ABSTRACT
Fourteen
Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell. Arg. genotypes were
evaluated at the experimental station of the Rubber Research Institute of
Institute of Nigeria, Ntang Inya in Uyo Akwa Ibom in 2011, 2012, 2012 and 2014
cropping seasons to generate information on the extent of genetic variation,
heritability and genetic advance among. Also, to identify the most adaptable
genotypes among the tested entries. As the knowledge and understanding of the
magnitude of genetic variability is centered for selection and development of
genotypes for specific purposes. The experimental design was randomized
complete block design with four replications. Data collected on twenty one
quantitative agronomic and yield characters were subjected to analysis of
variance, correlation analysis, to estimate the extent of genetic variability,
genetic variance, broad sense heritability and relationship of rubber yield and
its component. The combined analysis of variance revealed significant
differences (P<0.01) among the genotypes for all the studied characters
indicating the inherent genetic differences among the genotypes evaluated. Genotype
x year interaction was not significant (P>0.05) for seed thickness, seed
length/thickness ratio, seed volume and bark thickness relative to all the
other characters assessed. This implies that the performance ofthe genotypes
was not consistent in the different years of evaluation. Year effect was
significant (P<0.05) fbr all the characters except stem girth and seed
density. High magnitude of phenotypic and genotypic coefficient of variations
as well as high heritability along with high genetic advance recorded fbr stem
girth, bark thickness, leaf area provides evidence that these characters were
under the control of additive gene effects and effective selection could be
possible fbr improvement of these characters. While the moderate heritability
associated with low genetic advance obtained fbr rubber yield, seed
circumference, seed weight, seed sphericity, seed surface area, seed geometric
diameter revealed greater role of non additive gene action in its inheritance.
Significant correlation of seed width, seed thickness, seed geometric diameter,
seed surface area, seed sphericity, seed circumference, seed surface area/ seed
weight with yield and that of bark thickness, seed length, seed width ,seed
geometric diameter, seed surface area with stem girth suggested that these
characters possessed greater values fbr selection. However, negative
correlation between yield and stem girth, bark thickness, leaf width implies no
direct relationship between them. The study identified high yielding genotypes;
NIG 902, NIG 901, NIG 903, NIG 905, NIG 904, NIG 907, NIG 906, NIG 908 which
can be recommended fbr farmers in Uyo agro ecology.
EME, G (2024). Variability studies of some rubber tree (Hevea brasiliensis [Willd.ex.Adr.de Juss.] Muell. Arg.) genotypes established in an ultisol:- Ogidi, Eme G. O. Mouau.afribary.org: Retrieved Sep 08, 2024, from https://repository.mouau.edu.ng/work/view/variability-studies-of-some-rubber-tree-hevea-brasiliensis-%5Bwilldexadrde-juss%5D-muell-arg-genotypes-established-in-an-ultisol-ogidi-eme-g-o-7-2
G.O., EME. "Variability studies of some rubber tree (Hevea brasiliensis [Willd.ex.Adr.de Juss.] Muell. Arg.) genotypes established in an ultisol:- Ogidi, Eme G. O" Mouau.afribary.org. Mouau.afribary.org, 28 Mar. 2024, https://repository.mouau.edu.ng/work/view/variability-studies-of-some-rubber-tree-hevea-brasiliensis-%5Bwilldexadrde-juss%5D-muell-arg-genotypes-established-in-an-ultisol-ogidi-eme-g-o-7-2. Accessed 08 Sep. 2024.
G.O., EME. "Variability studies of some rubber tree (Hevea brasiliensis [Willd.ex.Adr.de Juss.] Muell. Arg.) genotypes established in an ultisol:- Ogidi, Eme G. O". Mouau.afribary.org, Mouau.afribary.org, 28 Mar. 2024. Web. 08 Sep. 2024. < https://repository.mouau.edu.ng/work/view/variability-studies-of-some-rubber-tree-hevea-brasiliensis-%5Bwilldexadrde-juss%5D-muell-arg-genotypes-established-in-an-ultisol-ogidi-eme-g-o-7-2 >.
G.O., EME. "Variability studies of some rubber tree (Hevea brasiliensis [Willd.ex.Adr.de Juss.] Muell. Arg.) genotypes established in an ultisol:- Ogidi, Eme G. O" Mouau.afribary.org (2024). Accessed 08 Sep. 2024. https://repository.mouau.edu.ng/work/view/variability-studies-of-some-rubber-tree-hevea-brasiliensis-%5Bwilldexadrde-juss%5D-muell-arg-genotypes-established-in-an-ultisol-ogidi-eme-g-o-7-2