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Broad sense heritability values and possible genetic gains in clonal selections of Hevea

Paulo de Souza Gonçalves^I; Antonio Lúcio Mello Martins^II; Nelson Bortoletto^III; Alderley Zani Carvalho^IV

^IPrograma Seringueira, Divisão de Plantas Industriais, Instituto Agronômico, Caixa Postal 28, 13001-970 Campinas, SP, Brasil. Send correspondence to P.S.G.
^IIEstação Experimental de Pindorama, Divisão de Estações Experimentais, Instituto Agronômico, Caixa Postal 24, Pindorama, SP, Brasil
^IIIEstação Experimental de Votuporanga, Divisão de Estações Experimentais, Instituto Agronômico, Caixa Postal 401. Votuporanga, SP, Brasil
^IVEstagiário bolsista do Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq)

ABSTRACT

Estimates of heritability of nine biometrical characters were computed using data from a replicated mature clonal trial involving 11 clones of rubber tree [Hevea brasiliensis (Wildd. ex Adr. de Juss.) Müell. Arg.] grown in Tabapuã, State of São Paulo, Brazil. The characters were: average yield over four years (MY), girth at opening (GO), girth after four years of tapping (GC), girth increment over four years of tapping (GI), virgin bark thickness (BT), total number of latex vessel rings (LV), overall density of latex vessels per ring per five millimeters of bark (DV), average diameter of latex vessels (DL) and average distance between consecutive latex vessel rings (AD). Total genetic variance (Vg), environmental variance (Ve), estimates of heritability (h²) on a single and replicated plot basis, and the expected gain (Gs) from selection, assuming the top 27.3% of the population, were computed. Broad sense heritability estimates (h²) were obtained for all characters and there was considerable genetic variation among clones for MY and GI, as indicated by large values of h² obtained for these traits. Heritability estimates for GO, GC and BT were moderately high. The expected gain in percent of the mean for MY was 29.3%, whereas estimates for GI, BT and LV were 30.55%, 13.73% and 11.00%, respectively.

Keywords: heritability; genetic gains; Hevea.

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