氮磷钾用量对小麦冠层不同层次光截获和干物质分配的影响

为明确不同氮、磷、钾用量对小麦冠层不同层次光截获和干物质分配的影响，以济麦22为供试材料，设置F0（不施肥）、F1（N 180 kg·hm^-2，P₂O₅ 75 kg·hm^-2，K₂O 60 kg·hm^-2）、F2（N 225 kg·hm^-2，P₂O₅ 120 kg·hm^-2，K₂O 105 kg·hm^-2）和F3（N 270 kg·hm^-2，P₂O₅ 165 kg·hm^-2，K₂O 105 kg·hm^-2）4个施肥量处理，比较分析开花后不同氮、磷、钾用量对小麦叶面积指数、冠层不同层次光截获特性和成熟期干物质分配的影响。结果表明，F1处理下叶面积指数显著高于F0处理，而与F2和F3处理间无显著差异；开花后15 d，F1处理下小麦冠层不同层次及总PAR截获率和截获量均显著高于F0处理，而与F2和F3处理间无显著差异。F1处理下成熟期干物质在小麦冠层不同层次营养器官中的分配量、籽粒中的分配量及总干物质积累量显著高于F0处理，而与F2和F3处理间无显著差异。成熟期干物质在小麦冠层不同层次营养器官和籽粒中的分配量以及总干物质积累量与冠层上层（顶部至株高2/3）、中层（株高2/3至株高1/3）和总PAR截获率均呈显著正相关。F1处理（N 180 kg·hm^-2，P₂O₅ 75 kg·hm^-2，K₂O 60 kg·hm^-2）为本试验条件下的最优处理。     

Comparing the behavioural thermoregulation response to heat stress by Atlantic salmon parr (Salmo salar) in two rivers

Climate change is expected to increase the frequency and magnitude of extreme thermal events in rivers. The Little Southwest Miramichi River (LSWM) and the Ouelle River (OR) are two Atlantic salmon (Salmo salar) rivers located in eastern Canada, where in recent years, water temperatures have exceeded known thermal limits (~23°C). Once temperature surpasses this threshold, juvenile salmon exploit thermal heterogeneity to behaviourally thermoregulate, forming aggregations in coolwater refuges. This study aimed to determine whether the behavioural thermoregulation response is universal across rivers, arising from common thermal cues. We detailed the temperature and discharge patterns of two geographically distinct rivers from 2010 to 2012 and compared these with aggregation onset temperature. PIT telemetry and snorkelling were used to confirm the presence of aggregations. Mean daily maximum temperature in 2010 was significantly greater in the OR versus the LSWM (p = 0.005), but not in other years (p = 0.090–0.353). Aggregations occurred on 14 and 9 occasions in the OR and LSWM respectively. Temperature at onset of aggregation was significantly greater in the OR (T_onset = 28.3°C) than in the LSWM (T_onset = 27.3°C; p = 0.049). Logistic regression models varied by river and were able to predict the probability of aggregation based on the preceding number of hours >23°C (R² = 0.61 & 0.65; P₅₀ = 27.4°C & 28.9°C; in the OR and LSWM respectively). These results imply the preceding local thermal regime may influence behaviour and indicate a degree of phenotypic plasticity, illustrating a need for localised management strategies.     

花期低温对水稻叶鞘生理及结实率的影响

盆栽条件下，以耐冷性不同的2个水稻（Oryza sativa L.）品种龙稻5（耐冷型）和龙粳11（冷敏型）为材料，于开花期在人工气候室进行低温（15℃，分别持续1，2，3，4，5 d）处理，研究开花期低温对不同耐冷性水稻结实率及叶鞘膜透性、抗氧化酶等生理指标的影响。结果表明：低温处理2 d时，龙稻5和龙粳11的花粉活力分别下降了8.21%和16.10%，差异达极显著水平；低温处理3 d后，龙稻5的结实率下降到99.90%，与CK相比差异达到显著水平；低温处理1 d后，龙粳11的结实率下降到60.04%，与对照相比差异达到极显著水平。低温处理提高了水稻叶鞘相对电导率和脯氨酸、可溶性蛋白含量，处理5 d时各指标达最大值，与CK相比，龙稻15和龙粳11分别提高了38.01%和20.77%、25.06%和84.85%、25.82%和23.63%。同时低温处理也提高了叶鞘超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性，处理3 d时酶活性达最大值，龙稻15和龙粳11分别较CK提高了10.57%和14.90%、86.26%和68.71%、17.73%和28.25%。综上所述，开花期低温引起水稻叶鞘膜脂过氧化程度升高，但也诱导水稻叶鞘抗氧化系统开启、保护酶活性上升以抵御低温伤害；开花期低温导致水稻花粉活力降低并引起结实率降低，耐冷品种较冷敏品种抵御能力强。     

