Differential tolerance of peas to prometryne and terbutryn

The phytotoxicity of 2,4-bis(isopropyl)-6-(methylthio)-s-triazine (prometryne) and 2-(tert-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine (terbutryn) to peas (Pisum sativum L. var. Perfection 3040) was studied. No differences were found when the herbicides were applied to the roots of intact plants in nutrient solution or directly to leaf discs. However, prometryne was much more toxic when uptake was from soil. Absorption and translocation of ¹⁴C-labeled prometryne and terbutryn showed that the majority of terbutryn accumulated in the roots, whereas prometryne was uniformly distributed between the roots and the shoot. Thin layer chromatography of extracts from prometryne-treated peas showed that only 20% of the absorbed compound was metabolized to produce one breakdown product. Extracts of terbutryn-treated plants contained three different metabolites. After 120 hr of exposure to terbutryn, about half of the absorbed herbicide was metabolized. The results show that the main factors responsible for the differential toxicity of the herbicides to peas were availability from the soil, translocation pattern and initial detoxication.     

Effect of pollen storage by drying and deep-freezing on the expression of different agronomic traits in maize (Zea mays L.)

Summary Pollen from the inbred maize line HMv 1645 was used to study the effect of pollen treatments (drying and deep-freezing) on the phenotypic performance of the next generation. Fresh and artificially dried pollen samples with different water contents (56%, 18%, 13% and 10%) were used for sib pollinations immediately after collection or drying. Samples containing low amounts of water were then stored in liquid nitrogen for 7 days. Fertilization ability of the samples with 13% water was the highest after storage. Plant characteristics of the next generation originated from the seeds set by differently treated (fresh, dried to 13% water and deep-frozen) pollen were examined and statistically analysed. Pollen treatments due to the pollen storage procedure did not cause detectable changes in quantitative characters of the next generation.     

小麦籽粒蛋白质组分及其与面条品质的关系

 采用新的蛋白质组分分离方法,对黄淮部分冬麦区25个小麦品种籽粒的单体蛋白含量、可溶性谷蛋白含量、不溶性谷蛋白含量进行了分析,同时对各蛋白质组分与其它蛋白质指标、面条品质的关系进行了研究。结果发现,黄淮冬麦区小麦的平均单体蛋白、可溶性谷蛋白和不溶性谷蛋白的比例为3.7∶1.0∶1.8;与有关文献比较,分析样品的单体蛋白含量偏低,可溶性谷蛋白含量偏高,不溶性谷蛋白含量较低,这可能就是面包小麦和面条小麦在蛋白质组成上的本质区别。单体蛋白对于面条拉伸特性作用小于谷蛋白。可溶性谷蛋白含量、不溶性谷蛋白含量与其它蛋白质     

Production of chitinolytic enzymes with Trichoderma longibrachiatum IMI 92027 in solid substrate fermentation

Thirty Trichoderma strains representing 15 species within the genus have been screened for extracellular production of chitinolytic enzymes in solid substrate fermentation (SSF). T.longibrachiatum IMI 92027 (=ATCC 36838) gave the highest yield (5.0 IU/g dry matter of substrate) after 3 days of fermentation on wheat bran-crude chitin (9:1 mixture) medium. The optimum moisture content (66.7%), chitin content (20%), initial pH of the medium (2-5) and time course (5 d) of SSF were determ…     

The application of small unmanned aerial systems for precision agriculture: a review

Precision agriculture (PA) is the application of geospatial techniques and sensors (e.g., geographic information systems, remote sensing, GPS) to identify variations in the field and to deal with them using alternative strategies. In particular, high-resolution satellite imagery is now more commonly used to study these variations for crop and soil conditions. However, the availability and the often prohibitive costs of such imagery would suggest an alternative product for this particular application in PA. Specifically, images taken by low altitude remote sensing platforms, or small unmanned aerial systems (UAS), are shown to be a potential alternative given their low cost of operation in environmental monitoring, high spatial and temporal resolution, and their high flexibility in image acquisition programming. Not surprisingly, there have been several recent studies in the application of UAS imagery for PA. The results of these studies would indicate that, to provide a reliable end product to farmers, advances in platform design, production, standardization of image georeferencing and mosaicing, and information extraction workflow are required. Moreover, it is suggested that such endeavors should involve the farmer, particularly in the process of field design, image acquisition, image interpretation and analysis.     

