氮素抑制剂对双季稻产量、氮素利用效率及土壤氮平衡的影响

【目的】 了解氮素抑制剂对双季稻产量、氮素利用效率及氮素在土壤中转化的影响，旨在为制定科学合理的农田氮素管理措施及节肥增效策略提供依据。 【方法】 以湘早籼45号和荆楚优148为材料，于2015年早、晚稻期间进行田间试验。试验设5个处理:不施肥 (CK)；100%尿素 (100%U)；80%尿素 (减氮20%，80%U)；80%尿素+脲酶抑制剂NBPT (80%U+NBPT)；80%尿素+硝化抑制剂DCD (80%U+DCD)。研究尿素减施条件下添加硝化抑制剂 (NBPT) 和脲酶抑制剂 (DCD) 对双季水稻产量、氮素养分吸收利用效率、土壤硝态氮、铵态氮、微生物量氮及土壤氮平衡的影响。 【结果】 NBPT和DCD均有利于提高早、晚稻产量、植株氮吸收量和氮素利用效率。减氮20%条件下添加NBPT(80%U+NBPT)处理早、晚稻稻谷较100%尿素处理 (100%U) 分别增产5.0%和6.1%，较施用80%尿素 (80%U) 分别增产8.0%和14.0%；80%U+DCD与100%U处理的早、晚稻稻谷产量差异不显著，较80%U处理分别增产6.0%和4.2%。80%U+NBPT较100%U处理早、晚稻植株氮吸收量分别增加4.5%和9.4%，较80%U处理分别增加10.3%和16.2%。80%U+NBPT和80%U+DCD处理氮肥表观利用率、氮肥农学效率、氮肥偏生产力和氮素吸收效率均较100%U和80%U处理提高。添加NBPT和DCD降低了早、晚稻收获后土壤硝态氮和铵态氮残留量，显著提高土壤微生物量氮积累量，降低氮表观损失，有利于维持作物-土壤体系氮素平衡。早、晚稻收获后80%U+NBPT较100%U处理氮表观损失降低42.2%和44.6%，较80%U处理降低27.5%和29.2%，80%U+DCD较100%U处理降低23.7%和31.6%，较80%U处理降低4.2%和12.6%。 【结论】 在该区域双季稻种植体系中，氮肥减量20%条件下添加NBPT和DCD能增加或维持水稻产量，提高氮素利用效率。供试条件下，添加NBPT提高氮素持续供应能力和保持土壤氮素平衡的效果好于DCD。      

嘧啶(氧)硫苯甲酸类除草剂研究进展

嘧啶(氧)硫苯甲酸类除草剂是超高效除草剂类型之一,是新一代绿色、安全、高效、低残留农药,具有很高的推广价值。本文综述了嘧啶(氧)硫苯甲酸类除草剂的主要类型、作用机理、国内外应用现状,总结了目前的研究进展;对其引发的杂草抗药性问题进行阐述。可为嘧啶(氧)硫酸苯甲酸类除草剂的农业应用及科学研究提供借鉴。     

Substitution of chemical fertilizer by Chinese milk vetch improves the sustainability of yield and accumulation of soil organic carbon in a double-rice cropping system

The double-rice cropping system is a very important intensive cropping system for food security in China. There have been few studies of the sustainability of yield and accumulation of soil organic carbon(SOC) in the double-rice cropping system following a partial substitution of chemical fertilizer by Chinese milk vetch(Mv). We conducted a 10-year(2008–2017) field experiment in Nan County, South-Central China, to examine the double-rice productivity and SOC accumulation in a paddy soil in response to different fertilization levels and Mv application(22.5 Mg ha~(–1)). Fertilizer and Mv were applied both individually and in combination(sole chemical fertilizers, Mv plus 100, 80, 60, 40, and 0% of the recommended dose of chemical fertilizers, labeled as F100, MF100, MF80, MF60, MF40, and MF0, respectively). It was found that the grain yields of double-rice crop in treatments receiving Mv were reduced when the dose of chemical fertilizer was reduced, while the change in SOC stock displayed a double peak curve. The MF100 produced the highest double-rice yield and SOC stock, with the value higher by 13.5 and 26.8% than that in the F100. However, the grain yields increased in the MF80(by 8.4% compared to the F100), while the SOC stock only increased by 8.4%. Analogous to the change of grain yield, the sustainable yield index(SYI) of double rice were improved significantly in the MF100 and MF80 compared to the F100, while there was a slight increase in the MF60 and MF40. After a certain amount of Mv input(22.5 Mg ha~(–1)), the carbon sequestration rate was affected by the nutrient input due to the stimulation of microbial biomass. Compared with the MF0, the MF100 and MF40 resulted in a dramatically higher carbon sequestration rate(with the value higher by 71.6 and 70.1%),whereas the MF80 induced a lower carbon sequestration rate with the value lower by 70.1% compared to the MF0. Based on the above results we suggested that Mv could partially replace chemical fertilizers(e.g., 40–60%) to improve or maintain the productivity and sustainability of the double-rice cropping system in South-Central China.     

