In order to evaluate the safety of four new herbicides applied in preceeding rice fields to succeeding tobacco, the effects of the four herbicides on tobacco growth were investigated through indoor pot experiments and field plot experiments. A QuEChERS pretreatment method combined with high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS） were employed to measure the residual level of quintrione in tobacco field soils. The results showed that florpyrauxifen, triafamone·tefuryltrione and mesotrione had no significant effects on the growth of tobacco. The inhibition rates of quintrione（750-2 250 g a.i./hm~2） to the leaf length, leaf width and plant height of tobacco in the pot and field experiments were 48.27%-69.00%, 66.30%-78.08%,58.76%-75.83% and 24.89%-43.79%, 35.47%-49.81%, 28.87%-48.75%, respectively. Quintrione caused serious phytotoxicity to succeeding tobacco. No quintrione（the residue level was lower to the LOQ, 0.002 mg/kg） was detected in the soils when tobacco seedlings were transplanted in the following year. Thus, there is a great risk that quintrione would cause phytotoxicity to succeeding tobacco, and it should be used with caution in tobacco-rice rotation areas.

Tobacco mosaic virus（TMV） is a major factor leading to the yield reduction of Solanaceae crops. In order to explore edible fungus-derived polysaccharide materials for the prevention and control of Tobacco mosaic virus, the control effect of six crude polysaccharides against TMV was determined by the half-leaf method, five-point injection test and systematic host infection activity evaluation. Among them, the extraction rate of crude polysaccharide from Agaricus blazei, 24.32%, was the highest, followed by Pleurotus ostreatus 18.56%, and that from Pleurotus eryngii,10.04% was the lowest. The total sugar content of A. blazei was significantly higher than that of other species, reaching 37.71%, followed by that of P. igniarius and G. Lucidum, exceeding 32.00%. In addition, the sulfate content of A. blazei crude polysaccharide was also as high as 2.10%. In this research, the inhibitory effect of the crude polysaccharides was determined by the half leaf method. Among the 6 tested polysaccharide treatments, the polysaccharides that were inoculated after treated for 48 h had a good inhibition on TMV. The preventive effects of P. ostreatus, C. versicolor and A. blazei reached more than 60.00%. Especially, the preventive effect of 24 mg/mL A. blazei crude polysaccharide was up to 92.04%, and the number of dead spots on the leaves was significantly less than those in the clear water control group. In the five-point injection test, the inhibition rate of A. blazei crude polysaccharide was 38.18%. The brightness of the fluorescent spots was weaker than that in the control group, the fluorescent area did not change much, and did not appeared in the new leaves. A. blazei crude polysaccharide had an inhibitory effect in the early stage of virus infection,which could delay the moving speed of TMV and slow down the system invasion process. On NC-89, the control effect of agaricus antler polysaccharide on TMV was as high as 76.81%, which was better than that of 0.5% lentinan water agent and 1.8% octinamine acetate water agent. When the concentration was 48 mg/mL, the plants were damaged, and the excessive concentration of polysaccharide formed precipitation on the surface of the plants, causing the plants to yellow. Field test showed that the treatment effect of A. blazei crude polysaccharides on TMV was 70.31%. The plants with twisted, curled leaves and stopped growing had an obvious improvement. At the same time, it had a certain inhibitory effect on TMV, the onset time of sprayed tobacco was delayed, the tobacco grew well, and the leaves were extended. The results of this study would lay a foundation for further study on the action mode and mechanism of fungal polysaccharides against Tobacco mosaic virus.

为了明确湖南省烟田杂草种群与分布,采用对角线五点取样法在全省烟田进行了系统调查.结果表明,烟田杂草共有30科77种,其中禾本科杂草占比14.29％,阔叶杂草占比81.82％,莎草科杂草占比3.89％;一年生杂草占比75.32％,多年生杂草占比24.68％.相对多度大于3％的杂草有铁苋菜、酸模叶蓼、稗、碎米荠、马唐、繁缕、喜旱莲子草、看麦娘、通泉草、鸭跖草、水苦荬等11种,其中铁苋菜、酸模叶蓼、稗为湖南省烟田优势杂草种群,碎米荠、马唐、繁缕、喜旱莲子草、看麦娘、通泉草、鸭跖草、水苦荬为湖南省烟田区域性优势杂草种群.湖南省烟田杂草防除主要采用苗前土壤处理和苗后茎叶处理相结合的化学防除方法,主要使用的化学除草剂是精异丙甲草胺和砜嘧磺隆.本研究结果表明,湖南省烟田杂草存在区域性差异,应因地制宜制定合适的化学防治方案.

为了评价几种除草剂对烟草田杂草的防除效果及对烟草的安全性,在浏阳市烟草基地开展了田间试验.结果表明,供试的除草剂对烟草安全性较好.土壤处理剂中,80％异·异丙甲乳油、50％仲灵·异松乳油、45％甲戊·异丙甲乳油这3种复配除草剂对烟草田杂草的防治效果较好,在药后30 d对杂草的株防效为89.20％～93.92％,药后60 d对杂草的株防效为83.38％～88.53％,鲜重防效为86.53％～90.36％,均要显著优于常规对照药剂960 g/L精异丙甲草胺.行间定向喷雾茎叶处理剂中,250 g/L氟磺胺草醚AS+10％精喹禾灵EC、10％乙羧氟草醚EC+10％精喹禾灵EC、200 g/L敌草快AS+10％精喹禾灵EC等3种复配除草剂的防效较好,药后10 d对烟草田杂草的株防效为94.98％～95.75％,药后20 d对烟草田杂草的株防效为93.86％～96.03％,鲜重防效为94.98％ ～96.41％,均要显著优于烟草田常规使用药剂25％砜嘧磺隆WG+10％精喹禾灵EC.在供试除草剂中,除二甲戊灵对烟草生长表现轻微抑制作用外,其余除草剂对烟草农艺性状均表现为一定的促进作用,但效果不显著.试验表明,上述除草剂及复配剂可以用于烟草田进行合理轮换使用,延缓烟草田杂草抗药性产生并提高烟草田杂草防治水平.

