An overview of the ongoing insights in selenium research and its role in fish nutrition and fish health

In the present review, the ongoing researches about selenium research in fish nutrition have been comprehensively discussed. Selenium research is getting popularity in fish nutrition as it is required for the normal growth and proper physiological and biochemical functions in fish. Its deficiency or surplus amounts create severe problems in fish. It is available as inorganic form, organic form, and nano form. In fish, most of the previous research is about the selenium requirements for fish by using only one selenium source mainly the inorganic one. Selenium shows maximum biological activity and bioavailability when it is supplied in proper form. However, to differentiate the more bioavailable and less toxic form of selenium, sufficient information is needed about the comparative bioavailability of different selenium forms in different fish species. In fish, important data about the new forms of selenoproteins is still scarce. Therefore, it is necessary to focus on the determination and elucidation of the new selenoproteins in fish through the utilization of recent approaches of molecular biology and proteomics. The adaptation of these new approaches will replace the old fashioned methodologies regarding the selenium research in fish nutrition. Moreover, the use of molecular biology and proteomics-based new approaches in combination with selenium research will help in optimizing the area of fish nutrition and will improve the feed intake, growth performance, and more importantly the flesh quality which has a promising importance in the consumer market.     

Demonstration of primary cilia and acetylated α-tubulin in fish endothelial,epithelial and fibroblast cell lines

Primary cilia (PC) were demonstrated for the first time in fish endothelial, epithelial and fibroblast cell lines through immunofluorescence staining with the monoclonal antibody, 6-11B-1, against acetylated α-tubulin. The study was carried out with eight recently developed cell lines from the walleye, Sander vitreus (Mitchill). These were three fibroblast-like cell lines, WE-cfin11f, WE-skin11f and WE-liver3 from, respectively, the caudal fin, skin and liver, and three epithelial-like cell lines, WE-cfin11e, WE-spleen6 and WErpe from, respectively, the caudal fin, spleen and retina. Also, endothelial-like WEBA from the bulbus arteriosus and glial-like WE-brain5 from the brain were used. Immunocytochemistry revealed strong staining for acetylated α-tubulin in mitotic spindles and midbodies for all cell lines, and in PC for all cell lines except WE-skin11f. Staining of cytoplasmic microtubules (fibrils) was absent in three cell lines, including WEBA, but present in the others, especially WE-skin11f, which might have obscured PC detection in these cells. Tubacin, an inhibitor of histone deacetylase 6, induced cytoplasmic fibrils in WEBA and the intensity of their staining in WE-cfin11f. These results suggest that the cell lines might differ in their deacetylase activities, making them useful for studying this tubulin modification in teleosts, as well as for studying PC.     

应用遥感图片对西班牙Guadalteba地区灌木土地退化的评估

自然(资源)土地覆盖信息对分析和理解当前的陆地形式,尤其是对面临着环境日益恶化的研究区起着重要的作用。本研究综合应用Aster遥感数据和现地实际情况,完善西班牙Guadalteba地区2001年的土地覆盖图,将精度从47％提高到70％。综合土地覆盖图反映了该地区的植物类型分布和目前的自然(资源)土地覆盖状况。基于该图,自然(资源)土地覆盖图显示了自然(资源)和农业用地的当前分布,灌木土地退化图表明了各种灌木区的分布位置及其退化的不同等级,并作了进一步分析和讨论。最终的成果图揭示,Guadalteba地区许多以灌木分布为主导形式的土地已经被改用为农业和其他用途用地。由于人类活动的干扰而导致该地区大部分土地退化,使灌木覆盖仅占约9％的土地面积。图4表3参8。     

Biological control of<Emphasis Type="Italic"> Bemisia tabaci</Emphasis> Biotype “B” (Homoptera: Aleyrodidae) by introduction,release and establishment of<Emphasis Type="Italic"> Eretmocerus hayati</Emphasis> (Hymenoptera: Aphelinidae)

For the biological control Bemisia tabaci (Genn.) Biotype B (Homoptera: Aleyrodidae) , about 200,700 individuals of the imported parasitoid Eretmocerus hayati Zolnerowich and Rose (Hymenoptera: Aphelinidae) were released during 2000 and 2002 on different host plants in Egypt. The average parasitism rates in different governorates on Lantana camara, Gossypium barbadence (cotton), Helianthus annus (soybean) and Solanum melongena (eggplant) were 10.3 and 14%, 16 and 11.4%, 12.9 and 8.7%, 18 and 13% during 2001 and 2002, respectively. The population of E. hayati correlated significantly with the buildup of the whitefly population in all three governorates, which indicated the establishment of the E. hayati parasitoid on these economically important crops in Egypt.     