鲤细胞因子多克隆抗体的制备及检测

为从蛋白质水平研究细胞因子在鲤体内免疫应答过程中的合成变化,本研究采用PCR技术克隆TNF-α、IL-1β、IL-6、IL-12、IL-10和TGF-β基因含有部分抗原决定簇的片段,引入双酶切位点Bam HⅠ和HindⅢ后连接至p ET-32a/21a,构建相应的表达载体,制备多克隆抗体。采用ELISA检测抗体效价,并以此作为实验工具,检测经嗜水气单胞菌感染后鲤血清中炎性细胞因子的合成变化。结果显示,基因TNF-α、IL-1β、IL-6、IL-12、IL-10和TGF-β融合蛋白分子量分别约为31.8、31.7、35.3、32.5、18.0和33.6 ku;抗体效价达到2.4×106;在病原菌感染后的不同阶段,促炎细胞因子TNF-α、IL-1β、IL-6、IL-12和抗炎细胞因子IL-10、TGF-β呈现出不同的合成变化。研究表明,制备的抗体具有较高的效价、亲和力和特异性,可用于鲤细胞因子的定量研究,该抗体的获得为鲤免疫应答与细胞因子合成的系统研究奠定了基础。同时,获取的鲤细胞因子TNF-α、IL-1β、IL-6、IL-12、IL-10和TGF-β的抗体亦可用于其他鱼类细胞因子蛋白质水平的定量研究。     

Soil Characteristics Overwhelm Cultivar Effects on the Structure and Assembly of Root-Associated Microbiomes of Modern Maize

Modern breeding primarily targets crop yield traits and is likely to influence root-associated microbiomes, which play significant roles in plant growth and health. The relative importance of soil and cultivar factors in shaping root-associated microbiomes of modern maize (Zea mays L.) remains uncertain. We conducted a pot experiment in a controlled environment using three soils (Mollisol, Inceptisol, and Ultisol) and four contrasting cultivars, Denghai 605, Nonghua 816, Qiaoyu 8, and Zhengdan 958, which are widely planted in China. We used 16S rRNA gene amplicon sequencing to characterize the bacterial communities in the bulk soil, rhizosphere, and endosphere. Our results showed that the four cultivars had different shoot biomass and root exudate total organic carbon and organic acid contents. The microbiomes in the bulk soil, rhizosphere, and endosphere were different. We observed apparent community divergence between soils rather than cultivars, within which edaphic factors substantially contributed to microbiome variation. Moreover, permutational multivariate analysis of variance corroborated significant contributions of soil type but not cultivar on the root-associated microbiome structure. Differential abundance analysis confirmed that each soil presented a distinct root microbiome, while network analysis indicated different co-occurrence patterns of the root microbiome among the three soils. The core root microbiome members are implicated in plant growth promotion and nutrient acquisition in the roots. In conclusion, root-associated microbiomes of modern maize are much more controlled by soil characteristics than by cultivar root exudation. Our study is anticipated to help improve breeding strategies through integrative interactions of soils, cultivars, and their associated microbiomes.     

Factor Analysis and Comprehensive Evaluation of the Fruit Quality of ‘Yangjiaocui’ Melons

【Objective】The aim of this study was to identify the typical indices of fruit quality and high quality materials of ‘Yangjiaocui’ melons to provide reference and basis for melon quality evaluation and breeding. 【Method】Eighteen indices, including economic trait and flesh quality of fruits from 6 cultivars and 26 high-generation inbred lines of ‘Yangjiaocui’ melons were determined. Based on factor analysis, stepwise regression, correlation analysis and two-dimension ordination map, the typical indices of fruit quality and high quality materials were identified. 【Result】 Among the 18 indices, single fruit mass, hardness, vitamin C (V_C) content, titratable acid content, sugar-acid ratio and solid acid ratio showed greater variability, and the variation coefficients were more than 20%. However, the variability of fruit transverse diameter, flesh thickness rate and pH were relatively lower and the variation coefficients were less than 10%. Three common factors were extracted from economic trait indices with 87.71% cumulative variance contribution rate and the explanatory indices were fruit longitudinal diameter, fruit transverse diameter, fruit shape index, fruit cavity longitudinal diameter, fruit cavity transverse diameter and flesh thickness rate. From quality indices, 4 common factors were extracted with 90.03% cumulative variance contribution rate and the explanatory indices were V_C content, hardness, total soluble solids content, total sugar content, titratable acid content, sugar-acid ratio and solid-acid ratio. Based on the comprehensive analysis of these selected 6 economic trait indices and 7 flesh quality indices, 5 common factors were extracted with 87.35% cumulative variance contribution rate. According to the correlation among the indices and the principle of simplicity and ease of use and avoidance of overlapping information, 5 indices, including fruit longitudinal diameter, flesh thickness rate, hardness, total sugar content and titratable acid content, could be used as typical indices to evaluate the fruit quality of ‘Yangjiaocui’ melons. The comprehensive quality score of all materials were ranked depended on scores and variance contribution rate of the above 5 common factor and two-dimension ordination map. Finally, 10 materials were selected as high quality materials. 【Conclusion】 Fruit longitudinal diameter, flesh thickness rate, hardness, total sugar content and titratable acid content could be used as typical indices to evaluate fruit quality of ‘Yangjiaocui’ melons. Inbred lines 25, 24, 22, 21, 8, 1, 17, 18, 20 and 23 were high quality materials.     

