彩色马蹄莲抗病·育种及快繁研究进展

近年来,随着花卉产业的不断发展,彩色马蹄莲以其独特的形状和靓丽的色调,赢得了很多花卉消费者的青睐,而彩色马蹄莲的病害和种苗快速繁殖一直是困扰花卉栽培者的重大问题。就彩色马蹄莲的病虫害防治及其育种和快速繁殖方面的研究进行阐述,并对存在的问题和今后的发展方向进行探讨,为今后彩色马蹄莲抗病虫育种和快速繁殖方面进一步研究提供一定的理论依据。     

木立芦荟和三角芦荟的组织培养和低成本快繁

以MS+BA3+NAA0.2和MS+BA4+NAA0.2分别为木立芦荟(AloearborescensMill)和三角芦荟(AloemitriformisMill)的诱导培养基.1/2MS+BA2+NAA0.2和MS+BA3+NAA0.2分别为两种芦荟的增殖培养基,对茎段、茎尖和吸芽进行离体培养.以4周为一个继代周期,每周期可增殖6～8倍,现已经过26个继代周期,一个外植体每年可增殖至813个芽苗.为减轻褐化,降低温度至22℃、光照强度800lx,附加活性炭3～5g@L-1.用白糖替代蔗糖,自来水替代蒸馏水,果酱瓶替代三角瓶,既不影响培养效果又可降低生产成本.     

兰州百合鳞茎再生繁殖体系的建立

[目的]建立兰州百合鳞茎快繁体系,并测定丛芽与鳞茎的淀粉含量,为系统研究兰州百合鳞茎离体再生过程中淀粉的代谢奠定基础.[方法]以兰州百合鳞片为外植体,探讨不同消毒剂组合、激素与蔗糖用量对鳞茎诱导培养过程的影响.[结果]随着75％乙醇（10～30 s）与0.1％升汞消毒时间（7～10min）的延长,外植体鳞片污染数不断下降,但诱导芽数表现为先上升后下降的趋势,以75％乙醇消毒30 s＋0.1％升汞消毒10 min组合的消毒效果最好,外植体污染率和芽诱导率分别为12.33％和91.00％.使用1000倍多菌灵处理10 min后,再使用75％乙醇30 s ＋0.1％升汞7～13 min组合进行消毒,可明显降低鳞片污染率3.00％～5.00％（绝对值）.在MS＋0.03 mg/L NAA＋30.0 g/L蔗糖＋5.0 g/L琼脂培养基中添加6-BA 0.5～1.0 mg/L,可显著提高平均芽诱导数;在MS＋5.0 g/L琼脂培养基中添加30.0～60.0 g/L蔗糖,对外植体芽诱导无明显影响;培养基MS＋1.0 mg/L 6-BA＋0.03 mg/L NAA＋30.0 g/L蔗糖＋5.0 g/L琼脂是外植体芽诱导的最适培养基.MS＋0.50 mg/L 6-BA＋0.03 mg/L NAA＋30.0 g/L蔗糖＋5.0 g/L琼脂为适宜增殖培养基,芽增殖系数达最高,为3.67.在MS培养基中添加60.0～90.0 g/L蔗糖可明显促进鳞茎的形成,以添加90.0 g/L蔗糖处理的鳞茎重量最高（99.30mg）.小鳞茎的淀粉质量分数比丛芽增加62.34％.[结论]以鳞片为外植体建立的兰州百合鳞茎再生繁殖体系具有可行性;在丛芽至小鳞茎形成阶段淀粉含量明显升高,小鳞茎的形成与淀粉含量升高密切相关.     

基于BP神经网络人均猪肉需求量预测

近年来,由于猪肉安全事故和供求关系等因素的影响,导致猪肉市场价格波动大,养猪业难以持续稳定发展。科学预测猪肉需求量,对科学指导生猪生产和宏观调控猪肉市场价格意义重大。笔者根据历年数据,采用BP神经网络预测方法,实现在MATLAB中运行,通过对模型的多次训练,选择隐层神经元数目为6个,达到了期望效果。预测结果表明,2012~2016年,我国人均猪肉需求量分别为34.10、38.12、38.66、40.28和40.60kg/a。     

京山桥米食味品质的评价

本试验采用人工感官品尝评定与仪器测定相结合的方式,研究了京山桥米的食味品质,并与3种具有代表性大米(稻花香米、泰国香米、京山晚籼米)食味品质进行了比较分析。结果表明,京山桥米的食味品质较好;4种仪器对京山桥米的测定结果具有一致性,仪器测定结果与人工品尝评定结果也具有一致性。     

杉木无性系扦插繁殖生根机理

杉木穗条不定根的发生属于诱性根原始体型。不定根发生部位有两种类型：皮层生根型和混合生根型，但以皮层生根型为主。不同无性系开始发根时间有显著差异。在观察期内，发根最早的无性系生根时间为２３ｄ。     

麻疯树茎段离体培养及快速繁殖研究

以麻疯树幼嫩枝条腋芽为外植体,以M S为基本培养基,附加不同浓度的激素组合(6 BA与IBA)进行芽诱导和增殖培养。结果表明,M S基本培养基利于不定芽的诱导与形成,出芽率可达75.0%。附加6 BA 2.5m g/L、IBA 0.1~0.5m g/L的组合芽增殖率可达47.6%~47.8%;随着6 BA浓度增加,芽增殖率也随着升高,但不同浓度IBA对芽增殖率的影响则没有一定规律,其增殖效果不如6 BA明显。此外,在M S基本培养基中是否添加激素对生根培养影响不大,两者生根率差异不明显。     

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.     

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.     

观赏性小苹果“特丽”的组织培养及快速繁殖技术

以MS为基本培养基，以观赏性小苹果“特丽”的茎段为外植体，建立了无菌培养体系，研究了不同的激素配比和不同茎段类型对增殖培养的影响以及不同的生长素组合对试管苗生根的影响。结果表明：MS+BA0.5 mg/L~2.0mg/L+NAA0.1mg/L均为适合的芽萌发培养基；MS+BA1.5mg/L+IBA0.1mg/L是最适合的茎段增殖培养基；继代增殖培养取留顶芽无侧芽和去顶芽带有1~2个侧芽两种类型的茎段有利于提高增殖系数；1/2MS+0.2mg/L IAA是最佳生根培养基。试管苗增殖系数达到5.6，生根率达91.9%。