QuEChERS-高效液相色谱法检测油料作物中氟磺胺草醚残留量

目的建立QuEChERS-高效液相色谱联用技术检测油菜籽、大豆、花生中氟磺胺草醚残留量的方法。方法样品用1%甲酸水溶液和乙腈提取,经N-丙基乙二胺粉末净化,色谱柱分离,以0.1%甲酸水溶液和乙腈为流动相进行洗脱,二极管阵列检测器检测,检测波长295 nm。结合保留时间和紫外光谱进行定性分析,峰面积进行定量分析。结果氟磺胺草醚在0.5～100μg/mL范围内线性良好,相关系数(r~2)为0.9999,方法检出限为0.021mg/kg;在油菜籽、大豆、花生中3个添加水平的平均回收率为89.9%～102.3%,相对标准偏差为2.5%～7.2%。结论该方法简便、快捷、节约溶剂,适用于油料作物中检测氟磺胺草醚残留量。     

我国燃料乙醇原料可持续供应初步分析

本文通过评价我国粮食供应形势、土地资源、农业生产的特点,资源禀赋等,对我国燃料乙醇原料供应进行了初步分析。我国人多地少,耕地资源紧缺,粮食供需处于紧平衡,以玉米为原料的燃料乙醇发展空间受到极大的限制,原料多元化势在必行。初步测算,2010年燃料乙醇的可供应量约360万t,2020年燃料乙醇的可供应量约1700万t,可以满足国家可再生能源中长期发展规划规定的目标。最后,提出依靠科技进步以及发展纤维素乙醇等措施。     

Response to fertilization and nutrient deficiency diagnostics in peach palm in Central Amazonia

Peach palm (Bactris gasipaes Kunth) is increasingly grown in the tropics for its heart-of-palm and fruit. Determining fertilization response and diagnosing nutrient status in peach palm may require methods that consider the particularities in nutrient acquisition and recycling of perennial crops. Responses to nutrient additions, and the diagnostic value of soil and foliar analyses were examined in three field experiments with three-year old peach palm stands on Oxisols in Central Amazonia. To diagnose P-deficiency levels in soils, samples from 0–5 cm and 5–20 cm depth were analyzed for available P by different methods (Mehlich-1, Mehlich-3 and Modified Olsen). The second and fifth leaves were analyzed to assess N, P and K deficiencies. Field experiments involved several combinations of N (from 0 to 225 kg ha^–1 yr^–1), K (from 0 to 225 kg ha^–1 yr^–1) and P (from 0 to 59 kg ha^–1 yr^–1). Palms on control plots (unfertilized) and those receiving 225 kg ha^–1 yr^–1 N and 2 Mg ha^–1 of lime yielded between 4 and 19% of the maximum growth which was obtained with N, P and K applications. In one of the experiments, yield of heart-of-palm was positively related to N additions at the lowest levels of P (8.6 kg ha^–1 yr^–1) and K (60 kg ha^–1 yr^–1) additions. In one experiment, critical leaf N level was 2.5% for the second leaf and 2.2% for the fifth leaf. Some growth responses to P additions at constant N and K levels were observed (e.g., 797 kg ha^–1 yr^–1 of heart-of-palm with 39.3 kg ha^–1 yr^–1 of applied P, and 632 kg ha^–1 yr^–1 of heart-of-palm with 10.9 kg ha^–1 yr^–1 of applied P in one experiment, and 2334 kg ha^–1 yr^–1 of heart-of-palm with 39.3 kg ha^–1 yr^–1 of P and 1257 kg ha^–1 yr^–1 of heart-of-palm with 19.7 kg ha^–1 yr^–1 of P in another trial). In the experiment for fruit production from peach palm, total plant height did not respond to P additions between 19.7 and 59 kg ha^–1 yr^–1 and K additions between 75 and 225 kg ha^–1 yr^–1. Leaf P levels were found to be above the proposed critical levels of 0.23% for the third leaf and 0.16% for the fifth leaf. Plants in this experiment, however, showed evident symptoms of Mg deficiency, which was associated with a steep gradient of increasing Mg concentration from the fifth leaf to the second leaf. Standard leaf diagnostic methods in most cases proved less useful to show plant N and P status and growth responses to N and P additions. Soil P determined by common extractions was in general too variable for prediction of growth.     

Switchgrass production and establishment in the Southern Italy climatic conditions

Standard productivity trials on switchgrass (Panicum virgatum L.) have been performed at the ENEA Research Centre Trisaia in the framework of the FAIR Project (IV FWP). The main objective of the research work was to develop knowledge about the adaptability of this new crop in the South Italy climatic conditions. To achieve this goal, two sets of experiments with various genotypes were conducted to determine the switchgrass yields at the field level. In the nursery trial, 15 varieties were tested, while in the production experiment, only five varieties at different nitrogen fertiliser levels (0, 75, 150 kg N ha⁻¹) were tested for their yield. The experimental results obtained relating to biomass yield and genotype response to nitrogen fertilisation are discussed in the present communication. Though it seems that the N fertilisation did not directly influence the switchgrass productivity, most of the switchgrass varieties showed quite a good response for biomass production.     

