Phenotypic stability and genetic gains in six-year girth growth of Hevea clones

Abstract

-Rubber tree [Hevea brasiliensis (Willd. ex Adr. de Juss.) Müell. Arg.] budgrafts of seven clones were evaluated on five contrasting sites in the plateau region of the São Paulo State, Brazil. The objective of this work was to study the phenotypic stability for girth growth. The experimental design was a randomized block design with three replications and seven treatments. Analysis of variance of girth at six-year plant growth indicated a highly significant clone x site interaction. Only linear sites and clone x site components of clone x year interaction were significant, indicating that the performance of clones over sites for this trait could be predicted. The clones GT 1 and PB 235 showed the greatest stability in relation to girth growth, with foreseen responses to change, introduced in the sites. The clones PB 235 and IAN 873 showed significative difference in relation to regression coefficient, representing clones with specific adaptability on favorable and unfavorable sites respectively. The clone GT 1 became the most promissory one in the study of stability and adaptability even showing low girth growth. Expected genetic gains from planting sites, along with estimates of clonal variance and repeatability of clonal means are generally greatest or close to the greatest when selection is done at the same site.Index terms: rubber tree, Hevea brasiliensis, heritability, repeatability. ESTABILIDADE FENOTÍPICA E GANHOS GENÉTICOS DE SEIS ANOS DE

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

“…The clone RRIM 600 was rated unstable in the present study by Goncalves et al (1999). Meenattor et al (1991) reported RRIM 600 stable for girth increment.…”

Genotype-environment interaction and phenotypic stability for girth growth and rubber yield of Hevea clones in São Paulo State, Brazil

“…Similarly, a recent study (Gonçalves et al, 1999) undertaken on the girth growth stability at six years also revealed very high fluctuations in the growing environments of São Paulo State. This shows the difficulties encountered by breeders in selecting new genotypes (clones) for release; these difficulties arise mainly from the masking effects of variable environments.…”

“…He studied temporal yielding, where the environments were represented by different months and years through an environmental index obtained by the mean performance of all the genotypes in each month and year. Later, Gonçalves et al (1992Gonçalves et al ( , 1999, using the same stability method, examined the magnitude of the genotype x environment interaction on girth growth of Hevea at different ages, searching for clone stability and genetic gains.…”

Genotype × environment interaction of Hevea clones in traditional and non-traditional rubber growing regions of Vietnam

“…On rubber tree, a large number of studies on genotypeenvironment interactions were conducted in Sri Lanka (Jayasekera 1983; Jayasekera et al 1994;Withanage et al 2005), Indonesia (Daslin et al 1986), Nigeria (Onokpise et al 1986;Omokhafe & Alika 2003;Omokhafe et al 2004a, b), Malaysia (Tan 1995), India (Menattoor et al 1991) and Brazil (Gonçalves et al 1992(Gonçalves et al , 1998(Gonçalves et al , 1999(Gonçalves et al , 2003(Gonçalves et al , 2008(Gonçalves et al , 2009Costa et al 2000;Gouvêa et al 2012;Silva et al 2013Silva et al , 2014. Several of these studies used the method developed by Eberhart and Russell (1966) to determine the genotype × environment interaction on growth and/or latex yield of Hevea clones (Gonçalves et al 1992(Gonçalves et al , 2003(Gonçalves et al , 2008(Gonçalves et al , 2009Omokhafe & Alika 2003;Omokhafe et al 2004a, b;Gouvêa et al 2012;Silva et al 2013Silva et al , 2014.…”