桉树不同成熟度叶片营养元素内循环特征

揭示桉树人工林不同成熟度的叶片器官所需营养元素变化以及土壤肥力对其影响,对于桉树营林和科学施肥具有重要的生产指导意义。选取广西隆安县小林镇和田东县思林镇的桉树2代萌芽林作为研究对象,测定两个人工林嫩叶、成熟叶、黄叶的C、N、P、K、B、Ca、Mg以及土壤C、N、P、K、Ca、Mg元素含量,并进行相关分析。结果表明,植物叶片的N、P、K、Mg营养元素转移规律是黄叶向成熟叶和嫩叶转移,但C、Ca、B营养元素则是随着叶片的生长发育逐渐积累,黄叶中含量最高,说明施肥时应关注Ca、B元素的持续和有效供给。两片人工林都表现出类似的规律,说明土壤肥力的差异不影响桉树人工林叶片营养元素的内循环规律。桉树嫩叶营养元素含量及其生态化学计量比学特征具有与成熟叶和黄叶不同的表征,在营养物质研究中应予以足够重视。     

浙农大A系意蜂生产性能考察试验报告

用杂交一代蜂群进行对比试验的结果表明,浙农大 A 系意蜂的产育力、群势增长速度、采蜜量等,与平湖意蜂和澳大利亚意蜂无显著差异或基本一致,但蜂王浆高产性能表现突出,产量比平湖意蜂高19.5%,比澳意高42.5%,而且质量指标符合国家规定和出口标准。     

A method to test wheat leaves for their reactions to inoculation with Septoria species

The construction and application is described of a polystyrol humidity box in which wheat leaves, while continuing to function as parts of living plants, can be tested for their reactions toSeptoria spp. in an atmosphere nearly saturated with water, as is required for successful infection. The method is simple, accurate ans inexpensive.Samenvatting Voor dit doel is een z.g. vochtdoos geconstrueerd (Fig. 1A). Het te toetsen blad wordt daar doorheen geleid en in de doos geïnoculeerd met een druppel conidiën-suspensie van de schimmel. Onder het blad staat wat water in de doos (Fig. 1B). Na afsluiting ontstaat in de doos de hoge luchtvochtigheid van bijna 100% die nodig is voor de infectie. Dit wordt op deze wijze eenvoudig en goedkoop gerealiseerd. De bladeren die zo worden getoetst blijven onbeschadigd functioneren aan de plant. Na enkele dagen kan de doos worden geopend en kan de symptoom-ontwikkeling worden afgewacht en gevolgd (Fig. 3A, 3B en 4). De methode leent zich voor nauwkeurig werk en vereist zeer weinig infectiemateriaal. De Technische en Fysische Dienst voor de Landbouw (TFDL), Wageningen, ontwierp en construeerde een statief voor het gebruik van de vochtdozen in serie (Fig. 2).     

芒果叶片生化特性与炭疽病发生的关系

研究了芒果叶片生化特性与炭疽病发生之间的关系。田间自然发病调查和室内人工接种鉴定结果均表明,随着芒果叶片由最初的古铜色向淡绿色和深绿色叶片的逐渐成熟老化,抗病性逐渐增强。对芒果叶片表面蜡质层和叶内可溶性糖、游离氨基酸、总酚含量及细胞膜相对透性的测定结果表明,与淡绿色叶片和老叶相比较,古铜色叶片含有较少的表面蜡质、叶内可溶性糖和总酚含量及较多的游离氨基酸,推断古铜色叶片对病害的易感性可能与其叶面蜡质和叶内总酚含量较少、叶内可溶性糖和游离氨基酸的比值(C/N比)较低有关。     

Polyphenols in Eucalyptus leaves improved the egg and meat qualities and protected against ethanol‐induced oxidative damage in laying hens

Polyphenols in Eucalyptus leaves (PE) were value resources due to various pharmacological activities, but data on the effect on laying hens are very scare. This study was conducted to determine the effect of PE on the laying performance, egg traits, meat quality, antioxidant status and liver tissues of laying hens. One hundred and twenty 256‐day‐old Yueqinhuang laying hens were randomly assigned to four treatment groups (different levels of PE at 0, 0.5, 0.8 and 1.2 g/kg diet) for 63 days with 15 replicates per group. Addition of 0.8 g/kg PE not only improved the egg trait by increasing the eggshell thickness and decreasing MDA production and cholesterol content in the egg yolk, but also significantly enhanced meat quality of hens, as suggested by the increase pH_45 min (p < .01) and a* value, and decrease drip loss rate (p < .01). Meanwhile, under acute ethanol‐induced oxidative damage condition, supplementation of 0.8 g/kg PE enhanced the serum antioxidant status by increasing enzymatic activities (GSH‐PX, T‐SOD, T‐AOC), inhibited oxidative damage and provided protective effect to liver tissue. In conclusion, addition of 0.8 g/kg PE not only improved the egg traits and meat quality without obvious adverse effects, but also increased the serum antioxidant status of the hens and protected their liver tissue from ethanol‐induced oxidative damage. This study indicated that PE could be utilized as an effective feed additive for laying hens to improve health performance and egg traits.     

