Insecticide resistance in Egyptian populations of the cotton whitefly,Bemisia tabaci (Hemiptera: Aleyrodidae)

Three collections of Bemisia tabaci were taken from cotton and vegetable crops at the beginning of the growing season in Egypt. These displayed marked resistance to the carbamates carbosulfan (ca 20- to 50-fold) and aldicarb (ca 40- to 80-fold) and moderate resistance to the pyrethroids cypermethrin (ca 10- to 30-fold) and lambda-cyhalothrin (ca 10- to 25-fold). They displayed no resistance to the organophosphates profenofos and pirimiphos-methyl, or to imidacloprid. Another population, collected at the end of the growing season, differed markedly in its response. In this population, resistance to carbosulfan remained high (ca 40-fold), resistance to profenofos and cypermethrin was increased (ca 20- and 50-fold respectively) and a slight resistance to imidacloprid was detected (ca 6-fold). Resistance to cypermethrin and profenofos was shown to be similar among adults and nymphs. Irrespective of collection date, none of the populations showed resistance to pyriproxyfen. These Egyptian populations were compared with two representative Israeli populations. The differences between their resistance profiles is discussed in terms of their collection date, their geographical proximity and the patterns of insecticide use at their sites of collection.     

以色列Har Keren沙漠黄土环境磁学特征研究

风成黄土是研究古气候变化的良好载体,在全球陆地分布广泛,而不同区域地理环境差异显著,其记录气候变化的机制亦有所不同。以色列南部黄土区地处亚热带沙漠边缘,为探究该区域黄土磁性特征及其对区域环境的响应机制,对内盖夫沙漠边缘黄土区进行野外考察并测试系统环境磁学及粒度参数。结果表明,Har Keren(HK)剖面中磁性矿物主要为碎屑磁铁矿和磁赤铁矿,磁性矿物含量较少,磁性颗粒主要为粗单畴(SD)和多畴(MD),磁性特征与中国西北干旱区黄土较为相似。HK剖面常温磁学参数整体变化范围较小,仅在剖面亚表层有所升高,可能是受现代成土作用影响。HK剖面中值粒径自底部至顶部呈减小趋势,但粒度整体偏粗,其频率分布曲线显示为正偏态,分选较差,反映出多种搬运方式的混合特征,与典型风成黄土有所差异。     

以色列野生二棱大麦籽粒多组分营养性状的相关性分析

为探讨起源地生态地理因素对野生二棱大麦营养性状的影响,对源自以色列不同地区9个野生二棱大麦群体的60个生态型材料的籽粒总氮、可溶性蛋白质、总淀粉含量等主要营养成分进行测定。经单因素方差分析(One-Way ANOVA)、相关性网络分析(correlation-based network analysis,CAN)和斯皮尔曼秩相关分析(Spearmanp’s Rho Correlation)等软件分析结果表明,以色列野生二棱大麦在群体、生态型水平和籽粒的主要营养成分均存在明显差异;总氮、可溶性蛋白质含量以及单粒重与起源地多个生态地理因素显著相关(P0.05)。因此得出结论,野生二棱大麦是在长期适应起源地生态地理环境的过程中,在自然选择压力下形成了其特有的营养性状遗传多样性。     

Edaphic interslope and valley bottom differences at “Evolution Canyon”, Lower Nahal Oren, Mount Carmel, Israel

The opposite slopes of lower Nahal Oren, Mount Carmel, Israel, designated “Evolution Canyon”, display physical and biotic contrasts, although both are cut in Upper Cenomanian calcareous limestone. The three-fold greater solar radiation makes the south-facing slope warmer, drier and more variable than the north-facing slope and valley bottom. Consequently, biodiversity is greater. Microclimate (mesic–xeric) is a major force driving adaptive evolution, and causing soil divergence. The soils on both slopes are Terra Rossas in the Israeli classification system (Rhodoxeralfs in US taxonomy). However, selected properties (pH, humus content, NH₄–N content, cation exchange capacity and others) display greater interslope than intraslope differences. The north-facing Terra Rossas have a dark-coloured A1 humic horizon, which is better developed than in south-facing Terra Rossas. Differences in soil morphology, moisture regime and microfabric between the north- and south-facing soils suggest that they belong to different taxonomic classes. These differences probably result in part from the forested ecosystem of the north-facing slope versus the savanna-like ecosystem of the opposite slope.     

