种子活力和作物产量

\t\t\t\t\t目的\t\t\t\t\t种茎质量是木薯增产的主要限制因素之一,研究筛选木薯种茎活力评价指标,可为木薯种茎处理技术提供理论依据。\t\t\t\t\t\t\t\t\t\t\t\t\t方法\t\t\t\t\t选用华南8号和南植199木薯为材料,从植后150 d开始,每隔30 d采样1次种茎,共采集6次,分别在正常供水和干旱胁迫条件下,开展种茎发芽试验;同时测定发芽前的种茎生理生化指标。通过主成分分析得到不同采样期的种茎活力综合得分,并进行种茎生理生化指标与综合活力得分的相关性分析。\t\t\t\t\t\t\t\t\t\t\t\t\t结果\t\t\t\t\t6次采样的种茎活力综合得分差异较大;华南8号种茎活力综合得分与丙二醛含量和含水量呈显著负相关(P<0.05),与淀粉含量呈极显著正相关(P<0.01),与可溶性蛋白和游离脯氨酸含量呈显著正相关(P<0.05);南植199种茎活力综合得分与丙二醛含量呈极显著负相关(P<0.01),与过氧化氢酶活性、淀粉含量、游离脯氨酸含量、含水量相关系数较高,但未达显著水平(P>0.05)。\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t结论\t\t\t\t\t推荐种茎的丙二醛含量作为木薯种茎活力的评价指标。\t\t\t\t     

干旱区矿区不同立地类型土壤种子库特征

矿区的自然或人工植被恢复是维持生物多样性及生态系统稳定的重要途径。通过室外萌发法对金昌镍铜矿区7种不同立地生境土壤种子库的研究表明:该区域土壤中物种丰富度较高,包括16科47属,共56种植物,分别为:藜科(Chenopodiaceae)、禾本科(Gramineae)、菊科(Compositae)、柽柳科(Tamaricaceae)、苋科(Amaranthaceae)、马齿苋科(Portulacaceae)、豆科(Leguminosae)、十字花科(Cruciferae)、车前科(Plantaginaceae)、胡颓子科(Elaeagnaceae)、蒺藜科(Zygophyllaceae)、莎草科(Cyperaceae)、大戟科(Euphorbiaceae)、紫草科(Boraginaceae)、蔷薇科(Rosaceae)、茄科(Solanaceae);植物组成以一年生草本植物占绝对优势(89.3%),多年生草本植物次之(7.54%),灌木种最少(2.59%)。土壤种子平均储量412粒·m~(-2),不同立地类型土壤种子库储量差异显著,与其他荒漠地区比较,土壤种子库储量偏低;土壤种子库物种Simpson多样性指数为:新尾矿周边自然植被区龙首矿自然植被区龙首矿开采废弃地供暖公司柽柳林地。     

蓝花棘豆硬实种子特性的研究

每天从发芽皿中挑选吸胀的蓝花棘豆种子作为对照。第一天的称为CK1，依此类推分别为CK2，CK3……等。对照种子的硬实程度随着吸胀时间的延长而增强，即CK5＞CK4＞CK3＞CK2＞CK1。将第八天尚未吸胀的作为硬实种子。用浓硫酸处理25分钟。结果表明，硬实种子的发芽率、活力指数、脱氢酶活性及抗逆性均高于对照。后者CK1→CK5的上述指标呈逐渐上升趋势。硬实种子的电导率则低于对照。后者CK1→CK5电导率呈下降趋势。综上所述，作者认为蓝花棘豆中硬实种子的活力高于非硬实种子，其活力随着硬实程度的增加而递增。     

党参种子的离散元仿真参数标定与试验验证

为设计及优化党参机械化播种设备,提供基础仿真参数,本文对甘肃省种植的两种党参种子(渭党1号和甘党2号)通过试验法确定其基本物理参数(形状尺寸、质量密度、体积密度、千粒重、含水率)和接触力学参数(恢复系数、静摩擦系数);通过斜面滚动试验结合EDEM仿真,预测党参种子与ABS塑料板间的滚动摩擦系数;通过调整党参种子模型间的...     

不同光照和温度下白花鬼针草和金盏银盘种子萌发研究

通过在人工培养箱内模拟环境条件,探讨了不同光照和温度对白花鬼针草和金盏银盘种子萌发的影响,结果表明：光照和温度不是白花鬼针草种子萌发的必要条件,白花鬼针草种子萌发的温度适应范围比金盏银盘宽,在15＇12／10oc、20℃／15℃、25℃／20℃、30℃／25oC、35℃／30℃、40℃／35℃下均能萌发,在15％／10气、20％／15℃、25％／20℃、30~E／25℃时萌发率均达94％左右,金盏银盘种子在40％／35℃时不能萌发;温度影响白花鬼针草和金盏银盘种子萌发高峰的出现时间及峰值大小,而光照不影响。     

吡虫啉及其复配剂不同施药方法对油菜蚜虫控制效果

2006-2009年,采用拌种和播种沟施药的方法,于河南郑州研究了新烟碱类杀虫剂吡虫啉及吡虫啉.辛硫磷复配剂对油菜蚜虫的全程控制效果。小区试验结果表明,用吡虫啉有效成分5g/kg种子拌种仅能有效控制苗期油菜蚜虫的危害,防治效果为90.79%～100%,对中后期油菜蚜虫控制效果不明显;用吡虫啉600g/hm2及吡虫啉.辛硫磷复配剂1320g/hm2采用播种沟施药对油菜蚜虫的防治效果分别为91.82%～94.49%和90.68%～95.34%;试验示范验证防治效果在92%以上,持效期长达7个月以上,可以达到一次用药控制油菜整个生长期蚜虫为害的效果,减少了用药次数,此方法简单易行、保护环境、保护天敌,是一种简化高效的具有推广价值的油菜蚜虫可持续控制技术。     

