4种微生物菌剂对辣椒主要病害的生物防治作用

本文选择4种不同微生物活性成分的生防菌剂，采用盆栽生物量测定、温室和田间小区试验对辣椒主要病害进行抗病效果及促生增产作用评价。结果表明，木霉-芽胞杆菌复合菌剂对辣椒的枯萎病、疫病、炭疽病和灰霉病防效分别达到72.2%、78.3%、71.9%和59.7%，枯草芽胞杆菌-粉红粘帚霉复合菌剂对辣椒4种病害的防效分别达到60.5%、62.1%、60.5%和50.9%；而淡紫紫孢菌菌剂只对辣椒炭疽病具有很好防效（77.5%）。同时，4种微生物菌剂对辣椒植株生物量均有显著促生作用，其中木霉-芽胞杆菌复合菌剂及枯草芽胞杆菌-粉红粘帚霉复合菌剂在盆栽试验中鲜重和干重增幅分别为132.79%、190.35%和211.80%、293.84%；两者在温室及田间小区试验中比对照增产182.3%、152.7%和65.0%、23.9%。本研究表明，生防菌剂可以替代化学药剂用于植物病害的防治，同时还能够促进作物植株生长，有增产作用。     

Long-term fertilization leads to specific PLFA finger-prints in Chinese Hapludults soil

Soil microbes play essential roles in the biogeochemical processes of organic carbon and nutrient cycling. Many studies have reported various short-term effects of fertilization on soil microbes. However, less is known about the effects of longterm fertilization regimes on the rhizosphere. Therefore, the objective of this study was to explore how the soil microbial communities in the rhizosphere respond to different long-term fertilization strategies. Based on a 21-year field treatment experiment in Guizhou, China, we extracted phospholipid fatty acids(PLFAs) to determine the microbial community structure in both the non-rhizosphere(NR) and rhizosphere(R). Six treatments were included: no fertilizer(CK), mineral nitrogen fertilizer(N), N with potassium(NK), phosphorus with K(PK), NPK, and NPK combined with manure(MNPK). The results showed that total PLFAs under unbalanced mineral fertilization(N, NK and PK) were decreased by 45% on average in the NR compared with CK, whereas MNPK increased fungi and G~– bacteria abundance significantly in both the NR(by 33 and 23%) and R(by 15 and 20%), respectively. In addition, all microbial groups in the R under these treatments(N, NK and PK) were significantly increased relative to those in the NR, except for the ratio of F/B and G~+/G~–, which might be due to the high nutrient availability in the R. Soil pH and SOC significantly regulated the soil microbial community and structure, explaining 51 and 20% of the variation in the NR, respectively. However, the rhizosphere microbial community structure was only significantly affected by soil pH(31%). We concluded that the soil microbial community in the NR was more strongly affected by long-term fertilization than that in the R due to the rhizosphere effect in the agricultural ecosystem. Rhizosphere nutrient conditions and buffering capacity could help microbial communities resist the change from the long-term fertilization.     

