银合欢种子研究进展

随着农业生产对银合欢种子需求的增加,确保银合欢种子的质量成为首要问题。综述近年来对银合欢种子成分、种子萌发、种子保存和种子健康等方面的研究概况,并对银合欢种子研究中存在的问题提出了展望。     

新银合欢叶片饲养禽畜研究初报

新银合欢叶片含粗蛋白25～29％,富含动物所必需的多种氨基酸,胡萝卜素的含量也很高,是一种比较高产、优质的蛋白质饲料。对鸡配以5％和猪配以15％的饲养试验效果达到显著水平,用50％的配比进行一个月喂鸡试验,未发现脱毛现象。     

中国南部新发现的入侵害虫——银合欢豆象

报道近年发生在我国南部的海南、广西、云南等省区的1种新的入侵害虫——银合欢豆象。经初步调查,该虫严重危害银合欢豆荚和种子。对其形态特征、寄主、分布等进行简要的介绍。     

金沙江干热河谷3种阔叶树育苗试验

将新银合欢、大叶相思和羽叶山黄麻的种子作酸蚀3,6,12 m in及水浸-凉水浸泡24 h、50℃温水浸烫浸泡24 h、开水浸烫浸泡24 h处理.处理后的种子室内和场圃发芽情况表明:酸蚀适用于3树种,酸蚀3水平对种子发芽率影响差异显著,效应为6 m in>12 m in>3 m in;而水浸3个水平对种子发芽影响差异不明显;3树种处理最优组合(A1B2C2,A2B2C3和A3B2C1)种子发芽率分别达90.0%,84.3%,76.4%.处理与不处理种子培育的苗木苗期和初植幼树生长情况表明:上述种子处理方法对苗木和幼树的生长无不良影响.     

The potential of alley farming in humid West Africa — a re-evaluation

Previously published hypothesis concerning the potential impact of alley farming on maize yields are re-examined relative to the humid regions of West Africa. When more realistic assumptions regarding the availability of organic nitrogen are used, it is concluded that alley farming may have potential in a wider range of maize yield environments in West Africa than previously proposed. A pragmatic approach to alley farming research is proposed, and the importance of on-farm research in the development of ‘farmer friendly’ alley farming is stressed. (Former Agronomist, International Livestock Centre for Africa, P.M.B. 5320, Ibadan, Nigeria)     

金沙江干热河谷新银合欢种源选择初步研究

通过对澳大利亚、广州新银合欢原种以及从广州引入宁南和会东栽培繁殖并扩繁到本区不同地点的后代采种进行种源比较试验,其结果表明：在苗期本地种源生长优于原种地,但造林后随着幼树生长,广州种源逐步赶上并超过除宁南种源外的其他种源。而宁南种源是所有参试种源中的最佳种源。建议今后可将宁南县划为金沙江干热河谷及其类似地区的新银合欢优良种子调拨区。     

Open-pollinated, interspecific F1 hybrid seed orchards of Leucaena: I. Rootstock effects

Seed orchards of Leucaena were established at two experimental sites in Hawaii to produce either triploid or tetraploid interspecific hybrid seed by interplanting clonal self incompatible diploid (L. diversifolia, L. esculenta) or tetraploid (L. pallida) species with self- compatible L. leucocephala lines and the F1 hybrid of L. diversifolia (2n = 4x) × L. leucocephala. The seed parents were grafted onto three seedling rootstocks (L. diversifolia (2n = 4x), shrubby L. leucocephala, and giant L. leucocephala) to compare rootstock effects on scion growth. This paper reports on the effects of rootstock on scion growth during the first year based on total truck cross sectional area, height growth, and crown habit. In the triploid seed orchard, rootstock significantly affected the growth of four of the six clones, while in the tetraploid orchard the growth of two of the five clones was significantly affected by rootstock. Crown habit was independent of rootstock. Our study suggests that rootstock effects depend on the specific scion and rootstock combination, and site. This revised version was published online in June 2006 with corrections to the Cover Date.     

