硅钨酸负载介孔分子筛SBA-15的制备及催化性能研究

[目的]探讨负载型介孔分子筛SiW12/SBA-15的制备及催化性能。[方法]采用水热合成法,以P123为模板剂制备介孔材料SBA-15,由硅钨酸浸渍进一步合成介孔催化剂SiW12/SBA-15。通过IR、TG、SEM和TEM进行表征,并且将负载型介孔分子筛SiW12/SBA-15用于催化α-蒎烯的环氧化反应。研究硅钨酸负载量、催化剂加入量、过氧乙酸与原料摩尔比及SBA-15的焙烧温度对环氧化产物得率的影响。[结果]将硅钨酸负载到SBA-15上并未破坏介孔分子筛的结构,硅钨酸仍保持着Keggin的基本结构。在550℃下焙烧SBA-15,负载量为30%,催化剂用量为2%,CH3COOOH与α-蒎烯的摩尔比为1.2∶1时,α-蒎烯的转化率为99.4%,产物2,3-环氧蒎烷的得率为90.45%。[结论]通过负载法能够制备负载型介孔分子筛SiW12/SBA-15。该催化剂对α-蒎烯的环氧化反应有良好的催化效果。     

谷子新品种陇谷12号选育报告

谷子新品种陇谷12号为甘肃省农业科学院作物研究所以抗病种质B476作母本,以会宁等身齐作父本杂交选育而成,2014年通过甘肃省农作物品种审定委员会认定(认定编号:甘认谷2014001)。在2011—2012年甘肃省谷子品种多点试验中,2 a平均产量4 735.5 kg/hm2,较对照增产13.9%。籽粒含粗蛋白105.2 g/kg、粗脂肪45.7 g/kg、粗淀粉763.6 g/kg、赖氨酸2.81 g/kg,人工接种黑穗病发病株率3.7%,高抗谷子黑穗病。适宜在甘肃省海拔1 900 m以下谷子产区种植。     

春小麦新品种酒春12号选育报告

为提高小麦产量和品质,保障地区粮食安全和粮食产业持续发展,酒泉市农业科学研究院以自育新品系酒9194为母本,引进(甘肃省农业科学院选育)9913-17为父本配制杂交组合,经过5 a连续单株选择,2015年稳定出圃。2018 — 2019年参加甘肃省(西片)水地组区域试验,2 a 12点(次)平均折合产量7 870.5 kg/hm2,较对照品种宁春4号增产4.24％。2020年参加甘肃省西片水地组生产试验,6试点平均折合产量8 339.3 kg/hm2,较对照品种宁春4号增产8.03%。生育期103 d,株高90.0 cm。株型紧凑,穗层整齐,穗数649.2万穗/hm2,穗粒数41.06粒,千粒重46.3 g,容重787.4 g/L。该品种品质优良,中抗白粉病,中感条锈病。适宜在甘肃省河西地区水地品种类型区种植。     

超级稻甬优12单产13.5t/hm~2以上超高产栽培技术

甬优12具有全生育期长,个体茎秆粗壮,群体苗穗较少,穗大粒多等特点,生产应用表现高产水平和超高产潜力。随着对其品种特征特性的了解,单产超13.5 t/hm2的高产攻关田和示范方逐年增多。根据各地高产攻关经验,总结形成了"一早二减三增四防"的甬优12单产13.5 t/hm2以上超高产栽培技术,即适期早播,减少播种量,减少种植丛数,增施有机肥,增开丰产沟,增施穗肥,防稻曲病,防止早衰,防断水过早,防割青。     

How relevant is recalcitrance for the stabilization of organic matter in soils?

Traditionally, the selective preservation of certain recalcitrant organic compounds and the formation of recalcitrant humic substances have been regarded as an important mechanism for soil organic matter (SOM) stabilization. Based on a critical overview of available methods and on results from a cooperative research program, this paper evaluates how relevant recalcitrance is for the long‐term stabilization of SOM or its fractions. Methodologically, recalcitrance is difficult to assess, since the persistence of certain SOM fractions or specific compounds may also be caused by other stabilization mechanisms, such as physical protection or chemical interactions with mineral surfaces. If only free particulate SOM obtained from density fractionation is considered, it rarely reaches ages exceeding 50 y. Older light particles have often been identified as charred plant residues or as fossil C. The degradability of the readily bioavailable dissolved or water‐extractable OM fraction is often negatively correlated with its content in aromatic compounds, which therefore has been associated with recalcitrance. But in subsoils, dissolved organic matter aromaticity and biodegradability both are very low, indicating that other factors or compounds limit its degradation. Among the investigated specific compounds, lignin, lipids, and their derivatives have mean turnover times faster or similar as that of bulk SOM. Only a small fraction of the lignin inputs seems to persist in soils and is mainly found in the fine textural size fraction (<20 µm), indicating physico‐chemical stabilization. Compound‐specific analysis of ¹³C : ¹²C ratios of SOM pyrolysis products in soils with C3‐C4 crop changes revealed no compounds with mean residence times of > 40–50 y, unless fossil C was present in substantial amounts, as at a site exposed to lignite inputs in the past. Here, turnover of pyrolysis products seemed to be much longer, even for those attributed to carbohydrates or proteins. Apparently, fossil C from lignite coal is also utilized by soil organisms, which is further evidenced by low ¹⁴C concentrations in microbial phospholipid fatty acids from this site. Also, black C from charred plant materials was susceptible to microbial degradation in a short‐term (60 d) and a long‐term (2 y) incubation experiment. This degradation was enhanced, when glucose was supplied as an easily available microbial substrate. Similarly, SOM mineralization in many soils generally increased after addition of carbohydrates, amino acids, or simple organic acids, thus indicating that stability may also be caused by substrate limitations. It is concluded that the presented results do not provide much evidence that the selective preservation of recalcitrant primary biogenic compounds is a major SOM‐stabilization mechanism. Old SOM fractions with slow turnover rates were generally only found in association with soil minerals. The only not mineral‐associated SOM components that may be persistent in soils appear to be black and fossil C.     

