药剂拌种防治大麦多种病害试验

药剂拌种是防治种传病害的一种简便易行效果好的办法,但能否作为防治多种病害的综合防治措施,近年来我们进行了研究。一、试验设计与方法处理:在前几年药剂筛选的基础上,今年主要以复配剂——麦病灵1号、2号、3号、4号、、5号、6号作大麦种子处理试验,用大麦清和不拌药处理作为对照,比较防病保苗效果。     

芝麻新品种驻J18的选育

驻J18是利用长势强、粒色洁白的81043作母本,适应性广、多抗芝麻病害的豫芝四号作父本杂交选育而成,2003年3月通过全国芝麻品种鉴定委员会鉴定.该品种平均单产1 294.26kg/hm2,比对照豫芝四号增产10.89%,脂肪含量57.07%,抗多种芝麻病害,适宜于长江以北芝麻主产区种植.     

拉萨市引进马铃薯品种(系)对病害抗性的筛选

马铃薯在西藏的种植面积越来越大,但其产量和品质受病害影响严重。为了在拉萨市生产上推广抗性好的品种,对引进的7个马铃薯品种(系)(‘鄂薯3号’、‘鄂薯4号’、‘鄂薯5号’、‘鄂薯7号’、‘鄂薯8号’、‘HB0389-18’、‘米拉’)进行病害抗性和块茎产量评价。试验结果表明:‘米拉’和‘鄂薯7号’的植株生长旺盛、病害发生少、产量高,适合在拉萨市推广种植。     

红麻主要土传病害的综合治理策略

红麻是一种重要纤维作物,随着红麻造纸工业的开发,它在我国国民经济中的地位将不断提高。目前生产上存在的一个主要障碍是病虫害,尤其是土传病害对其产量和品质的影响。据研究报道,我国红麻产区主要土传病害有由南方根结线虫(Meloidogyne incognita)1号和2号小种,爪哇根结线虫(M.javanica)和花生根结线虫(M.arenaria)2号小种诱致的根结线虫病,立枯丝核菌(Rhizoctonia     

贵州省六盘水市马铃薯青枯病病原菌的初步研究

马铃薯(Solanum tuberosum L.)是贵州省六盘水市第三大粮食作物,具有重要的经济地位。由茄科雷尔氏菌(Ralstonia solanacearum)引起的马铃薯青枯病(Bacterial wilt)是一种世界性病害,是马铃薯生产中继晚疫病之后第二个最主要的限制性病害。本试验通过对贵州省六盘水市的马铃薯青枯病病原菌的生理小种及生化变种进行调查,为六盘水市马铃薯的抗病育种、引种栽培及青枯病的综合防治提供参考价值。结果表明,生理小种3号(生化变种2号)为优势小种,但生理小种1号(生化变种3号)、生理小种3号(生化变种2号)在本地区普遍流行,且两个生理小种分布无明显的地域特征,在海拔高度上亦无差异。     

INIBAP引进香蕉种质资源对枯萎病的抗性评价

香蕉枯萎病己成为香蕉的毁灭性病害。该病属于土传性病害,扩散蔓延速度快,难于进行生物控制、药物防治及轮作、浸田等常用防治方法的防治。因此,防治香蕉枯萎病的最佳方法是进行香蕉遗传改良,培育抗病品种。选用从INIBAP[(International Network for the Improvement of Bnana and Plantain,国际香(大)蕉改良网络)]引进的42份香蕉种质资源,采用伤根侵染法,用含2×106个孢子/L的香蕉枯萎病1号和4号小种菌液分别对42份香蕉幼苗进行处理,筛选抗香蕉枯萎病种质。结果表明：在侵染1号小种时,7份材料表现高感,13份感病,22份中抗,无高抗;在侵染4号小种时,25份材料表现高感,12份感病,5份中抗,无高抗。综合分析显示,M11和M25对枯萎病1号和4号小种均表现中抗。     

玉米杂交种咏丰1号的选育技术报告

咏丰1号是山西省农业科学院高粱研究所以自选系R9703为父本,以外引系早48为母本组配成的玉米杂交种。经过5年的各级试验示范结果表明,在山西省两年区域试验中该品种比对照屯玉8号平均增产15.7%。咏丰1号幼苗顶土能力较强,出苗快,苗势壮,植株生长健壮,抗各种病害,抗倒伏,活秆成熟,平均产量为10500kg/hm2。     

玉米新品种生态适应性研究

2005～2006年在新宁开展了玉米新品种生态适应性试验，结果表明：科玉2号、蠡玉23比对照临奥1号增产幅度较大，其农艺、经济性状较优，适宜该地作春玉米栽培品种推广；洛玉1号产量较高，生育期短，日产量高，其农艺、经济性状较好，适宜该地特别是干旱地区作春玉米栽培；东单57和渝单7号产量优势明显，但应注意中、后期的病害防治。     

