滇中冷凉山区不同播期反季花椰菜产量效益分析

为摸索滇中高海拔冷凉山区反季节栽培花椰菜的最佳播期以集成高效栽培技术推广应用,于2017—2018年选择海拔2250 m的云南省峨山县塔甸镇大西村地块进行9个播期的2年随机区组试验。结果表明,花椰菜生育期随播期推迟而延长,而花球采收期除播期7月10日外随播期推迟而逐渐增长;花椰菜株高、外叶数、开展度、球高、球径和单球重等农艺性状有随播期延迟呈现先逐渐减小而后又逐渐增大的趋势;莲座期黑腐病和霜霉病的病情指数随着播期的延迟呈现先逐渐升高而后又逐渐下降的趋势;花椰菜小区产量随着播期的延迟呈现先逐渐下降而后又逐渐提高的趋势,播期4月20日和4月30日与其余7个播期产量之间的差异达极显著水平。综合花椰菜在冷凉山区反季节栽培的生产实际和各播期产量产值及商品性表现,推荐滇中高海拔冷凉山区反季节栽培花椰菜的最佳播期为4月20—30日。     

基于离子液体与超声波辅助提取普洱茶茶多酚的工艺优化

本试验利用新型绿色环保溶剂离子液体(1-丁基-3-甲基咪唑溴盐,[BMIM]Br)为提取溶剂,采用超声波辅助提取普洱茶中茶多酚.在以[BMIM]Br浓度、提取时间、提取率及料液比为单因素的试验基础上,进行响应面法优化普洱茶茶多酚的提取工艺.确定最佳提取工艺为:[BMIM]Br浓度0.3 mol/L,料液比1:30,提取时间20 min,超声波功率590 W.在此条件下,普洱茶茶多酚的提取率为8.40％.离子液体与超声波协同作用有效提升了普洱茶茶多酚的提取率,为茶叶中茶多酚的提取工艺提供了新的参考.     

鸡Ii结合Rab5a和Rab7b分子的分析

本研究旨在探明鸡恒定链（invariant chain，Ii）与内吞体转运蛋白Rab5a和Rab7b结合的结构域和在细胞内共定位的特征。首先，用PCR和基因突变技术将Ii胞浆区与跨膜区[Ii_{（Cyt-Tra）}]、Ii CLIP （class Ⅱ-associated invariant chain peptide）-三聚体区[Ii_{（CLIP-TRIM）}]和Ii突变体[Ii_{（M81-87aa）}、Ii_{（M91-99aa）}和Ii_{（M81-99aa）}]分别插入pET-32a和pEGFP-C1构建相应的原核和真核重组质粒。其次，将构建的含有绿色荧光蛋白的重组质粒与实验室保存的含有红色荧光Rab5a和Rab7b的重组质粒共转染至人胚胎肾细胞系293 T，观察它们的共定位。将构建的原核重组质粒进行表达和纯化，最后用拉下法和免疫印迹检测Ii与Rab5a和Rab7b的结合域。结果表明，成功构建Ii结构域及Ii突变体的重组质粒。Ii_{（Cyt-Tra）}及Ii突变体均能与Rab5a和Rab7b在细胞内共定位，而Ii_{（CLIP-TRIM）}与空载体却不能。Ii的胞浆区和跨膜区是与Rab5a和Rab7b结合的功能结构域，而不是CLIP与三聚体区。综上所述，鸡Ii与Rab5a和Rab7b共定位和结合的区域是其胞浆区和跨膜区，而不是内质网腔区。这些结果提示Rab分子参与了Ii在胞内细胞器的转运机制，为进一步研究Ii及其载体在细胞内的转运机制和功能提供了新的途径。     

