The technology and mechanism of removal of plastic mulch and land preparation

In this article,the characteristic of the field plastic mulch, the craft for mechanization removal and land preparation of plastic mulch and the mechanism frequently used in the removal and land preparation of plastic mulch were introduced, which offered references for the design of removal mechanism and land preparation of plastic mulch and structural optimization combination of working components.     

Growth and fatty acid composition of sesame (<Emphasis Type="Italic">Sesamum indicum</Emphasis> L.) genotypes as influence by planting dates and nitrogen fertilization in semiarid region of Northwest,Pakistan

A field experiment was conducted on silty clay loam soil in the years 2011–2012. Two sesame (Sesamum indicum L.) cultivars (Local Black and Local White) were evaluated using various 3 different sowing dates (20th June, 10th and 30th July) and four agrotechnical level (0, 40, 80 and 120 kg N ha^–1) at New Developmental Farm The University of Agriculture, Peshawar, Pakistan. The objective of this study was to evaluate the effects of sowing dates on growth, yield and oil fatty acid composition of two sesame cultivars grown under different nitrogen fertilization. Results showed that cv. Local Black was characterized by significantly higher content of oil (47%), seed yield (696 kg ha^–1) and oil yield (335 kg ha^–1) while cv. Local White had higher palmitic acid (8%) and linoleic acid (38.7%). Yield and its main components were positively affected by the earlier sowing date. With regard to fatty acid composition, a decrease in oleic and stearic acid and an increase in linoleic and palmitic acid were observed. At early sowing, oleic and palmitic acid decreased whereas linoleic and stearic acid increased. The decrease in the oleic/linoleic acid ratio observed at early sowing, suggests a possible role of temperature on the activity of oleate desaturase in the developing seeds. Intensive technology of cultivation (120 kg N ha^–1), compared to the economical technology (40 kg N ha^–1), significantly increased the seed yield of both sesame cultivars. This was due to higher number of branches, Capsules m^–2, capsules plant^–1, seeds capsule^–1 and 1000 seed weight (g). The intensive technology of cultivation had a beneficial effect on the content of palmitic acid, linolenic acid and oleic acid in sesame seed.     

不同播期和秧龄对机插秧全生育期及产量形成的影响

采用双因素随机区组设计方法,以水稻品种黄华占为试验材料,分析在机插秧栽培模式下,不同的播期、插期组成的四种秧龄组合对产量性状和叶龄发生规律的影响。结果表明,随着播期和插期的推迟,产量水平呈下降趋势,其中以35d为最适秧龄,返青快、产量最高;且随着播期推迟,主茎叶片有减少趋势。     

新型水稻钵体摆栽秧盘及秧盘注塑模具的设计

通过对现有水稻钵体摆栽秧盘结构的改进设计,可以大大提高秧盘的使用寿命,并设计出用于改进后的秧盘生产用的注塑模具。     

5%甲拌磷对油菜苗期害虫的防治效果

5%甲拌磷颗粒剂随种条播法防治油菜苗期主要害虫,小区试验,按照活性成分0.75～1.5kg/ha剂量于油菜春播期一次性施入播种沟内,对全体越冬成虫的平均防效,跳(虫甲)类为68.1%,黄曲条跳(虫甲)[Phyllotreta vittata(Fabr.)]为66.7%、油菜茎龟象为63.7%。大田应用以活性成分0.75kg/ha为宜。     

蚕豆染色体Ag—NOR技术的应用

本试验对蚕豆进行染色体Ａｇ－ＮＯＲ（银染核仁组成区）技术的研究，采用根尖压片，短时间固定，ＡｇＮＯ３染色，Ｇｉｅｍｓａ复杂，最后得到２个黑色的核仁组成区，证明蚕豆组型中有２处ＮＯＲ，这和蚕豆核型是一致的，此方法可以广泛应用于次缢痕难以确定的核型研究中。     

沿江丘陵区土壤酶活性与土壤肥力的关系

对12种不同种植模式的6个土壤酶活性和7个土壤肥力因子进行测定,运用相关分析和典型相关分析方法对数据进行分析,以期阐明沿江丘陵地区土壤酶活性与土壤肥力因子的关系。相关分析的结果表明土壤酶活性与土壤肥力因子密切相关,多数呈极显著正相关。典型相关分析的结果表明“综合土壤酶活性因子”与“综合土壤肥力因子”存在极显著的典型相关关系,其中过氧化物酶、脲酶、多酚氧化酶和淀粉酶与有机质和全氮关系密切。综合土壤肥力因子可以作为土壤肥力评价的重要指标。     

核桃外果皮的开发利用研究（Ⅰ）

对不同地方采集的核桃外果皮用同样的方法进行干燥后 ,以水为萃取剂 ,提取棕褐色色素并对其稳定性进行了测试和比较。结果表明 :该色素水溶性好 ,耐氧化一还原性能较强 ,耐热性、耐光性较好。盐、蔗糖、金属离子对色素的色泽无不良影响 ,水提取率高、工艺简单、无污染且成本低。通过试验知各采样点核桃外果皮所含色素具有相同的稳定性     

6SF-40型加工番茄色选设备性能试验与参数优选

为研究加工番茄色选设备作业参数对其工作性能的影响规律,以分选精度和带出比为评价指标,对传送带速度、工作绝对压力及电磁阀脉频宽度等试验因素进行正交试验,对结果进行极差分析和方差分析,研究各因素对色选设备性能影响的主次关系和影响规律,确定较优工作参数组合.结果表明:输送带速度为0.816m/s、工作绝对压力0.5MPa、电磁阀脉频宽度为20ms时为较优参数组合,分选精度可达98%,带出比低于4,满足工厂加工要求.     

根癌农杆菌Ⅵ型分泌系统关键组分ClpⅤ型ATPase基因表达及活性位点分析

细菌Ⅵ型分泌系统（type Ⅵ secretion system,T6SS）是近年发现的一种分布广泛且与细菌致病性密切相关的新型分泌系统,ClpⅤ型ATPase是不同细菌T6SS中均含有的关键保守组分,据推测可能为底物蛋白的分泌提供动力,但对其生化功能尚未进行深入鉴定。在本研究中,我们克隆了根癌农杆菌（Agrobacterium tumefaciens）C58中的ClpⅤ型ATPase基因atu4344并在大肠杆菌中表达,酶学检测证实了其ATPase活性,定点突变分析发现K232/608和E299/675突变体均丧失ATPase活性,表明Walker A模体和Walker B模体与其活性密切相关。这是首次对植物病原细菌T6SS中的ClpⅤ型ATPase进行生化鉴定和突变分析研究。