Rainfall variability and its influence on surface flow regimes examples from the central highlands of Ethiopia

The article shows results of an international and interdisciplinary project with the title ‘Rainfall and its Erosivity in Ethiopia’. Rainfall variability affects the water resource management of Ethiopia. The influence of rainfall variability on flow regimes was investigated using five gauging stations with data availability from 1982–1997. It was confirmed that the variability in rainfall has a direct implication for surface runoff. Surface runoff declined at most of the gauging stations investigated. Therefore, effective water resource management is recommended for the study area. Future research should focus on watershed management which includes land-use and land cover. The question posed here is whether the variability in rainfall significantly affected surface flow in the study area.     

Comparative Studies on the Green Algae Chlorella homosphaera and Chlorella vulgaris with Respect to Oil Pollution in the River Nile

The effect of oil pollution on growth and metabolic activitiesof the fresh water algae Chlorella homosphaera and C.vulgaris was studied. The study was conducted on two locationsin the river Nile, one is oil polluted and the other is notpolluted. The assemblage of the different algal groups wasmonitored in both locations. Chlorophyta was more dominant thanCyanophyta and Bacillariophyta in both locations during allseasons except in winter when Bacillariophyta is the mostdominant group. The presence of crude oil or its refineryproducts (solar and lubricating) in the culture media of algaemarkedly influenced their growth, proteins and nucleic acidcontents. The toxicity of oil was a concentration dependent. Thelow concentrations stimulated growth, protein content andnucleic acids, whereas high concentrations had an inhibitoryeffect. Although DNA and RNA responded similarly to crude oil inthe two tested organisms, DNA showed more sensitivity than RNAto solar oil. Lubricating oil had a little phytotoxic effect onnucleic acids. Different species of algae response differentiallyto oil pollution; Chlorella vulgaris can be referred to asoil-sensitive, while Chlorella homosphaera can toleraterelatively higher concentrations of oil.     

优质高品质陆地棉品种(系)数量性状因子分析及稳定性评价

[目的]为指导优质陆地棉常规育种提供科学参考.[方法]对63个高品质陆地棉资源(即纤维长度30 mm、以上比强度31 cN/tex以上、马克隆值3.7 ～4.2)的14个数量性状进行因子分析并聚类,对其纤维品质进行稳定性评价.[结果]前5个公因子的累积贡献率达到90.0;,分别代表籽指、铃重、比强度、铃数、纤维整齐度、纤维细度等陆地棉的主要特征,并根据这63个品种(系)的前5个公因子的得分值,采用离差平方和法将其聚为9类,其中大铃优质、早熟性、高衣分上表现好的分别是Ⅸ、Ⅷ、Ⅵ类.[结论]通过因子分析聚类以及稳定性评价后最终预测出12个较理想的亲本,即贝尔斯诺、Acala1517-77、Aca1a1 517-70、巴州5628、SI2、霍皮卡尔、MO-78-344、117169-6、新陆中9号、巴州6501、长绒67-12和新培育品系.     

Morphological and molecular characterization of garlic (Allium sativum L.) genotypes sampled from Turkey

Genetic Resources and Crop Evolution - Garlic is a vegetable widely used both in food and as a pharmaceutical raw material in the world due to its contents. Although morphological differences are...     

陆地棉机采性状对皮棉产量的遗传贡献分析

 采用加性-显性-加加上位性及其与环境互作的遗传模型（ADAA模型）,对8个陆地棉亲本（其中有6个机采棉品种）及其F₁和F₂的28个组合5个机采性状和单株皮棉产量的新疆阿拉尔和石河子2试点资料,进行了贡献分析。结果表明,5个机采性状对皮棉产量表型值的贡献变化范围为－20%～－14%;在显性贡献中,第一果枝高度对皮棉产量的贡献率最大（CR_D=10%）,其次是节间长度的贡献（CR_D=8%）,而霜前花率对皮棉产量有较大的抑制作用（CR_D=－25%）;霜前花率对皮棉产量的加加上位贡献率最大（CR_AA=86%）,其次是第一果枝节位（CR_AA=24%）。霜前花率在特殊的环境中对皮棉产量表现为很大的显性正向贡献（CR_DE=78%）和加加上位效应抑制作用。不同亲本5个机采性状对其皮棉产量的显性和加加上位效应贡献不同。5个机采性状对不同组合皮棉产量显性效应的贡献较小,霜前花率对皮棉产量的显性效应的贡献在2个地点的表现往往和单株皮棉产量在不同地点表现显性效应的性质（正或负）相一致,并且在5个机采性状中对皮棉产量的显性贡献是最大的。加加上位效应在皮棉产量的遗传中起着很重要的作用,而在8个亲本及其后代各组合的5个机采性状中,霜前花率可作为选择皮棉产量加加上位效应的主选性状。在不同的环境中,皮棉产量加加上位效应的主选机采性状随组合有所不同。     