甘露糖修饰的壳聚糖聚乳酸-羟基乙酸共聚物纳米微球作为口蹄疫病毒核酸疫苗递送载体的特性评价

旨在对制备的甘露糖修饰的壳聚糖聚乳酸-羟基乙酸共聚物[poly （D，L-lactide-co-glycolide），PLGA]纳米微球作为口蹄疫病毒（foot-and-mouth disease virus，FMDV）核酸疫苗递送载体进行评价。采用西佛碱反应和元素分析制备具有一定取代度的甘露糖修饰的壳聚糖衍生物（mannose modified chitosan，MCS），然后，经双重乳化挥发法制备得到甘露糖修饰的壳聚糖PLGA纳米微球（MCS-PLGA-NPs）。采用纳米粒径仪检测MCS-PLGA-NPs粒径分布和表面电势（zeta）、扫描电镜考察其形态、琼脂糖凝胶电泳观察其对质粒的吸附和吸附质粒后抵抗核酸酶降解能力、CCK-8法检测MCS-PLGA-NPs的细胞毒性、激光共聚焦观察巨噬细胞对MCS-PLGA-NPs-质粒DNA复合物的摄取、荧光显微镜和Western blot验证MCS-PLGA-NPs加载质粒DNA在细胞中的表达。元素分析结果表明，成功制备了取代度为5%~10%的MCS。纳米粒径测定和扫描电镜结果表明，MCS-PLGA-NPs的zeta为正值、粒径分布均匀且形态规则呈球形。琼脂糖凝胶电泳结果显示，MCS-PLGA-NPs吸附质粒的能力随着其质量的增加而增强并且可以在一定程度上抵抗核酸酶降解质粒DNA。在细胞毒性试验中，不同浓度的MCS-PLGA-NPs与RAW264.7细胞共孵育24 h后，细胞存活率仍在85%以上。在细胞摄取试验中，用激光共聚焦显微镜可以明显观察到质粒DNA结合到纳米微球表面被RAW264.7细胞摄取。荧光显微镜和Western blot试验证明MCS-PLGA-NPs加载质粒DNA可以在细胞中进行表达。综上表明，本研究成功制备了MCS以及具有递送核酸疫苗能力的MCS-PLGA-NPs，为FMDV核酸疫苗的递送研究提供了新的方向和见解，也为该递送载体携带特定抗原靶向抗原递呈细胞表面甘露糖受体以及应用于动物免疫的研究奠定基础。     

The priority of management factors for reducing the yield gap of summer maize in the north of Huang-Huai-Hai region,China

Understanding yield potential, yield gap and the priority of management factors for reducing the yield gap in current intensive maize production is essential for meeting future food demand with the limited resources. In this study, we conducted field experiments using different planting modes, which were basic productivity(CK), farmer practice(FP), high yield and high efficiency(HH), and super high yield(SH), to estimate the yield gap. Different factorial experiments(fertilizer, planting density, hybrids, and irrigation) were also conducted to evaluate the priority of individual management factors for reducing the yield gap between the different planting modes. We found significant differences between the maize yields of different planting modes. The treatments of CK, FP, HH, and SH achieved 54.26, 58.76, 65.77, and 71.99% of the yield potential, respectively. The yield gaps between three pairs: CK and FP, FP and HH, and HH and SH, were 0.76, 1.23 and 0.85 t ha~(–1), respectively. By further analyzing the priority of management factors for reducing the yield gap between FP and HH, as well as HH and SH, we found that the priorities of the management factors(contribution rates) were plant density(13.29%)fertilizer(11.95%)hybrids(8.19%)irrigation(4%) for FP to HH, and hybrids(8.94%)plant density(4.84%)fertilizer(1.91%) for HH to SH. Therefore, increasing the planting density of FP was the key factor for decreasing the yield gap between FP and HH, while choosing hybrids with density and lodging tolerance was the key factor for decreasing the yield gap between HH and SH.     