硅钙钾镁肥配施黄腐酸钾对土壤酶活性及桃幼树生长的影响

为探究硅钙钾镁肥配施黄腐酸钾对桃树生长的效应,以盆栽一年生瑞蟠21号毛桃(Amygdalus persica Linn.)为试验材料,设置3种不同施肥方式(T1:硅钙钾镁;T2:硅钙钾镁+黄腐酸钾;CK:空白对照),在桃幼树生长季进行追肥处理,研究硅钙钾镁肥及硅钙钾镁肥配施黄腐酸钾对土壤酶活性、土壤养分状况及桃幼树根系构型和植株生长的影响。结果表明,与CK相比,T1、T2均显著提高了桃幼树生长季各时期土壤酸性磷酸酶、脲酶和过氧化氢酶活性,以及土壤中碱解氮、有效磷、速效钾和有效硅等含量,且配施黄腐酸钾后作用更明显。与CK相比,T1、T2细根比重分别提高了11.2%和26.2%,根系活力分别提高了12.2%和18.1%,根系总长度分别增加了28.1%和61.9%,且有效延缓了根系衰老;T1、T2植株总干重分别提高了1.2倍和2.0倍,根冠比分别提高了9.4%和17.0%,且差异显著。与CK相比,T1、T2各器官中全氮、全磷、全钾含量均显著增加,地上部硅含量分别提高了61.3%和91.9%,地下部硅含量分别提高了62.3%和102.5%,且差异显著。同时,T1、T2桃幼树叶片叶绿素含量和净光合速率均显著提高。综上所述,硅钙钾镁肥可有效提高土壤酶活,促进桃幼树细根的生长,延缓根系衰老进程,增加氮、磷、钾、硅等营养元素积累量,提高叶片光合速率,促进植株生长;硅钙钾镁肥配施黄腐酸钾后,提高了土壤有效硅及植株硅含量,比单施硅钙钾镁肥效果更加显著。本研究结果为桃树合理施用硅钙钾镁肥提供了理论依据。     

不同生育时期低温胁迫对水稻保护酶的影响

通过吉林省内外优质水稻品种为材料，分别在苗期、分蘖期、减数分裂期、灌浆成熟期进行低 温胁迫处理，并进行其生理特性研究。结果表明，低温胁迫下水稻的CAT、POD、SOD 酶活性均有所 增高，其中部分品种的SOD 酶活性整体较强，在各个时期均有所增幅，而CAT 和POD 酶活性在不同 时期存在品种差异，且分蘖期大部分品种的三种保护酶均有明显提升。本试验材料中，不同时期低温 胁迫下，通系935、龙稻18、吉粳816、绥粳14、延粳22、通35 的整体酶活性在各个时期表现优异，优于 其余品种。     

Comparative study on the effects of buckwheat by roasting: Antioxidant properties,nutrients, pasting,and thermal properties

The increasing need to prolong the shelf life of buckwheat has prompted the use of roasting techniques in buckwheat processing. For effective roasting, the responses of common buckwheat (CB) and tartary buckwheat (TB) to the process should be explored. Herein, the antioxidant properties, nutrients, pasting, and thermal properties of raw and roasted buckwheat flours (roasted at 200 °C for 50 s) from two CB and three TB varieties were investigated. Results showed that roasting considerably reduced the total flavonoid content (TFC) and total phenolic content (TPC) of TB. The TPC of CB was significantly improved by roasting, whereas the TFC significantly decreased. The total antioxidant capacities were consistent with the TPCs. Additionally, the colour deepened as the amount of antioxidant compounds increased. Unexpectedly, roasting enhanced the protein and fat contents of CB and decreased those of TB. Roasting improved the nutritional quality and antioxidant capacity of CB, and opposite results were obtained in TB. In conclusion, CB was more suitable to the development of roasted specialty products with nutritional applications than TB. We suggest that differences among varieties should be considered first in the buckwheat roasting process.     

Thermal,structural and functional properties of rice bran defatted with alcoholic solvents

Samples from combinations of different alcoholic extraction process parameters of rice bran oil, solvents (ethanol or isopropanol) and temperatures (60 or 80 °C) were evaluated and compared with samples from industrial processing regarding the physicochemical, structural and functional characteristics of the defatted meal since these properties are directly associated with the quality of the products. The results obtained for solids from alcoholic extraction did not differ significantly from those obtained from industrial processing using hexane. Although the use of alcohols and high temperatures led to reductions in the nitrogen solubility (21% to 13.5–16.7%), emulsifying activity (31% to 14–25%) and thermal stability, possibly as a function of protein structural modifications due to denaturation, stable foams were produced (26–50%), and adequate values for the water and oil absorption capacities were determined (4 and 3 g/g sample), allowing the application of this material in baking and meat products.     

