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.     

Sustainable use of eucalypt biomass grown on short rotation coppice for bioenergy

Bioenergy is one of the alternatives to reduce the dependence of global energy on fossil fuels. The short rotation coppice (SRC) of eucalypt species appears as an interesting option for forest biomass production in a short time. However, the harvesting of whole trees (included the crown) in SRC systems has implications on sustainable land use. More information is required on the increase of biomass as renewable energy resource to achieve the sustainability of these crops. The main objective of this research was to evaluate the sustainable use of biomass from very high-density eucalypt plantations, managed at tropical conditions for bioenergy. To accomplish this objective, the tree was fractionated into three fractions: stem, branches, and leaves, and there was determination of the dry matter, energy yield, and nutrients export. This experiment used a short rotation coppice, a hybrid clone of Eucalyptus urophylla × Eucalyptus grandis, of 2 years old. According to the results obtained, the density planting and fertilization levels have a greater influence on the dry matter yield, energy yield, and nutrient exports. The higher density planting reaches mean values of 30.9 tonnes of dry matter per hectare (t DM ha⁻¹) and 743.3 GJ ha⁻¹. Considering the biomass yield and nutrients export of short rotation coppice of eucalypt, the higher density planting with the lower dose of fertilization is more indicative of sustainable use. The leaves have an important participation in nutrients export and should be retained in the soil of forest.     

Multicriteria analysis for the selection of the most appropriate energy crops: the case of Cyprus

Energy crops are considered key actors in meeting the international and European carbon reduction targets, increasing the national energy security through renewable energy production, mitigating climate change impacts, and promoting sustainability. Multicriteria analysis is a suitable decision-making tool for the energy sector, where the final decisions have to consider for a range of aspects, and can be utilised as well for deciding on appropriate energy crops. In this paper, a popular multicriteria method, PROMETHEE, is employed for the identification of the most optimal energy crops for their exploitation in Cyprus. The criteria and the weights of each are defined, and accordingly five different scenarios are developed and examined. The obtained results indicated that the promotion of second-generation energy crops is more ideal in terms of the set objectives, as well as more sustainable than the exploitation of any first-generation energy crop.     

作物盐害与合理施肥

介绍作物盐害的基本概念和盐害产生的原因,评价影响作物生长盐害的主要指标:盐度和盐度指数,讨论主要作物的耐盐性、不同肥料的盐度指数,以及研究作物盐害下的合理用肥。     

Future crop yields and water productivity changes for Nebraska rainfed and irrigated crops

ABSTRACT

We assessed future rainfed and irrigated crop yield and water productivity changes in Nebraska across multiple climate and emission scenarios using an empirical modeling approach. We found rainfed crops showed slightly increased crop water productivity while irrigated crops showed no change or decreased water productivity. Contrary to U.S.-wide studies reporting declines in crop yields, we projected Nebraska crop yields to increase overall with greatest increases in current rainfed fields due to combined effects from maximum and minimum temperatures. However, the increased rainfed yields are not sufficient to fully close the gap between rainfed and irrigated yields.

Abbreviations: USDA: U.S. Department of Agriculture; RegCM4.3: ICTP Regional Climate Model version 4.3; NCEP: National Centers for Environmental prediction; DOE: U.S. Department of Energy; CGCM: Canadian Climate Centre general circulation model; GFDL: Geophysical Fluid Dynamics Laboratory general circulation model; CRCM: Canadian Climate Centre regional climate model; CCSM: National Center for Atmospheric Research general circulation model; HRM3: Hadley Centre’s Regional Model 3; HADCM3: Hadley Centre’s general circulation model; WRFG: the NCAR Weather Research and Forecasting model; CCCma: Canadian Centre for Climate Modelling and Analysis; CanESM2: Canadian Centre Earth System Model 2; ICHEC-EC: A European community Earth-System Model; IPCC: Intergovernmental Panel on Climate Change; RMSE: Root Mean Square Error     

Biomass to bio-ethanol: The evaluation of hybrid Pennisetum used as raw material for bio-ethanol production compared with corn stalk by steam explosion joint use of mild chemicals

