绿黄隆残留对后茬水稻的药害及预防措施

绿黄隆比绿麦隆、异丙隆等取代脲类除草剂具有用药量低、活性高、杀草谱广和对小麦较安全等特点,是目前麦田除草较理想的药剂。但它降解缓慢,在田间有一定残留,若使用不当,对后茬作物会产生药害。太湖地区为稻麦两熟区,水稻是主要粮食作物,绿黄隆能     

玉米几种常见除草剂的药害症状识别

正玉米田使用除草剂防除杂草,是一种省工、省力、省时的除草方法。但玉米田使用除草剂有比较严格的要求,特别是在对除草剂的选择和混用上,稍有疏忽就会造成严重的药害,甚至会带来改种的危险。现将玉米田常见的几种除草剂使用不当对玉米造成的药害症状介绍如下。烟嘧磺隆药害。笔者曾发现过量使用烟嘧磺隆,造成处于6~7叶期玉米全被杀死的典型药害实例。烟嘧磺隆属于磺酰脲类除草剂中的高效药剂,在玉米田使用不当易产生药害,使用时应严格按照     

谨防除草剂对水稻产生药害

正稻田推广化学除草既减轻了农民劳动强度,又能取得较大的经济效益和社会效益。但是,由于一些地方对除草剂的药性及使用技术掌握不够,常常会在使用后出现不同类型的药害症状。除草剂对水稻的药害因品种、施药量、使用期等不同而出现不同的症状,现根据各地多年使用的情况及观察试验数据,将常见的一些药害介绍如下:甲磺隆、氯磺隆、胺苯磺隆等磺酰脲类除草剂,     

土壤微生物降解磺酰脲类除草剂的研究进展

简要地综述了土壤微生物对磺酰脲类除草剂的降解、降解机理及影响微生物降解磺酰脲类除草剂的因素,并指出了利用土壤微生物修复磺酰脲类除草剂的残留药害是一个有效手段。     

新除草剂esprocarb

esprocarb是英国ICI公司开发的硫代氨基甲酸酯类除草剂,对以稗草为主的一年生杂草有较高的防效。特别是该剂与美国杜邦公司开发的磺酰脲类除草剂苄嘧黄隆混合后,具有杀草谱广、对稗草有增效的防除效果、并可减轻对水稻的药害等特点。混剂有     

AC322140''''一种选择性防除稻田和谷物田杂草的新的广谱除草剂

AC322140系由美国氰胺公司开发的新颖除草剂,可用以防除谷物和水稻田中的许多双子叶杂草和蓑衣草。此药剂属磺酰脲类,但与通常的磺酰脲类除草剂在桥的化学及在苯环邻位取代基有很大不同。AC322140以其独特的化学结构成为具有很高选择性和对环境安全的除草剂。     

除草腐脲颗粒剂防除稻田杂草的效果及其推广应用

除草腐脲颗粒剂是一种新研制的稻田新型药肥除草剂,集除草肥田增产等特点,水稻移(抛)栽后3～5d,每667m2用除草腐脲颗粒剂15kg,对稻田杂草的防效可达90%以上,并对稻苗安全无药害,促水稻壮苗多分蘖,增产10%以上,明显优于常规除草剂,值得在水稻上推广应用。     

国外除草剂发展近况

本文按结构分七类介绍了国外近几年除草剂发展情况:取代脲类除草剂;二苯醚类除草剂;苯氧羧酸类除草剂;有机磷类除草剂;有机杂环类除草剂;酰胺类除草剂及其他除草剂。文中只是概略地介绍了一下上述几类主要除草剂品种,未涉及每个药剂的合成方法等,故仅供参考。     

酰胺类除草剂的药害表现与安全应用

酰胺类除草剂 ,是目前生产中应用较为广泛的一类除草剂 ,如乙草胺、异丙甲草胺、丁草胺等 ,可以用于玉米、花生、大豆、棉花等多种作物 ,防除一年生禾本科杂草和部分阔叶杂草 ,由于该类药剂杀草谱广、效果突出、价格低廉、施用方便等优点 ,在生产中推广应用面积逐渐扩大。然而 ,酰胺类除草剂对作物存在着隐性药害〔1,2〕,特别是用药量过大、或施药后遇持续低温高湿天气时 ,可能会严重影响作物的生长 ,作者对此进行了广泛研究 ,生产中应充分了解该类除草剂的药害发生原因和症状表现 ,做好该类除草剂的安全应用。1　酰胺类除草剂药害的典型药…     

磺酰脲类除草剂在草坪杂草防除中的应用

磺酰脲类除草剂具有超高效、低毒和高选择性等特性,是除草剂中品种最多,销售额仅低于草甘膦等氨基酸类除草剂的第二大类除草剂品种.此类除草剂主要应用于水稻、玉米、小麦和大豆等粮食作物田中进行杂草防除.介绍了磺酰脲类除草剂用于冷季型和暖季型草坪防除杂草和春季草坪转换时防除冷季型草坪草的情况以及草坪应用中存在的问题和发展前景.     

