生活垃圾微生物强化堆肥对放线菌群落的影响

为了探讨微生物强化堆肥对生活垃圾好氧堆肥过程及堆肥过程中放线菌群落的影响,在堆肥过程中接种高效细菌复合菌剂和真菌复合菌剂,并以不接种的堆体为对照,对堆肥过程的温度变化和木质纤维素的降解效率进行了测定,并借助于PCR-DGGE方法对堆肥过程中放线菌群落的动态变化和种群多样性进行研究。结果表明：微生物强化堆肥能缩短堆体起爆时间,并能有效提高堆体降温期和二次发酵期的温度;和自然堆肥相比微生物强化堆肥使半纤维素、纤维素和木质素的降解率分别提高8.95%、12.72%和10.13%。DGGE图谱显示：2种堆肥方式的放线菌多样性指数表现出极显著差异,微生物强化堆肥能增加堆体中优势菌群的种类和数量,能有效提高腐熟期的放线菌群落多样性,有利于堆肥腐熟。优势条带测序结果表明：在接种堆肥过程中检测到了放线菌门的棒杆菌属、分支杆菌属、链霉菌属、热孢菌属、迪茨菌属、糖丝菌属和放线菌属。     

棉花叶螨的发生及其综合防治技术措施

该文阐述了棉叶螨形态、危害症状、发生规律、传播途径和因地制宜地采取农业、化学、生物等多种手段进行综合防治技术措施。     

Quantitative methods for estimating foliar uptake of zinc from suspension‐based Zn chemicals

The present study developed methods for quantifying foliar Zn uptake from suspension‐based Zn chemicals of low solubility, which were ZnO (particle size: 0.15^–1.34 μm) and a newly synthesized Zn hydroxide nitrate crystal (Zn‐HNC) (50^–100 nm thickness and 0.2^–1 μm lateral dimension). Recently matured leaves of citrus (Citrus aurantium L. cv. Valencia), capsicum (Capsicum annume L. cv. Giant Bell), and/or tomato (Solanum lycopersicum L. cv. Roma) were in vitro–treated with microdroplets (5 μL per droplet) of Zn‐HNC‐ and ZnO‐suspension solutions on the adaxial surface and incubated under controlled conditions for up to 72 h. Leaf‐washing protocols were compared, including: dilute ethanol (3%), dilute nitric acid (2%), and their combination. The methods for quantifying Zn uptake were: (1) whole‐leaf loading by which droplets of the Zn suspension solutions were loaded onto central regions of both left and right sides of leaf blades and (2) half‐leaf loading by which soluble‐Zn (ZnSO₄) droplets were loaded onto only one side of leaf blades while the other was used as the background Zn control. Foliar‐surface characteristics of the plant species affected the effectiveness of the washing methods. The dilute nitric acid (2%; ± 3% ethanol) was required to remove residue particles of the ZnO and Zn‐HNC suspensions from foliar surfaces of capsicum and tomato (highly trichomatic), but the residue Zn chemicals on citrus leaves (nontrichomatic and highly waxy) were similarly and effectively removed by the three washing methods. For quantifying Zn uptake by the leaves, the half‐leaf loading method showed its advantages over the whole‐leaf loading method, because it did not stringently require similar background Zn concentrations in the control and treated leaves at the start and had little risks of secondary absorption of soluble Zn in the washing solution.     