氯虫苯甲酰胺拌种对稻纵卷叶螟的防治效果及安全性评价

为减少水稻抽穗前田间稻纵卷叶螟的化学防治次数及用药量，降低对天敌的伤害及农药残留，最终实现稻纵卷叶螟的简约化防控，采用氯虫苯甲酰胺对水稻种子进行拌种处理，室内测定了药剂拌种对种子发芽的安全性，并结合不同栽培模式下的田间试验，评价了不同用量下氯虫苯甲酰胺拌种对稻纵卷叶螟的控制时长及保叶效果，明确了药剂拌种对天敌蜘蛛的影响及最终残留情况。结果表明:当氯虫苯甲酰胺按有效成分用量30~120 g/hm2拌种时，对种子的发芽率及出苗均无影响。直播稻模式下，氯虫苯甲酰胺按有效成分60 g/hm2拌种，播种后110 d，其保叶效果仍高达97.13%；旱育手栽秧模式下，氯虫苯甲酰胺按有效成分90 g/hm2拌种，播种后108 d保叶效果为82%以上，旱育机插秧模式下按有效成分90~120 g/hm2拌种，播种后90 d保叶效果仍在95%以上；3种模式下拌种处理的保叶效果及持效期均远优于常规喷雾防治。研究表明，利用氯虫苯甲酰胺对水稻种子进行拌种处理，可有效控制水稻前期及中期稻纵卷叶螟的为害，降低后期田间虫口基数，并且对田间天敌蜘蛛安全性高，同时在收获的稻谷中未检出氯虫苯甲酰胺残留(残留量低于定量限0.000 8 mg/kg)。在江苏省丘陵地区粳稻区应用氯虫苯甲酰胺拌种处理，可确保水稻直至抽穗初期无需再进行稻纵卷叶螟的防治，并可显著减少后期稻纵卷叶螟虫源基数，实现稻纵卷叶螟的简约化防治。     

Looking back on development and disaster‐related displacement and resettlement,anticipating climate‐related displacement in the Asia Pacific region

The realisation that climate change might necessitate resettlement of people displaced initially raised interest in the experience of development‐forced displacement and resettlement (DFDR). Looking back, in 1980 the first international policy on involuntary resettlement was approved to address perceived weaknesses in state property and expropriation law to safeguard people in the way of development projects. Since then international policy and praxis have brought global attention to developmentally displaced people but have not guaranteed them an effective safeguard. Recently, renewed attention has focussed on state legal and governance frameworks substantively and procedurally. Identifying four key policy objectives that resonate with climate change displacement I analyse their treatment in a data base of DFDR laws and regulations from 40 Asia Pacific states. This analysis finds overall little legal congruence. Innovative new formulations in some Asian state laws address recent public criticisms and research findings, but mostly are yet to demonstrate positive outcomes for displaced people. Pacific states increasingly abandon expropriation law to negotiate lease terms for public infrastructure projects with customary landowners that do not extinguish customary title. Any laws governing climate change relocations must protect rights, livelihoods, well‐being, inclusive decision‐making and community initiatives with procedures whilst not relinquishing climate‐change‐reducing action.     