Developments in breeding cereals for organic agriculture

The need for increased sustainability of performance in cereal varieties, particularly in organic agriculture (OA), is limited by the lack of varieties adapted to organic conditions. Here, the needs for breeding are reviewed in the context of three major marketing types, global, regional, local, in European OA. Currently, the effort is determined, partly, by the outcomes from trials that compare varieties under OA and CA (conventional agriculture) conditions. The differences are sufficiently large and important to warrant an increase in appropriate breeding. The wide range of environments within OA and between years, underlines the need to try to select for specific adaptation in target environments. The difficulty of doing so can be helped by decentralised breeding with farmer participation and the use of crops buffered by variety mixtures or populations. Varieties for OA need efficient nutrient uptake and use and weed competition. These and other characters need to be considered in relation to the OA cropping system over the whole rotation. Positive interactions are needed, such as early crop vigour for nutrient uptake, weed competition and disease resistance. Incorporation of all characteristics into the crop can be helped by diversification within the crop, allowing complementation and compensation among plants. Although the problems of breeding cereals for organic farming systems are large, there is encouraging progress. This lies in applications of ecology to organic crop production, innovations in plant sciences, and the realisation that such progress is central to both OA and CA, because of climate change and the increasing costs of fossil fuels.     

Regulatory perspective of pesticide analytical enforcement methodology in the United States

A critical overview is presented of the current regulatory problems encountered by the U.S. Environmental Protection Agency in evaluating the adequacy of pesticide analytical enforcement methodologies submitted in support of proposed pesticide tolerances. One of these problems is the development and validation of appropriate, adequate enforcement analytical methods which account for all free or bound/conjugated residue components of the "total toxic residue" in the commodities of concern. Also included is a detailed discussion of suggested improvements in the development and validation of these enforcement methods, for example, integrating radiolabeled metabolism studies with the subsequent development and validation of proposed analytical enforcement methodologies. New procedures are proposed to facilitate the availability of analytical methods to enforcement agencies and other organizations during the method validation process. Future initiatives to use the collaborative study process in the development and validation of Pesticide Analytical Manual, Volume 2, enforcement methods for contemporary pesticides are also discussed.     

Effects of carnitine and taurine on fatty acid metabolism and lipid accumulation in the liver of cats during weight gain and weight loss

OBJECTIVE: To determine the effects of carnitine (Ca) or taurine (Ta) supplementation on prevention of lipid accumulation in the liver of cats. ANIMALS: 24 adult cats. PROCEDURE: Cats were fed a weight-gaining diet sufficient in n-6 polyunsaturated fatty acids (PUFAs), low in long-chain n-3 PUFAs (n-3 LPUFA), and containing corn gluten for 20 weeks. Cats gained at least 30% in body weight and were assigned to 4 weight-reduction diets (6 cats/diet) for 7 to 10 weeks (control diet, control plus Ca, control plus Ta, and control plus Ca and Ta). RESULTS: Hepatic lipids accumulated significantly during weight gain and weight loss but were not altered by Ca orTa after weight loss. Carnitine significantly increased n-3 and n-6 LPUFAs in hepatic triglycerides, decreased incorporation of 13C palmitate into very-low-density lipoprotein and hepatic triglycerides, and increased plasma ketone bodies. Carnitine also significantly increased weight loss but without altering the fat to lean body mass ratio. Taurine did not significantly affect any variables. Diets low in n-3 LPUFAs predisposed cats to hepatic lipidosis during weight gain, which was further exacerbated during weight loss. Mitochondrial numbers decreased during weight gain and weight loss but were not affected by treatment. Carnitine improved fatty acid oxidation and glucose utilization during weight loss without correcting hepatic lipidosis. CONCLUSIONS AND CLINICAL RELEVANCE: The primary mechanism leading to hepatic lipidosis in cats appears to be decreased fatty acid oxidation. Carnitine may improve fatty acid oxidation but will not ameliorate hepatic lipidosis in cats fed a diet low in n-3 fatty acids.     

A Simple Wheat Flour Swelling Test

Flour swelling tests have been widely used to assess the intercultivar differences in starch properties. This note describes a modified flour swelling test which uses ≈30 mg of flour. It avoids the use of a high-temperature water bath, and does not require a set of uniform and leak-proof tubes. The modified procedure offers a simpler and more rapid alternative to those previously reported, and provides a similar level of discrimination and precision. It is particularly suitable as a micro-scale early generation test for wheat flour swelling properties.