The second generation biomass to bio-ethanol production is of growing interest. Energy crop were becoming important for second generation biomass to bio-ethanol production for their growth advantages. Hybrid Pennisetum as a new hybrid energy crop was selected as a model to compare with corn stalk. As pre-treatment methods, steam explosion and its combined action with dilute sulfuric acid, bisulfite, and mixed dilute acid and bisulfite were selected. The enzymatic hydrolysis demonstrated that the cellulose conversion is a strong function of the pre-treatment method applied, with corn stalk providing slightly better results. With dilute acid steam explosion (DA-SE), conversions were 67.6% and 54.5% for corn stalk and pennisetum, respectively. This can be attributed to the higher Cr. I of pennisetum (65.03%) than of corn stalk (54.05%). The cell lumen of pretreated pennisetum was smaller than for corn stalk as shown in SEM photos, meaning there was a substantially higher enzyme accessible surface and porosity in pennisetum, thus responsible for the higher cellulase adsorption of pretreated pennisetum. DA-SE was the most effective pre-treatment method, but the inhibitors' concentration was higher than in other methods. Combined dilute acid and bisulfite can moderately remove hemicelluloses and lignin. Cr. I values, lignin content, accessible surface and porosity were supplied the energy crop evaluation standards for bio-ethanol production.     

Responses of the novel bioenergy plant species Sida hermaphrodita (L.) Rusby and Silphium perfoliatum L. to CO2 fertilization at different temperatures and water supply

Two North American tall perennials, Sida hermaphrodita L. Rusby and Silphium perfoliatum L. have been recognized in Europe as high-yielding novel bioenergy species. While the latter is recommended for biogas production in Germany, the ligno-cellulosic stems of S. hermaphrodita are widely used as a solid fuel in Poland. Since information on the adaptation of the species to drought and heat and interactions with the CO₂ fertilization effect were lacking, growth chamber experiments were performed with seed-grown and established plants. A full factorial combination of two temperatures, two water levels and two CO₂ levels was applied using the long-term seasonal climate of southwestern Germany as a reference. Non-destructive parameters (length, phenology and senescence) and five harvests served to identify treatment effects on growth and allocation patterns. Shoot material was subjected to chemical and bioenergetic analyses (methane production and energy contents) and NIR-spectroscopy. While seedlings showed stronger growth responses to the treatments than established plants, interspecific differences of the responses were mostly related to allocation patterns and senescence. S. perfoliatum, which has a greater proportion of leaf mass was able to profit from CO₂ fertilization even under dry conditions, while in S. hermaphrodita such effects were absent. Chemical quality (crude protein, ash, fat and fibre) was mainly affected by the reduced water supply and energetic values in S. hermaphrodita and specific methane yields of S. perfoliatum tended to be lower. NIR spectra showed a good representation of percentage leaf mass, which in both species determines the quality of the shoot.     

Sweet sorghum for bioethanol production: Crop responses to different water stress levels

Cultivation of sweet sorghum for the production of bioenergy is an attractive option to cope with the challenges of climate change and variability. In fact, on one hand it represents an interesting strategy of mitigation and, on the other, the use of drought resistant species could be considered as an opportunity of adaptation to the change of precipitation patterns. Anyway, when considering the production of agricultural feed stocks, particular attention should be addressed to the environmental sustainability of field production in order to avoid trade-offs in relation to food production, land use and pressure on the water resources. In this context, the cultivation of drought-tolerant energy crops as sweet sorghum (Sorghum vulgare (L.) var. Saccharatum) could be an interesting option. On the bases of these considerations, the current study had the aims i) to monitor the sweet sorghum growth and productive responses to different water treatments, in order to assess the extent of tolerance to constant water stress and ii) to assess the potential for first and second-generation bioethanol production obtainable from soluble sugars and residual biomass at two different development stages, flowering and physiological maturity.Results show that the length of the growing period should be decided on the bases of the objective pursued.If the objective is just the production of bioethanol, a longer cultivation period could be more suitable, but, on the contrary, if the objective is more addressed to an optimization of water, flowering should be considered the best harvest time.