All-male broods of Tilapia nilotica × T. aurea hybrids

The proportion of males in single pair crosses between Tilapia nilotica females and T. aurea males was found to vary between 50 and 100%. There was no apparent influence of the T. aurea males on these proportions. In a similar test nine T. vulcani females were paired with T. aurea males, and the proportion of males in their hybrid offspring ranged between 93 and 98%. Two T. nilotica mothers of all-male hybrid broods mated with unselected T. nilotica males, and all their daughters also reproduced all-male hybrid broods when crossed with T. aurea males. The reciprocal cross of T. aurea females with T. nilotica males reproduced three males to each female offspring. Growth rate tests of the all-male T. nilotica × T. aurea hybrids, and the T. vulcani × T. aurea hybrids did not reveal heterosis.     

从美国、以色列、瑞典农业合作组织中得到的启示

由于我国人多地少，又受到土地制度的制约，我国农户拥有的土地使用权的规模比较小，又由于生产效率不高，使得资本积累有限，有限的资本又不足以完成劳动向资本的转换，这样造成的恶性循环导致无法形成规模经济．中国农业只有不断地革新才能够解决农民所遇到的各种问题．本文通过对美国、以色列、瑞典农业合作组织的发展模式进行研究．探讨我国农业合作组织发展的建议对策，解决我国农业合作社遇到的问题，寻求更好的发展模式     

Evaluation and variation in response to infection with Puccinia striiformis and Puccinia recondita of local wheat landraces

The purpose of this study was to identify the species of local landraces of wheat (Triticum spp.), held in the Israel Gene Bank, to evaluate them for basic characters and to assess their response to infection by two rust fungi under artificial inoculation conditions. One-hundred-thirty one seed samples were collected from local or Beduin farmers during 1978–1981 throughout the Galilee, Mt. Gilboa. Judean Desert and the south Negev. The samples were collected and stored in the Israel Gene Bank without any characterization or evaluation. Each accession was planted in a 1 m row at Bet Dagan and grown under favorable conditions for plant growth and rust development. Determination of the species, data of plant height, days to heading and reaction of the landraces to artificial inoculation with a composite inoculum of Puccinia recondita and P. striiformis were collected from each row. A small part of the landraces collection consisted of mixed populations of T. durum and T. aestivum plants, where one of the two species was predominant. One-hundred-fourteen and 17 accessions from this collection represented, respectively, Triticum durum and T. aestivum Israel landraces. Large variations were found for all the characters examined. Of the total accessions, 6.5% (8 accessions) and 32% (42 accessions) were resistant, respectively, to yellow- and leaf-rust. It was concluded that the diversified populations of the local landraces of wheat can be used as a source not only for genes affecting basic characters such as plant height and heading date, but also for resistance to leaf rust and yellow rust. This revised version was published online in July 2006 with corrections to the Cover Date.     

以色列红罗非鱼耐盐性的初步研究

在0、15、25及32四种盐度梯度下，测试了以色列红罗非鱼仔鱼、稚鱼及幼鱼的耐盐性。结果表明：以色列红罗非鱼的耐盐性高于尼罗罗非鱼和奥利亚罗非鱼，低于佛罗里达红罗非鱼和莫桑比克罗非鱼，与莫桑比克和尼罗罗非鱼的杂交种相当。以色列红罗非鱼的耐盐性与其日龄有关，日龄越大，其耐盐性越强。幼鱼与仔、稚鱼间耐盐性存在极显著差异，仔鱼和稚鱼间耐盐性差异不显著。几种耐盐指标中，ST50最灵敏，MST和BT次之，MLS-96和死亡率较差。     

A new genus and species of soft scales (hemiptera: Coccoidea: Coccidae) from oaks in Israel

A new genus of soft scales,Kenima, is described forKenima galilit, a new species off oaks in Israel.     

The presence of crown gall of grape incited byagrobacterium tumefaciens biovar 3 in Israel

Crown gall was previously reported on grape in Israel but the pathogen was not isolated and characterized. The three recognized biovars ofAgrobacterium tumefaciens can be tumorigenic on grape, but biovar 3 is the most important world wide. A single occurrence of tumors in a vineyard yielded bacteria which incited galls on grape,Nicotiana glauca and tomato, but not on bryophyllum. The bacteria were confirmed asA. tumefaciens because they contained DNA which hybridized with T-DNA from a Ti plasmid. Biochemical and physiological tests, octopine production and utilization, and agrocin 84 insensitivity conformed with those of bv. 3. Subsequent occurrences of the grape disease have not been found, but the presence ofA. tumefaciens bv. 3 in Israel is a potential threat to nurseries and vineyards.