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

Lígia Regina Lima Gouvêa,Paulo De Souza Gonçalves,Alisson Fernando Chioratto,Luciana Benchimol Rubiano,Maria Imaculada Zucchi

doi:10.1590/s1415-47572010005000039

Lígia Regina Lima Gouvêa, Paulo De Souza Gonçalves + Show 3 more

Open Access

https://doi.org/10.1590/s1415-47572010005000039

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Abstract

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.

Highlights

The Hevea genus belongs to the Euphorbiaceae family and comprises 11 species native to the Amazon region (Pires et al, 2002)
Until about 1913, Brazil was the major producer of natural rubber, which was obtained from wild rubber trees growing in the rain forest of the Amazon basin
The present study reports the suitability of H. brasiliensis microsatellite markers, developed from the GenBank database, for evaluation of genetic diversity in rubber tree clones

Summary

Introduction

The Hevea genus belongs to the Euphorbiaceae family and comprises 11 species native to the Amazon region (Pires et al, 2002). Ex Adr. de Juss.) Muell-Arg. is the only cultivated species and the main source of natural rubber. Until about 1913, Brazil was the major producer of natural rubber, which was obtained from wild rubber trees growing in the rain forest of the Amazon basin. With the introduction of the Wickham material in 1876, Southeast Asia has gradually become the major producer of natural rubber accounting for more than 90% of the total production worldwide. Hevea brasiliensis is cultivated in several tropical countries, most of which have active plant-breeding programs (Sedgley and Attanayake, 1988)

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