Latex Vessels Research Articles

Estimation of genetic parameters in rubber progenies

This study was designed to evaluate the genetic variability, the potential for rubber yield and secondary traits of rubber tree progenies at three locations in the state of Sao Paulo. The experiments were conducted in a randomized block design with 22 progenies and 6 replications. At the age of three years, the progenies were evaluated for rubber yield, girth growth and total number of latex vessel rings. The results showed the existence of genetic variability among progenies for each location separately as well as between locations, with differences in the progeny performance for the traits. The individual heritabilities calculated for rubber yield, girth growth and total number of latex vessel rings (0.30, 0.63 and 0.29, respectively), associated with high genetic gains with selection for the traits studied at each site, showed that the populations can be considered suitable for the rubber breeding program, provided that an appropriate selection procedure is used.

Genetic parameters and correlation in early measurement cycles in rubber trees

Knowledge of the traits present in plant populations of a species is essential to carry out selection and breeding. The objective of the present study was to estimate the genetic parameters and correlate genetically and phenotypically the variables rubber yield, annual trunk girth increase, number of latex vessel rings and bark thickness in early measurement cycles. A total of 22 rubber tree progenies (Hevea brasiliensis) were assessed in three locations during three early measurement cycles. The bark thickness variable correlated significantly for the three increase measurements made in the locations of Jau, Pindorama and Votuporanga. The progeny mean based joint hereditability showed mean values greater than individual plants and within progeny plants of 0.848, 0.286 and 0.242, respectively. The variables annual trunk girth increase and bark thickness are genetically correlated variables. Rubber yield is correlated genetically with bark thickness that permits simultaneous selection for the two characteristics. The early measurement cycles were efficacious for finding genetic variability among the genotypes.

Monitoring the Wall Mechanics During Stent Deployment in a Vessel

Clinical trials have reported different restenosis rates for various stent designs1. It is speculated that stent-induced strain concentrations on the arterial wall lead to tissue injury, which initiates restenosis2-7. This hypothesis needs further investigations including better quantifications of non-uniform strain distribution on the artery following stent implantation. A non-contact surface strain measurement method for the stented artery is presented in this work. ARAMIS stereo optical surface strain measurement system uses two optical high speed cameras to capture the motion of each reference point, and resolve three dimensional strains over the deforming surface8,9. As a mesh stent is deployed into a latex vessel with a random contrasting pattern sprayed or drawn on its outer surface, the surface strain is recorded at every instant of the deformation. The calculated strain distributions can then be used to understand the local lesion response, validate the computational models, and formulate hypotheses for further in vivo study.

Monitoring the Wall Mechanics During Stent Deployment in a Vessel

Clinical trials have reported different restenosis rates for various stent designs. It is speculated that stent-induced strain concentrations on the arterial wall lead to tissue injury, which initiates restenosis. This hypothesis needs further investigations including better quantifications of non-uniform strain distribution on the artery following stent implantation. A non-contact surface strain measurement method for the stented artery is presented in this work. ARAMIS stereo optical surface strain measurement system uses two optical high speed cameras to capture the motion of each reference point, and resolve three dimensional strains over the deforming surface. As a mesh stent is deployed into a latex vessel with a random contrasting pattern sprayed or drawn on its outer surface, the surface strain is recorded at every instant of the deformation. The calculated strain distributions can then be used to understand the local lesion response, validate the computational models, and formulate hypotheses for further in vivo study.