RNA干扰对烟草NtPPO8基因沉默的效应分析

多酚氧化酶（PPO）是发生酶促褐变的关键酶,PPO活性过高会使烟叶变褐。为明确烟草NtPPO8基因对PPO活性的影响,建立降低NtPPO8基因表达量的病毒诱导的基因沉默（virus induced gene silencing,VIGS）体系,探究使用RNA干扰技术对烟叶NtPPO8基因表达量及PPO活性的影响。以中烟100和K326为材料,分析在移栽后50d进行VIGS载体侵染的植株,并在侵染后10、20、30、40d分别测定NtPPO8基因表达量及PPO活性。结果表明,接种VIGS载体的转化植株,其中在侵染后20d时NtPPO8基因的沉默效率最高,为78.46%;随着侵染时间推移,NtPPO8基因的沉默效率逐渐降低,在接种后40d内有效表达;且转化植株中的病毒载体会随着植株的生长而向上传导,随着接种部位的上移,沉默效率逐渐降低。因此,研究建立VIGS体系能够有效沉默NtPPO8基因的表达,并且有效降低PPO活性,为提高烟叶耐烤性及降低烟叶褐变比例提供了新的思路和方法。     

采煤塌陷裂缝对降雨后坡面土壤水分的影响

为探究采煤塌陷裂缝对坡面储蓄降水的影响,本文对降雨后不同坡向上裂缝两侧的不同土层水分动态变化特征进行了研究。结果表明:降雨主要补充坡面地表0~20 cm土层土壤水分,且在雨后0~20 cm土层土壤水分散失也较为严重;雨后阴坡土壤含水率最高,0~10cm、10~20cm和20~40 cm土层土壤水分差异显著(p0.05)。降雨结束8 d后,裂缝附近的土壤水分变化幅度较大,尤以坡面裂缝上部边缘处最为明显,裂缝处与远离裂缝的土壤水分之间差异显著(p0.05);阳坡土壤水分损失最高,阳坡裂缝周边土壤水分平均损失量高达3.31%。可见,裂缝的出现会在一定程度上打破坡面储蓄降水的格局,加剧坡面局部土壤水分散失,这一点在植被恢复与建设过程中不容忽视。     

青海渔水河嗜盐耐盐放线菌的初步研究

对青海渔水河河水、底泥及河旁沙土进行盐分离子及pH值的测定,并通过不同培养基、盐种类和添加量的设计对渔水河中嗜盐耐盐放线菌资源进行了初步研究.结果表明:渔水河样品均偏碱性;河水的水溶性总盐及盐分离子含量均远远低于沙土,其中泥土的水溶性总盐含量最高,为158.67 g/kg;盐分阴离子中Cl-含量最高,阳离子中K+和Na+含量最高,所以推断样品盐分离子主要以NaCl和KCl的形式存在;分离共获得89株放线菌,其中底泥中分离到的放线菌最多,且改良淀粉酪素培养基的分离效果最好;通过嗜盐耐盐放线菌的筛选,得到8株嗜盐放线菌,其中极端嗜NaCl菌3株,极端嗜KCl菌7株,还有1株嗜K型放线菌.     

Relationship between photosynthesis and leaf nitrogen concentration in ambient and elevated [CO2] in white birch seedlings

To study the effects of elevated CO2 concentration ([CO2]) on relationships between nitrogen (N) nutrition and foliar gas exchange parameters, white birch (Betula papyrifera Marsh.) seedlings were exposed to one of five N-supply regimes (10, 80, 150, 220, 290 mg N l(-1)) in either ambient [CO2] (360 micromol mol(-1)) or elevated [CO2] (720 micromol mol(-1)) in environment-controlled greenhouses. Foliar gas exchange and chlorophyll fluorescence were measured after 60 and 80 days of treatment. Photosynthesis showed a substantial down-regulation (up to 57%) in response to elevated [CO2] and the magnitude of the down-regulation generally decreased exponentially with increasing leaf N concentration. When measured at the growth [CO2], elevated [CO2] increased the overall rate of photosynthesis (P(n)) and instantaneous water-use efficiency (IWUE) by up to 69 and 236%, respectively, but decreased transpiration (E) and stomatal conductance (g(s)) in all N treatments. However, the degree of stimulation of photosynthesis by elevated [CO2] decreased as photosynthetic down-regulation increased from 60 days to 80 days of treatment. Elevated [CO2] significantly increased total photosynthetic electron transport in all N treatments at 60 days of treatment, but the effect was insignificant after 80 days of treatment. Both P(n) and IWUE generally increased with increasing leaf N concentration except at very high leaf N concentrations, where both P(n) and IWUE declined. The relationships of P(n) and IWUE with leaf N concentration were modeled with both a linear regression and a second-order polynomial function. Elevated [CO2] significantly and substantially increased the slope of the linear regression for IWUE, but had no significant effect on the slope for P(n). The optimal leaf N concentration for P(n) and IWUE derived from the polynomial function did not differ between the CO2 treatments when leaf N was expressed on a leaf area basis. However, the mass-based optimal leaf N concentration for P(n) was much lower in seedlings in elevated [CO2] than in ambient [CO2] (31.88 versus 37.00 mg g(-1)). Elevated [CO2] generally decreased mass-based leaf N concentration but had no significant effect on area-based leaf N concentration; however, maximum N concentration per unit leaf area was greater in elevated [CO2] than in ambient [CO2] (1.913 versus 1.547 g N m(-2)).     

