|ISHS Acta Horticulturae 1218: IX International Symposium on Kiwifruit
Analysis of components of genetic variance and breeding value of kiwifruit (Actinidia chinensis Planch.) using best linear unbiased prediction (BLUP) and pedigree information
|Authors: ||C. Pinto, R. Testolin, G. Cipriani|
|Keywords: ||fruit genetics, quantitative genetics, heritability, general combining ability (GCA), specific combining ability (SCA), BLUP, REML|
Analysis of genetic components of variance in controlled mating designs allows estimation of the heritability of traits, the combining ability of cross parents and, in turn, their breeding value.
The present paper report the analysis of a North Carolina model 2 mating design, where three female parents and 12 male parents were intercrossed, producing 35 cross families (one cross combination failed to produce seeds). The cross families, consisting of 40 to 142 offspring each, were observed in two subsequent years for time of bud break, time of flowering, flowers per cyme, flowering intensity, productivity, fruit weight, soluble solids content (SSC), flesh firmness, and flesh color.
The genetic components of variance were computed using restricted maximum likelihood (REML) and best linear unbiased prediction (BLUP) on the R environment with the ASReml-R package.
The narrow-sense heritability (h2) was low (<0.30) for flowering time, flowers per cyme, flowering intensity, and productivity; intermediate (0.30-0.60) for time of bud break, fruit weight, SSC, and flesh color; and high (>0.60) for flesh firmness as an index of ripening time.
Parents and secondary parents were ranked according to their breeding value for the main traits and the best parents as well the best parental combinations were also ranked for both productivity and fruit weight.
The paper concludes by commenting on the importance of the evaluation of breeding value carried out on male genotypes, in which fruit-related traits cannot be phenotypically evaluated.
Download Adobe Acrobat Reader (free software to read PDF files)