THE WATER RELATIONS OF RUBBER (HEVEA BRASILIENSIS): A REVIEW

SUMMARYThe results of research done on water relations of rubber are collated and summarised in an attempt to link fundamental studies on crop physiology to crop management practices. Background information is given on the centres of origin (Amazon Basin) and production of rubber (humid tropics; south-east Asia), but the crop is now being grown in drier regions. The effects of water stress on the development processes of the crop are summarised, followed by reviews of its water relations, water requirements and water productivity. The majority of the recent research published in the international literature has been conducted in south-east Asia. The rubber tree has a single straight trunk, the growth of which is restricted by ‘tapping’ for latex. Increase in stem height is discontinuous, a period of elongation being followed by a ‘rest’ period during which emergence of leaves takes place. Leaves are produced in tiers separated by lengths of bare stem. Trees older than three to four years shed senescent leaves (a process known as ‘wintering’). ‘Wintering’ is induced by dry, or less wet, weather; trees may remain (nearly) leafless for up to four weeks. The more pronounced the dry season the shorter the period of defoliation. Re-foliation begins before the rains start. The supply of latex is dependent on the pressure potential in the latex vessels, whereas the rate of flow is negatively correlated with the saturation deficit of the air. Radial growth of the stem declines in tapped trees relative to untapped trees within two weeks of the start of tapping. Roots can extend in depth to more than 4 m and laterally more than 9 m from the trunk. The majority of roots are found within 0.3 m of the soil surface. Root elongation is depressed during leaf growth, while root branching is enhanced. Stomata are only found on the lower surface of the leaf, at densities from 280 to 700 mm−2. The xylem vessels of rubber trees under drought stress are vulnerable to cavitation, particularly in the leaf petiole. By closing, the stomata play an essential role in limiting cavitation. Clones differ in their susceptibility to cavitation, which occurs at xylem water potentials in the range of −1.8 to −2.0 MPa. Clone RRII 105 is capable of maintaining higher leaf water potentials than other clones because of stomatal closure, supporting its reputation for drought tolerance. Clones differ in their photosynthetic rates. Light inhibition of photosynthesis can occur, particularly in young plants, when shade can be beneficial. Girth measurements have been used to identify drought-tolerant clones. Very little research on the water requirements of rubber has been reported, and it is difficult to judge the validity of the assumptions made in some of the methodologies described. The actual evapotranspiration rates reported are generally lower than might be expected for a tree crop growing in the tropics (<3 mm d−1). Virtually no research on the yield responses to water has been reported and, with the crop now being grown in drier regions, this is surprising. In these areas, irrigation can reduce the immaturity period from more than 10 years to six years. The important role that rubber plays in the livelihoods of smallholders, and in the integrated farming systems practised in south-east Asia, is summarized.

Prediction of direct and indirect genetic gains and genotypic correlations in rubber tree progenies

The objective of this work was to estimate the genetic parameters, genotypic and phenotypic correlations, and direct and indirect genetic gains among and within rubber tree (Hevea brasiliensis) progenies. The experiment was set up at the Municipality of Jaú, SP, Brazil. A randomized complete block design was used, with 22 treatments (progenies), 6 replicates, and 10 plants per plot at a spacing of 3x3 m. Three‑year‑old progenies were assessed for girth, rubber yield, and bark thickness by direct and indirect gains and genotypic correlations. The number of latex vessel rings showed the best correlations, correlating positively and significantly with girth and bark thickness. Selection gains among progenies were greater than within progeny for all the variables analyzed. Total gains obtained were high, especially for girth increase and rubber yield, which were 93.38 and 105.95%, respectively. Young progeny selection can maximize the expected genetic gains, reducing the rubber tree selection cycle.

Pharmacognosy in Turkey

This presentation will give an overview on the wide range of studies of Pharmacognosy in Turkey, since its establishment as a discipline during the Ottoman Empire, up until contemporary times. Studies of Pharmacognosy have begun in 1839 together with the official education of pharmacy. Dr. Charles Ambroise Bernard (1808–1844), Dr. Mehmed Akif Aykut (1887–1939), Prof. Dr. Alfred Heilbronn (1885–1961) and Prof. Dr. Sarım Hüsnü Çelebioğlu (1897–1982) were the first scholars who had initially developed the education of Pharmacognosy. Prof. Dr. S.H. Çelebioğlu obtained the PhD degree under the supervision of Prof. Dr. E. Gilg at Berlin Friedrich-Wilhems University in 1932. In his dissertation, Çelebioğlu investigated the occurence of the opium alkaloids in the root ends of Papaver somniferum, and, its transfer to the whole plant by latex vessels. Çelebioğlu is the founder of the Institute of Pharmacognosy in Istanbul University (1945) and the first author of a Pharmacognosy textbook in Turkey (1949). Three PhD studies performed by Dr. Turhan Baytop (1920–2002), Dr. Mekin Tanker and Dr. Nevin Tanker on Ephedra campylopoda C.A.May, Marsdenia erecta R.Br. and Juniperus nana Wild. had been completed under his supervision, respectively. Dr. Baytop, a distinguished scientist focusing mostly on „Medicinal Plants and the Flora of Turkey“ and the „History of Pharmacy in Turkey“, initiated the National Pharmacognosy Meetings in 1976. Since then, these meetings have been biennially organized by the collaborative efforts of Departments of Pharmacognosy and Pharmaceutical Botany of the different faculties of whose number has risen to twenties. Moreover, the members of these departments have been the founders and pioneers of the Turkish Society of Pharmacognosy & Pharmaceutical Botany. Materials for research carried out by these scientists are provided from the flora of Turkey which represents more than 11000 taxa, including over 3000 endemic species. The richness and diversity of the flora and the knowledge on medicinal plants of this geographical region, continuing the tradition of Hippocrates, Dioscorides, Galenos, Avicenna and Ibn el-Beithar, are still offering an invaluable opportunity to Turkish plant scientists. The scientific studies conducted can be mainly classified as floristic, ethnobotanical, ethnopharmacological, chemical structures and/or activity guided studies. During the last two decades pharmacognostic studies have become interdisciplinary, encouraging collaborative works of multiple disciplines, resulting in most fruitful results.

