甲胺磷预处理小菜蛾对菜蛾绒茧蜂的影响

分别在菜蛾绒茧蜂处于卵期、早期幼虫和中期幼虫时,饲喂小菜蛾2龄幼虫亚致死剂量甲胺磷,研究甲胺磷处理对寄主体内菜蛾绒茧蜂结茧率和羽化率的影响.试验表明,经亚致死剂量甲胺磷处理后,菜蛾绒茧蜂的结茧率和羽化率与对照相比均显著降低.在菜蛾绒茧蜂处于卵期时饲喂寄主幼虫,菜蛾绒茧蜂的结茧率和羽化率分别下降59.1%和32.5%;在菜蛾绒茧蜂处于早期幼虫时饲喂寄主幼虫,菜蛾绒茧蜂的结茧率和羽化率分别下降40.5%和32.8%;而在菜蛾绒茧蜂处于中期幼虫时饲喂寄主幼虫,菜蛾绒茧蜂的结茧率和羽化率分别下降18.2%和37.2%.结果表明,在绒茧蜂处于不同发育阶段时,饲喂小菜蛾幼虫甲胺磷对菜蛾绒茧蜂结茧率的影响较大,但对羽化率的影响不大.     

环鄱阳湖地区浅层地下水化学特征及成因分析

[目的]分析环鄱阳湖地区浅层地下水化学特征及成因。[方法]于2010年对环鄱阳湖地区7个县市的地下水质状况进行调查,从矿化度、硬度、水化学类型等方面对鄱阳湖区域不同地区浅层地下水质状况进行分析对比,揭示区域浅层地下水质现状及其变化特征与原因。[结果]环鄱阳湖地区地下水质指标除pH外均较好,均属Ⅰ类水质标准;其中南昌市矿化度、硬度、电导率、Na+、K+、Ca2+、Mg2+、Cl-、HCO3-为最高值,都昌县pH和SO42-为最高值,鄱阳县Mg2+和pH为最低值,永修县硬度、K+、Ca2+、SO42-、Cl-为最低值,进贤县Na+、矿化度和电导率为最低值。江西整体经济发展水平不高是环鄱阳湖地区地下水质较好的主要原因;南昌市地下水多项水质指标最大,甚至趋于Ⅱ类水质标准,是由于经济发展水平较高,人类活动起决定性作用。[结论]该研究为区域浅层地下水管理对策提供依据。     

酥梨产量构成因素的通径分析

两年定树调查测定44株次的酥梨产量及其相关的树高/冠径、花芽数、总果数、座果率、枝/果,叶面积系数、每果叶面积、平均单果重等8个性状。应用逐步回归法逐个别除对于产量没有显著线性效应的性状,得到包括总果数、每果叶面积和平均单果重在内的最优多元线性回归方程。再对入选的各个主要性状进行通径分析,明确其对产量构成的直接和间接效应。结果说明,提高酥梨单株产量。首先要具有一定的果量,其次是增加平均单果重,再次是维持叶面积与果实的适当比例。在树冠大小基本稳定的情形下,增加每果叶面积会造成果量减少而使产量下降,同时又可提高平均单果重而使产量上升。每果最佳叶面积应是提高平均单果重而使产量的上升量大于因果量减少而使产量的下降量,这样不仅可以增加产量,而且可提高果实的商品竞争力。     

玉米雌穗小花类型,形态,决定时期及其与成粒的关系

玉米雌穗有完全花与不完全花之分,不完全花又分退化花和畸形花。总花数受品种遗传性制约,栽培措施影响较小,吐丝前后的温光条件影响较大。性器官形成期是不完全花发生的重要时期。夏播时品种间花数变幅为543——840朵。雌穗分化终止期因品种而异,大多于吐丝前7d至吐丝后1—2d。结实率达总花数80%,其中11—17%为败育粒,是影响小花成粒的首要因素,败育花影响甚微。高产栽培时花数较稳定,减少籽粒败育是提高产量的有效途径,中低产区增花增粒和保花增粒亦不可忽视。     

