Heritability Estimates of Agronomic Traits and Essential Oil Content in Iranian Fennels

Fennel (Foeniculum vulgare Mill.) benefits from a lot of useful medicinal properties. Iran is known as one of the main producers of fennel. In spite of high medicinal values, fennel’s cultivation is not economically feasible, mainly due to its low yield. It grows wild in different areas in Iran from where diverse ecotypes have evolved. Genetic variance and heritability estimates of traits in a plant’s primary germplasms are needed before planning of a new breeding program. In the present study the genetic diversity and broad sense heritability for 50 fennel ecotypes were assessed under field conditions for a duration of two years. Seed yield, essential oil content and some morphological traits were recorded during a two experimental years. Through stepwise regression, the yield affecting traits and essential oil content were determined. During the first and second experimental years the most effective traits affecting essential oil content were found to be the number of leaves per plant and days to 50% flowering, respectively. The weight of dry biomass affected seed yield the highest during any of the two years and for each separate year. The broad sense heritability during the two experimental years, for essential oil content and seed yield, were 0.46 and 0.63, respectively. However, some such traits as, days to 50% flowering and length of middle internodes showed higher comparative heritability (0.90 and 0.79, respectively). The high heritability of the studied traits in this germplasm indicates the germplasm’s high genetic potential to be made use of in breeding programs.