Knockdown of HMGA2 gene inhibits TGF-β1-induced human embryonic lung fibroblast growth and collagen synthesis

AIM: To investigate the effects of high mobility group A2(HMGA2) gene knockdown on the cell viability, apoptosis, collagen synthesis and oxidative stress of human embryonic lung fibroblast (HELF) induced by transforming growth factor-β1 (TGF-β1). METHODS: The HELF were divided into blank group, TGF-β1 group,negative control (NC) group and HMGA2 siRNA(si-HMGA2) group. The protein levels of HMGA2, AKT and p-AKT were determined by Western blot. The cell viability and apoptotic rate was analyzed by MTT assay and flow cytometry,respectively. The mRNA expression of collagen I (COL-Ⅰ) and COL-Ⅲ was detected by RT-qPCR. DCFH-DA was used to detect the content of reactive oxygen species (ROS). RESULTS: Compared with blank group, the protein levels of HMGA2 and p-AKT, the cell viability, the mRNA expression of COL-Ⅰ and COL-Ⅲ in TGF-β1 group were significantly increased, but the apoptotic rate and ROS level were significantly decreased (P<0.05). Compared with TGF-β1 group, the protein levels of HMGA2 and p-AKT, the cell viability, the mRNA expression of COL-Ⅰ and COL-Ⅲ in si-HMGA2 group were significantly decreased, but the apoptotic rate and ROS level were significantly increased (P<0.05). CONCLUSION: Knockdown of HMGA2 gene expression decreases the viability and collagen synthesis, and promotes apoptosis and ROS production of human embryonic lung fibroblasts induced by TGF-β1. The mechanism may be related to down-regulation of PI3K/AKT signaling pathway.     

我国蔬菜作物耐低温性研究进展

低温胁迫是蔬菜生产过程中的主要逆境因子，对蔬菜作物的生长发育、商品产量形成影响极大。本文综述了蔬菜作物耐低温性的遗传模型、生理调节和分子机制，展望了蔬菜作物耐低温性的研究前景。     

不同油葵种植方式对银北灌区盐碱地土壤温度、含水率和电导率的影响

为了探究油葵不同种植方式对盐碱地土壤水、热、盐分布状况的影响,以平播（T1）为对照,开展了半膜平播（T2）、半膜平播+膜间覆秸秆（T3）、起垄沟播（T4）、起垄沟播+沟覆秸秆（T5）、垄膜沟播（T6）、垄膜沟播+沟覆秸秆（T7）等6种种植方式对油葵田土壤温度、水分和电导率的影响研究。结果表明：与对照相比,不同种植方式均提高了早上7:00时5cm深度的土温,但油葵花期土壤增温效果明显弱于苗期,垄膜沟播种植方式更有利于减缓地 表5cm深度土温的剧烈变化。与对照相比,在油葵苗期,T7和T6的0~20cm土层土壤含水率分别提高了6.30%和5.01%,20~40cm土层分别提高了6.00%和3.38%,在油葵开花期,土壤含水率较对照提高幅度有所降低。与播种前0~20cm土层土壤电导率相比,T6在苗期和开花期均有所下降,其中开花期下降了33.81%,T7在苗期略有增加,在开花期则略有下降,其他处理在苗期增加幅度较大。因此,在银北灌区油葵生产中,垄膜沟播是一种适宜的油葵种植方式。     

微波处理条件对蛋清结构和IgG结合能力的影响

为探究降低蛋清致敏性的新方法,在不同的微波条件下处理蛋清蛋白,通过SDS-PAGE(十二烷基磺酸钠-聚丙烯酰氨凝胶电泳)分析分子量变化、圆二色光谱分析二级结构变化、紫外光谱分析三级结构变化、外源性荧光光谱分析疏水性变化、间接ELISA(酶联免疫吸附试验)分析IgG(免疫球蛋白G)结合能力的变化,研究微波对蛋清的影响。研究证实,微波处理降低蛋清蛋白的潜在致敏性,其中400 W/30 s处理后的蛋白显示出最低的IgG结合能力,所有条件下处理后的蛋清蛋白的二、三级结构均发生显著改变。80 W的微波功率下,蛋白质的结构先折叠,该条件下处理30 s后,蛋白结构又展开;当微波功率达到640 W时,处理时间较长的蛋白分子产生堆叠。蛋白质分子的结构变化导致了其抗原性的变化。     

鄂托克前旗近50年降水变化特征分析

本文利用鄂托克前旗1967-2018年气象观测站近50年的气象资料,对鄂托克前旗降水特征进行分析。结果表明：整体来说，鄂托克前旗的年降水量变化呈现微弱降低趋势，每10a大约减少1.2mm；28a时间尺度决定的主周期控制着该地区的年降水变化特征，通过周期和突变分析，预计未来三年左右降水高于多年平均值，随后的14年左右时间内降水量呈现减少趋势，逐渐低于多年平均降水量。