烟草是我国重要的经济作物,杂草是影响烟草产业发展的关键因素之一.本文对全国主要烟区烟田杂草的种类与分布,当前烟田杂草化学防除现状及面临主要问题,引起烟草药害的除草剂种类及其药害症状,烟草除草剂药害的主要修复技术等进行了综述,并展望了未来烟田杂草防治中需引起重视的几个重要问题,可为烟田除草剂的合理使用及烟草药害的治理提供参考.

比较分析了病毒生物学测定、DAS-ELISA、胶体金试纸条检测和RT-PCR等4种方法检测TMV的灵敏度及特异性,发现病毒生物学测定比其它3种方法具有更高的灵敏性,但耗时较长,胶体金试纸条检测耗时最短,但其灵敏性显著低于RT-PCR,ELISA操作时间长且灵敏度低.因此,确定了RT-PCR作为植烟土壤中TMV检测的主要方法.对我国主要植烟区土壤TMV的污染状况进行了分析.检测结果表明,我国植烟区土壤TMV污染严重,TMV检出率达55.6％,以旱地植烟土壤TMV污染最为严重.

This study through the observation under the condition of total artificial breeding of giant salamander embryo development and the formation process of organs,the contrast of copy is natural the salamander embryo developmental process of ecological breeding,the salamander from fertilized egg to hatch for seedlings out membrane on the morphology observation of continuous system.Results: artificial breeding of the strain to its embryonic stage in embryonic development and organ formation,there are obvious "nerve ditch","optic vesicle formation" and "heart beat" characteristics,and on the basis of the traditional stage increased "neural groove period","optic vesicle formation" and "heart beat" period,and the appearance of embryonic development process is divided into 23 times;Although the same strain of artificial breeding and imitated ecological breeding way most basic same,appearance features of development but in cleavage stage and neural embryo stage still exist differences;And by using artificial breeding technology,improve its hatching rate,hatching rate.Providing theoretical basis for further study on the artificial breeding of giant salamander and experimental materials.

赤眼鳟(Squaliobarbus curriculus)属硬骨鱼纲、鲤形目、鲤科、雅罗鱼亚科、赤眼鳟属,俗称野草鱼、红眼鱼.具有生长快、适应性强、商品鱼售价高等优点,其肉质细嫩、味道鲜美、营养丰富,深受消费者青睐,是江河主要优质经济鱼类之一,也是淡水养殖的热门种类.赤眼鳟分布广,几乎遍布全国各大水系.目前国内外有关赤眼鳟的报道较多,笔者从几个方面综述赤眼鳟的研究现状,并提出合理开发利用的建议. 1 形态结构与生长特性 赤眼鳟体修长,略呈圆筒状,体色银白,因眼上缘有一红斑而得名[1-2].赤眼鳟为广温性经济鱼类,广泛分布于我国不同纬度的淡水水域.在不同的水域生长速度不同:长江水系种群的体长生长速度最快,较黑龙江水系种群快2～3倍,达到相同体长要比珠江水系种群快约一年.赤眼鳟的体长生长速度在低龄阶段较快,随年龄增加,体长生长速度逐渐变慢;体长生长加速度呈减速上升趋势[3].

对大麻安全性最低的除草剂是48%地乐胺EC,苗后7 d受害株率为23%。50%乙草胺EC和96%精异丙甲草胺EC对大麻的药害较轻。对大麻株高影响最大的是48%地乐胺EC,药后7 d和14 d的株高均显著低于空白对照,其他处理均接近空白对照。药后15 d对大麻田杂草的株防效最好的是96%精异丙甲草胺EC和50%乙草胺EC,分别为90.7%和89.8%,显著高于25%扑草净WP的79.7%和48%地乐胺EC的77.5%。药后30 d各处理对杂草的株防效都略有下降,但趋势基本一致。对大麻田杂草鲜重防效最好的除草剂为96%精异丙甲草胺EC和50%乙草胺EC,鲜重防效分别达到了89.4%和89.1%。在保证对大麻安全的前提下,96%精异丙甲草胺EC 1 050 mL/hm2和50%乙草胺EC 750 mL/hm2均可作为大麻田播后苗前除草剂使用,且能对杂草起到良好的防除效果。

In order to research the action and effects of gibberellin in promotion for growth and flowering of the Senecio×hybridus,the plants was treated by exogenous gibberellin (concentration were 0, 50, 100, 150, 200 mg·L-1) and the morphological and physiological items related to growth and development were measured. The results showed that:(1)GA treatment promoted stem and pedicel elongation of Senecio×hybridus, and the chloroplyll content in leaves reduced;(2)The number of flowers were increased ,and the flowering period were prolonged,and flowering were earlier in all gibberellin treated plants, and the more effective concentration was 100 mg·L-1 and 150 mg·L-1;(3)The phenomenon of 'there are flowers in flowers' appeared in the three groups(A,B,C) treated with gibberellin (the maximum rate is 35.71% ), and all of the new flowers were double. The minimum rate appeared in the groups(C) treated with 200 mg·L-1 gibberellin was 1.56%.