金刚砂辅助农杆菌进行玉米基因转化研究

对超声波处理方式进行改进,在超声波处理时,加入金刚砂以辅助EPSPS基因转导到玉米幼胚中。结果表明,800粒处理种子播种出苗93株,玉米苗经大田glyphosate筛选有27株具有抗性,进行PCR电泳检测,显示23株阳性,初步证明EPSPS基因已经转化到玉米植株中,转化率为29%。金刚砂辅助处理玉米基因转化具有可行性,利于生产实际操作。     

黑龙江省水稻产业现状分析及未来发展思路

对黑龙江省水稻产业发展现状进行了小结,并针对黑龙江省水稻生产过程中存在问题提出了相应的对策。具体对策如下:有针对性的选育适于不同生态区域的优质、抗逆水稻新品种,并对新品种的轻简高效配套栽培技术进行研究;适时开展水稻直播关键技术集成与应用,及开展秸秆还田技术研究;开展稻米精加工技术研究。     

油菜角果数量及关键表型参数的自动化检测方法研究

为有效替代人工方式考种油菜、观测角果,研究了一种用于测量批量角果的数量和关键表型参数的自动化检测方法。设计了角果散铺和图像采集装置,利用拨动加振动的方式将堆积角果均匀散开并拍摄视频;使用二维码作为标记块,以有效地提取关键帧并拼接为包含全部角果的整幅图像;提出了基于凹点提取与匹配的图像分割方法,分割各种形态下的重叠角果,准确率达到98%以上。在关键表型参数测量中,利用了最大类间方差法以判断角果的正置或侧置姿态,以此估计角果横切面的近似椭圆长短轴,再计算角果的长度、表面积和体积。实验结果表明该方法具有很好的检测精度,对不同品种的油菜适应性较好,长度、表面积和体积的估计误差分别不大于2.9%、4.8%和5.0%。该方法可以有效替代人工方式的油菜考种,为相关农业科研领域提供基础数据。     

中国不同地区‘富士’苹果品质评价

【目的】确定‘富士’苹果核心品质指标,建立‘富士’苹果品质综合评价模型。【方法】从河北、河南、辽宁、宁夏、山东、山西、陕西、新疆等8个苹果主产省（区）68个市（县）的代表性果园采集176份‘富士’苹果样品进行品质测定,共测定单果重、带皮硬度、去皮硬度、可溶性固形物含量、可溶性糖含量、可滴定酸含量、维生素C含量、山梨醇含量、葡萄糖含量、果糖含量、蔗糖含量、甜度、固酸比、糖酸比、甜酸比等15项指标。通过主成分分析和聚类分析法确定‘富士’苹果核心品质指标,运用层次分析法确定指标权重,采用灰色关联度法建立‘富士’苹果品质综合评价模型。【结果】不同产区间‘富士’苹果品质指标存在差异性,新疆‘富士’苹果硬度、维生素C含量、可溶性固形物含量、可溶性糖含量、山梨醇含量、果糖含量、蔗糖含量、甜度值等8项品质指标均高于其他省（区）‘富士’苹果。维生素C含量、山梨醇含量、蔗糖含量和甜酸比的变异系数均大于30%,可溶性糖含量的变异系数最小（仅为9.8%）。‘富士’苹果某些品质指标间存在极显著的相关性,可滴定酸含量与固酸比、糖酸比之间相关系数分别为-0.844、-0.854,果糖和甜度值之间相关系数达0.963,固酸比与糖酸比之间相关系数为0.941。通过主成分分析和聚类分析,确定单果重（X₁）、去皮硬度（X₂）、可滴定酸含量（X₃）、固酸比（X₄）和果糖含量（X₅）为‘富士’苹果核心品质指标。通过灰色关联度法建立了‘富士’苹果品质综合评价模型Y=0.2601X₁+0.1378X₂+0.0819X₃+0.2601X₄+0.2601X₅。【结论】单果重、去皮硬度、可滴定酸含量、固酸比和果糖含量为‘富士’苹果核心品质指标,以其建立的评价模型可用于‘富士’苹果品质的综合评价。