Assessment of rubber tree panels under crowns resistant to South American leaf blight

The objective of this work was to assess the performance of panel clones under crowns resistant to South American leaf blight (Microcyclus ulei). The experiment was carried out with 18 panel clones crown-budded with Hevea pauciflora x H. guianensis, in a Xanthic Ferralsol (Oxisol) in Manaus, AM, Brazil. The following parameters were evaluated: dry rubber yield, plant nutritional status, and anatomical and physiological characteristics of the latex vessels. In the first three years of evaluation, the panel clones IAN 2878, IAN 2903, CNS AM 7905, CNS AM 7905 P1, and PB 28/59 showed the highest dry rubber yield potential, while the clones IAN 6158, IAN 6590, and IAN 6515 should not be recommended for crown budding. Higher potassium and copper foliar content in panel clones were associated to an increase in dry rubber yield. The simultaneous evaluation of anatomical and physiological characteristics of latex is fundamental for the selection of panel clones in the Amazon region. Crown budding is an efficient technology for South American leaf blight management in endemic regions.

SKIN DAMAGE TO TWO NEW MANGO CULTIVARS DURING IRRADIATION AND COLD STORAGE

Mangoes can express several skin disorders following important postharvest treatments. Responses are often cultivar specific. This paper reports the responses of two new Australian mango cultivars to some of these treatments. 'Honey Gold' mango develops skin browning early during cold storage. This is thought to be partly caused by a discolouration of the latex vessels which then spreads to the surrounding cells. The symptoms appear to be worse in fruit from hotter production areas and that have been cooled to temperatures below 18C soon after harvest. Current commercial recommendations are to cool fruit to 18C, which limits postharvest handling options. Recent trials have confirmed that delayed or slowed cooling after harvest can reduce under skin browning. The defect may also be associated with physical injury to the skin during harvesting and packing. Irradiation is potentially an important disinfestation treatment for fruit fly in Australian mangoes. The 'B74' mango cultivar develops significant skin damage following irradiation, mainly due to discolouration of the cells surrounding the lenticels. Recent results confirmed that fruit harvested directly from the tree into trays without exposure to water or postharvest chemicals are not damaged by irradiation, while commercially harvested and packed fruit are damaged. Several major harvest and postharvest steps appear to increase lenticel sensitivity to irradiation. Further work is required to develop commercially acceptable protocols to facilitate 'Honey Gold' and 'B74' mango distribution and marketing.

A Human Gastric Simulator (HGS) to Study Food Digestion in Human Stomach

The objective of this study was to develop an in vitro stomach model, the Human Gastric Simulator (HGS), for studying gastric digestion of foods. The HGS is designed in such a way as to simulate the continuous peristaltic movement of stomach walls, with similar amplitude and frequency of contraction forces as reported in vivo. The HGS mainly consists of a latex vessel, simulating the stomach chamber, and a series of rollers secured on belts that are driven by motor and pulleys to create a continuous contraction of the latex wall. It also incorporates gastric secretion, emptying systems, and temperature control that enable accurate simulation of dynamic digestion process for detailed investigation of the changes in the physical chemical properties of ingested foods. The simulated gastric contraction force demonstrates a similar pattern as in vivo stomach forces. The precise control of gastric secretion and emptying and the adjustable mechanical forces in the HGS provide a useful tool to study transformation of food constituents under simulated physiological conditions.

