Seasonal chemical composition of wall barley (Hodreum murinum L.) under sub-humid Mediterranean climate

Wall barley (Hodreum murinum L.) is an annual cool-season grass species that grows in areas with a Mediterranean climate. It has potential as a forage source in Jordan. The objective was to determine seasonal chemical composition of wall barley grown under sub-humid Mediterranean conditions. A field trial was conducted during 2000 and 2001 growing seasons at Samta (32°23'N, 35°50'E) in the Ajloun Mountains, Jordan. Data were collected on 28 February, 15 March, 30 March, 15 April and 15 May. The lowest fibre content of leaves was on 28 February and 15 March, with a range of 19.5% to 23.3%. Fibre content of leaves (73.3%) and stems (79.9%) peaked when the plants were mature (15 May). In contrast to fibre, the protein content decreased gradually with age. Protein content of the leaves on 28 February was 25%, after which it declined gradually and reached 2.9% at maturity. The calcium content of the leaves was higher than that of the stems and was sufficient to meet ewes' maintenance requirements. The Ca content of leaves during the period from 28 February to 30 March was 1.2% to 1.1%, whereas, the content declined with age and reached the lowest value (0.01%) at maturity. The phosphorus content did not show significant variation. It is concluded that age and environmental conditions may affect the nutritive value of wall barley.     

广西德保猪抵抗素基因的克隆与分析

[目的]克隆广西德保猪抵抗素（Resistin,RENT）基因并进行系统生物信息学分析,阐明德保猪脂肪细胞分化与脂肪生成的分子机制.[方法]根据NCBI已公布的猪RENT基因序列（NM 213783.2）设计特异性引物,以从德保猪血液中提取的总RNA为模板,PCR扩增RENT基因序列,T-A克隆至pEASY-T1载体后进行测序分析,并将所得测序结果用BLAST程序、MEGA 5.0软件、EXPASY服务器、SMART程序、SignIP程序、Softberry服务器和DNASTAR软件进行生物信息学分析.[结果]扩增获得468 bp的RENT基因序列片段,包含全长的德保猪RENT基因编码区和部分非编码区序列.多重序列比较分析结果显示,德保猪RENT基因编码区核酸序列与猪、牛、山羊、绵羊、人、兔、猕猴和豚鼠的同源性分别为100.0％、85.5％、85.5％、84.5％、81.2％、80.3％、80.0％和77.3％.德保猪RENT蛋白结构预测结果显示,其理论分子质量11.69 ku,等电点7.82,为弱碱性蛋白;N-末端存在信号肽,定位于胞质外,仅具有1个低复杂度结构域,包含1个α-螺旋、8个β-折叠、7个T-转角及两个无规则卷曲.[结论]RENT基因在德保猪中呈高度保守特征,是其脂肪细胞分化中的重要调控基因.     

Kikuyu over-sown with ryegrass and clover: dry matter production,botanical composition and nutritional value

The seasonality of growth and low nutritional value of kikuyu (Pennisetum clandestinum) pasture restrict milk production. The aim of the study was to determine the dry matter yield, botanical composition and nutritional value of irrigated kikuyu over-sown with annual ryegrass (Lolium multiflorum var. westerwoldicum), white clover (Trifolium repens) and red clover (T. pratense) or a mixture of perennial ryegrass (Lolium perenne) with white and red clovers under intensive grazing conditions with dairy cows. The incorporation of annual ryegrass, perennial clover or perennial ryegrass–clover into kikuyu pasture changed the seasonal fodder flow and increased the spring dry matter (DM) production. The over-sowing of kikuyu with annual ryegrass had no effect on the DM production of kikuyu during the summer and autumn. Kikuyu and kikuyu–ryegrass, fertilised with nitrogen fertiliser, had a higher DM production rate than kikuyu–clover pastures. Kikuyu–ryegrass pasture transformed from ryegrass-dominant in spring to kikuyu-dominant in summer and only kikuyu in autumn. This led to a decrease in metabolisable energy (ME) and increase in neutral detergent fibre (NDF) content of the pasture during spring, summer and autumn as kikuyu became more dominant. The clover content of kikuyu over-sown with clover decreased annually but was still higher than 30% at the end of two years after establishment. As the kikuyu content of the kikuyu–clover pastures increased, the seasonal growth rate changed from a low autumn growth (37.9 kg DM ha^?1 d^?1) in the first year to a higher autumn growth (48.5 kg DM ha^?1 d^?1) in the second year. The over-sowing of kikuyu with clover resulted in lower DM production and NDF values and higher crude protein (CP), ME and calcium (Ca) values. The lowest CP content in kikuyu–ryegrass pasture was during summer and autumn when kikuyu was dominant. The Ca content of the grass pastures (kikuyu and kikuyu–ryegrass) was low. The phosphorus (P) content of both the kikuyu–clover and grass pastures exceeded the requirement needed for dairy production (0.38%). The mean Ca:P ratio of the kikuyu–clover pasture meets the 1.6:1 ratio needed by dairy cows. The kikuyu and kikuyu–ryegrass pasture had a Ca:P ratio lower than 1:1 and Ca supplementation would be needed for dairy cows. The incorporation of annual ryegrass, perennial clover or perennial ryegrass–clover into kikuyu pasture improved the seasonal DM production and nutritional value of the pasture.     

