便携式XRF仪现场快速测定土壤中Pb的可行性研究

便携式XRF分析仪具有轻便、快速和可测对象较多与测量元素较广等特点而广泛应用于矿石、土壤等方面快速检测,但土壤的现场快速测定结果的准确性有待进一步研究与探讨。以安宁河谷平原土壤中Pb为研究对象,通过对便携式XRF仪现场快速检测结果与实验室分析结果的对比和影响因素的分析,建立基于安宁河谷平原表层土壤快速测定结果的线性函数为y=1.170 9x-17.326 0(R~2=0.992 9,x为现场检测结果),探讨其影响因素,为该区域表层土壤中Pb快速检测结果提供依据。     

烟青虫初孵幼虫的高效快速收集方法

比较了常用的烟青虫人工收集方法和新研发的烟青虫初孵幼虫快速收集方法的效果。试验结果表明,与人工收集方法相比,快速收集方法获得初孵幼虫所用时间少,收集的初孵幼虫存活率搞,达96.33%,且收集的幼虫发育更加整齐,雌、雄蛹单头质量(雌蛹295.33 mg,雄蛹284.66 mg)略大;还可节省大量人力,避免了人工挑虫对初孵幼虫的伤害,保障了烟青虫实验种群的大量优质扩繁。     

薄荷的快速繁殖与栽培技术的研究

本文介绍了薄荷的特性、栽培技术及用途，表明它在我们日常生活中起着重要的作用。用薄荷的组织培养方法可加速其繁殖系数，以达到迅速应用的目的。     

白菜型油菜DFR基因的克隆与序列分析

By using RACE (rapid amplification ofcDNA ends) based homologous cloning strategy, we have successfully isolated the genomic and full-length cDNA sequences of a gene encoding typical DFR (dihydroflavonol-4-reductase) from black-seeded Brassica campestris L. var. oleifera DC.. The gene, designated BcDFR here, is 1 722bp in length and harbors 5 introns with typical splice sites of plant DFR genes. BcDFR cDNA is 1311bp in length with a 1 158bp ORF as well as a 25bp 5‘ UTR and a 128bp 3‘ UTR. The encoded BcDFR protein is 385 aa with a calculated Mw of 42.85kD and a pI value of 5.55. The nucleotide and amino acid sequences of this gene share extensive homologies to plant DFR genes of wide origins especially high similarities to Cruciferous DFR genes. Sequence analyses such as phylogenetic analysis, conserved domain search and substrate specificity region detection all indicated that BcDFR gene is a quite potentially biofunctional gene. Its cloning enables us to further dissect the possible relatedness between DFR gene and Brassica seed coat color traits and to create transgenic novel yellow-seeded rapeseed germplasm through antisense- or RNAi-suppression of DFR gene expression in black-seeded elite cultivars.     

A logistic analysis of the factors determining the decision of smallholder farmers to intercrop: A case study involving rubber–tea intercropping in Sri Lanka

The factors influencing the decision of smallholder farmers to adopt new farming technologies were studied with reference to rubber–tea intercropping in Sri Lanka. Rubber–tea intercropping has been recommended previously to rubber farmers as a means to improve productivity and income during the early pre-tapping phase of rubber growth. Although crop trials have shown that the two crops are agronomically compatible and potentially produce a combined economic yield superior to the yield of a sole crop grown on the same area of land, there is little evidence of widespread adoption of this practice among smallholder farmers in Sri Lanka. The aim of the study was to determine the major factors that influence the decision to undertake rubber–tea intercropping and to construct a predictive model that describes the likelihood of adoption of intercropping by traditional smallholder rubber growers. A rapid rural appraisal (RRA) was undertaken based on semi-structured interviews of 90 smallholder farmers in the main rubber growing low wet zone of Sri Lanka. Among a number of factors shown to significantly influence the decision to intercrop tea with rubber, three were shown to operate independently, namely level of income, source of income (i.e. solely from own farm or from farm plus additional off-farm enterprises), and availability of land considered suitable for tea cultivation. A statistical model developed through correlation and logistic analysis, which predicts the likelihood of a smallholder adopting intercropping based on these factors, is presented and discussed. The most likely combination of circumstances (82% probability) under which rubber–tea intercropping is practiced is shown to be where the farmer’s income is greater than Rs. 10,000 per month, where the farmer’s income is based solely on own farm enterprises, and where more than 80% of the farmer’s land area was judged to be suitable for tea cultivation. Conversely, 30% of smallholder farmers that chose not to intercrop did possess land suitable for tea cultivation. Qualitative responses to the RRA indicated that limitation of technical knowledge was the main problem subsequently faced by rubber farmers who had adopted rubber–tea intercropping. Results indicate that there is need for both income support through farm subsidies and further agricultural extension services, if rubber–tea intercropping is to be adopted more widely in Sri Lanka. The wider usefulness of the developed logistic model in determining the likelihood of adoption of intercropping by smallholder farmers is discussed.     

