An overview of the potentials of natural rubber (Hevea brasiliensis) engineering for the production of valuable proteins

Nigeria has in recent times exhibited great commitment to the use of biotechnology as a tool to enhance agricultural and general socioeconomic development. Plant biotechnology and genetic engineering have led to the production of various pharmaceutical proteins from plant sources. Plantsare potential bio-farming factories because they provide an inexpensive and convenient system for the large scale production of valuable recombinant proteins. The objective of this paper is to highlight theprospects and potentials of transgenic rubber plant as a unique protein factory which will act as additional source of income to the rubber farmer especially in Nigeria. Rubber has the advantage of having continuous harvesting from same tree for a minimum of twenty years. The International Rubber Research Organizations have successfully developed transgenic rubber plants that produce foreign proteins of potential commercial value. Among such routines is an antibody and human serum albumin. Tapping rubber trees for valuable proteins will be more profitable compared to other options. The technologies have been developed and only needs to be adapted to our local conditions. It is hoped that this paper will be instructive to rubber farmers, policy makers, executors of policies or citizens wishing to join the Nigerian rubber farmers in their bid to increase their prosperity or alleviate their poverty

Genetic divergence of rubber tree estimated by multivariate techniques and microsatellite markers

Genetic diversity of 60 Hevea genotypes, consisting of Asiatic, Amazonian, African and IAC clones, and pertaining to the genetic breeding program of the Agronomic Institute (IAC), Brazil, was estimated. Analyses were based on phenotypic multivariate parameters and microsatellites. Five agronomic descriptors were employed in multivariate procedures, such as Standard Euclidian Distance, Tocher clustering and principal component analysis. Genetic variability among the genotypes was estimated with 68 selected polymorphic SSRs, by way of Modified Rogers Genetic Distance and UPGMA clustering. Structure software in a Bayesian approach was used in discriminating among groups. Genetic diversity was estimated through Nei's statistics. The genotypes were clustered into 12 groups according to the Tocher method, while the molecular analysis identified six groups. In the phenotypic and microsatellite analyses, the Amazonian and IAC genotypes were distributed in several groups, whereas the Asiatic were in only a few. Observed heterozygosity ranged from 0.05 to 0.96. Both high total diversity (HT' = 0.58) and high gene differentiation (G st' = 0.61) were observed, and indicated high genetic variation among the 60 genotypes, which may be useful for breeding programs. The analyzed agronomic parameters and SSRs markers were effective in assessing genetic diversity among Hevea genotypes, besides proving to be useful for characterizing genetic variability

Preliminary Investigation into Tree Dryness in Hevea brasiliensis (Wild. Ex Adr. De Juss) Muell. Arg. by Path Analysis of Tree Dryness and Latex Parameters

The correlative path analysis between tree dryness and four latex parameters was studied in eleven clones of Hevea brasiliensis. The latex parameters used for evaluation were initial volume, initial flow rate, final volume and plugging index with tree dryness as the dependent factor. Estimates of direct and indirect effects of each of the latex parameters on tree dryness were calculated through linear correlation and path analysis. The correlation coefficient between initial volume and initial flow rate was 1.00 and both characters had the same correlation coefficients with other latex parameters and tree dryness. This implies that initial volume and initial flow rate are alternatives for evaluation of correlation between latex parameters and tree dryness. There was significant correlation between initial volume, initial flow rate and tree dryness at V = -0.52 and high indirect effect of initial volume and initial flow rate through final volume. In addition, despite the low correlation coefficient of V = -0.20 between final volume and tree dryness, the direct effect of final volume on tree dryness was high at 0.812. Final volume is therefore an important factor in the incidence of tree dryness

Multivariate analysis of pollination and seed characters in Hevea brasiliensis (Muell.Arg.)

No Abstract.Nigerian Journal of Genetics Vol. 16&17 2002: pp. 28-3

Correlation and Path Coefficients of Seed and Juvenile Characters with Respect to Latex Yield in Hevea brasiliensis Muell. Arg

Ten Hevea clones were evaluated for direct and indirect effects of sixteen seed and juvenile characters on latex yield. Each clone was evaluated for five juvenile characters, eleven seed characters and latex yield. Genotypic variance and correlation were obtained through analysis of variance and covariance respectively. Phenotypic correlation was calculated as simple correlation of clonal means. The phenotypic correlation of each seed and juvenile character with latex yield was partitioned into direct and indirect effects through path analysis. The most reliable character for indirect selection for latex yield was ratio of seed length/width, which had relatively high direct effect and significant phenotypic and genotypic correlation with latex yield. This relationship had the stabilizing influence of ratios of seed/shell weight and seed weight/volume. The pattern of use of effect coefficients for simultaneous improvement of latex yield and associated characters is provided

Clonal stability of latex yield in eleven clones of Hevea brasiliensis Muell. Arg.

Eleven Hevea brasiliensis clones were evaluated for clonal stability of latex yield. A randomized complete block design was used with four replicates, two locations, seven years and three periods per year. Stability analysis was based on clone x year and clone x year x location interactions. Five stability parameters viz environmental variance, shukla's stability variance, regression of clonal latex yield on environmental index, variance due to regression and variance due to deviation from regression were applied. There was significant clone x environment effect at the two levels of interaction. Among the eleven clones, C 162 was outstanding for clonal stability and it can serve as donor parent for stability alleles. Three clones (C 76, C 150 and C 154) were also stable. The four stable clones (C 76, C 150, C 154 and C 162) are suitable for broad-spectrum recommendation for latex yield. Five clones (C 83, C 143, C 163, C 202 and RRIM 600) will require environment-specific recommendation because of their unstable phenotype. The stability feature of two clones (C 145 and C 159) was not clear and this will be investigated in subsequent studies