Correlações e análise de trilha em clones de seringueira

O conhecimento das características presentes nos genótipos é de extrema importância na condução de trabalhos de seleção e melhoramento. O objetivo foi avaliar as relações entre os caracteres agronômicos e anatômicos da casca, bem como seus efeitos diretos e indiretos sobre a produção de borracha seca da seringueira, mediante análise de trilha. Avaliaram-se seis clones de seringueira no delineamento experimental em blocos casualizados com quatro repetições, no Pólo Regional de Desenvolvimento Tecnológico dos Agronegócios do Centro Norte da Agência Paulista de Tecnologia dos Agronegócios, município de Pindorama, São Paulo, Brasil, no ano de 2005. Valor de correlação positivo e significativo foi observado apenas entre a produção de borracha seca e o número de anéis de vasos laticíferos (r = 0,88). Os caracteres perímetro do caule e número de anéis de vasos laticíferos apresentaram os maiores efeitos diretos sobre a produção de borracha seca. Por outro lado, a espessura da casca e o diâmetro dos anéis de vasos laticíferos mostraram efeitos diretos negativos e com altas magnitudes. A seleção indireta via número de anéis de vasos laticíferos proporcionará ganhos durante o processo de seleção em programas de melhoramento da seringueira.

ENVIRONMENTAL FACTORS CAUSING PHYSIOLOGICAL DISORDERS IN PAPAYA PLANTS

Brazil is the world largest grower and exporter of papayas. The climate of the regions where the fruit is cultivated makes it possible to produce, harvest and provide the market with papayas on a year-round basis. The light and environmental conditions, together with modern planting techniques that utilize low levels of agricultural chemicals furnish the market a high quality fruit. Knowledge of how papaya responds to environmental factors provides a scientific basis to develop management strategies to optimize fruit yield and quality. A better understanding of genotypic responses to specific environmental factors will contribute to efficient agricultural zoning and papaya breeding programs. Main physiological disorders affecting papaya are pulp gelification and skin freckles. Magnesium and calcium deficiencies in the pulp of the gelled tissue may be related to the disruption of proton pump functioning. Identifying the mechanisms of the disorder is an active research area in Brazil. Skin freckles (SF) in papaya is a visual disorder that reduces the commercial value. In Brazil, SF incidence was observed in the common cultivars and has been observed in almost all countries with commercial papaya production. Since SF was not associated with low calcium tissue levels in January, we proposed a re-assessment of the concept that the low tissue calcium contents in the January sampling may reduce cell wall stability and membrane integrity facilitating latex leaking. It is proposed that the high calcium contents associated with high temperature and large diurnal temperature fluctuations in September contributed to greater cell wall rigidity facilitating increased turgor pressure resulting in the rupture of the latex vessels and latex leaking. Environmental factors profoundly affect the physiological disorders in papaya and an understanding of their interaction with physiological processes is extremely important for economically sustainable production in the nursery or field plantation. With improved, science-based management, growers will increase papaya fruit productivity and quality.

Musostrobocaulon skutchii gen. et sp. nov., a permineralized musaceous inflorescence axis from the Deccan Intertrappean beds of Mohgaonkalan, India

Musostrobocaulon skutchii gen. et sp. nov., is a complete inflorescence axis attached with a part of leaf sheath embedded in a chert matrix collected from the Deccan Intertrappean beds of Mohgaonkalan, District Chhindwada, Madhya Pradesh, India. It has a cylindrical, 2.2 x 2.5 cm axis having thin cortex and wide vascular region indistinctly divisible into peripheral and central regions. Typical scitaminean or Musa-type of vascular bundles; large air canals bounded by uniseriate diaphragms; articulated laticifers and latex vessels suggest its affinity with Musa L. (Order-Zingiberales: Family-Musaceae).

CDNA, from Hevea brasiliensis latex, encoding 1-deoxy- d-xylulose-5-phosphate reductoisomerase