银合欢引种栽培技术

\t\t\t\t\t目的\t\t\t\t\t银合欢是优质高蛋白饲草,筛选在中国热带地区种植条件下生物量、营养价值较高或具有育种潜力的银合欢种质资源,可为银合欢优良新品种的选育和推广提供科学依据。\t\t\t\t\t\t\t\t\t\t\t\t\t方法\t\t\t\t\t对48份采集自世界不同地区的银合欢种质资源的生物量和干物质量（DM）、粗蛋白（CP）、粗脂肪（EE）、粗纤维（CF）、粗灰分（Ash）、无氮浸出物（NFE）、磷（P）和钙（Ca）的含量进行测定和评价。\t\t\t\t\t\t\t\t\t\t\t\t\t结果\t\t\t\t\t48份银合欢种质的生物量变异系数为16.315%。CIAT17488的平均单株生物量最高,为301.968 g（鲜重）,是48份种质平均生物量的159.922%。供试材料干物质含量变化范围为90.436%~93.916%,变异系数为1.108%;粗蛋白、无氮浸出物、磷、钙含量范围分别为17.229%~26.281%,29.450%~55.648%,0.130%~0.220%,0.825%~1.332%,其变异系数范围为9.995%~13.093%;粗纤维、粗灰分的含量范围分别为10.027%~29.769%和3.244%~7.374%,变异系数分别为24.348%,20.921%;粗脂肪含量种质间的差异最大,变异系数达31.559%,其含量范围为1.963%~9.143%。\t\t\t\t\t\t\t\t\t\t\t\t\t结论\t\t\t\t\t参试银合欢种质蕴含丰富的遗传资源。CIAT18479粗蛋白和粗灰分含量最高,兼具较高的磷和钙含量,是高品质种质;CIAT17488是高产的种质且综合营养价值评价也位列中上水平,有望通过选择直接获得高品质和高生物量的新品种。\t\t\t\t     

Growth Parameters and Nutrient Content in Four Multipurpose Tree Species with Potential Characteristics for Agroforestry Systems in a Cerrado Region in Botucatu,São Paulo State,Brazil

Abstract

In order to evaluate growth characteristics, adaptability, biomass production, nutrient recycling, nutrient distribution and the ability to regenerate degraded land, a trial using four multipurpose tree species (Leucaena leucocephala, Leucaena diversifolia, Acacia melanoxylon and Mimosa scabrella) was undertaken over two years in a distrophic red yellow latosol (oxisol) following a randomized block experimental design with four replications.

At the age of two years, A. melanoxylon and L. diversifolia were the tallest species (5.25 and 4.97 m, respectively) and A. melanoxylon and M. scabrella had the largest diameters at 20 cm from tree base.

Mimosa scabrella and A. melanoxylon had the highest dry matter production and quantity of nutrients in the above ground biomass. In all species, the highest nutrient contents were found in the leaves, followed by branches and stems. From all species, the highest Nutrient Utilization Efficiency Indexes were obtained for sulphur, phosphorous, and magnesium; L. diversifolia was the most efficient for nitrogen, potassium, calcium, sulphur, and manganese, while A. melanoxylon was the most efficient for phosphorus, magnesium, boron, iron, and zinc. Litter production levels over a three month period were as follows: M. scabrella > A. melanoxylon > L. diversifolia > L. leucocephala. Litter nutrient content was higher in M. scabrella than in the other species.     

不同经营模式下新银合欢的枝系特征差异分析

在中国科学院东川泥石流定位观测站附近,对不同经营模式下新银合欢的枝系特征进行了统计分析,结果表明：新银合欢在不同经营模式下的总体分枝率和逐步分枝率SBR1:2发生显著变化,逐步分枝率SBR2:3则未表现出显著差异;截干新银合欢二、三级枝长度,枝径比2：1及一、二、三级枝倾角显著大于未截干新银合欢;两种经营模式下叶片的分布特征未发生显著差异。通过对各种枝系特征综合分析,发现截干新银合欢的生长对策表现为向上拓展自身生长空间,保持其原有的生态位。