Biochar Mitigates Salinity Stress in Potato

A pot experiment was conducted in a climate‐controlled greenhouse to investigate the growth, physiology and yield of potato in response to salinity stress under biochar amendment. It was hypothesized that addition of biochar may improve plant growth and yield by mitigating the negative effect of salinity through its high sorption ability. From tuber bulking to harvesting, the plants were exposed to three saline irrigations, that is 0, 25 and 50 mm NaCl solutions, respectively, and two levels of biochar (0 % and 5 % W/W) treatments. An adsorption study was also conducted to study the Na⁺ adsorption capability of biochar. Results indicated that biochar was capable to ameliorate salinity stress by adsorbing Na⁺. Increasing salinity level resulted in significant reductions of shoot biomass, root length and volume, tuber yield, photosynthetic rate (A_n), stomatal conductance (g_s), midday leaf water potential, but increased abscisic acid (ABA) concentration in both leaf and xylem sap. At each salinity level, incorporation of biochar increased shoot biomass, root length and volume, tuber yield, A_n, g_s, midday leaf water potential, and decreased ABA concentration in the leaf and xylem sap as compared with the respective non‐biochar control. Decreased Na⁺, Na⁺/K⁺ ratio and increased K⁺ content in xylem with biochar amendment also indicated its ameliorative effects on potato plants in response to salinity stress. The results suggested that incorporation of biochar might be a promising approach for enhancing crop productivity in salt‐affected soils.     

The importance of reduced light intensity on the growth and development of six weed species

Crops limit light for photosynthesis and growth of weeds. We studied the effect of reduced light on performance of six weed species [one invasive species (Amsinckia micrantha), three common species (Veronica persica, Capsella bursa‐pastoris, Viola arvensis) and two less common weeds (Anagallis arvensis and Scleranthus annuus)]. In two glasshouse experiments, six light levels were achieved aiming at 0%, 20%, 50%, 80%, 90% and 95% reduction of light and corresponding with daily light integrals (DLI) of 12.4, 9.63, 7.13, 2.74, 0.95 and 0.69 mol m^?2 day^?1 in experiment 1 and 21.2, 18.0, 10.7, 3.71, 1.64 and 1.20 mol m^?2 day^?1 in experiment 2. The number of leaves was strictly controlled by DLI. Chlorophyll content index, maximum photochemical efficiency of photosystem II (F_v/F_m), stomatal conductance, flowering and dry matter were strongly reduced when DLI was reduced to 0.69–3.71 mol m^?2 day^?1 for all species. Threshold DLI for flowering was ca. 3.71 mol m^?2 day^?1 for S. annuus, V. arvensis, A. arvensis and V. persica, while C. bursa‐pastoris deviated by flowering at DLI of 0.95 mol m^?2 day^?1. This may explain why C. bursa‐pastoris is common in the seedbank of Danish arable soils in spite of intensive farming with well‐fertilised and dense crops.     

Short‐term physiological role of thyroxine administration on plasma metabolites and growth performance of Sterlet sturgeon Acipenser ruthenus

Thyroid hormones (THs) play important roles in regulating growth, development and physiological functions in vertebrates. To study the role of short‐term effects of thyroxine (T4) on metabolism and growth in female Sterlet sturgeon, thirty fish with a weight of 707.97 ± 37.15 g were divided into six tanks. Fish were injected intraperitoneal with (a) coconut oil alone (control), (b) 1 mg T4 kg per BW in coconut oil (T₁) and (c) 10 mg T4 kg per BW in coconut oil (T₁₀). Blood samples were collected at 0, 4, 7, 14, 28 and 60 days for plasma biochemical analysis, and body length and mass were determined at day 60. Based on results, higher growth was indicated in T₁₀ group. The highest T4 levels were observed on day 4 in the T₁ and T₁₀ treatments and gradually declined during the trial. Plasma T3 levels were highest on days 4 and 7 in the T₁ and T₁₀ groups, respectively. Plasma triglyceride levels were significantly elevated on day 28 in the T₁ group and on day 60 in the T₁₀ group. Plasma glucose concentrations were significantly elevated on days 7 and 14 in T₁₀ group. Overall, the present results suggest that a single injection of T4 can improve growth via changes in the metabolic profile of Sterlet sturgeon.     

Assessing cetacean body condition: Is total lipid content in blubber biopsies a useful monitoring tool?

1. Measuring the energy stores, or body condition, of cetaceans is vital for monitoring population health. Cetaceans are exposed to a range of anthropogenic stressors, including, for example, noise, contaminants, habitat degradation, reduced prey availability, ship strike, and entanglement. Tools to assess body condition in these inaccessible and vulnerable animals are required to better understand the energetic consequences of anthropogenic stressors that can impact population health and, ultimately, conservation status.
2. Remotely obtained, dart biopsy samples are becoming an increasingly standard method of tissue collection from live, large cetaceans. Here, the potential applicability of using total lipid content in such biopsy samples to estimate overall body condition was assessed using full‐depth dorsal blubber samples from stranded ziphiids (n = 8) and balaenopterids (n = 9). First, variation in total lipid content through the blubber depth was investigated to assess the representativeness of shallow‐depth dart biopsies taken from live animals. Second, how lipid content varies by species, cause of death, sex, age class, and morphometric indices of body condition was assessed to evaluate what information about individual energy stores can be gained from such analyses.
3. Total lipid content in dorsal, shallow‐depth blubber biopsy samples from both cetacean families provides little information on overall body condition. Stratification of lipid content through the blubber layer in the balaenopterids means that superficial biopsy samples are not representative of the lipid stores available for mobilization through the rest of the tissue. A lack of variation in blubber lipid content, both within and between the ziphiid individuals, resulted in no ability to correlate these measures with morphometrics or other health, sex, or age class covariates.
4. Other potential markers in the blubber from remote biopsy sampling should be explored in order to further develop robust tools for estimating the body condition of free‐ranging cetaceans.

