印楝扦插育苗及造林观察

以印楝树冠顶部1年生木质化、半木质化枝条及树冠下部木质化枝条作插条,用不同种类、不同浓度的生长调节剂处理,在两种基质上作扦插育苗对比试验,结果表明：不同基质上的插条生根天数存在显著差异,树冠不同部位的插条、不同生长激素及浓度、不同育苗基质间插条的生根率也存在显著差异,基质以无菌的细河沙为好;生长激素以1g/L吲哚丁酸为好;插条以树冠顶部1年生木质化枝最佳,其生根率可达95％,初步观察表明：定植后,扦插苗幼龄林与实生苗幼龄林相比生长无明显差异。     

Aerial Spraying Trials in West Africa for Blackfly Control

Abstract

Organochlorine, organophosphate (o.p.) and carbamate insecticides have been extensively used in Australia to combat Lucilia cuprina Wied. the main initiator of fly-strike of sheep occurring wherever sheep are run on the continent. The improved mules operation, mid-season crutching and insecticides are important in the management of Merino sheep. Insecticides are particularly valuable against body strike, especially in young sheep, in years with intermittent rain during the warmer months. Resistance to larvicides developed in the blowfly over a period of 10y from 1957. The time between the introduction of various insecticides and development of resistance is considered and a comparison made between the emergence of resistance problems to the newer synthetic insecticides in the housefly in Denmark, and in the blowfly in Australia. To provide a complete history of insecticides against the blowfly reference is made to arsenicals, to which there was no suspicion of resistance until low order cross resistance was diagnosed in o.p.-carbamate resistant strains. Some seven years after their introduction DDT and γ BHC were replaced by cyclodiene insecticides in 1954/1955. Reasons are advanced to explain the non-emergence of resistance to DDT and BHC in that period. Resistance to dieldrin and aldrin developed in late 1957 after which diazinon was introduced. The resistance has a typical BHC/dieldrin resistance spectrum and is due to a semi-dominant gene which has persisted in the field in the absence of pressure from cyclodiene insecticides. Non-specific resistance to o.p. insecticides developed in two steps. Low order resistance, diagnosed in 1965, was supplemented by an additional resistance mechanism in 1966, three alleles on two chromosomes are involved. The carbamate, butacarb, was effective against o.p. resistant strains of the blowfly when introduced in the 1966/67 season. In 1967, resistance to butacarb was diagnosed and rapidly became widespread. For the past three fly seasons larvae have been used to monitor resistance levels to o.p. and carbamate insecticides; resistance factors to both these classes of insecticide are significantly higher in larvae than adult females. Resistance levels to o.p. insecticides have stabilised. By contrast resistance levels to butacarb have doubled. A combined o p.-carbamate resistance generally applies in field samples. Larvae from o.p.-carbamate resistant strains form artificial strikes earlier than susceptible larvae, particularly on sheep treated with butacarb. It is concluded that registered o.p. insecticides, but not butacarb, will still give considerable protection against fly-strike, providing the maximum levels of o.p. resistance, reached in laboratory selection programmes, are not exceeded in the field. Investigation into o.p. resistance in the species suggests that the resistance mechanisms place their carriers at a disadvantage in the absence of selection pressure. Measures to minimise the amount of insecticide used against the blowfly are therefore strongly advocated—these include: the improved mules operation, mid season crutching and good animal husbandry.     

不同年代中籼水稻品种的产量与氮肥利用效率

本研究旨在探明中籼水稻在品种改良过程中产量与氮肥利用效率的变化特点。以江苏省近70年来不同年代在生产上广泛应用的12个代表性中籼水稻品种(含杂交稻组合)为材料,依据应用年代将其分为20世纪40—50年代、60—70年代、80—90年代和2000年以后4个类型,设置0 N(全生育期不施氮)、MN(全生育期施氮210 kg hm–2)和HN(全生育期施氮300 kg hm–2)3个施氮量处理,研究其产量、氮肥利用效率及其生理特性。结果表明,随品种应用年代的演进,不同年代中籼水稻品种的产量和氮肥利用效率均获得较大提高。2000年以后的品种(超级稻)产量和氮肥利用效率较高,根系性状和叶片光合特性以及氮代谢相关酶活性强是其重要生理基础。超级稻抽穗后根系氧化力和剑叶光合速率下降的幅度较大可能是导致超级稻结实率较低的一个重要原因。提高灌浆中后期超级稻的根系氧化力和剑叶光合速率,有望提高超级稻的结实率。     