Management of soil organic matter in semiarid Africa for annual cropping systems

Ensuring sustainable agriculture in semiarid Africa requires the implementation of methods to balance nutrients and to conserve soil organic matter (SOM). There is an urgent need to improve the management of all types of SOM input. In this paper; the authors review a wide range of agricultural practices and discuss their advantages, limitations and feasibility. They distinguish ‘traditional systems’ such as traditional fallow, parkland and manuring from ‘improved systems’ such as ‘improved fallow’, forest fallow, alley cropping, cover crops and application of composted manure. Biomass production (BMP) for ‘improved systems’ is mainly linked: (i) for agroforestry, to the tree species used in forest fallow, to the synchronization of nutrient supply by the soil with the cereal demand in alley cropping, and generally to the efficiency of the root system and its development with the depth; (ii) for cover crops, BMP is mainly linked to the initial soil fertility and to the ecological zone: establishment and management of cover crops are not yet fully mastered under some conditions such as an annual rainfall below 800 mm and/or on very clayey soils; (iii) for manure, BMP is mainly linked to the improvement of fallow in order to ensure sufficient forage resources. Because semiarid Africa is mainly a livestock zone, the authors emphasise manure: constraints, quality indicators and tools used to encourage its production, are analysed. Thus it was concluded that the intensification of manure production and its rational use in semiarid African regions, threatened by drought and malnutrition, is very important: this cannot be separated from the production of plant biomass, whose possibilities have been examined above. This revised version was published online in June 2006 with corrections to the Cover Date.     

植物氯素营养与含氯化肥科学施用

文章主要概述了植物的氯素营养及科学施用含氯化肥三准则。     

转基因作物与农药

近几年来转基因作物的商品化种植迅猛发展,一大批具有抗虫、抗病、抗除草剂的转基因作物投入市场,对农药工业造成巨大的冲击。本文对转基因作物的发展及其对农药工业的影响进行了述评。     

高效液相色谱法同时测定粮食中6种大豆异黄酮

目的建立高效液相色谱法(high performance liquid chromatography,HPLC)测定粮食中6种大豆异黄酮(大豆苷、大豆黄苷、染料木苷、大豆素、大豆黄素和染料木素)含量的分析方法。方法准确称取一定量粉碎混匀后的样品,经80%甲醇提取后取上清液,过0.22μm有机相滤膜上机。采用Thermo Syncronis C18柱(250 mm×4.6 mm,5μm),以0.5%甲酸水溶液(A)、乙腈(B)和甲醇(C)作为流动相进行梯度洗脱,流速0.8m L/min,柱温为35℃,于紫外检测器波长260 nm处检测,大豆异黄酮各组分含量以外标法进行定量。结果本方法在30 min内完成6种大豆异黄酮的分离分析,大豆异黄酮各组分浓度在0.2~50μg/mL范围内呈良好的线性关系(r0.999),平均加标回收率为96.9%~107.8%,相对标准偏差(relative standard deviation,RSD)为0.6%~5.0%,检出限为0.03~0.1μg/mL,定量限为0.1~0.3μg/mL。结论建立的方法具有较高的灵敏度和重复性,能满足不同粮食种类中大豆异黄酮含量测定。     

Application of Upstream Open Reading Frames (uORFs) Editing for the Development of Stress-Tolerant Crops

Global population growth and climate change are posing increasing challenges to the production of a stable crop supply using current agricultural practices. The generation of genetically modified (GM) crops has contributed to improving crop stress tolerance and productivity; however, many regulations are still in place that limit their commercialization. Recently, alternative biotechnology-based strategies, such as gene-edited (GE) crops, have been in the spotlight. Gene-editing technology, based on the clustered regularly interspaced short palindromic repeats (CRISPR) platform, has emerged as a revolutionary tool for targeted gene mutation, and has received attention as a game changer in the global biotechnology market. Here, we briefly introduce the concept of upstream open reading frames (uORFs) editing, which allows for control of the translation of downstream ORFs, and outline the potential for enhancing target gene expression by mutating uORFs. We discuss the current status of developing stress-tolerant crops, and discuss uORF targets associated with salt stress-responsive genes in rice that have already been verified by transgenic research. Finally, we overview the strategy for developing GE crops using uORF editing via the CRISPR-Cas9 system. A case is therefore made that the mutation of uORFs represents an efficient method for developing GE crops and an expansion of the scope of application of genome editing technology.