显著，可在花生产区推广应用。     

Spatiotemporal patterns of mountain whitefish (Prosopium williamsoni) in response to a restoration of longitudinal connectivity

To examine the role of longitudinal connectivity on the spatial and temporal dynamics of mountain whitefish (Prosopium williamsoni), we quantified movement and population dynamics following installation of the Landsburg Dam fishway, Cedar River, WA, USA. Mountain whitefish is widely distributed, poorly studied and not the focus of restoration. Before the fishway, mountain whitefish were not observed above the dam. Here, we focus on snorkel counts collected at reach and mesohabitat (e.g. pools) scales over 11 summers on the 20‐km above‐dam segment following restoration. A camera within the ladder provided number, size and movement timing, thereby informing on behaviour and recolonisation. Segment‐scale abundance increased following fish passage reaching an asymptote in 7 years, and mountain whitefish were detected throughout the main stem in 10 years. Annual movement through the ladder increased over time and was positively correlated with instream abundance and discharge, but negatively correlated with water temperature. About 60% of fish movements occurred in spring and early summer, potentially for foraging opportunities. Reach‐scale abundance peaked between 7 and 10 km from the dam; deep, cool (~10.6 to 11.6°C) conditions characterised these reaches. At the mesohabitat scale, mountain whitefish detection increased with depth and velocity after accounting for distance from the dam. Our results show how restoring longitudinal connectivity allowed this nontarget species to colonise newly available habitat. Their response supports the critical roles of longitudinal connectivity and environmental conditions, that manifest at different spatial scales, in dictating how freshwater fish respond to habitat disturbance.     

Epidermal growth factor-like activity in mares' milk.

Epidermal growth factor (EGF)-like activity was measured in mares' colostrum and milk by radioreceptor assay. Milk samples were collected from 22 mares 1 or more times during early lactation. Samples of colostrum were taken after parturition and before the foal first suckled (presuckle), within 6 hours after the foal first suckled (postsuckle), and on days 1, 2, 4, and 8 of lactation. In the 5 mares from which milk samples were obtained at each sampling time, presuckle colostral mean EGF-like activity (17.8 ng/ml) was greatest (P less than 0.05). The mean values for EGF-like activity at all other sampling times were not significantly different from each other (postsuckle colostrum, 9.7 ng/ml; day 1, 9.6 ng/ml; day 2, 8.5 ng/ml; day 4, 8.0 ng/ml; day 8, 7.8 ng/ml).     

Evaluation of the Hennessy grading probe to predict yields of lamb carcasses fabricated to multiple end points.

Lamb carcasses (n = 278) were selected immediately after slaughter and fat thickness was measured with the SP2 Hennessy grading probe (HP) at the interface of the 12th and 13th ribs, 3.8 cm from the backbone. After a 24-h chilling period, carcasses were graded by a USDA grader and probed with the HP to obtain a fat thickness measure on the chilled carcass. One hundred sixty-five carcasses were fabricated into wholesale cuts (.64 cm of external fat trim), and 113 carcasses were fabricated into tray-ready retail cuts (.25 cm of external fat trim). Carcass weight, fat thickness (metal probe), adjusted fat thickness, hot and chilled carcass HP fat measures, as well as kidney and pelvic fat percentage and USDA yield grade, were highly correlated to cutting yield for both fabrication methods. Regression models developed to predict wholesale cut yields using HP or grader-collected measures were similar with respect to predictive accuracy. Fat thickness explained most of the variation in wholesale and tray-ready cut yields among the variables collected by the grader. Kidney and pelvic fat accounted for more of the variation in yield of wholesale cuts during stepwise regression to determine HP equations, but for predicting tray-ready yields, fat thickness taken with the HP accounted for the largest amount of variation. Equations developed to predict tray-ready retail cut yields using the HP or USDA grader-collected carcass measures were similar in the amount of variation explained. Kidney and pelvic fat percentage must be included in equations to maximize predictive accuracy when this depot site is left in carcasses.