Regional distribution of wheat yield and chemical fertilizer requirements in China

Quantification of currently attainable yield and fertilizer requirements can provide detailed information for assessing the food supply capacity and offer data support for agricultural decision-making. Datasets from a total of 5 408 field experiments were collected from 2000 to 2015 across the major wheat production regions in China to analyze the spatial distribution of wheat yield, the soil nutrient supply capacity(represented by relative yield, defined as the ratio of the yield under the omission of one of nitrogen(N), phosphorus(P) and potassium(K) to the yield under the full NPK fertilizer application), and N, P and K fertilizer requirements by combining the kriging interpolation method with the Nutrient Expert Decision Support System for Wheat. The results indicated that the average attainable yield was 6.4 t ha~(-1), with a coefficient of variation(CV) of 24.9% across all sites. The yields in North-central China(NCC) and the northern part of the Middle and Lower reaches of the Yangtze River(MLYR) were generally higher than 7 t ha~(-1), whereas the yields in Southwest China(SWC), Northeast China(NEC), and the eastern part of Northwest China(NWC) were usually less than 6 t ha~(-1). The precentage of area having a relative yield above 0.70, 0.85, and 0.85 for N, P, and K fertilizers accounted for 52.3, 74.7, and 95.9%, respectively. Variation existed in N, P, and K fertilizer requirements, with a CV of 24.8, 23.9, and 29.9%, respectively, across all sites. More fertilizer was needed in NCC and the northern part of the MLYR than in other regions. The average fertilizer requirement was 162, 72, and 57 kg ha~(-1) for N, P_2O_5, and K_2O fertilizers, respectively, across all sites. The incorporation of the spatial variation of attainable yield and fertilizer requirements into wheat production practices would benefit sustainable wheat production and environmental safety.     

不同水肥条件下夏玉米/冬小麦农田生态系统碳平衡研究

农田生态系统碳平衡取决于农作物固定碳量和土壤异养呼吸排放碳量。为揭示水肥用量对农田生态系统碳平衡的综合影响，设置3个灌水水平：高水、中水和低水（W1、W0.85、W0.7夏玉米季分别为90、76.5、63mm，冬小麦季分别为140、119、98mm），4个施氮水平：高氮、中氮、低氮和不施氮（N1、N0.85、N0.7、N0夏玉米季分别为300、255、210、0kg/hm2，冬小麦季分别为210、178.5、147、0kg/hm2），4个施磷水平：高磷、中磷、低磷和不施磷（P1、P0.85、P0.7和P0夏玉米季分别为90、76.5、63、0kg/hm2，冬小麦季分别为150、127.5、105、0kg/hm2）进行了田间试验。结果表明：不同水肥处理下夏玉米/冬小麦农田生态系统表现为碳汇，夏玉米季净生态系统生产力固碳量（CNEP）为6805~7233kg/hm2，冬小麦季CNEP为5842~6434kg/hm2，夏玉米CNEP高于冬小麦。在高、中、低肥水平下，增加灌水量，夏玉米/冬小麦周年净初级生产力固碳量（CNPP）提高2.48%~5.96%，土壤微生物异养呼吸碳释放量（CRm）增加2.15%~15.20%，净生态系统生产力固碳量（CNEP）增加1.16%~6.47%。在高、中、低供水水平下，增加施肥量，夏玉米/冬小麦周年CNPP增加2.95%~3.43%，土壤CRm增加5.23%~18.67%，CNEP增加0.93%~2.79%，CNEP增加比例与供水水平呈负相关。在低水条件下，氮磷肥配施处理夏玉米/冬小麦农田周年CNEP较单施氮、磷肥分别增加4.86%、7.34%，且氮磷肥交互作用显著（P<0.05），水肥供应水平相差15%时对冬小麦农田CNEP有显著的正交互作用。氮磷肥配施、水肥协调供应均有助于促进夏玉米/冬小麦农田生态系统的净碳输入，在节水节肥原则下，夏玉米和冬小麦分别在W0.85N0.85P0.85和W0.7N0.85P0.85水肥供应条件下有利于增加农田CNEP。     