印楝的世界地理分布与引种栽培概况

印楝在原产地和广泛引种的地区被誉为神奇之树，在热带干旱和半干旱地区的植被恢复和环境治理中发挥了重要作用。印楝的起源地被认为是印－巴次大陆及和东南亚的干旱地区，约一百年前引种非洲和拉丁美洲。中国最早于20世纪80年代引种于雷州半岛和海南，1995年引种云南干热河谷地区，种植面积正迅速扩大。     

百色杧果栽培种质果实品质多样性分析

广西的杧果(Mangifea indica L.)以百色右江干热河谷为重要栽培地区,百色地区的杧果栽培品种仍然以传统品种为主,伴随着新兴杧果产区的崛起,急需选育适宜百色的杧果新品种,以提升百色杧果的竞争力.目前,在广西以外的其他地区已经开展了不同杧果品种性状评价的研究,而针对广西百色地区杧果栽培种质的多样性分析评价鲜有...     

印楝活性物质超临界CO2萃取技术

印楝(Azadirachta indica A.Juss)种子中含有大量杀虫活性较高的柠檬素类物质,印楝油可促进柠檬素类物质的稳定性和生物活性。本实验通过超临界CO2萃取得到含柠檬素类物质和印楝油混合的粗提物,以印楝素A为检测指标,使用均匀设计优化萃取工艺的压力、温度、时间和夹带剂的体积4个因子,确定最佳提取工艺条件为压力37MPa,温度43℃,时间165min,夹带剂的体积13mL,此时印楝种仁中印楝素A萃取率为0.37%。初步测定超临界CO2萃取产物对玉米象(Sitophilus zeamais Motschulsky)成虫的驱避活性,并对该技术应用于印楝产业化的前景和可行性进行分析探讨。     

籼粳交后代亚种分类性状与经济性状关系的研究

在对水稻籼粳交F1、F2 代及籼粳杂交育成品种进行分类的基础之上 ,分析籼粳交F1、F2 代及籼粳杂交育成品种亚种分类性状与经济性状的相关关系。研究结果表明 :籼粳交F1、F2 代及籼粳杂交育成品种亚种分类性状与主要经济性状存在密切的相关关系 ,依据这些相关关系可以利用程氏指数亚种分类性状进行籼粳杂交亲本和杂交后代的适宜选择     

5个优质籼型不育系的选育策略及应用研究

对常德市1985年至2012年育成的5个籼型优质不育系的选育策略与应用情况进行了分析思考。地方优良品种基因的引入是杂交稻品质改良的关键;三系育种存在对抗性育种未予重视,遗传基础狭窄,常规育种效率低下等问题,提出了三系育种今后努力的方向,即加强生物技术与常规育种技术的结合,适当延长不育系的生育期,对不育系的性状进行形态改良。     

紫薇种子发芽特性研究

利用3种试验方法探讨了紫薇种子发芽特性,一是直接在温室苗床内播种,二是进行发芽温度试验,三是利用赤霉素(GA),ABT生根粉和自来水(对照)分别对紫薇种子进行12h浸种,再将浸种处理后的种子分别置于室温和15℃、20℃、25℃恒温箱内进行发芽试验.结果表明:紫薇种子发芽速度随温度升高而加快,发芽率随温度上升而提高,25℃是紫薇种子发芽的最佳温度.赤霉素对提高种子发芽率有显著的促进作用.     

园林植物修复污泥施肥土壤重金属污染的应用研究

以美人蕉(Canna indica)、天堂草(Cynodon dactylon)为试材,通过盆栽试验研究了植物对污泥中Cu、Zn、Pb、Cd、Cr 和Ni等重金属的吸收、分布与去除效果.结果表明,美人蕉和天堂草地下部的重金属含量普遍高于地上部,于盆栽土中分别施用质量分数50%和25%的污泥后,美人蕉和天堂草对Zn、Ni、Cd的去除效果较好.