Prediction of genotypic values for yield in rubber tree-clone test trials using REML/BLUP procedure
Reginaldo Brito da Costa; Marcos Deon Vilela de Resende; Paulo de Souza Gonçalves; Eduardo José de Arruda; Lincoln Carlos Silva de Oliveira and Nelson Bortoletto
The present study was carried out to estimate variance components, prediction of genotypic values and repeatability for yield trait in rubber tree clones [Hevea brasiliensis (Willd. Adr. ex Juss.) Muell.-Arg.], through the procedure REML/BLUP. In the study were utilized twenty clones established in the Experimental Station of Votuporanga, São Paulo, Brazil, in the randomized block design with three replications. Each plot was represented by six trees, planted in the spacing of 7.0 m between lines and 3.0 m among plants. Data of yield of dry rubber were obtained when the trees reached a girth of 45.0cm at 1.20m above the bud union. The tapping system used was 1/2S d/4 6d/7. ET 2.5%. The results showed, a high genetic variability among clones, which can inferred on the estimates of the genotypic variation among clones ( 2 g σ =92.79) and broad sense heritabilities based on mean annual tapping yield (h2 b1 =0.82) and of mean of five annual tapping yield (h 2 b5 =0.89). The broad sense individual heritability (2 bi h = 0.22), showed the presence of dominance for the trait and heterose should be explored with larger emphasis in the studied population. The clones IAC 301, IAC 56 and IAN 3156 presented superior genotypic values when compared to the average of the population. Based on the values of the repeatability coefficient and the found efficiency results it is supposed that there is no advange in more than three annual tapping, considering the necessary time for the selection and the obtained additional progress.