中链脂肪酸及其酯对致病菌的抑菌作用

中链脂肪酸甘油酯已经成为抗生素替代物研究的新热点。文章旨在探究月桂酸、单辛酸甘油酯、单月桂酸甘油酯、辛葵酸甘油酯对大肠埃希菌、金黄色葡萄球菌、肠炎沙门氏菌和鸡白痢沙门氏菌的抑菌效果。结果显示:月桂酸、单月桂酸甘油酯、单辛酸甘油酯对大肠埃希菌有显著(P<0.05)抑制作用;月桂酸、单月桂酸甘油酯、单辛酸甘油酯、辛葵酸甘油酯对金黄色葡萄球菌有显著(P<0.05)抑制作用;月桂酸、单月桂酸甘油酯、单辛酸甘油酯、辛葵酸甘油酯对肠炎沙门氏菌有显著(P<0.05)抑制作用;月桂酸、单月桂酸甘油酯、单辛酸甘油酯对鸡白痢沙门氏菌有显著(P<0.05)抑制作用。其中,月桂酸、单月桂酸甘油酯、单辛酸甘油酯对4种致病菌的作用效果随时间延长而增强。     

过氧化氢(H2O2)介导的光合诱导系统信号

研究光照玉米幼苗顶部叶片产生的系统信号对底部叶片光合诱导过程的影响,探讨玉米叶片对光斑高效利用可能机制.以玉米(Zea mays L.)幼苗为试验材料,光照其顶部叶片,其余叶片处于遮蔽状态,利用Li-6400便携式光合仪测定玉米幼苗底部叶片光合诱导过程.通过预先光照玉米幼苗顶部叶片,底部叶片光合诱导过程从最低值到达最高值所需时间显著缩短,中间叶片光合诱导过程T50和T90分别下降,底部叶片光合诱导过程T50和T90分别下降29％和37％.玉米叶片全部遮荫条件下,底部叶片喷施过氧化氢(H2O2)促进光合诱导过程.三氯乙酸(TCA)和二苯基碘化钾(DPI)处理玉米顶部叶片基部,即使顶部叶片受到预光照,也无法改变底部叶片光合诱导过程.预先光照玉米顶部叶片,产生系统信号,信号物质为H2O2,通过韧皮部转运,可调节其他叶片光合诱导过程,有利于玉米底部叶片对动态光能利用和碳积累.该系统信号对玉米冠层底部叶片高效利用光斑发挥重要作用.     

Screening and Verification of Low Nitrogen Tolerant and Nitrogen Sensitive Cotton Germplasm

[Objective] The aim of this study is to evaluate nitrogen efficient cotton germplasms and improve nitrogen use efficiency. [Method] Eighty cotton germplasms were selected and evaluated in the hydroponic experiment under low (0.25 mmol·L^－1) and high (5 mmol·L^－1) nitrogen concentration. Different traits for screening were identified and nitrogen use efficiency types were classified. Field experiments were also performed for comparison and confirmation of the identified germplasms. [Result] The results showed that there were significant differences in the total plant dry matter, shoot nitrogen accumulation and nitrogen absorption efficiency in cotton germplasms at the two nitrogen levels. Based on coefficient of variation, principal component analysis and correlation, six traits including total plant dry matter, shoot dry matter, root dry matter, total nitrogen accumulation, shoot nitrogen accumulation and nitrogen absorption efficiency were used as screening indicators. According to the Heatmap clustering analysis and the nitrogen efficiency comprehensive index, two germplasms (Lu05R59 and CCRI 69) were identified as low nitrogen tolerant and nitrogen efficient, and two germplasms (Coker 201 and Xinluzhong 30) as low nitrogen sensitive and nitrogen inefficient. The results of field experiment were consistent with the results of the hydroponic culture at the seedling stage. [Conclusion] It was finally determined that Lu05R59 and CCRI 69 were the low nitrogen tolerant and nitrogen efficient germplasms, and Coker 201 and Xinluzhong 30 were low nitrogen sensitive and nitrogen inefficient germplasms. The results of these studies provide the possibility for screening and rapid identification of nitrogen use efficiency in cotton at the seedling stage, and provide the ideal materials and theoretical basis for further study of cotton nitrogen efficient.