不同采收年限和月份对大丰95橡胶树产胶量的影响

为探讨不同采收年限和月份对大丰95橡胶树产胶量的影响,采用统收统测的方式对13个5~18 a中低割龄的大丰95无性系树位的5~12月份干胶产量进行测定分析。结果表明,不同割龄和不同采割月份的大丰95月株产干胶量和月公顷产干胶量差异均明显,其中,8个采割期中,株产干胶量和公顷产干胶量由高到低的月份均依次为11、7、6、8、9、10、12、5月。13个割龄中,11 a的年株产干胶量最高,达4.90 kg,16 a的年公顷产干胶量最高,达1 807.97 kg,18 a的年株产干胶量和年公顷产干胶量均最低,分别为2.59、373.82 kg,最高值与最低值间差异达极显著水平(P0.01)。13个割龄的月公顷产干胶量和年公顷产干胶量与月株产干胶量和年株产干胶量均呈极显著正相关(P0.01),而所有割龄与年株产干胶量和年公顷产干胶量的正相关均不显著。综上可见,大丰95中低割龄橡胶树的干胶产量显著受采收月份影响,而随采收年限变化则不明显。     

Biological activity of soils under rubber trees (Hevea brasiliensis) affected by trunk phloem necrosis

Trunk phloem necrosis (TPN) is currently one of the most economically important diseases of the rubber tree (Hevea brasiliensis). Investigations of the aetiology of the disorder have failed to identify any biotic causal agents but a multidisciplinary study has recently suggested that the disease may be caused by a combination of exogenous and endogenous stresses. These stresses can affect plant physiology and may also have an impact on soil biology and soil biochemistry. In this study, macrofauna diversity and soil enzyme activities were compared for the soils under trees affected by TPN and under healthy trees. Principal component analysis revealed associations between TPN and macrofauna diversity and soil enzyme activities. Groups of ants and termites were associated with the soil under healthy and trees affected by TPN respectively. Polysaccharidase (cellulase, xylanase and, particularly, amylase) activities were lower in the soil under trees affected by TPN whereas N‐acetylglucosaminidase activity was higher. These findings suggested that termite density and N‐acetylglucosaminidase activity are useful indicators of TPN, while lower values of polysaccharidases activities are the consequence of this disease. The impact of TPN on soil ecosystem was discussed.     

Intra- and inter-clonal tree growth variations of Hevea brasiliensis

We evaluated the effects of planting densities (500, 1,000,1,500 and 2,000 trees·ha-1) on tree growth performance (diameter atbase, diameter at breast height, and clear bole height) of two clones(RRIM 2020 and RRIM 2025) of nine years old plantations of rubber tree(Hevea brasiliensis Muell. Arg) in Malaysia. For the four planting densities of the two clones, basal area and diameter at breast height declined with increasing planting density. Clear bole heights were greatest at 1,500 trees·ha-1 and lowest at 500 trees·ha-1 for the clone RRIM 2020, andat 2,000 trees·ha-1 and 500 trees·ha-1 for clone RRIM 2025. We conclude that the ideal planting density is 2,000 trees·ha-1 for obtaining high volume of wood production and 500 trees·ha-1 for high wood quality.     

嫁接对橡胶树砧木甲基化水平的影响

选择IAN873、GT1、RRIM600三品种实生树作为接穗,IAN873、GT1、RRIM600播种移栽苗为砧木,用MSAP方法对嫁接前后砧木的甲基化水平进行分析。结果表明,对砧木进行嫁接后发生了甲基化变化,且IAN873接穗引起砧木的甲基化变化大于GT1和RRIM600接穗引起的变化;砧木嫁接后,甲基化变化主要以半甲基化与无甲基化间的相互转换为主,而由半甲基化转化为全甲基化或者由全甲基化转换为半甲基化的很少,全甲基化与无甲基化间的转换居中。     

天然橡胶胶清化学成分的研究

对天然橡胶胶清的化学成分进行了研究.运用硅胶柱色谱及葡聚糖凝胶LH-20柱色谱进行化学成分的分离和纯化,用理化方法及波谱手段解析其化学结构.从天然橡胶胶清中分离得到13个化合物,鉴定了其中12个化合物的结构,分别为:木栓酮(Ⅰ)、羽扇豆醇(Ⅱ)、β-谷甾醇(Ⅲ)、棕榈酸(Ⅳ)、硬脂酸(Ⅴ)、胡萝卜苷(Ⅵ)、尼古丁酸(Ⅶ)、琥珀酸(Ⅷ)、没食子酸(Ⅸ)、果糖(Ⅹ)、白坚木皮醇(Ⅺ)和6-hydroxy-cleistopholine (Ⅻ).经检索,其中化合物Ⅰ、Ⅱ、Ⅵ、Ⅶ、Ⅸ和Ⅻ为首次从天然橡胶胶清中分得.     