黄鳝精巢发育的周年变化

对黄鳝精巢显微和超微结构的观察结果表明 ,其精原细胞可分两种类型 :初级精原细胞和次级精原细胞 ;精子鞭毛轴丝由外周 9组微管和两根中央微管构成 ;间质细胞分布有广泛的滑面内质网和具小管的线粒体。据对10 6尾 (体重为 17～ 32 0 g)黄鳝精巢切片观察 ,黄鳝由雌性完全转变为雄性后 ,精巢已接近发育成熟 ;经 χ2 检验表明 ,其性腺成熟度与体重关系不大 (P >0 0 5 )。性成熟后 ,精巢所处发育阶段 (Ⅰ -Ⅵ期 )主要随不同季节而变化     

亚热带低山区填闲混播冬性一年生牧草与水稻轮作的经济生态效益

１９９２１９９４年在亚热带低山区（四川芦山县）进行了填闲混播冬性一年生牧草与水稻轮作的经济生态效益的研究。结果表明，混播冬性一年生禾草和豆草与水稻轮作，即意大利黑麦草＋紫云英→水稻、意大利黑麦草＋南苜蓿→水稻和意大利黑麦草＋白三叶草（营养体）→水稻三种轮作方式在水稻产量高于或稍低于对照（ＣＫ→Ｒ）但差异不显著的情况下，获得了高的饲料价值（ＴＤＯＭ５．１８５．４５ｔ／ｈｍ２，ＣＰ１．６９１．８４ｔ／ｈｍ２，ＭＥ３．７６４．０１×１０４ＭＪ／ｈｍ２）和良好的营养互补作用。填闲混播一年生豆、禾牧草提高了农田生态位的利用效率，改善了土壤结构和营养状况。     

TREES,SHRUBS AND CLIMBERS IN KLOOF—HILL CREST AREA

The annual extreme fire hazard in the Natal Drakensberg will limit forestry and the rugged topography and vulnerability of the soil discourage use of the area for grazing.

Judicious patch-burning alternatively in spring and in autumn will reduce costs of fire protection and is expected to keep the veld stable. Quality and quantity of runoff is expected to be as favourable as possible in this very important catchment area.

The area is especially suited for a nature and recreation reserve. The burning system proposed above is wholly compatible with management for water yield and nature conservation.     

云阳县坡耕地作物产量低的原因及对策

为了合理利用旱地资源，发展贫困落后山区经济。本文详述了云阳县坡耕地的特点，着重分析了作物产量低的原因，并对坡耕地的综合治理和合理利用提出了建议。     

The influence of sowing rate on the production and growth of wild oat (Avena fatua) in the depleted semi-arid rangelands of Jordan

The objective of this work was to determine the proper sowing rate of wild oat (Avena fatua) in the depleted north-eastern semi-arid grasslands of Jordan. Wild oat seeding rates of 15, 30, 45 and 60 kg ha^?l were evaluated in field studies that were conducted over two years at Jordan University of Science and Technology Campus located 22 km to the east of Irbid, Jordan. Measurements recorded each year included plant height, number of tillers per plant, oven-dry forage mass and seed yield. Forage and seed production increased in response to increasing sowing rate. The highest production values were obtained at a sowing rate of 45 kg ha^?l Increasing sowing rate to 60 kg ha^?l reduced both forage and seed yield, indicating that the optimum seeding rate for wild oat is 45 kg ha^?1 Forage and seed yield had a cubic relationship with sowing rate, having R² values of 0.55 and 0.78, respectively. Tiller production showed a negative linear relationship with sowing rate (R² = 0.35).     

试论成都高新区土地年租制中年租金的确定

年租金的确定是实施国有土地使用权年租制的核心问题,它既要有一定的理论依据,又要切合中国和各地方的具体实际,其方案应具可行性和可操作性。本文结合我国和成都高新技术产业开发区的实际情况,从理论到实践对土地年租制中年租金的确定进行了探讨,初步提出了适合成都高新技术产业开发区的土地年租金体系,并对其可行性进行了分析和讨论