罗布麻属和白麻属种子形态特征及生活力的测定方法

以采自新疆维吾尔自治区阿勒泰市阿拉哈克镇境内的罗布麻属(Apocynum)和白麻属(Poacynum) 8个基因型植物的种子为材料,进行了8个基因型植物种子形态特征、千粒重和生活力测定方法探究。研究结果显示,参试罗布麻种子的长为2.75 mm,宽为0.68 mm,厚为0.49 mm。白麻属7个基因型中以紫斑中花的种子最长,为4.51 mm;青杆白花最宽,为0.90 mm;青杆白花和大叶白麻最厚,为0.61 mm。8个基因型种子的长、宽、高的变化范围分别为2.75～4.51、0.68～0.90和0.48～0.61 mm。其中,紫斑中花为最大基因型,罗布麻为最小基因型。千粒重变化范围在0.38～1.32 g,所有参试种子颜色均为褐色,其中以大叶白麻颜色最深。参试种子均表现出非休眠性种子萌发的特征,萌发时间较短,可以用来快速测定参试种子的生活力。采用四唑染色测定生活力时,参试种子均表现出不透四唑的特征,应该纵切切破种皮,预湿时间为12～14 h,染色时间为12 h,鉴定标准为种子胚80%完全染色。此次针对罗布麻属和白麻属种子形态特征与生活力测定方法的研究,能够为罗布麻种子生活力鉴定、大规模种...     

Ethoxylated rapeseed oil derivatives as novel adjuvants for herbicides

Ethoxylates of rapeseed oil and of methylated rapeseed oil were synthesized and tested as adjuvants for 2,4-D and phenmedipham. Provided they had less than 6 units of ethylene oxide (EO), 1.0 to 10 g litre(-1) ethoxylates in water induced droplet spreading on barley leaves. In an acetone-based medium all derivatives strongly promoted the foliar uptake of 2,4-D, with no clear influence of the ethoxylation degree. In the same medium there was a negative influence of ethoxylate chain length on the foliar uptake of phenmedipham. In a water-based medium, phenmedipham applied with rapeseed oil emulsified with ethoxylated (20 EO) rapeseed oil displayed uptake rates close to a commercial preparation. The same was true for phenmedipham applied with ethoxylated (2 EO) methylated rapeseed oil. In bioassays, phenmedipham prepared with methylated rapeseed oil emulsified with ethoxylated (20 EO) rapeseed oil was as efficacious on barley as a commercial formulation. The same was true for phenmedipham prepared with ethoxylated (2 EO) methylated rapeseed oil. However, neither rapeseed oil nor methylated rapeseed oil emulsified with ethoxylated (2 EO) methylated rapeseed oil conferred good efficacy to phenmedipham. Hence, ethoxylated rapeseed oil derivatives are promising adjuvants or formulants for herbicides.     

新疆哈密瓜细菌性斑点病离体叶片种子带菌检测及致病力分化

应用甜瓜离体叶片检测甜瓜种子的带菌情况，分别采用不同的缓冲液和不同的接菌方法进行检测，发现PBＳ缓冲液富集病原菌效果好，注射接种效率高。同时，离体叶片是菌株致病力分化初步检测较好的材料，从田间分离所得菌株来看，黄瓜细菌性角斑和西瓜果腐菌株致病力均被分化为强、中、弱，而且从种子上分离的病原菌的致病力弱。     

Influence of dietary palm oil on growth, tissue fatty acid compositions, and fatty acid metabolism in liver and intestine in rainbow trout (Oncorhynchus mykiss)

This study aimed to investigate the effects of dietary crude palm oil (CPO) on fatty acid metabolism in liver and intestine of rainbow trout. Triplicate groups of rainbow trout for 10 weeks at 13 °C were fed on diets in which CPO replaced fish oil (FO) in a graded manner (0–100%). At the end of the trial, fatty acid compositions of flesh, liver and pyloric caeca were determined and highly unsaturated fatty acid (HUFA) synthesis and fatty acid oxidation were estimated in isolated hepatocytes and caecal enterocytes using [1‐¹⁴C]18:3n‐3 as substrate. Growth performance and feed efficiency were unaffected by dietary CPO. Fatty acid compositions of selected tissues reflected the dietary fatty acid composition with increasing CPO resulting in increased proportions of 18:1n‐9 and 18:2n‐6 and decreased proportions of n‐3HUFA, 20:5n‐3 and 22:6n‐3. Palmitic acid, 16:0, was also increased in flesh and pyloric caeca, but not in liver. The capacity of HUFA synthesis from 18:3n‐3 increased by up to threefold in both hepatocytes and enterocytes in response to graded increases in dietary CPO. In contrast, oxidation of 18:3n‐3 was unaffected by dietary CPO in hepatocytes and reduced by high levels of dietary CPO in enterocytes. The results of this study suggest that CPO can be used at least to partially replace FO in diets for rainbow trout in terms of permitting similar growth and feed conversion, and having no major detrimental effects on lipid and fatty acid metabolism, although flesh fatty acid compositions are significantly affected at an inclusion level above 50%, with n‐3HUFA reduced by up to 40%.