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.     

广西5种人工林地土壤微生物数量及土壤酶活性分析

为当地珍贵速生树种人工林的发展及合理利用提供理论依据。分析广西5种珍贵树种人工林土壤微生物数量及土壤酶活性差异,以相同立地条件下12年生的黑木相思(Acacia melanoxylon)、老排(Mytilaria laosensis)、红椎(Castanopsis hystrix)、黧蒴椎(Castanopsis fissa)和火力楠(Michelia macelurei)人工纯林为研究对象,采用稀释平板涂布法和土壤酶活性测定法,测定和分析该5种人工林地土壤微生物数量及酶活性。结果表明:5种林地的土壤微生物总数和细菌数量大小均为:火力楠黧蒴锥红椎黑木相思米老排。但5种林地的土壤酶活性大小不一,蔗糖酶、脲酶、蛋白酶、酸性磷酸酶活性在5种林地之间的差异极其显著,而过氧化氢酶活性不显著。5种林地中土壤酶活性相对较强的是米老排人工林,较弱的是黑木相思林和火力楠林。土壤酶活性与微生物数量的相关分析表明,土壤中蔗糖酶活性与放线菌数量呈极显著正相关关系,其余相关性没有达到显著水平。     

国土空间详细规划现状底图底数转换方法研究

统一底图底数是编制各类空间规划的重要前提和基础,第三次国土调查数据作为当前权威性最高、现势性最强的国土空间利用现状数据,所采用的工作分类与国土空间规划采用的用地用海分类存在较大差异。本文通过对工作分类和用地用海分类进行衔接分析,提出了基于第三次国土调查数据的国土空间详细规划现状底图底数转换的总体技术思路、关键技术方法。     

湘西北长果安息香种群数量与分布格局

对湖南石门壶瓶山景关门、桑植龙潭坪茅垭村样地的长果安息香(Changiostyrax raxdolichocarpa)种群数量和分布格局进行调查和分析。结果表明：长果安息香种群的年龄结构呈衰退型，个体数量主要集中在小树(IV龄段)，幼龄级株数和老龄级株数匮乏；长果安息香种群在进入生理死亡年龄前有2个死亡高峰，第1个峰值产生于幼树(II、III龄段)，主要原因是种内和种间竞争(主要是光照)，第2个峰值产生于中树长成大树阶段(V、VI龄段)，除种内、种间对环境的竞争外，生长地土层浅薄、大树倒伏及人为砍伐亦加剧了该峰值的产生；种群整体呈聚集分布类型，小树向中树、大树变化过程表现出聚集分布向随机分布转变，导致长果安息香濒危的主要原因是种子萌发率极低、种群竞争能力较差以及人为干扰等。     

银杏-杜仲叶发酵物对脂多糖应激肉仔鸡的肠道功能和免疫反应的影响

本试验旨在研究饲粮中添加银杏-杜仲叶发酵物（FGEL）对脂多糖（LPS）应激肉仔鸡的生长性能、肠道结构、消化吸收功能和免疫反应的影响，并与未发酵银杏-杜仲叶（GEL）进行比较。采用2×3双因子试验设计，即2种免疫应激处理（腹腔注射LPS或注射等量生理盐水）和3种饲粮处理（基础饲粮及在基础饲粮中添加0.40%GEL或0.40%FGEL的试验饲粮）。选取1日龄健康爱拔益加（AA）肉仔鸡360只，随机分为6个处理，每个处理均设6个重复，每个重复10只鸡。试验期为21 d。在试验第13、15、17、19和21天，3个应激处理的试鸡腹腔注射500μg/kg BW的LPS，其他3个处理注射等量的生理盐水。在试验第21天最后1次注射后2～4 h进行屠宰取样。结果表明：1）与对照饲粮相比，饲粮添加FGEL的肉仔鸡料重比（F/G）有显著改善（P=0.024），饲粮添加FGEL显著缓解了LPS应激肉仔鸡平均日增重（ADG）(P=0.023)和血清D-木糖的含量（P=0.011）的降低。2）与对照饲粮相比，饲粮添加FGEL显著缓解了LPS应激肉仔鸡十二指肠（P=0.011）和空肠（P=0.030）的相对重量...