黑穗醋栗(Ribes nigrum L.)茎的解剖结构与不定根形成的研究

本实验结果表明,黑穗醋栗“厚皮”和“薄皮”品种之间茎的结构无明显区别,幼茎均由表皮、皮层、维管柱、髓和髓射线组成。仅“厚皮”茎的角质膜较厚;皮层和髓细胞较小,排列紧密;“薄皮”品种茎的角质膜较薄;皮层和髓部的细胞较大,排列疏松,髓部体积亦较“厚皮”的大,“薄皮”的茎较柔软容易下垂。两品种幼茎的表面均有腺体分布,分泌挥发性物质。未经扦插的一年生成熟茎内有“先成不定根原基”。经过水培(或扦插)的成熟茎内有“诱发不定根原基”。不定根原基常起源于髓射线(或多列射线)与形成层带交接的部位;其位置可能正对皮孔内方或在其一侧,也可在无皮孔区的周皮内侧。不定根可从皮孔内伸出,亦可从皮孔一例或其附近的周皮缝隙中伸出。常簇生在插条的茎节附近或沿插条节间排列成2～3纵列。     

沙尘暴尘源形成及分布

沙尘暴(sand—duststorm)系指强风把地表大量沙尘卷入到空中，使空气特别浑浊，水平能见度低于1000m的灾害性天气现象。是1种危害性极大的灾害性天气。它的发生和发展是加速土地荒漠化的重要过程，又是土地荒漠化发展到一定程度的具体体现。沙尘暴尘源物质的形成及分布是形成沙尘暴必不可少的物质条件。本文在查阅分析了大量关于沙尘暴研究等文献的基础上，从沙尘暴尘源形成因素、尘源种类及分布等方面，对沙尘暴尘源的研究进行了简要的总结，反映沙尘暴尘源方面的研究进展。     

不同水解程度丝素肽对黑色素生成抑制能力的研究

探讨了脱胶丝素经盐溶解后进行碱水解时 ,不同条件对丝素水解程度及不同水解程度丝素肽对蚕血黑色素生成的抑制能力的影响 .结果发现 ,温度对丝素的水解程度影响最大 ,时间其次 ,浓度的影响最小 ;丝素蛋白液未水解时 ,其对黑色素抑制率很低 ,只有 2 8.34% ,而丝素水解后 ,抑制率迅速提高到 4 8.95 % ,并且随着水解程度的加深不断提高 ,当氨基氮浓度达 0 .4 76 5g·L-1时 ,其对黑色素生成抑制率达最高值 6 7.14 % ;之后 ,随着水解程度的增加 ,其黑色素生成抑制率反而下降 .     

不同外源激素对糜子成穗及产量的影响

研究不同种类外源激素对糜子成穗及产量的影响。用5种外源激素在糜子3~4叶期喷施,连续处理2次,喷清水为对照。记录糜子苗期基本苗数、拔节期总茎数、成熟期穗数等性状,用统计软件SPSS 17.0进行统计分析。结果表明,施用脱落酸（ABA）能够显著降低糜子的分蘖数,施用赤霉素（GA₃）、吲哚乙酸（IAA）、矮壮素（CCC）也能减少糜子分蘖数,但是与对照差异不显著,施用多效唑（PP₃₃₃）对糜子分蘖数没有明显影响;施用GA₃、IAA、CCC能够增加分蘖穗数,而ABA、PP₃₃₃降低分蘖穗数;各处理分蘖成穗率都较对照高,ABA处理分蘖成穗率为最高达到25.20%;ABA处理主茎穗占比较对照增加,分蘖穗占比降低;GA₃、IAA、CCC处理主茎穗占比相对于对照降低,分蘖穗占比增加,PP₃₃₃处理与对照相近;5种外源激素对糜子产量的影响差异显著,施用ABA产量最高,可能与主茎穗占比高和分蘖成穗率高有关系。在糜子3~4叶期喷施5种外源激素,对糜子有显著作用的是ABA,主要表现在ABA能够降低糜子分蘖数,保证了主茎的成穗数量,增加了分蘖成穗率,从而提高了糜子产量。     

Effects of Exogenous Materials on Nitrogen Photosynthetic Efficiency and Yield Formation of japonica Rice in Cold Region Under Cold Water Stress at Booting Stage

