Combining ability analysis in varietal crosses of fennel (Foeniculum vulgare Millo)

Abstract

Fennel (Foeniculum vulgare Mill), an important spice crop, is being cultivated for its seeds which are used for mastication and chewing. The crop has potential as cash crop in the state of Rajasthan, yet it has not received due attention for its genetic improvement. In the present investigation, an effort was made to study the combining ability effects for yield and its components in fennel. Material for the study comprised of nine genetically diverse varieties (open pollinated populations) namely RF-125, UF(M)-1, UF-90, RF-101, UF-134, JF-29, HF-71, HF-102 and local type. Diallel crosses, excluding reciprocals, were made during rabi 1997-98 and their progenies evaluated in rabi 1998-99. Thirty-six F1S along with their nine parents were evaluated in randomized complete block design with three replications. In each replication, parents and F1S were sown in a plot of 2.0 m x 0.9 m size accommodating two rows of 2.0 meters length spaced 45 cm apart with an intra-row spacing of 20 cm maintained by dibbling. Observations were recorded on ten randomly selected plants from each plot for height up to main umbel (cm), total plant height (cm) branches per plant, umbels per plant, umbellets per umbel, seeds per umbel, biological yield per plant (g), harvest index (%) and seed yield per plant (g) while for days to 50% flowering and test weight (g), the data were recorded on whole plot basis. Data on growth and yield attributes were subjected to the analysis of variance of variety cross diallel and estimation of genetic constants was done as per the method II as enumerated by Gardner and Eberhart [1]. This model assumes that parents used are a fixed set of random mating varieties with no epistasis and diverse gene frequencies. The genetic effects are defined as functions ot gene frequencies and additive and dominance effects for individual loci.