Studies on changes in fatty acid composition and content of endogenous antioxidants during γ irradiation of rice seeds

Accelerated aging effects, induced by y irradiation, were investigated on the fatty acid composition of lipids and on the content of endogenous antioxidants of four Indica and four Japonica rice seeds with and without intact hull. While the linoleic acid content of the phospholipids decreased gradually with the increase in irradiation doses, there was a corresponding increase in the linoleic acid content of the free fatty acids. Such changes were drastic, especially in the case of Japonica rice seeds irradiated without intact hull. However, the neutral lipids were found to be resistant to γ irradiation. The α-tocopherol content was found to decrease (markedly) in rice seeds irradiated with or without hull, especially in the Japonica rice seeds. At a dose of 15 kGy only traces of a-tocopherol could be detected in Japonica and Indica rice seeds irradiated with and without intact hull. Oryzanol, a relatively weaker anti-oxidant, was found to be more resistant to oxidative damage than a-tocopherol. At 15 kGy, the oryzanol content ranged from 59 μg to 170 μg/g lipid in rice seeds irradiated with intact hull, while the corresponding value for rice seeds irradiated without hull was 52 μg to 153 μg/g lipid. The overall susceptibility to oxidative damage was less in Indica rice seeds, indicating that the antioxidative defense system offered better protection in overcoming oxidative stress in Indica rice hull than in Japonica rice hull.     

Fatty Acid Composition of Indica-and Japonica-Types of Rice Bran and Milled Rice

Fatty acid compositions of 10 cultivars each of Indicaand Japonica types of rice bran and milled rice were investigated. The Indica-type, as compared with the Japonica-type, had significantly higher palmitic, stearic, linolenic, and arachidic acid contents and lower linoleic and eicosenoic acid contents in the bran and milled rice, and lower oleic acid content in the bran. The correlation coefficient between oleic and linoleic acid contents of bran and milled rice was negative in the Indica-and Japonica-types and was the highest between all fatty acids. The regression line in the scatter diagrams between oleic and linoleic acid contents of bran and milled rice divided the Indica and Japonica lines.     

稻田杂草群落的变化和化除技术的进展

肥床旱育,少免耕,抛秧,移载稻扩行距缩株距等使稻田杂草总发生数量增加。在群落结构上,稗草,眼子菜数量下降,矮慈姑,野荸荠,水莎草等阔叶杂草和莎草科杂草数量上升。稻田化除的进展主要表现在新除草剂、一次性复配除草剂大面积的推广使用;难除恶性杂草化除技术的提高和除草剂新剂型的开发与应用等。长残效除草剂的药害,部分除草剂对水稻的隐性伤害,除草剂复配剂含量上升配比不统一等是存在的主要问题。     

Haplotype Analysis of BADH1 by Next-Generation Sequencing Reveals Association with Salt Tolerance in Rice during Domestication

Betaine aldehyde dehydrogenase 1 (BADH1), a paralog of the fragrance gene BADH2, is known to be associated with salt stress through the accumulation of synthesized glycine betaine (GB), which is involved in the response to abiotic stresses. Despite the unclear association between BADH1 and salt stress, we observed the responses of eight phenotypic characteristics (germination percentage (GP), germination energy (GE), germination index (GI), mean germination time (MGT), germination rate (GR), shoot length (SL), root length (RL), and total dry weight (TDW)) to salt stress during the germination stage of 475 rice accessions to investigate their association with BADH1 haplotypes. We found a total of 116 SNPs and 77 InDels in the whole BADH1 gene region, representing 39 haplotypes. Twenty-nine haplotypes representing 27 mutated alleles (two InDels and 25 SNPs) were highly (p < 0.05) associated with salt stress, including the five SNPs that have been previously reported to be associated with salt tolerance. We observed three predominant haplotypes associated with salt tolerance, Hap_2, Hap_18, and Hap_23, which were Indica specific, indicating a comparatively high number of rice accessions among the associated haplotypes. Eight plant parameters (phenotypes) also showed clear responses to salt stress, and except for MGT (mean germination time), all were positively correlated with each other. Different signatures of domestication for BADH1 were detected in cultivated rice by identifying the highest and lowest Tajima’s D values of two major cultivated ecotypes (Temperate Japonica and Indica). Our findings on these significant associations and BADH1 evolution to plant traits can be useful for future research development related to its gene expression.     

Genetic diversity for lipid content and fatty acid profile in rice bran

Rice (Oryza sativa L.) bran contains valuable nutritional constituents, which include lipids with health benefits. A germplasm collection consisting of 204 genetically diverse rice accessions was grown under field conditions and evaluated for total oil content and fatty acid (FA) composition. Genotype effects were highly statistically significant for lipid content and FA profile (P<0.001). Environment (year) significantly affected oil content (P<0.05), as well as stearic, oleic, linoleic, and linolenic acids (all with P<0.01 or lower), but not palmitic acid. The oil content in rice bran varied relatively strongly, ranging from 17.3 to 27.4% (w/w). The major FA in bran oil were palmitic, oleic, and linoleic acids, which were in the ranges of 13.9–22.1, 35.9–49.2, and 27.3–41.0%, respectively. The ratio of saturated to unsaturated FA (S/U ratio) was highly related to the palmitic acid content (r ²=0.97). Japonica lines were characterized by a low palmitic acid content and S/U ratio, whereas Indica lines showed a high palmitic acid content and a high S/U ratio. The variation found suggests it is possible to select for both oil content and FA profile in rice bran.     