番茄生长素响应因子基因SlARF12在果实发育过程中的功能分析

以番茄‘Micro-Tom’为材料,研究了生长素响应因子基因SlARF12 （序列号：HM565127.1）在果实发育过程的生物学功能。实时定量PCR 检测表明,SlARF12在花蕾中表达量逐渐降低,而在授粉后的子房中显著高于去雄后未授粉的子房。利用RNA干扰（RNAi）技术抑制SlARF12表达,对番茄植株营养生长与花的发育没有显著影响,但SlARF12 RNAi果实显著大于野生型与空载转化植株的果实,且开花前去雄未授粉不能形成单性结实的果实。利用半薄切片观察转基因番茄果实早期发育细胞学特性发现,转化植株的果实果皮细胞显著大于对照果实细胞,但是两者果皮细胞层数没有显著差异。基因表达分析发现在SlARF12 RNAi的子房与幼果中细胞分化相关基因CycB1.1和CDKB2.1等的表达水平同对照相比下降,而SlPEC等细胞膨大基因表达量显著高于对照。所以抑制SlARF12可增强果实中细胞膨大相关基因的表达,从而促进果实膨大。以上结果表明,SlARF12可负调控番茄果实膨大但不参与坐果启动调控过程,显示了生长素通过ARF信号精细调控果实发育的各个阶段。     

“十二五”时期我国现代农业技术研究进展

"十二五"时期是我国战略发展的关键时期,863计划现代农业技术领域设立了植物分子设计与品种创制技术、动物分子与细胞工程育种技术、农业生物制剂创制技术、农业生物环境控制与修复技术、农林生物质高效转化技术、数字农业技术与装备、食品制造与安全技术7个主题,围绕这些主题对"十二五"以来国家863计划现代农业技术领域的发展进行了阐述,并着重强调了各个领域取得的重要性成果,总结"十二五"期间的经验,并为今后工作的开展提出了相应的建议,为"十三五"重点研发计划的顺利实施打下良好的基础。     

土壤接种棘孢木霉菌降低小油菜砷胁迫及其可能机理

农田土壤中砷的过量累积会影响作物生长,砷可通过食物链影响人体健康。缓解土壤砷对作物生长的胁迫和累积是亟待解决的科学问题之一。本文以具有高耐砷和砷形态转化能力的棘孢木霉菌为研究材料,通过盆栽试验研究了棘孢木霉菌对外源砷胁迫下小油菜生长的影响及其可能机理。结果表明： 120 mg· kg^-1外源砷污染土壤上小油菜生长受到显著抑制,接种棘孢木霉菌可显著促进小油菜生长;接种棘孢木霉菌降低了小油菜对砷的吸收及富集系数,与未接菌污染土相比,小油菜地上部和地下部砷含量分别降低了12.4%和20.2%,砷富集系数降低了7.8%。接种棘孢木霉菌使土壤有效态砷含量降低了15.7%,土壤和小油菜地上部均检测到一甲基砷和二甲基砷,表明接种棘孢木霉菌促进了土壤中砷的甲基化,降低了土壤中砷有效性和小油菜体内砷的毒性。此外,外源砷胁迫下小油菜超氧化物歧化酶和过氧化氢酶活性,以及谷胱甘肽、抗坏血酸及丙二醛含量显著升高,而接种棘孢木霉菌可降低小油菜部分抗氧化胁迫相关酶活性,表明接种棘孢木霉菌有效缓解了砷对小油菜生长的胁迫。研究结果可为今后砷高风险农田的安全利用与风险调控提供材料与技术参考。     

“十二五”木本粮油树种研究领域科技成果推广示范的立项分析

为给木本粮油树种研究领域科技成果推广示范提供参考依据,依托中央财政林业科技推广示范项目数据库,分析了"十二五"期间核桃、油茶、枣、栗、香榧、榛子、油橄榄、柿等木本粮油树种研究领域的科技成果在不同省(区、市)推广的主要技术和内容。结果表明:核桃领域的研究成果在全国20个省(区、市)进行了推广示范,推广区域较广,但成果的技术推广能力仍处于较低水平;油茶研究领域的先进科技成果在全国15个省(区、市)进行了应用,推广内容全面,成果水平较高;枣、栗、香榧、榛子、油橄榄、柿等树种的研究成果只在特定区域进行了推广示范,成果水平和推广能力尚需进一步提高。文中指出,不同木本粮油树种研究领域科技成果具有区域推广特征,今后应加大和拓宽不同木本粮油树种、同一树种不同技术在全国推广示范的力度和范围。