苹果与八棱海棠的试管苗外植体植株再生

苹果品种（新乔纳金、嘎拉）及八棱海堂的试管苗外植体（叶片、叶柄、节间茎段）,在附加ＢＡ与ＮＡＡ的ＭＳ培养基上,均能分化不定芽。基中在ＢＡ４ｍｇ／Ｌ＋ＮＡＡ０．２ｍｇ／Ｌ浓度组合的ＭＳ培养基上,嘎拉与枚棱海棠叶片的再生频率达到１００％。八棱海棠叶片再生苗在附加ＩＢＡ０．５ｍｇ／Ｌ的１／２ＭＳ培养基上生根效果最好。     

A soil temperature control system for ecological research in greenhouses

We designed and tested a soil temperature control system for plant ecophysiological experiments in greenhouses and growth chambers. The system consists of a plywood box, polyethylene liner, insulation, seedling containers, a water pump, and a flow-through heater or chiller. One hundred and twelve seedling containers (11cm diameter, 13.5 cm high) are mounted in the plywood box. There is a hole at the bottom center of each container to allow the free drainage of irrigation water and fertilizer solution. The space between containers is filled with water that is circulated through the chiller/heater. The water is also circulated within the plywood box by a water pump to increase the uniformity of temperature. The system was tested for three soil temperatures (5, 20, and 30°C) over a period of four months. The containers were filled with a peat-moss vermiculite mixture and planted with tree seedlings. The test showed that the soil temperature was almost equal to the water temperature for all three soil temperatures (regression slop = 0.99, intercept = 0.12,r ² = 1.00). The average soil temperatures were within (0.41°C of the set values. The soil temperature of the 112 containers within the same box followed a normal distribution with a small standard deviation (0.34°C for the 30°C treatment). There was a temperature gradient from the top to the bottom of the container (< 1°C). The direction of the temperature gradient was determined by the direction of temperature difference between the soil and the ambient air. When the soil temperature was lower than air temperature, the soil temperature decreased from the top to the bottom of the container, and vise versa. The soil temperature was higher during the day than at night (difference < 1.5°C). Funding for this research was provided by Lakehead University, CFI, ORDCF, and NSERC research grants to Dang, and an NSERC PGS A to Cheng.     

2020年山东省牛羊疫病报告及监测数据分析

为了解山东省牛羊疫病的流行及免疫现状,汇总2020年山东省牛羊疫病报告数据以及监测数据等信息,分析牛羊疫病的时间分布、空间分布及病种分布;结合监测情况,分析牛羊疫病的免疫状况和暴发风险.2020年山东省牛病以新生犊牛腹泻、牛病毒性腹泻和牛传染性鼻气管炎为主,突发输入性牛结节性皮肤病,羊病以沙门氏菌病、绵羊疥癣和布鲁氏菌...