     

3个越橘品种叶片光合生理及果实品质的比较

以3个越橘品种‘奥尼尔’‘密斯梯’和‘北陆’为试验材料,比较光合生理特性和果实品质的差异。结果表明:越橘叶片为异面叶,角质层、上表皮和叶片厚度以‘密斯梯’最大,下表皮厚度以‘密斯梯’最小;‘密斯梯’光饱和点(LS,P)比‘奥尼尔’和‘北陆’高,补偿点(LC,P)比‘奥尼尔’和‘北陆’低,对光环境的适应性强;‘奥尼尔’和‘密斯梯’最大净光合速率(Pnmax)高于‘北陆’,光合潜力足;3个越橘品种单果质量由大到小依次为‘密斯梯’、‘奥尼尔’、‘北陆’;可溶性固形物和有机酸质量分数最高的是‘密斯梯’,维生素C质量分数最高的是‘奥尼尔’;单株产量由高到低依次为‘密斯梯’、‘奥尼尔’、‘北陆’。相关性分析表明:Pnmax与叶片厚度呈显著(P<0.05)正相关;LS,P与角质层厚度和上表皮厚度呈极显著(P<0.01)正相关;光合生理各项指标与果实品质存在一定的相关性。     

引入科研前沿对植物生理学教学方法的改进和效果分析

大学生普遍存在科研创新意识差、缺乏科研热情的现象.补充相关科研进展,将科研前沿引进课堂成为一种趋势,笔者对植物生理学光合作用这一章关于补充光合碳同化科研进展与否的教学实践结果进行对比分析,采用调查问卷的形式,围绕已讲授和未讲授光合碳同化适应性进化这一科研前沿进行调查,旨在实现学生对光合碳同化途径多元化发展进化的理解和深化,启发学生对固有知识的质疑和求解热情,达到提升科研兴趣和创新能力,实现精品课程培养满足国家和地方发展需要的高素质人才的目的.     

Phenotypic Changes in Grain Sorghum Over the Last Five Decades

Sorghum [Sorghum bicolor (L.) Moench] is a drought‐tolerant crop, and its productivity in rain fed environments has increased since the 1950s. This increase is due to changes in agronomic practices and hybrid improvement. The objective of this study was to determine what aspects of grain sorghum morphology, physiology and water use have changed with hybrid improvement and might have contributed to this yield increase. A 2‐year greenhouse experiment was conducted with one hybrid from each of the past five decades. The hybrids were studied in well‐watered and pre‐ and post‐flowering water deficit conditions. Total water use, transpiration, stomatal conductance and photosynthesis were measured during the growing period. Biomass and biomass components were measured at harvest. There was no consistent change in the leaf physiological parameters resulting from hybrid advancement. In contrast, total water use increased in rate of 8.5 cm³ kg soil^?1 year^?1 from old to new hybrids in the well‐watered treatments. Root biomass also increased in rate of 0.2 g plant^?1 year^?1. Leaf biomass and panicle length also was greater for the newest compared with the older hybrids. Hybrid advancement was related to increase in panicle length but decrease in peduncle length. Results indicated that hybrid development programmes created hybrids with improved drought avoidance, due to better root density of newly released hybrids, or hybrids with better resource use which ultimately increased yield under rain fed conditions.     

不同运输方式对生菜采后生理的影响

为研究运输方式对生菜采后生理及保鲜效果的影响,以‘橡生2号’生菜为研究对象,选择3种常见的运输方式:保温箱包装常温运输(A)、保温箱加制冷剂包装在常温下运输(B)、PE包装袋加纸箱包装在0℃下运输(C)进行试验。结果表明,采用C方式在0℃冷藏条件下运输的生菜,其失重率和呼吸强度均低于另外2组,VC含量和感官评价高于另外2组。因此在运输时间在12 h内可以采用A方式运输,在24 h内可以采用B方式运输,如超过24 h则最好使用C方式运输来保证生菜的货架期及品质。     

动物生理学实验教学单独设课之重要性

在高校的动物生理学教学中,实验教学是其中的一个重要组成部分。作为课堂教学的重要辅助和补充,动物生理实验教学效果对课堂教学具有极大的驱动作用。为突出动物生理实验教学的重要性,对动物生理学实验施行单独设课,这是考查理论教学效果、促进实验课教学质量的一种重要措施。     

草类植物抗病机制研究进展

草类植物病害是限制草牧业生产和发展的主要因素之一。目前抗病品种的开发利用是目前防治病害最经济有效的方法，植物抗病机制的研究对开发抗病品种和构建生态环境友好型病害防治至关重要。植物受病原菌侵染时形成多种复杂的防御机制，本研究主要从植物组织结构抗性、生理生化抗性、抗性基因和抗性数量性状位点（QTLs）定位等分子机制方面综述草类植物抗病机制研究进展，并提出我国草类植物抗病机制研究中面临的主要问题与解决办法，以期为草类植物抗病育种提供理论依据。