Effect of Different Concentrate-roughage Ratios on Rumen Degradability of Cassava Stems and Leaves Total Mixed Ration in Goat

The rumen degradations of TMR were studied in this experiment,in which cassava stems and leaves were used as roughage and formulated with concentrate in different proportions.The purpose of this study was to formulate the available TMR for finishing goat,and provide a theoretical basis for the applications of cassava stems and leaves in goat production.Six Hainan Black goats with permanent rumen fistulas were selected,the rumen degradabilities of DM,CP,NDF and ADF of TMR with 6 different concentrate to forage ratio（2:8,3:7,4:6,5:5,6:4 and 7:3）were tested using nylon bag method.The results showed that,the DM effective degradabilities at the ratio of 4:6,5:5,6:4,7:3 were significantly higher than that of 2:8 and 3:7（P<0.05).CP effective degradabilities at the ratio of 2:8,3:7,4:6 were significantly higher than that of 5:5,6:4 and 7:3（P<0.05).The NDF effective degradation at the ratio of 5:5 was significantly higher than that in the other groups（P<0.05).The ADF degradation at the ratio of 3:7 was significantly higher than that of 4:6,5:5, 6:4 and 7:3（P<0.05).The results indicated that,the nutrient degradation in rumen were higher when the concentrate to forage（cassava stems and leaves）ratio in TMR were 3:7,4:6 and 5:5,and the recommended ratio range were 4:6 to 5:5 in production practice.     

椰子组培研究四十年

组织培养对于椰子快速繁殖以及全球椰子产业发展具有重要意义。本文就40年来国内外在椰子组培快繁技术,包括椰子组培技术的重要性,不同外植体如胚芽、花序、子房等在组织培养中的应用与优劣,不同培养基和培育环境对组培效果的影响等要素,进行了详细的总结和讨论。同时总结了椰子组培快繁技术的进展,分析了目前限制椰子组培快繁技术发展的因素,提出了应对策略与具体建议。本文对椰子快繁技术及椰子种质资源保存具有参考价值。     

不同固定条件对几种植物样品超微结构的影响

为比较几种固定条件对不同植物材料样品电镜超微结构图像清晰度的影响。以3个不同科属4种植物[油棕(Elaeis gineansis Jacq.)、拟南芥(Arabidopsis thaliana.)、花生(Arachis hypogaea Linn.)、柱花草(Stylosanthes guianensias Sw.)]为研究主体代表,探讨了2.5%戊二醛与4%戊二醛固定过夜、锇酸固定2 h及过夜的制备方法对其叶片超微结构的影响,并成功观察了柱花草接种胶苞炭疽野生型菌株CH008后的病菌侵入过程。结果表明:油棕、拟南芥、花生及柱花草叶片经4%戊二醛与1%锇酸固定液固定过夜,其组织成像的效果均较为理想,各种细胞器整体信息丰富、结构组织完好、线条清晰。表明,此制备方法能够较好的保存植物叶片和细胞组织,提高制样的成功率及观察分辨率。     

我国热区疫霉种的分布、疫病及其防治研究进展

综述了我国热带地区疫霉种类及其引起的植物病害,并总结了疫病的防治措施,最后对疫病防治的新策略进行了展望。     

RFID阅读器的驱动及模块设计

当前，大部分有关RFID的文章，都在探讨RFID在提高产品物流速度和信息采集质量方面的作用或研究有关RFID硬件设备，而有关RFID阅读器的驱动及接口技术方面的研究很少。主要介绍了RFID阅读器的驱动模块及模块工作原理，同时介绍阅读器与上层数据管理器之间的接口设计。     