优质高产香型杂交水稻新组合宜香2292的选育与应用

宜香2292系四川省宜宾市农业科学研究所用浓香型优质不育系宜香1A与优质恢复系宜恢2292组配而成的中籼迟熟香型优质杂交水稻新组合,其农艺性状优、香味浓、产量高、品质优、适应性广、制种产量高。2002年荣获四川省第三届“稻香杯”优质米称号,2004年通过国家和江西省品种审定。本文介绍了该组合的选育经过、特征特性及其运用技术。     

Characterization of correlation between grain moisture and ear rot resistance in maize by QTL meta-analysis

Ear rot (ER) in maize is a prevalent disease worldwide which reduces yield and grain quality. Grain moisture content (GM) is an important factor which impacts the fungal development of ER species. Our purpose was to identify the genomic regions of maize in the control of GM and ER resistance, and the correlations between two traits. A meta-analysis was carried out using 241 quantitative trait loci (QTL) from 29 studies to propose meta-QTL (MQTL) on a high-density genetic linkage map (IBM 2 neighbors 2008). For GM content, 44 MQTL were identified on all chromosomes except for chromosome 9, while 29 MQTL were found for ER resistance, mainly located on chromosomes 3, 6 and 7. Moreover, 14 overlapping domains for GM MQTL and ER MQTL were observed on chromosomes 2, 3, 6 and 7, mainly focused on five active regions (bins 2.08–2.09, 3.04, 3.06, 6.04–6.06 and 7.03–7.03). There were 13 genes in the overlapping domain which could be divided into five classes: stress-related gene, photosystem-related gene, architecture-related gene, dynamic-related gene and seminal-related gene. It was possibly that the five-class genes were simultaneously related with GM and ER.     

Using morphological characteristics for assessing seedling vitality in small-scale tree nurseries in Kenya

Small-scale tree nurseries are important in fulfilling the goals of reforestation and agroforestry implementation schemes in Kenya and other developing countries. The focus in seedling production has been on quantity, instead of quality, but a change can be seen in recent tree nursery manuals. These manuals are emphasising morphological characteristics as tools for assessing potential field performance of seedlings. However, morphological criteria are debatable and their value is questioned. A survey was carried out among tree nursery operators in the Meru area, in the Eastern province of Kenya, to determine how operators perceived seedling vitality, and how they separated acceptable seedlings from those of poor vitality. Based on the survey, 3 pairs of criteria were chosen, size (tall versus small), colour (green versus yellowish), and sturdiness quotient (sturdy versus lanky). These criteria were tested on survival and growth in a field trial, a controlled bench trial, and in a root growth potential test. The results showed that the nursery operators were aware of quality differences in seedlings, but they did not cull accordingly. The results from the field trial showed that mango (Mangifera indica L.) performed poorly compared to grevillea (Grevillea robusta A. Cunn. ex. R. Br.), probably due to the high altitude. The altitudinal range for mango and grevillea are 0-1,200 m and 0-2,300 m, respectively, and the trial site was located on an altitude of 1,725 m. In grevillea, small seedlings grew better than tall in the field trial, but no differences could be found in the other trials. In mango, sturdy seedlings grew better than lanky ones in the field trial, while in the controlled trials tall seedlings grew better than small ones. The results showed that morphological characteristics as seedling quality assessment criteria could be unreliable as the effect differs with species and planting site.     

Storability of onion bulbs contaminated by<Emphasis Type="Italic">Aspergillus niger</Emphasis> mold

In the course of pre- and postharvest epidemiological studies on bulbs contamination byAspergillus niger, two Sudanese onion cultivars were tested: ‘Saggai Red’ and ‘El-Hilo White’.A. niger spores, whether seedborne, soilborne or airborne, were avirulent to the healthy growing onion plants. The fungus heavily contaminated the dead onion tissues, mainly the dead leaves followed by the dry scales, the dead roots and, to a lesser extent, the bulb necks, preferring the red-skinned cultivar to the white one. The initial spores carried from naturally contaminated field soil on the dead tissues could germinate and produce massive numbers of new spores on bulbs stored at average climatic conditions of Sudan (23–39°C, 29–93% relative humidity). Under laboratory-controlled conditions, optimal growth occurred at 75–85% r.h. on bulbs with dry scales and maximum losses occurred at 100% r.h. and ambient temperature. Underin vitro conditions, the optimal growth and sporulation temperature forA. niger was in the range of 30–35°C. Early harvesting and removal of the dead onion tissues improved bulb storability in aseptic stores under low temperature and relative humidity conditions. http://www.phytoparasitica.org posting Oct. 20, 2003.     

Production Objectives and Management Strategies of Livestock Keepers in South-East Kenya: Implications for a Breeding Programme

A survey of pastoralist and agropastoralist households in south-east Kenya was conducted to determine their production objectives and management strategies in order to optimize and extend a breeding programme for indigenous small East African Shorthorn Zebu cattle. The reasons for keeping cattle and the breed/trait preferences identified reflect the multiple objectives of the livestock keepers, with both adaptive traits and productive/reproductive traits rated as important. Although the Maasai and Kamba zebu (M&KZ) breeds were ranked highly with regard to adaptive traits, the population is considered to have been in decline over recent years. In order to promote the conservation and sustainable use of the M&KZ cattle, the formation of an open nucleus breeding scheme is recommended. In particular, such a scheme would be able to address several existing constraints (e.g. individual herds are very small and communal use of pastures/water makes controlled mating difficult). Such interventions would require the full participation of the livestock keepers, as well as ensuring that a holistic approach to species and breed attributes is taken into account in setting breeding goals, such that the full array of contributions that livestock make to livelihoods and the genetic characteristics related to these contributions are fully incorporated into the programme.