Growth performance and RNA/DNA ratio of noble crayfish (Astacus astacus) and narrow‐clawed crayfish (Pontastacus leptodactylus) fed fish waste diets

New and viable species for aquaponics and integrated multi‐trophic aquaculture (IMTA) in freshwater systems can improve yields and sustainability of aquaculture. Freshwater crayfish species such as Astacus astacus and Pontastacus leptodactylus are omnivorous feeders and considered candidates for feeding on faecal matters in existing aquaculture systems. Feeding trials were conducted to determine growth response and RNA/DNA ratio in freshwater crayfish fed fish waste. Carapace length and wet weight were measured to determine the growth response. Juvenile A. astacus was fed faeces of hybrid striped bass (Morone chrysops × Morone saxatilis) and rainbow trout (Oncorhynchus mykiss), while adult P. leptodactylus was fed with two commercial pellet diets and pikeperch (Sander lucioperca) faeces. The nutritional composition of hybrid striped bass faeces was close to optimal diet composition of A. astacus, and crayfish showed significantly higher carapace growth, weight gain and weight gain per moult as the group fed rainbow trout faeces. The growth of P. leptodactylus was significantly lower in terms of weight gain and weight gain percentage per moult for crayfish fed on pikeperch faeces. Thus, this study can recommend a co‐cultivation of hybrid striped bass and A. astacus within one system, but cannot recommend co‐cultivation of P. leptodactylus with pikeperch. Additionally, this study showed controversial results of RNA/DNA ratio and weight gain of both crayfish species. Thus, RNA/DNA ratio cannot be approved for investigations on crayfish physiological status in controlled feeding experiments if animals are fed with an inadequate diet.     

Glycoalkaloids in potato tubers grown under controlled environments

Tuber content of α-solanine, α-chaconine, and total glycoalkaloids (TGA) was determined for the potato cultivars, Norland, Russet Burbank, and Denali grown under different environmental conditions in growth chambers. The lowest TGA concentrations (0.30 to 0.35 mg g¹ dry tissue) were found in the cv. Norland with 400 μnol m^-2 s^-1 photosynthetic photon flux (PPF), 12 h day length, 16 C temperature, and 350 μmol mol^-1 carbon dioxide. The ratio of α-chaconine to α-solanine was close to 60:40 under all growing conditions, except that it was 50:50 under the low temperature of 12 C. Cultivars responded similarly to environmental conditions although TGA was about 20% greater in cv. Russet Burbank and about 30% greater in Denali compared to Norland. The largest changes in TGA occurred with changes in temperature. In comparison to 16 C, TGA were 40% greater at 12 C, 80% greater at 20 C, and 125% greater at 24 C (0.70 mgg ^-1 dry weight). The TGA concentratation increased from 10 to 25% with an increase in light from 400 to 800 μmol m^-2 s^-1 PPF for all three cultivars. TGA increased 20% with extension of the day length from 12 to 24 hr and also increased 20% when carbon dioxide was increased from 350 to 1000 umol mol^-1. TGA concentrations were not influenced by changes in relative humidity from 50 to 80%. TGA concentrations decreased only slightly in harvests made from 9 to 21 weeks after planting. Variations in TGA among the different growing conditions and cultivars were below 20 mg/100 g fresh weight (= 1.0 mg g^-1 dry weight) recognized as the upper concentration for food safety. However the results suggest that TGA should be considered when potatoes are grown at temperatures above 20 C.     

喀麦隆棕榈酒酵母分离物的酒精和糖的耐量及其蔗糖酶活性(英文)

在87 个喀麦隆棕榈酒酵母分离物中, 和2 个分离物对乙醇(16% ～17% ,v/v)和糖类具有高的耐量,可生长于含有高达50% (w /v)葡萄糖的培养基中,而且具有较高的蔗糖酶活性。在以糖蜜发酵乙醇的生产中具有潜在的价值。按形态学和生理特性推断,Ya2 属中间假丝酵母(Candida interm edia)而Yao4 为啤酒酵母(Saccharom yces cerevisiae)。     

Ciliary photoreceptors with a vertebrate-type opsin in an invertebrate brain

For vision, insect and vertebrate eyes use rhabdomeric and ciliary photoreceptor cells, respectively. These cells show distinct architecture and transduce the light signal by different phototransductory cascades. In the marine rag-worm Platynereis, we find both cell types: rhabdomeric photoreceptor cells in the eyes and ciliary photoreceptor cells in the brain. The latter use a photopigment closely related to vertebrate rod and cone opsins. Comparative analysis indicates that both types of photoreceptors, with distinct opsins, coexisted in Urbilateria, the last common ancestor of insects and vertebrates, and sheds new light on vertebrate eye evolution.     