Natural rubber from Hevea brasiliensis is synthesized by enzymic polymerization of isopentenyl diphosphate (IDP) units. This has been proposed to occur inside the latex vessel in a thread-like tubular reticulum, connecting rubber particles to single- (lutoid) and double- (Frey-Wyssling, FW) membrane-bound organelles. We show that a membrane-free preparation from FW particles converted [ 14C] glucose into radio labeled prenyl products and this was more efficiently inhibited by fosmidomycin, the MEP pathway inhibitor, than mevilonin, the inhibitor used to block the MVA pathway. This implicated the alternative plastid associated MEP pathway for IDP synthesis. We then identified a cDNA clone ( Hbdxr) from a Hevea rubber latex cDNA library, encoding for 1-deoxy- d-xylulose-5-phosphate reductoisomerase (DXR), a key enzyme of the MEP pathway for the IDP biosynthesis. Sequence analysis and the deduced amino acid sequence had >80% homology to other plant DXR enzymes with an ORF consisting of 1413 bp capable of encoding a 50.97 kDa polypeptide. A highly conserved binding site for NADPH was identified and an N-terminal transit peptide with a putative conserved cleavage site. The Hbdxr-gfp gene, transformed into Arabidopsis cells was located in the chloroplasts, thus Hbdxr may be expressed and localized in the FW plastids. The levels of Hbdxr mRNA detected in young latex containing tissues, inflorescence and seedling stems, were higher than those found in the latex from the tree and were barely detectable in the mature leaves. We therefore suggest that one function of the FW particles could be to supply IDP for rubber biosynthesis through the tubular thread-like reticulum.

Keragaan dan Hubungan Berbagai Komponen Hasil Tanaman Karet (Hevea brasiliensis Muell. Arg.) pada Dua Populasi Hasil Persilangan PB 260 dengan PN

Latex yield of rubber tree ( Hevea brasiliensis Muell. Arg.) is a complex trait influenced by external and internal factors. In this trial, F1 progenies of two populations (crossing PB 260 as high latex yielder x PN as low latex yielder) and their parents were used to study the characteristic of yield components, namely physiology, anatomy and growth characters which influence latex yield. Based on statistic analysis, it showed that latex yield of two populations had high variation among their F1 progenies. The other variables such as girth, bark thickness, number of latex vessel rings, plugging index, sucrose content and inorganic phosphate content also showed high variation. Based on path analysis and stepwise regression, it showed that the number of latex vessel rings and plugging index had bigger direct effect on determining latex yield of A population (PB 260 x PN 7111), while girth and plugging index variables had bigger direct effect on latex yield of C population (PB 260 x PN 7). Key words: Hevea brasiliensis Muell. Arg., latex yield, F1 progenies, physiology and anatomy characters

Feasibility of fluid volume conductance to assess bladder volume

Ambulatory urodynamics has the potential to provide measurements of bladder function during activities of daily living; however, no method of real-time continuous bladder volume measurement exists. The present study was conducted to determine the feasibility of using fluid volume conductance to continuously assess bladder volume. Prototype devices consisted of four electrodes mounted on a polymer body. Each was tested in an in vitro organ bath system using latex vessels filled to 500 ml with saline matching the conductivity of urine. One device was selected and used to test the effects of fluid concentration (25%, 50%, 100%, 200%, and 400% physiological saline) in latex vessels as well as the effects of fluid concentration (25%, 50%, 100%, 200%, and 400% Tyrodes solution) and temperature (32, 37, and 42 degrees C) in excised pig bladders. Conductance demonstrated a linear increase at low volumes but approached an asymptotic value at high volumes. Conductivity increased with increased temperature or concentration. With the exception of the differences between 25% and 50% concentrations, 32 degrees C and 37 degrees C, and 37 degrees C and 42 degrees C temperatures, each concentration and temperature produced statistically different conductance measurements from all others. The conductance method is sensitive to changes in both concentration and temperature of the intravesical solution, likely due to changes in solution conductivity. Clinical application of conductance for measurement of bladder volume will require real-time conductivity compensation for the dynamically varying properties of urine. However, improved sensitivity at high volumes is necessary before this method has the potential to provide real-time bladder volume measurement for use in ambulatory urodynamics.

A role for a Hevea latex lectin-like protein in mediating rubber particle aggregation and latex coagulation

An in vitro aggregation of washed lutoid membrane and rubber particles, respectively, prepared from the bottom (lutoid) fraction and rubber layer of centrifuged fresh latex, leading to the formation of rubber coagulum necessary for a latex coagulation was demonstrated. A Triton X-100 extract of washed lutoid membrane proteins, isolated and prepared from the bottom fraction of centrifuged fresh latex was examined for its role in the latex coagulation process. It induced agglutination of rabbit erythrocytes, indicating the presence of a lectin-like protein. Hevea latex lectin-like protein (HLL) was purified to homogeneity by active chitin binding separation, followed by DEAE-Sepharose chromatography. Its M r analyzed by SDS–PAGE was 17 kDa, whereas that determined by gel filtration was 267 kDa. The HLL had a pI value of 7.2. Several glycoproteins were shown to inhibit the HLL-induced hemagglutination. The hemagglutinin activity of HLL was enhanced by Ca 2+. Of most interest was the finding that HLL strongly induced aggregation of the Hevea latex rubber particles (RP). This strong RP aggregation leads to latex coagulation, indicating the possibility that it is involved in the formation of the coagulum that plugs the latex vessel ends and stops the flow of latex upon tapping. In addition, the purified HLL also induced aggregation of RP taken from several other non- Hevea latex producing plants. This might indicate either a common or universal role of this lectin-like protein in RP aggregation and hence latex coagulation. This paper, for the first time, provides clear and unequivocal evidence for either a key biological role or physiological function of an endogeneous latex lectin-like protein in the sequential process of latex coagulation.

