Study on heritability of some growth characteristic of Sorbus torminalis (L.) seedlings

This research was conducted to determine genetic variation and estimate heritability for one mountainous population of wild service tree (Sorbus torminalis (L.) Crantz), named Ashak (2100 to 2300 m.a.s.l) were specified on central Mazandaran forests (Farim). Seeds were collected from twenty healthy mother trees and planted in Orimalek nursery (1550 m.a.s.l). To perform the progeny test, thirty seedlings were used from each one of the mother trees and planted in a randomised complete block design with three replications at beside the Orimalek nursery of Farim Corporation Wood. Ten seedlings from each one of the mother trees were randomly allocated to each replication on a row. Establishment, vigour, collar diameter, height growth and number of branches were recorded on the progenies during the two years period of the experiment. The results indicated that different between genotypes was statically significant (p<0.01) both in first and second year in their progeny collar diameter and height growth. Genetic variance and heritability of height growth was higher than another traits. Heritability of height for the two years were nearly constant. Based on these results according to high heritability of progenies height growth, the genetic variation was high in Ashak population and height would be regarded as more suitable characteristic for increasing the genetic gain by selection in mother trees.