Analysis of the Offspring Sex Ratio of Chicken by Using Molecular Sexing

The overall sex ratio of offspring （dead embryos and hatch chicks） from all the fertilized eggs of 140 hens collected for 30 days was studied using duplex PCR of certain fragments of sex chromosomes. Additional 894 dead embryos over a period of 21 days of incubation were also investigated to verify the sex ratio of the dead embryos. The sex of the early dead embryos was identified using this molecular sexing technique. The sex ratio of the hatch chicks and the total offspring of the hens investigated in this experiment did not differ from the expected sex ratio （i.e., 1：1）., However, the number of female dead embryos was significantly more than that of males. The data indicated that the different physiologic function of males and females contributed to female-biased mortality during incubation. It was also found by further analysis that the sex ratios of the offspring of some hens were significantly biased to female or male over the period investigated, which suggested that the sex ratio of offspring might be influenced by the maternal condition to some degrees.     

Deficit irrigations during soybean reproductive stages and CROPGRO-soybean simulations under semi-arid climatic conditions

This study was carried out to determine the effect of water stress on five different generative stages of soybeans and to evaluate the CROPGRO-soybean model under semi-arid climatic conditions. The study was conducted at the Faculty of Agricultural Engineering, Harran University research field in 2003 and 2004 growing seasons. Plants received full irrigation during vegetative stages, after which it was cut off at different reproductive stages (treatments): R_1-2, beginning of flowering and full bloom; R₃, beginning of pod; R₄, full pod; R₅, beginning of seed; and R₆, full seed. The control treatment was full irrigation throughout. Observed yields ranged from 1955 (R₆) to 3684 kg ha⁻¹ (control) in 2003, and from 1867 (R₆) to 3952 kg ha⁻¹ (control) in 2004, respectively. Generally, in both of the years any water stress imposed on soybeans in three different generative stages (R₃, R₅, and R₆) resulted in substantial yield reduction compared with full irrigation; yield reduction was greatest at the R₆ stage. Biomass and 1000 seed weight also showed significant difference. Overall, CROPGRO-soybean simulated parameters from all treatments were higher compared with observed ones. Although simulated yield results were close to measured ones, they could not track observed yield patterns. Generally, the CROPGRO-soybean simulation model failed to satisfactorily mimic observed soybean yield, biomass, and 1000 seed weight and therefore it is suggested not to be used for similar scenarios and climatic conditions.     

Cultured meat from muscle stem cells:A review of challenges and prospects

Growing muscle tissue in culture from animal stem cells to produce meat theoretically eliminates the need to sacrifice animals. So-called "cultured" or "synthetic" or "in vitro" meat could in theory be constructed with different characteristics and be produced faster and more efficiently than traditional meat. The technique to generate cultured muscle tissues from stem cells was described long ago, but has not yet been developed for the commercial production of cultured meat products. The technology is at an early stage and prerequisites of implementation include a reasonably high level of consumer acceptance, and the development of commercially-viable means of large scale production. Recent advancements in tissue culture techniques suggest that production may be economically feasible, provided it has physical properties in terms of colour, flavour, aroma, texture and palatability that are comparable to conventional meat. Although considerable progress has been made during recent years, important issues remain to be resolved, including the characterization of social and ethical constraints, the fine-tuning of culture conditions, and the development of culture media that are cost-effective and free of animal products. Consumer acceptance and confidence in in vitro produced cultured meat might be a significant impediment that hinders the marketing process.