欧美国家针叶树容器苗生产与启示

针叶树是芬兰、瑞典、挪威、美国、加拿大等欧美国家主要的商品林树种。容器苗是针叶树重要的育苗类型。与裸根苗比较，容器苗具有育苗周期更短、造林季节可延长、苗木适应性更广、苗木质量更一致的优点。因此，容器育苗成为精准林业发展的必然趋势。为了借鉴欧美容器育苗的技术方法，提高我国容器苗的质量，为我国针叶树容器苗发展提供参考，文中主要从4个方面综述了欧美国家检测与提高苗木质量的方法，即列举了针叶树常用的苗木质量检测指标，总结了育苗容器与育苗基质的改良进展，介绍了养分、水分、光照与温度等培养条件的优化手段，简要概述了容器苗病虫害防控的进展，提出了我国相关树种容器苗生产的启示与借鉴。     

云南不同气候带农业气候资源变化特征研究

为分析全省平均以及各气候带光能、热量、水分资源的时空变化特征,使用云南115站及6个气候带代表站1961—2018年的气候要素计算各地农业气候资源统计量。结果表明,光能资源变化以减少趋势为主,出现显著突变,各气候带太阳辐射变化可能会引起云南太阳辐射高低值中心发生变化,2009年以来辐射明显增加可能会导致太阳辐射出现新的变化趋势和突变点;热量资源一致显著增加,喜凉及喜温作物的活动积温、积温持续时间及无霜期长度均显著增加,并且呈现初日提前、终日推后的趋势,对作物生长有利;水分资源总体呈现减少趋势,尤其21世纪以来下降趋势明显,亚热带地区暖干化现象突出,干旱风险等级较高。     

Expression of Anti-Lipopolysaccharide Factor Isoform 3 in Chlamydomonas reinhardtii Showing High Antimicrobial Activity

Antimicrobial peptides are a class of proteins with antibacterial functions. In this study, the anti-lipopolysaccharide factor isoform 3 gene (ALFPm3), encoding an antimicrobial peptide from Penaeus monodon with a super activity was expressed in Chlamydomonas reinhardtii, which would develop a microalga strain that can be used for the antimicrobial peptide production. To construct the expression cluster, namely pH2A-Pm3, the codon optimized ALFPm3 gene was fused with the ble reporter by 2A peptide and inserted into pH124 vector. The glass-bead method was performed to transform pH2A-Pm3 into C. reinhardtii CC-849. In addition to 8 μg/mL zeocin resistance selection, the C. reinhardtii transformants were further confirmed by genomic PCR and RT-PCR. Western blot analysis showed that the C. reinhardtii-derived ALFPm3 (cALFPm3) was successfully expressed in C. reinhardtii transformants and accounted for 0.35% of the total soluble protein (TSP). Furthermore, the results of antibacterial assay revealed that the cALFPm3 could significantly inhibit the growth of a variety of bacteria, including both Gram-negative bacteria and Gram-positive bacteria at a concentration of 0.77 μM. Especially, the inhibition could last longer than 24 h, which performed better than ampicillin. Hence, this study successfully developed a transgenic C. reinhardtii strain, which can produce the active ALFPm3 driven from P. monodon, providing a potential strategy to use C. reinhardtii as the cell factory to produce antimicrobial peptides.     

基于应用型人才培养教学中思政教育的融入策略实施

思政教育是高职院校教学的重点内容,对学生的思想、行为会产生直接影响,同时与工匠精神存在紧密关系,需要对其予以融合。为了提升高职机械类专业教学的质量,引入思政教育极为重要,其在推动学生全面发展方面也发挥出了重要作用。基于此,主要以机械基础类专业教学为例,分析了高职机械类专业课程与思政教育的联系为切入点。同时,通过调整教学思路与路径,结合机械发展史展开思政教育,引入大国重器实际研发案例,落实全面评价这些思政教育的融入策略。     

Utilizing a DUALEM‐421 and inversion modelling to map baseline soil salinity along toposequences in the Hunter Valley Wine district

In the oldest commercial wine district of Australia, the Hunter Valley, there is the threat of soil salinization because marine sediments underlie the area. To understand the risk requires information about the spatial distribution of soil properties. Electromagnetic (EM) induction instruments have been used to identify and map the spatial variation of average soil salinity to a certain depth. However, soils vary with depth dependent on soil forming factors. We collected data from a single‐frequency and multiple‐coil DUALEM‐421 along a toposequence. We inverted this data using EM4Soil software and evaluated the resultant 2‐dimensional model of true electrical conductivity (σ – mS/m) with depth against electrical conductivity of saturated soil pastes (EC_p – dS/m). Using a fitted linear regression (LR) model calibration approach and by varying the forward model (cumulative function‐CF and full solution‐FS), inversion algorithm (S1 and S2), damping factor (λ) and number of arrays, we determined a suitable electromagnetic conductivity image (EMCI), which was optimal (R² = 0.82) when using the full solution, S2, λ = 3.6 and all six coil arrays. We conducted an uncertainty analysis of the LR model used to estimate the electrical conductivity of the saturated soil‐paste extract (EC_e – dS/m). Our interpretation based on estimates of EC_e suggests the approach can identify differences in salinity, how these vary with parent material and how topography influences salt distribution. The results provide information leading to insights into how soil forming factors and agricultural practices influence salinity down a toposequence and how this can guide soil management practices.     

西南地区油菜品种根肿病抗性及布局分析

为明确西南地区主栽油菜品种根肿病抗性,以期为合理品种布局提供依据,降低根肿病的危害和损失。结合病圃根肿病菌生理小种鉴定,在四川安县、大邑、广汉三地区,采用病圃自然发病法,对80个油菜品种进行根肿病抗性评价,并对22个品种连续3年进行抗性跟踪。结果表明：三地区病圃根肿菌为存在基因型分化的4号生理小种;供试油菜品种中无免疫根肿病品种,安县、大邑、广汉三地感病品种分别占比88.75%、83.75%、87.50%,其中55个品种在三地区均表现感病,即不适宜在根肿病菌为4号生理小种区域种植;抗性跟踪评价显示不同品种的抗性稳定性存在差异。‘浙油50’、‘油罐罐’适宜安县地区种植,‘黄金荚’、‘金油858’、‘油研9号’、‘种都油998’和‘渝黄4号’适宜大邑地区种植,‘志远油8号’适宜广汉地区种植。‘绵丰油5号’、‘德名油1号’表现抗性丧失趋势;‘丰油精’、‘高油48’抗性不稳定;‘矮架早’抗性完全丧失。     

株行距及穴苗数的配置对寒地水稻产量和品质的影响

为明确垦稻26和龙粳31高产优质栽培的株行距和穴苗数处理,采取裂区设计进行试验研究。结果表明,最优群体因品种而异,垦稻26在株距10cm、行距30cm、5苗/穴产量最佳,龙粳31则以株距13.3cm、行距27cm、9苗/穴产量最佳;垦稻26在5苗/穴、行株距30cm×10cm处理,有利于提高稻米的碾磨品质,不利于改善稻米的外观品质,营养品质较低,利于改善稻米的食味品质,且食味评分值高达86.5,显著高于最低处理;龙粳31在5苗/穴、行株距27cm×13.3cm处理,碾磨品质较高,不利于营养品质和外观品质的改善,食味品质得到明显改善,食味评分值高达86.0,与最低处理差异达显著水平。因此,高产优质栽培要因品种选择适宜的穴苗数和株行距,是实现水稻高产优质最为快捷、最为经济有效的措施。