原卟啉原氧化酶抑制性除草剂的发展

原卟啉原氧化酶是四吡咯生物合成途径中最后一种酶,是包括二苯醚、环状亚胺、噁二唑等多种类型除草剂的靶标。作用于该酶的此类除草剂引起细胞成分在光诱导的过氧化作用遭到破坏,从而造成细胞渗漏、光合作用受阻,最终导致植物死亡。综述了原卟啉原氧化酶抑制性除草剂的开发、特性及若干品种。     

Influence of Some Herbicides on the Physical and Chemical Characteristics of Soybean Oil

The effect of some herbicides on the soybean oil quality and quantity has been studied. Herbicides caused a highly significant increase in soybean oil content. Statistical analysis showed that there was no and highly significant differences in acid value; unsaponifiables and saponification value and iodine value respectively of soybean oil extracted from plants subjected to various herbicides. The increase of herbicides application rates exhibited profound effects on the physical and chemical characters of soybean oil. The application of herbicides leads to the following changes on soybean oil fatty acids: decrease the concentrations of 13:0, 15:0, 18:0 and 20:0; increase the quantity of 16:0 and the appearance of 10:0, 11:0, UC15, 16:1 and 17:0 as new synthetically fatty acids. The total unsaturated to total saturated fatty acid ratios showed that cobex and linuron at low application rates caused desaturation some of 18:1 to form 18:2. On the contrary, these herbicides at high application rates exhibited the reverse effect.     

Direct and Indirect Effects of Invasive Plants on Soil Chemistry and Ecosystem Function

Invasive plants have a multitude of impacts on plant communities through their direct and indirect effects on soil chemistry and ecosystem function. For example, plants modify the soil environment through root exudates that affect soil structure, and mobilize and/or chelate nutrients. The long-term impact of litter and root exudates can modify soil nutrient pools, and there is evidence that invasive plant species may alter nutrient cycles differently from native species. The effects of plants on ecosystem biogeochemistry may be caused by differences in leaf tissue nutrient stoichiometry or secondary metabolites, although evidence for the importance of allelochemicals in driving these processes is lacking. Some invasive species may gain a competitive advantage through the release of compounds or combinations of compounds that are unique to the invaded community—the “novel weapons hypothesis.” Invasive plants also can exert profound impact on plant communities indirectly through the herbicides used to control them. Glyphosate, the most widely used herbicide in the world, often is used to help control invasive weeds, and generally is considered to have minimal environmental impacts. Most studies show little to no effect of glyphosate and other herbicides on soil microbial communities. However, herbicide applications can reduce or promote rhizobium nodulation and mycorrhiza formation. Herbicide drift can affect the growth of non-target plants, and glyphosate and other herbicides can impact significantly the secondary chemistry of plants at sublethal doses. In summary, the literature indicates that invasive species can alter the biogeochemistry of ecosystems, that secondary metabolites released by invasive species may play important roles in soil chemistry as well as plant-plant and plant-microbe interactions, and that the herbicides used to control invasive species can impact plant chemistry and ecosystems in ways that have yet to be fully explored.     

A Two-in-One Strategy: Target and Nontarget Site Mechanisms Both Play Important Role in IMI-Resistant Weedy Rice

The introduction of Clearfield technology allows the use of imidazolinone (IMI) herbicides to control weedy rice. Imidazolinone herbicides stop the acetolactate synthase (ALS) enzyme from synthesizing branched-chain amino acids, resulting in the death of the plant. Since the launch of Clearfield technology in Malaysia in 2010, many farmers have replaced traditional cultivars with Clearfield (CL) rice lines (MR220-CL1 and MR220-CL2). This technology was initially effective; however, in recent years, local farmers have reported the reduced efficacy of IMI herbicides in controlling the spread of weedy rice. Under IMI herbicide treatment, in previous weedy rice studies, the target-site resistance (TSR) mechanism of the ALS gene has been suggested as a key factor conferring herbicide resistance. In our study, a combination of ALS gene sequencing, enzyme colorimetric assay, and a genome-wide association study (GWAS) highlighted that a non-target-site resistance (NTSR) can be an alternative molecular mechanism in IMI-resistant weedy rice. This is supported by a series of evidence, including a weak correlation between single nucleotide polymorphisms (SNPs) within the ALS exonic region and ALS enzyme activity. Our findings suggest that the adaptability of weedy rice in Clearfield rice fields can be more complicated than previously found in other rice strains.     

水稻用三大类农药市场及产品开发

简要介绍了水稻用杀虫剂、除草剂、杀菌剂的使用情况,及其主要市场、主要品种,概述了水稻用各类新农药的开发情况,并对水稻用农药市场前景进行了展望。