Performance of new Hevea clones from IAC 400 series

The Hevea breeding program of Instituto Agronômico de Campinas (IAC) has completed clonal evaluation on the following series: IAC 100, IAC 200 and IAC 300. The performance of 22 clones of Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg., evolved at IAC, over a period of eleven years was evaluated in the Western Central part of the São Paulo State, Brazil. Among these 22 new clones, six were intraspecific hybrid clones (IAC 400, IAC 404, IAC 405, IAC 406, IAC 410, IAC 412) and the remaining are primary those resulted from selected ortets within half-sib progenies. An old popular clone RRIM 600, of Malaysian origin, was used as the control. The trial was laid out in a randomized block design with three replications. Yield performance over a period of four years, mean girth at the 11th year, girth increment before tapping and on tapping, thermal property of natural rubber produced, bark thickness, number of latex vessel rows in seven year virgin bark, percentage incidence of tapping panel dryness, wind damage and diseases like leaf and panel anthracnose have been observed. Sixty one percent of the clones were superior in relation to the control for yield. The clone IAC 400 recorded the highest yield (97.40 g tree-1 tap-1) over four years of tapping, followed by IAC 411 (78.87 tree-1 tap-1), whereas the control clone RRIM 600 recorded 50.86 g tree-1 tap-1. All selected clones were vigorous in growth. Girth increment of these clones was average to above average. Except for IAC 423, other clones had thick virgin bark at opening ranging from 4.84 mm for IAC 401 to 6.38 mm for IAC 416. The natural rubbers from IAC clones have shown good thermal stability up to 300ºC and no differences in the thermal behavior among rubber from clones of the IAC series and the clone RRIM 600 were found in inert atmosphere.

Vascular wall elasticity measurement by magnetic resonance imaging

The goal of this current study was to determine whether an MRI-based elastography (MRE) method can visualize and assess propagating mechanical waves within fluid-filled vessels and to investigate the feasibility of measuring the elastic properties of vessel walls and quantitatively assessing stenotic lesions by using MRE. The ability to measure the Young's modulus-wall thickness product was tested using a thin-walled latex vessel model. Also tested in vessel models was the ability to quantitate the degree of stenosis by measuring transmitted and reflected mechanical waves. This method was then applied to ex vivo porcine models and in vivo human arteries to further test its feasibility. The results provide preliminary evidence that MRE can be used to quantitatively assess the stiffness of blood vessels, and provide a non-morphologic method to measure stenosis. With further development, it is possible that the method can be implemented in vivo.

Genetic variability for girth growth and rubber yield in Hevea brasiliensis

Basic knowledge of genetic characteristics of populations is necessary to conduct effective breeding and selection. The objective of this paper is describing the genetic variation of rubber yield and the correlation with other traits, and estimating the genetic parameters for girth growth and total number of latex vessels. Sixty seven clones of Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg. were tested at five sites during 10 years. Characters girth growth at panel opening and rubber yield, showed broad sense heritability on plot mean level, from 0.32 to 0.66 and 0.59 to 0.92, respectively. Predicted genetic gains equal to 0.73 cm and 0.79 g increase respectively on girth and yield in the opening panel and mature phases seems realistic, even with moderate selection intensities. Genetic correlations with rubber yield, bark thickness and total number of latex vessels were very large, and almost no genotype-environment interaction was present for girth growth. High genotype-environment interaction was present for rubber yield with genetic and phenotypic correlations across the sites, ranging from 0.64 to 0.92 (genetic) and 0.63 to 0.89 (phenotypic). Total number of latex vessels rings had a high heritability, ranging from 20.0% to 64.0% in the sites E and B, respectively.