作物品种稳定性分析不同模型的比较

为确定应用不同稳定性分析模型在作物品种特性评价中的效果,基于SAS PROC MIXED程序,选取稳定性方差模型、Finlay-Wilkinson回归模型、Eberhart-Russell回归模型、加性主效乘式互作模型(AMMI)和环境方差模型等5种常用稳定性分析模型,对10套不同的作物品种区域试验资料进行分析.结果表明,每种模型都可以得出其对试验数据拟合的信息量指标值、一种品种稳定性序列和品种均值差异显著性检验的结果.这些模型在数据拟合效果、品种稳定性评判和品种均值差异检验等方面存在明显的差异;没有一个模型对所有试验资料的拟合效果均最佳,而是与具体分析的试验数据有关.不同稳定性分析模型适用于不同的试验数据,模型选择对品种稳定性评价和品种效应差异显著性检验有较大的影响.为提高对作物品种特性评价的准确性, 应针对具体的试验数据,利用Akaike信息量准则选用最佳的分析模型.     

Spelz (Triticum spelta L.), andere Kulturpflanzen und Unkräuter in der frühen Eisenzeit Mitteldeutschlands

Zusammenfassung Aus einer früheisenzeitlichen Vorratsgrube von Bösenburg (Kr. Eisleben) werden Reste von Kulturpflanzen und Unkräutern beschrieben. Gerste (Hordeum vulgare L. s. lat.) ist das vorherrschende Getreide. Daneben finden sich Emmer (Triticum dicoccon Schrank), Einkorn (Triticum monococcum L.), Spelz (Triticum spelta L.), Rispenhirse (Panicum miliaceum L), Lein (Linum usitatissimum L.), Pferdebohne (Vicia faba L.) und Unkräutenals Beimischungen. Der Spelz konnte für Mitteldeutschland erstmalig nachgewiesen werden. Dieser Nachweis und eine Zusammenstellung weiterer Funde zeigen, daß diese Art in prähistorischer Zeit eine wesentlich weitere Verbreitung hatte als bisher angenommen wurde. Die erreichbaren prähistorischen, genetischen, landwirtschaftlichen und linguistischen Daten über den Spelz machen wahrscheinlich, daß die Art ebenso wie Gerste, Einkorn und Emmer in Südwest-Asien entstanden ist.

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Summary Remains of cultivated plants and weeds of early iron age are described from Bösenburg near Eisleben (Central Germany). Barley (Hordeum vulgare L. s. lat.) is the predominant cereal. Emmer (Triticum dicoccon Schrank), einkorn (Triticum monococcum L.), spelt (Triticum spelta L.), millet (Panicum miliaceum L.), flax (Linum usitatissimum L.), horse bean (Vicia faba L.), and weeds are found as admixture. Spelt was found in Central Germany for the first time. This find and a list of further finds prove a much more extensive prehistoric area of this species as assumed till now. The prehistoric, genetic, agricultural, and linguistic dates available on spelt show that this species originated in southwestern Asia as barley, einkorn and emmer.

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am ¶rt;au - ( ), . (Hordeum vulgare L. s. lat.). ¶rt; (Triticum dicoccon Schrank), (T. monococcum L.), (T. spelta L.), (Panicum miliaceum L.), (Linum usitatissimum L.), ¶rt;¶rt; (Vicia faba L.) . . , , ¶rt; , ¶rt; . , , , ¶rt; , , , , - .

     

卵磷脂可改善家禽的生产性能

卵磷脂是什么 ?为什么它能改善家禽的生产性能 ?将其添加入饲料有多大好处 ?添加多少 ?     

Fusarium – Problematik bei Körnermais (Zea Mays L.)

In the last few years in maize stalk and ear rots caused by fusarium spp. was increasing, often causing contamination with mycotoxins. Most prevalent was fusarium graminearum, mainly producing Deoxynivalenol (DON) in kernels and stalk. DON is suspected to cause several diseases in humans and livestock. In our study, injection of conidial suspension in the silk channel was the most successful method for artificial inoculation. Due to significant differences between several hybrids, it could be concluded that resistance against the fungus is genetically controlled. Intensity of resistance is varying extremely, depending on environment. The mycotoxin concentration of the kernels was positively correlated with percentage of visible infected kernels, obtaining levels up to 95?ppm. Susceptible hybrids even showed in the rest plant extremely high levels of DON (up to 60?ppm). Naturally infected plants showed high mycotoxin concentrations above and below the main ear, exceeding the recommended level of forage for cattle. High mycotoxin levels in kernels and rest plants show the importance of resistance breeding against fusarium.