橡胶树二斑素瓢虫初步观察

报道在西双版纳发现一种取食橡胶树粉孢菌的二斑素瓢虫,对二斑素瓢虫各虫态的形态及成虫雄性外生殖器特征进行了描述。     

Root rot diseases of Hevea brasiliensis

A study on biochemical mechanisms of the rubber tree aggression by two root rotting fungi Rigidoporus lignosus and Phellinus noxius was carried out. The activity of eight enzymes and their spatial distribution in adult tap root tissues were measured. Finally their origin, host or parasite, and physiological signification in the pathogenic process were discussed.     

Evaluation of unconstrained and constrained mathematical functions to model girth growth of rubber trees (Hevea brasiliensis) using young age measurements

No attempt has been made to date to model growth in girth of rubber tree (Hevea brasiliansis). We evaluated the few widely used growth functions to identify the most parsimonious and biologically reasonable model for describing the girth growth of young rubber trees based on an incomplete set of young age measurements. Monthly data for girth of immature trees (age 2 to 12 years) from two locations were subjected to modelling. Reparameterized, unconstrained and constrained growth functions of Richards (RM), Gompertz (GM) and the monomolecular model (MM) were fitted to data. Duration of growth was the constraint introduced. In the first stage, we attempted a population average (PA) model to capture the trend in growth. The best PA model wasfitted as a subject specific (SS) model. We used appropriate error variance-covariance structure to account for correlation due to repeated measurements over time. Unconstrained functions underestimated the asymptotic maximum that did not reflect the carrying capacity of the locations. Underestimations were attributed to the partial set of measurements made during the early growth phase of the trees. MM proved superior to RM and GM. In the random coefficient models, both Gf and G0 appeared to be influenced by tree level effects. Inclusion of diagonal definite positive matrix removed the correlation between random effects.The results were similar at both locations. In the overall assessment MM appeared as the candidate model for studying the girth-age relationships in Hevea trees. Based on the fitted model we conclude that, in Hevea trees, growth rate is maintained at maximum value at t0, then decreases until the final state at dG/dt ≥ 0, resulting in yield curve with no period of accelerating growth. One physiological explanation is that photosynthetic activity in Hevea trees decreases as girth increases and constructive metabolism is larger than destructive metabolism.     

温度对橡胶树微型芽条培育的影响

以橡胶树优良品系云研73-477花药组培试管苗的茎尖、茎段和基部为外植体,进行不同温度条件下微型芽条培育的比较试验,结果表明:外植体在昼温28℃,夜温26℃的平均不定芽数在1.50个以上,萌生枝较健壮,枯顶较少,培养效果优于其他处理。     

不同程度木栓化芽条对橡胶树籽苗芽接苗生长的影响

以橡胶树云研77-4当年生3种不同木栓化芽条为试材,研究其在GT1籽苗砧木上芽接的成活率、抽芽率、成苗率等表现,以期进一步优化橡胶树籽苗芽接育苗技术。结果表明,用Ⅰ类芽条(未木栓化,芽片颜色为绿色)进行籽苗芽接,成活率为86.11%,成苗率为90.67%,均显著高于半木栓化和全木栓化芽条,但3种类型芽条在抽芽率及后期生长量上差异较小。     

不同月龄砧木对橡胶树小苗芽接苗生长的影响

以云研77-4的小茎绿色芽条为接穗,GT1实生苗为砧木,在温室大棚条件下,研究了移苗后培养60~117 d不同月龄砧木对橡胶树小苗芽接苗生长的影响,结果表明:培养60~67 d的砧木芽接苗高、粗生长量最大,出圃的合格苗、优质苗最多,隶属函数值综合评价质量最好,显著优于其它月龄的砧木。     

巴西橡胶树胶乳药用研究综述

巴西橡胶树胶乳是乳管细胞的胞质液,作为天然橡胶工业产品仅利用了其中的橡胶烃。近年,胶乳中含有的许多初级和次级代谢产物具有的药用价值逐渐被发现。全胶乳和其组分B-乳清与C乳清都具有抗菌作用,B-乳清和C乳清还表现出抑制癌细胞生长,并且对正常细胞为低毒性的特性。胶乳中含有的如白坚木皮醇、植物甾醇、萜类和蛋白质等成分都表现出抑制肿瘤细胞生长、抗真菌、抗氧化等药用功能。     

橡胶树抗旱栽培技术试验示范

抗旱栽培技术的试验与推广应用,是提高天然橡胶种植水平的重要途径之一。本试验示范,对多种抗旱栽培定植技术方法与多种种植材料抗旱定植作试验比较选择,芽接桩苗围洞法辅以示范印证。取得的结果是:芽接桩苗围洞法为优选,籽苗芽接苗常规抗旱定植法、薄膜覆盖+保水剂法为抗旱定植可选之技术方法,建议此三法在生产上推广应用。     

The histology of Hevea brasiliensis phloem necrosis

Phloem necrosis of rubber tree(hevea brasiliensis)is characterized by cel wall degradation, alteration of the middle lamella, the vesiculation of endomembranes, the formation of tylosoids and the internal coagulation of rubber.     