中蔗系列甘蔗品种的黑穗病抗性鉴定

黑穗病是广西蔗区最主要的病害。本研究利用人工接种结合病区大田自然发病的方法,用4对甘蔗黑穗病菌交配型单倍体菌株分别注射接种,对本实验室培育的甘蔗新品种(系)中蔗1号、中蔗6号和中蔗9号及广西主栽品种ROC22进行甘蔗黑穗病抗性评价。结果表明,4个甘蔗品种对黑穗病抗性从强到弱排序依次为:中蔗9号>中蔗1号>中蔗6号>ROC22。对重病区田间一年宿根自然发病进行全年跟踪调查,中蔗1号和中蔗6号黑穗病发病率为零,中蔗9号发病率为0.4%,ROC22为6.8%。结论:中蔗系列甘蔗品种有很强的黑穗病抗性。     

12个马铃薯品种对晚疫病抗性比较与药剂防治

通过田间试验,探讨常用马铃薯晚疫病防治药剂对不同马铃薯品种晚疫病防治效果,对产量影响及筛选出对马铃薯晚疫病有抗性的品种。结果表明,田间晚疫病发病初期,银法利单用或与其他药剂混用均可以有效控制马铃薯晚疫病,并且增加田间产量;‘荷兰7’,‘黄麻子’、‘荷兰15’和‘尤金’为马铃薯晚疫病易感品种,因此田间管理要提前预防马铃薯晚疫病的发生;‘克新18号’、‘麦肯’、‘延薯4号’和‘克新13号’对晚疫病有较高的抗性;‘中兴202’、‘Lt-5’、‘夏波蒂’和‘克新1号’对晚疫病表现中抗,病害发生初期施药可以有效的控制病害扩展。     

Mechanism of action of insecticidal secondary metabolites of plant origin

Insect pest management is facing the economic and ecological challenge worldwide due to the human and environmental hazards caused by majority of the synthetic pesticide chemicals. Identification of novel effective insecticidal compounds is essential to combat increasing resistance rates. Botanicals containing active insecticidal phytochemicals appear to be promising to address some of these problems. Therefore, there is a continuous need to explore new active molecules with different mechanisms of action. Secondary metabolites present in plants apparently function as defense (toxic), which inhibits reproduction and other processes. The phytochemical biomolecules could be used for maximizing the effectiveness and specificity in future insecticide design with specific or multiple target sites, while ensuring the economic and ecological sustainability. In this article, the current state of knowledge on phytochemical sources and insecticidal activity, their mechanism of action in insects, resistance, and promising advances made in phytochemical research are reviewed.     

Use of mechanics of cohesive granular media for analysis of hardness and vitreousness of wheat endosperm

The characterisation of the wheat endosperm by mechanical tests of compression highlighted a relation between the rupture energy and the elasticity modulus for different varieties of wheat; this relation allows us to distinguish mealy and vitreous endosperms. An approach based on the micromechanics of cohesive granular materials is used to analyse these experimental results. A geometrical model of the wheat endosperm made of grains linked by cohesive bonds is proposed. We introduced two parameters, the first one α represents the percentage of active bonds (bonds where the stiffness and strength are non-zero), and the second one β represents the threshold of the bond's rupture. The parameter β can be related to the cross-section of the bond. This model successfully describes the mechanical tests on the wheat endosperm. The comparison with the experimental tests makes it possible to clearly differentiate vitreous wheats and mealy wheats and then attribute this property to the parameter β. The model shows the same tendency as regards the evolution of the rupture energy and the elastic modulus with the parameter α. The modelling of endosperm by the mechanics of cohesive granular media provides a new theoretical framework to interpret the rheology of endosperm. This approach allows us to connect this rheology to the mechanical actions at the scale of the granules.     

芦笋枯萎病病原鉴定

对造成福建省漳州市东山县的芦笋枯萎病病原菌进行分子鉴定,以期确定病原菌的属、种名,为防治该病害寻求理论依据。试验对分离纯化的病原菌核糖体DNA的ITS区进行测序,在Genbank中搜索其同源性并构建它们的系统发育树,结果表明：引起芦笋枯萎病的病原菌是镰刀属中的尖孢镰刀菌(Fusarium oxysporum),且病原菌之间的同源性高达89%,遗传差异不显著。     

Application of Polymer Science to Properties of Gluten

Much of the knowledge from polymer science studies can be usefully applied to increase understanding of the properties of gluten and how they are related to composition. Low solubility of gluten proteins compared to many other proteins that have been studied evidently arises from the low entropy of mixing of the largest-sized glutenins and a relatively high value for the Flory-Huggins interaction parameter mainly due to a low concentration of ionisable groups. Grain hardness is a property that appears to depend on the proteins that are concentrated at the starch/matrix interface and how they control adhesion. Dough mixing properties, dough strength and extensibility can be understood in terms of the extension of large glutenin molecules giving rise to rubber elasticity and to the presence of molecular entanglements which contribute strength and extensibility to dough systems.     

