evaluation of morphological, phenological and pomological diversity of some persian walnut (juglans regia l.) genotypes north of fars prouince

the initial step in any breeding program including the breeding of walnut is an evaluation of the genetic diversity of its population and on identification of its superior and promising genotypes. this research was carried out during 2009-2010 growing seasons to evaluate the walnut genotypes, population grown in the vicinities of eghlid city, as one of the richest walnut population regions in the north of fars province, iran. according to local ministry of jehad agriculture office expert,s recommendations, and also orchard owners, views, 110 walnut genotypes were selected. following primary observations based upon the fruit, not showing any symptoms of blight and chilling with nut weight being more than 6.5 g, 48 genotypes were selected for further evaluations. phenological and pomological traits of selected genotypes were evaluated according to upov and ipgiri descriptors. the results revealed that nut weight, kernel weight, kernel percentage and shell thickness varied in the ranges of: 8.6-18.8 g, 2.8-9.5 g, 17.5-62.6 % and 0.86-3 mm, respectively. the superior and promising genotypes included e5, e9, e20, e22, e26, e28, e30, e34, e35, e35 and e49, for which the nut and kernel weights varied within the ranges of 11-19.8 and 6.5-9.2 g.