新疆棉花黑根腐病的初步研究

 棉花黑根腐病[Thilaviopsis basicola (Berk&Br·) Ferravis]也称褐根病或黑色烂根,近年来,在新疆的阿克苏、库尔勒、喀什和石河子等地均有发生,以海岛棉受害最重,威胁棉花生产。为此,我们对该病进行了有关病原菌生长特性、品种抗性鉴定及药剂防治等的初步探讨。     

兰州地区梨树、草莓疫酶菌种的研究

 梨树、草莓疫病,是当前梨树、草莓上普遍发生的一种病害。在兰州地区5月下旬-6月发病严重,梨树发病率在30%以上,草莓烂果率一般在10-20%,严重年份高达50%(1986年)。     

半荒漠地区灌木饲料林营造技术研究

本文对半荒漠地区灌木饲料林的树种选择、经营管理等问题进行了初步探讨，给出了花棒、杨柴、柠条、沙柳、毛条、毛柳、白沙蒿、油蒿８个半荒漠地区灌木饲料林树种的造林适宜立地类型、最适造林季节、最佳造林密度、最适收获期以及最佳平茬年龄。     

草业在绿洲生态农业中的地位和作用与优化体系建立的原理

本文重点阐述了干旱区绿洲建设的必要性和原则；草业在绿洲生态农业中的地位和作用；建立以草业为纽带，农牧林草结合，综合发展的绿洲生态农业体系的原理     

沙冬青根系的研究

沙冬青为轴根冬植物，主根粗壮，侧根发达。根系分布与土壤基质条件密切相关，基主体部分集中在０－３０ｃｍ土层内，根瘤位于侧根末端。冠幅平均为０．７６ｍ＾２的沙冬青，单株平均根系干重２３１．６ｇ，体积４１１．１ｃｍ＾３、表面积１３７７５ｃｍ＾２。     

丰抗2号冬小麦抗锈性基因的染色体定位研究

 用"中国春"单体系和抗锈品种"丰抗2号"杂交,对其抗病基因进行染色体定位。结果表明,丰抗2号对条锈菌小种25号的单显性抗病基因位于5B染色体上;对叶锈菌小种38号的单显性抗病基因位于5A染色体上。位于5B和5A染色体上的两个分别抵抗条锈和叶锈病的基因可能是新的抗病基因。     

搞好山区综合开发迎接世界山区年

我国山区综合开发试点示范工作进入第6个年头.114个示范县按照"改土、治水、植树、修路、办电"的十字方针,通过国家专项贴息贷款的扶持和带动,促进了县域经济的发展,也辐射带动了周边山区县的经济发展,并取得了明显的生态效益和社会效益.山区正在成为我国生态建设、森林旅游、生态产品等世界潮流趋势最具发展潜力的地区.要利用2002年"世界山区年"的国际环境、实施西部大开发、即将加入WTO和我国林业实施六大工程战略的良机,加大工作力度,加快山区开发的步伐.2001年的山区综合开发要重点做好7个方面的工作.     

韭菜防虫网栽培和品种比较试验

对韭菜覆盖50目防虫网进行的栽培试验结果表明,覆盖防虫网后避免了韭蛆的发生,并且减少使用农药辛硫磷3次;防虫网栽培对韭菜累计产量无明显影响。对天津地区栽培普遍的三个韭菜品种的比较试验结果表明,一年生韭菜汉中冬韭和津引一号的产量极显高于791。二年生韭菜汉中冬韭的产量显高于791和津引一号。因此天津地区露地韭菜栽培以汉中冬韭为适宜品种。     

Effects of foliar- and root-applied silicon on the enhancement of induced resistance to powdery mildew in Cucumis sativus

Two cucumber ( Cucumis sativus ) cultivars differing in their resistance to powdery mildew, Ningfeng No. 3 (susceptible) and Jinchun No. 4 (resistant), were used to study the effects of foliar- and root-applied silicon on resistance to infection by Podosphaera xanthii (syn. Sphaerotheca fuliginea ) and the production of pathogenesis-related proteins (PRs). The results indicated that inoculation with P. xanthii significantly suppressed subsequent infection by powdery mildew compared with noninoculation, regardless of Si application. Root-applied Si significantly suppressed powdery mildew, the disease index being lower in Si-supplied than in Si-deprived plants, regardless of inoculation treatment. The resistant cultivar had a more constant lower disease index than the susceptible cultivar, irrespective of inoculation or Si treatment. Moreover, with root-applied Si, activities of PRs (for example peroxidase, polyphenoloxidase and chitinase) were significantly enhanced in inoculated lower leaves or noninoculated upper leaves in inoculated plants of both cultivars. Root-applied Si significantly decreased the activity of phenylalanine ammonia-lyase in inoculated leaves, but increased it in noninoculated upper leaves. However, Si treatment failed to change significantly the activity of PRs in plants without fungal attack. Compared to the control (no Si), foliar-applied Si had no effects either on the suppression of subsequent infection by P. xanthii or on the activity of PRs, irrespective of inoculation. Based on the findings in this study and previous reports, it was concluded that foliar-applied Si can effectively control infections by P. xanthii only via the physical barrier of Si deposited on leaf surfaces, and/or osmotic effect of the silicate applied, but cannot enhance systemic acquired resistance induced by inoculation, while continuously root-applied Si can enhance defence resistance in response to infection by P. xanthii in cucumber.     

基于分子遗传标记技术的实蝇种群遗传关系研究进展

分子遗传标记技术已用于分析实蝇的种群遗传关系,本文介绍了分子遗传标记技术在实蝇的起源、入侵、定殖、扩散及其他方面的研究进展,首次分析了我国实蝇种群遗传研究的现存问题并针对检疫性实蝇种群遗传关系研究提出了建议.