Mixed model for combining selection in segregate progeny of papaya

Abstract

Although Brazil stands out as a leading global producer of papaya still exists a small number of lines/hybrids available for its cultivation. To obtain new cultivars it is necessary to direct efforts towards the identification and selection of superior genotypes and broadening the genetic basis of the species. This study aimed to select lines between and within families in a segregating population of papaya for advancement of self pollination and backcross. Originally the backcross population aimed the introgression of the physiological disturb (Golden type) into the UENF/CALIMAN01 genitors. For this a selection index named IG2 was used supported in individual genotypic values obtained through mixed models by REML/BLUP. Analysis of results permitted selection of eight progenies and segregated for the trait “Golden Type”: 11, 13, 14, 15, 16, 19, 18 and 12. The selected genotypes within each progeny showed higher values of gain and predicted average than the controls (JS12, SS72/12 and Golden) for the following characteristics: height of insertion of the first fruit, firmness of fruit and production. Twenty plants e selected with the characteristic “Golden Type” for the advancement of generation of selfing and backcross.