火龙果杂交实生苗快速繁育技术研究

以杂交得到的红皮红肉型火龙果自然成熟果实的种子为外植体,进行改良的组织快繁实验,筛选适宜的培养基、激素浓度配比,并对组培苗进行了移栽。结果显示,萌芽诱导培养1/2MS NAA0.3 mg/L。实生苗增殖培养MS 6-BA5.0 mg/L NAA0.3 mg/L,增殖系数可达,且芽生长势强,质量好。子叶二次萌芽培养1/2MS 6-BA1.5 mg/L,生根培养1/2MS NAA0.3mg/L IBA0.3 mg/L,生根率达95%。炼苗后7天的幼苗移栽至处理好的苗床上,20天后成活率达96%以上。     

蝴蝶兰‘红天鹅’组织培养及快繁技术

[目的]探索‘红天鹅’花梗的不定芽诱导、丛生芽继代增殖和生根诱导技术。[方法]以蝴蝶兰新品种‘红天鹅’的花梗作为外植体,开展组织培养技术研究。[结果]用0.1%的HgCl2消毒外植体20 min,污染率可降低至27.2%,萌芽率达91.0%;不定芽继代增殖培养的最适培养基为MS+6-BA 6.0 mg/L+NAA 0.1 mg/L+AD 5.0 mg/L+香蕉50 g/L+土豆50g/L+蔗糖30g/L+琼脂7.5 g/L,增殖系数达3.80;最适合的生根诱导培养基为1/2MS+NAA0.4 mg/L+香蕉50 g/L+土豆50g/L+C 1.0 g/L+蔗糖15 g/L+卡拉胶7.0 g/L,生根时间为15 d,生根率达100%。[结论]发现了适宜‘红天鹅’的从消毒到增殖,再到生根中各试剂和激素的合理用量,为蝴蝶兰快繁技术发展提供了参考。     

Rapid screening of genetically modified ingredients in soybean and cotton processing by-product and waste using direct qPCR

To develop a simple and fast method for screening genetically modified ingredients from processing by-product and waste, direct quantitative PCR (qPCR) kit-Taqman which omitting multi genomic DNA preparing steps was developed in this study. A total of 18 oil crop processing by-products and wastes including 10 soybean and 8 cotton materials were collected from food processing factories. Compared with 2 commercial direct qPCR kits, conditions of DNA releasing procedure and PCR amplification were optimized. Element screening was performed at the initial step of genetically modified (GM) ingredient testing procedure via direct qPCR. GM event identification was carried out in positive samples by initial screening. Totally 5 screening elements (P–35S, T-NOS, Cp4-epsps, bar and pat) for soybean materials and 6 screening elements (P–35S, T-NOS, NPTII, Cry1Ac, bar and pat) for cotton samples were detected. In GM event identification, MON531 and MON1445 were found in cotton materials. Results were further confirmed by real-time PCR with DNA extraction and purification. The direct qPCR system proposed by this research was convenient for rapid screening and identification of GM ingredients in oil crop primary by-product and waste.     

瑞昌山药茎段组织培养研究

用不同种类、浓度的植物生长调节剂对瑞昌山药茎段进行离体培养试验.试验结果表明,诱导瑞昌山药不定芽萌发最佳培养基为MS+6-BA 1.5 mg/L+NAA 1.0 mg/L,不定芽萌芽率为90%:继代培养用MS+6-BA 0.5 mg/L+NAA 0.5 mg/L,长势较理想;生根培养用1/2 MS+NAA 0.5 mg/L+0.2 g/L活性炭的培养基,瑞昌山药生根的效果最佳.     

基于设计模板的快速变型设计方法

传统的变型设计方法存在变型过程复杂,容易产生约束冲突的问题.针对零部件之间依赖关系复杂,设计过程需要通过交互和人工干预的形式才能完成配置与变型的问题,提出了在模板框架下的快速变型设计方法.利用模板的灵活性和信息载体功能,提出了可变型单元的概念,通过可变型单元之间建立相互关联实现对象之间的参数联动,在模板定义域范围内实现产品零部件的快速变型.以变速箱为实例,通过产品的结构变型实现产品的系列化,在同系列产品中通过几何参数的变更实现产品的多样化.