Rheology of Mixtures of Glutenin Subfractions

The dynamic rheological behaviours of mixtures of glutenin fractions extracted from wheat cultivar Hereward were investigated as a function of the relative concentration of high to low molecular weight glutenin concatenations. Time-temperature superposition could be applied to both the mixtures and to the total gluten, as long as heat-treated samples were distinguished from unheated samples. The ratio of high to low molecular weight concatenations was found to be very important for the rheological behaviour of the network. High molecular weight fractions promoted the network properties of the mixture, as could be seen from the presence of a plateau in the rheological spectrum. Low molecular weight fractions gave rise to a plasticizing effect as indicated by their narrowing effect on the width of the plateau region in the rheological spectrum. Upon heating, the modulus increased over the full range of frequencies, as for single fractions. This increase indicated that a thermal association occurred in the concatenations at temperatures around 40 °C. As a result of heating, the transition zone became apparent in the spectrum at high frequencies. The slopes of the loss modulus G” in the transition zone were found to be higher for mixtures rich in low molecular weight concatenations. The effect of the relative abundance of each fraction on the rheological characteristics of the mixtures was summarized in a number of simple rheological blending rules for the small-deformation rheological properties of glutenin.     

水稻抗旱性的研究进展

随着全球水资源的日益匮乏和旱灾的日趋严重,水资源短缺正成为制约我国农业发展的重要因素。培育抗旱栽培稻品种并实现水稻旱种,不但可较大程度地节约水资源,且有利于稳产增产、节约能源和减少环境污染,故栽培稻的抗旱性研究作为稻作科学研究的重要课题显得愈来愈重要。本文从水稻抗旱性鉴定形态指标、生理指标和分子标记研究三方面分别概述,并对今后水稻抗旱性方向进行了探讨。     

芸薹属种子贮藏蛋白质亚基构成及亲缘关系分析

采用线性梯度SDS－PAGE分析芸薹属4个种17个品种（系）的种子贮藏蛋白亚基组成，表明种子贮藏蛋白比较复杂，共有58条带，分子量范围是8000～300000D，不同种不同品系带型不同，种间差异主要表现在8000～70000D之间，品种（系）的差异主要在70000～300000D之间，相似度指数也表现出同种内不同的品种之间相似度高，种内品种间相似度大于种间。     

褐飞虱不同品系杂交子代抗药性和适合度的变化

通过室内筛选得到了对甲胺磷具有极高水平抗性的抗性品系（抗性倍数198.63）。利用该抗性品系与敏感品系、田间种群杂交,杂交子代的抗性水平都明显地倾向于抗性品系,表明杂交子代的抗性水平有利于本地抗性的发展。通过建立实验种群生命表,发现与敏感品系和田间种群相比,抗性品系及其与敏感品系、田间种群杂交子代的生物适合度都有显著下降,表明抗性品系及其杂交子代种群增长具有很大的不利性,从而减少了抗性虫源数量,有利于本地敏感性的回复。从褐飞虱迁飞、杂交子代抗药性及生物适合度变化的角度,讨论了迁飞扩散对褐飞虱的甲胺磷抗性发展的影响。     

云南干旱地区芒果园生草栽培对土壤肥力的影响

为提高云南干旱地区芒果园管理技术和水平,通过田间试验研究不同豆科植物行间间作后土壤养分的变化。结果表明：生草间作两年后,0～60 cm土壤有机质降低;20～60 cm土壤全氮和全磷增加,0～60 cm土壤全钾增加;新诺顿豆和大翼豆将20～60 cm土壤pH从酸性提高至中性;饭豆＋绿肥提高了0～60 cm土壤碱解氮和速效磷,饭豆＋绿肥、饭豆以及田箐提高了0～60 cm土壤速效钾。试验所选生草可以增加20～60 cm土壤全氮、全磷和全钾的积累,饭豆＋绿肥轮作可以有效提高0～60 cm土壤碱解氮、速效磷和速效钾     

辣木叶提取物对百香果生根的影响

[目的]研究辣木叶不同提取物对百香果扦插苗成活率及生根的影响,获得较好的促进百香果生根的提取物。[方法]通过水培法,以百香果插条为供试对象,研究辣木提取物的促生根活性。[结果]不同浓度提取物处理的百香果插条表现出不同的活性,培养至40 d时,均无萎蔫现象。0.5000和1.0000 g/L乙醇提取物、1.0000 g/L石油醚提取物处理的插条生根率达到100%。1.0000 g/L石油醚提取物处理插条生根数最大,达到4.45条/株;0.0625 g/L乙酸乙酯提取物处理的插条表现为最大的生根根长。[结论]为获得较高品质扦插成活苗,建议选用1.0000 g/L石油醚提取物处理插条,既可获得100%的生根率,也可获得较多的生根根数。