砖红壤香蕉园土壤养分空间变异研究

运用统计学和ArcGIS软件的地统计分析模块对海南砖红壤香蕉园59个土壤采样点两个取样土层（0～20 cm和20～40 cm）养分进行空间变异性研究。结果表明：香蕉园土壤各养分变异系数均为中等变异。0～20 cm土层土壤各养分含量大于20～40 cm土层。0～20 cm和20～40 cm土层中的碱解氮、交换性钙和交换性镁及0～20 cm土层的有机质均符合高斯模型，0～20 cm土层速效磷与20～40 cm土层速效钾符合球状模型，而20～40 cm土层速效磷与0～20 cm土层速效钾符合圆形模型，20～40 cm土层有机质符合指数模型。各养分的变程范围为109.217～279.796 m，有机质具有强烈的空间相关性。0～20 cm土层速效钾的块金效应值小于20～40 cm土层，0～20 cm土层碱解氮、速效磷、交换性钙、交换性镁高于20～40 cm土层。有机质、20～40 cm土层速效磷、0～20 cm土层速效钾的块金效应小于25%，其它养分均在25%～75%，具有中等的空间相关性。确定了合理取样数，0～20 cm碱解氮、速效磷、速效钾、交换性钙、交换性镁、有机质合理取样数分别为：5、30、26、29、25、3；20～40 cm碱解氮、速效磷、速效钾、交换性钙、交换性镁、有机质合理取样数分别为：4、44、30、26、25、3，就可以满足变量施肥的要求。     

7株根瘤菌菌株与热研2号柱花草共生最适磷浓度研究

采用水培的方法,设3个磷水平,7个菌株,通过对株高、茎叶鲜重、茎叶干重、固氮酶活性、茎叶氮含量、茎叶磷含量的测定及综合分析,确定使热研2号柱花草接种不同根瘤菌菌株达到最佳促生性能的磷浓度。结果表明:7个菌株在中磷时鲜重和含氮量最大,低磷不利于鲜重和含氮量的增加;经主因子综合分析,菌株YM11-1、RJS9-2、PN13-3在高磷时对热研2号柱花草有最好的固氮促生效果,菌株LZ3-2、BS1-1、PN13-3在中等磷条件下有最好的固氮促生效果,菌株FS3-1-1在高磷和中磷都有最好的固氮促生效果。     

Assessing the sustainability of cropping systems in single- and multi-site studies. A review of methods

The multiple new challenges facing agriculture require the development of innovative cropping systems with high environmental, economic and social performances. Many research programmes are currently focusing on the design of such cropping systems. Some include the multicriteria assessment of cropping systems by diverse methods and approaches. Some of these research programmes are supported by experimental or farmers’ networks, generating new opportunities for data analysis and raising new research and methodological questions. In this article, we provide an overview based on a review of 56 articles, comparing the various methods for sustainability assessment in single- and multi-site studies. Articles were classified according to three characteristics: (i) their objectives, (ii) the study design (single- vs. multi-site), (iii) the type of system assessed (fictitious vs. real). Our analysis was structured around four items: (i) the variables used to describe cropping systems and production situations and the use of these variables in the assessment process, (ii) the criteria and associated indicators assessed, (iii) the methods used to explore multiple aspects of the performance of cropping systems, (iv) the use of reference values. We identified key points to be taken into account in multi-site studies. The application of the proposed guidelines to experimental networks should facilitate the identification of high-performance cropping systems and the identification of the drivers of cropping system performance.     

巴西橡胶树乳管细胞HbWRKY1基因克隆及表达分析

采用PCR和RACE技术,从巴西橡胶树无性系热研7-33-97的乳管细胞中克隆了WRKY转录因子家族的一个成员HbWRKY1。该基因全长为1755 bp,含有1个1440 bp阅读框,编码479个氨基酸。生物信息学分析表明,HbWRKY1含有2个WRKY结构域和C2H2锌指结构基序,与蓖麻、杨树、葡萄、黄瓜、拟南芥的WRKY成员的氨基酸序列同源性分别为64.14%、60.04%、42.54%、40.61%和35.4%,属于Ⅰ类WRKY家族成员。实时荧光定量PCR分析表明,割胶和乙烯显著上调HbWRKY1基因的表达,但茉莉酸和机械伤害对HbWRKY1的表达没有明显影响,表明HbWRKY1可能在乙烯信号途径对防卫蛋白的调节中起重要作用。