HERITABILITY OF MORPHOLOGICAL AND ARCHITECTURAL CHARACTERS IN THREE PEAR PROGENIES

This study was aimed at analysing architectural traits in the pear tree, in order to provide results on their heritability, which can be used for breeding programmes. It was carried out on three pear progenies obtained from crossing the ‘Harrow Sweet’, variety which is of high agronomic interest, with three classical cultivars (‘Lombacad’, ‘Abbé Fétel’ and ‘Doyenné du Comice’). The trees were grafted on quince BA29 rootstock and were seven years old at the time of the study, each tree represented a given genotype. Two branches were observed per tree on thirty trees per progeny. The considered variables were classified into (i) morphological i.e. related to branch form, (ii) topological i.e. related to growth and branching (iii) flowering and fruiting traits. The genotypic influence on these variables was studied thanks to the decomposition of their total variance into different components and broad sense heritabilities were calculated. The different values of broad sense heritability obtained in the three progenies and for the different features will be presented and discussed with respect of the total variability measured and the genetic proximity of the parents. In addition, correlation between variables will be discussed in order to simplify the field observations.