秸秆还田与优化施氮改善烤烟根际土壤碳氮转化及氮素吸收

针对华南沙泥田烟区氮肥过量施用导致烟叶品质下降的问题,拟通过秸秆还田与氮肥优化配施调节烤烟各生育期氮吸收、根际土壤碳氮转化及相关酶的活性。试验采用随机区组设计,设水稻秸秆还田与氮肥两因素,其中3个碳（秸秆还田）水平：C0,无秸秆还田,0 kg/hm ²;C1,中量秸秆还田,4500 kg/hm ²;C2,全部秸秆还田,9000 kg/hm ²;2个氮水平：N1,传统施氮,169.50 kg/hm ²;N2,优化施氮,105.00 kg/hm ²。结果表明,与N1相比,N2处理秸秆还田下烤烟前期烟叶和根系氮吸收和累积正常,而后期有所下降;C1、C2处理时,与现蕾期相比,成熟期时根系氮含量均降低4.2 g/kg,叶片氮含量降低3.8、3.0 g/kg;成熟期时,与N1处理相比,N2处理时C1、C2处理的土壤无机氮含量降低30.4%、20.0%,前期2个氮处理间土壤无机氮含量无差异,优化施氮下中量秸秆还田（C1N2）处理烤烟土壤NH₄ ⁺-N含量在整个生育期内较高且呈降低趋势,而硝态氮和土壤无机氮含量在成熟期最低,表明中量秸秆还田下优化施氮能够维持生育前期土壤无机氮含量,且降低成熟期土壤无机氮含量。2个秸秆还田量处理时,团棵期N2处理的土壤转化酶活性是N1处理的1.30、1.13倍;旺长期土壤转化酶活性是N1处理的1.27、1.10倍;与传统施氮相比,秸秆还田下优化施氮处理增加了整个生育期土壤脲酶、磷酸酶、过氧化氢酶活性。在中量秸秆还田（C1）处理下,与N1水平相比,现蕾期和成熟期的N2处理土壤水溶性碳含量提高11.2%和14.1%;与N1相比,N2处理的土壤微生物量氮含量呈降低趋势。综上所述,优化施氮耦合中量秸秆还田（C1N2）能够提高土壤水溶性碳含量,维持土壤氮素合理供应,稳定烤烟生育前期对氮素吸收与累积,减少生育后期烟叶氮素奢侈吸收,与烤烟吸氮规律比较吻合。     

黄蝉花素抑制斜纹夜蛾生长发育作用

室内测定了黄蝉花素对斜纹夜蛾幼虫的抑制生长发育活性。结果表明,黄蝉花素对斜纹夜蛾幼虫的抑制生长发育活性与其处理浓度具有一定的相关性。与对照相比,处理组食物消耗量减少,幼虫生长发育被抑制,发育历期延长。处理组幼虫在蛹期不能正常化蛹而形成畸形蛹,羽化后的成虫表现为形态畸形。在预蛹期和蛹期由于不能正常蜕皮导致死亡率较高。研究显示黄蝉花素作为一类新型的昆虫生长发育控制剂或害虫田间种群管理的先导化合物值得进一步研究。     

洋槐蜜和椴树蜜结晶前后的主要物质组成和热力学性质变化研究

为实现对不同类型蜂蜜的特征和质量的科学评价，测定了不同蜜源(洋槐蜜和椴树蜜)和不同结晶状态蜂蜜的主要成分，并利用差示扫描量热技术分析了其热力学性质。结果表明：无论结晶与否，不同蜜源蜂蜜中的葡萄糖和果糖含量均差异显著。相对于椴树蜜样品，洋槐蜜样品的水分活度可能更不利于酵母菌的滋生。玻璃转化温度、放热峰峰温和放热峰焓变等热力学参数，对于区分不同的蜂蜜样品较为灵敏。蜂蜜样品的热力学性质主要受到结晶状态的影响，而与蜜源特征相关性较小。基于以上结果，及时监测蜂蜜的水分活度有助于控制微生物(尤其是酵母菌)的滋生。通过测定蜂蜜的玻璃转化温度、放热峰峰温和放热峰焓变等指标，可以预测蜂蜜的结晶程度。