STUDY OF GENETIC VARIABILITY, HERITABILITY AND REPEATABILITY FOR FRUIT QUALITY CHARACTERS IN Citrus sinensis

The quality has become paramount in commercial Citrus and new cultivar, being developed through plant breeding. Also, it is very important for the international market and is major determinants for cultivar selection. The purpose of the present work is to better understand the mode of transmission of some characters and take into account the improvement of the program, in order to make the choice of parents less empirical. Likewise, this study evaluated a diverse orange variants and theirs females parents for mature fruit phenotypic traits, genetic diversity, repeatability and heritability in order to select superior genotypes of Citrus. The analysis of variance for most characters indicated no significant variation among the oranges variants and their female parent. For each Family, the studied variants is half-sibling. While, the comparison between all studied oranges clones showed a difference in value for all the characters studied. The results obtained confirm the great influence of the genetic factor on the transmission, from one generation to another, of fruit quality (seedless, size, total soluble solid, juice continent, acidity, index of maturity). In the other hand, low phenotypic coefficient of variation estimated as compared to genotypic coefficient of variation showed low environmental influence on the expression of traits. For the traits with high heritability, selection can be done at any of the environments. Thus, these traits can be confirmed at the breeding site. Higher broad sense heritability estimates could be a valuable tool for breeders to select improved genotype. Repeatability coefficients were estimated with accuracy values higher for all variables and are important for plant breeding, since it is equivalent to the maximum value that broad sense heritability can achieve. The repeatability values observed in this study were higher. Hence the possibility of genetic improvement of varieties of Citrus to better meet the national and international market requirements.