Seasonal patterns of radial root growth and starch dynamics in plantation-grown Sitka spruce trees of different ages

Seasonal patterns of radial root growth within 1 m of tree stems were examined in Scottish plantations of Sitka spruce trees aged 9, 15 and 20 years. Results were compared with parallel measurements of shoot extension, radial growth of stems and amounts of starch stored in tissues external to root wood. Youngest trees produced the largest annual increments in root cross-sectional area and numbers of new cells along radial files of tracheids. Irrespective of tree age, new cells were present in roots before bud burst and the onset of radial growth occurred progressively later with increasing distances from the stems. At ages 15 and 20, both stem cross-sectional area and radial root growth up to 0.5 m from the stem base had a minor peak of activity preceding and a major peak following shoot elongation. Further than 0.5 m from the stem, root growth was frequently restricted to the period following shoot extension. Starch storage in the roots reached a maximum in April and May, which was greatest for 9-year-old trees and least for 20-year-old trees. At all ages, radial root growth in early spring occurred concurrently with increased starch storage. Later in the season starch reserves declined rapidly during the period of shoot elongation and root growth occurred whilst reserves were low. At all ages for positions on the root at the base of the stem and 0.25 m from it, starch depletion, at its maximum rate during June, accounted for less than the measured increment of root wood growth at that point. This indicates a substantial translocation of substrates to these zones during growth. At the same time, the reduction in starch concentrations at more distal points from the stem far exceeded that required for local root thickening.     

巴西橡胶树野生种质植物学性状变异分析

植物学性状特征是研究植物遗传分化及多样性最基础、最直观的方法,是区分橡胶树品种和判断种质遗传变异的重要依据。本研究对129份橡胶树野生种质的茎围、株高、分枝角度、嫩叶色、老叶色、叶柄长、叶长、叶宽、叶厚、叶面积等10个植物学性状参数进行了测量,并作变异性及相关性分析。结果表明,变异性方面,分枝角度变异系数为40.53%,茎围变异系数为28.52%,其余植物学性质变异系数也较大;相关性方面,橡胶树野生种质生长量相关的茎围、株高、叶面积、小叶长、小叶宽等5个植物学性状具显著相关性,说明上述性状可为橡胶树速生品种选育提供参考。本研究通过橡胶树植物学性状变异性及相关性分析,初步阐明了橡胶树野生种质的资源丰富程度,可为后续的橡胶树性状全基因组关联分析及种质创新研究提供基础数据。     

橡胶树魏克汉种质资源抗寒性研究

以20份橡胶树魏克汉种质资源一年生枝条为试材,设置4℃、0℃、-2℃及-5℃等4个低温处理,测定其树皮相对电导率,并结合树皮的含水量及厚度,对橡胶树抗寒性进行比较分析。结果表明,随着胁迫温度的下降,相对电导率呈现"S"型上升趋势。20个橡胶树无性系半致死温度(LT_(50))在-2.366～-0.395℃;根据LT_(50)的高低可将其分为3类,即抗寒性强的、抗寒性一般的及抗寒性弱的,其中抗寒性强的占总群体的25%,说明抗寒性强的资源较少。相关性分析显示,LT_(50)与树皮厚度具显著负相关,橡胶树树皮越厚,抗寒性越强,可作为后期抗寒鉴定的指标之一。     

巴西橡胶树胶乳生理诊断的研究与应用

橡胶树胶乳生理诊断法是一批法国学者于20世纪80年代发展起来的,用于判断胶树代谢与健康状况的方法。在研究了巴西橡胶树胶乳的各种成分在胶树中的生理功能及其变化规律,以及这些成分与胶树产量之间的相关性后,可以将无性系划分为不同的代谢类型,并根据不同的代谢类型,安排不同的采胶方法;同时也可以根据随机抽样理论找到这些成分的标准参考值,用来判断开割胶树的健康状况,以指导采胶生产。现在胶乳生理诊断主要用于无性系代谢类型判断与采胶强度判断。     

巴西橡胶新种质鉴定及利用研究初报

对从科特迪瓦和CIRAD -CP引进的 198个巴西橡胶新种质和 10个IRCA橡胶树新品种在云南植胶区的农业气象条件下进行适应性鉴定。这些新种质和新品种生长表现良好。经试割 ,新种质几乎无胶可收 ,新品种试割6个 ,有 4个产量超过RRIM60 0 ,抗寒能力普遍差。