【Objective】Our goal is to develop disaster-reducing, production-preserving and chemical-controlling cultivation techniques to effectively resist cold damage at the booting stage of japonica rice in cold region.【Method】The split plot design and the central combination test design were used to screen out the optimal application concentrations of CaCl2, glutamic acid(Glu), and γ-aminobutyric acid(GABA) through the membership function values of yield-related indicators under cold-water stress at booting stage.【Result】1) Under cold water stress at the booting stage, the optimal concentrations of exogenous CaCl2, Glu and GABA (CGG) were 1.87 mmol/L, 2.76 mg/L, 4.40 mmol/L, respectively and the average membership function value is the largest (0.932). 2) Compared with normal irrigation, the nitrogen photosynthetic efficiency of cold-region japonica rice decreased under cold stress at the booting stage. Compared with cold water stress at the booting stage, CGG application at the optimal concentration significantly increased the leaf area index (5.37%) and nitrogen photosynthetic efficiency (4.53%) of Dongnong 428 at the full heading stage; significantly increased leaf biomass per leaf area (2.56%) and leaf area index (3.39%) of Songjing 10 at the full heading stage. 3) Compared with cold water stress at the booting stage, the application of the optimal concentration of CGG increased the dry matter accumulation from heading stage to maturity in the cold-region japonica rice, but it was still lower than that of the normal irrigation, and there were differences between varieties and treatments. 4) Compared with cold water stress at booting stage, the yield and yield components of cold-region japonica rice increased with the application of the optimal concentration CGG, and the impact on cold-sensitive varieties was more significant. 5) Compared with the cold water stress at the booting stage, the average increase in temperature production efficiency of Dongnong 428 and Songjing 10 was 5.55% and 23.72% under the optimal concentrations of CGG, respectively. The contribution rate of exogenous CGG to the gap of temperature production efficiency is 8.99%.【Conclusion】The application of the optimal concentration of CGG under cold water stress at the booting stage promoted leaf growth of cold-region japonica rice at the full heading stage and increased the population nitrogen photosynthetic efficiency, which was beneficial to dry matter accumulation and yield formation after heading stage, thereby reducing the loss of cold-region japonica rice under cold water stress at booting stage and improving the temperature production efficiency of cold-region japonica rice.     

Effects of docosahexaenoic, eicosapentaenoic, and arachidonic acids on the early growth, survival, lipid composition and pigmentation of yellowtail flounder (Limanda ferruginea): a live food enrichment experiment

The role of dietary ratios of docosahexaenoic acid (DHA, 22:6n−3), eicosapentaenoic acid (EPA, 20:5n−3) and arachidonic acid (AA, 20:4n−6) on early growth, survival, lipid composition, and pigmentation of yellowtail flounder was studied. Rotifers were enriched with lipid emulsions containing high DHA (43.3% of total fatty acids), DHA+EPA (37.4% and 14.2%, respectively), DHA+AA (36.0% and 8.9%), or a control emulsion containing only olive oil (no DHA, EPA, or AA). Larvae were fed differently enriched rotifers for 4 weeks post-hatch. At week 4, yellowtail larvae fed the high DHA diet were significantly larger (9.7±0.2 mm, P<0.05) and had higher survival (22.1±0.4%), while larvae fed the control diet were significantly smaller (7.3±0.2 mm, P<0.05) and showed lower survival (5.2±1.9%). Larval lipid class and fatty acid profiles differed significantly among treatments with larvae fed high polyunsaturated fatty acid (PUFA) diets having higher relative amounts of triacylglycerols (18–21% of total lipid) than larvae in the control diet (11%). Larval fatty acids reflected dietary levels of DHA, EPA and AA while larvae fed the control diet had reduced amounts of monounsaturated fatty acids (MUFA) and increased levels of PUFA relative to dietary levels. A strong relationship was observed between the DHA/EPA ratio in the diet and larval size (r²=0.75, P=0.005) and survival (r²=0.86, P=0.001). Following metamorphosis, the incidence of malpigmentation was higher in the DHA+AA diet (92%) than in all other treatments (50%). Results suggest that yellowtail larvae require a high level of dietary DHA for maximal growth and survival while diets containing elevated AA exert negative effects on larval pigmentation.