Determination of the genetic variation in Ajowan (Carum Copticum L.) populations using multivariate statistical techniques

Abstract

The experiment was conducted at Urmia University, to assess genetic diversity in populations of Iranian Ajwain based on agronomical and morphological characteristics. Ten populations, collected from different regions, were evaluated in a completely randomised design with eight to ten replications. Various agronomical and morphological characteristics were measured, including stem diameter, plant height, number of branches, number of leaves and leaflets, number of umbels, number of umbellules per inflorescence, number of flowers per umbellule with inflorescence, leaf length, average internodal distance, shoot dry matter, one hundred seed weight, number of seeds, biological production, single plant yield, length of ripening period and harvest index. Among the characteristics studied, a high coefficient of variation was observed for the number of seeds (197.58), single plant yield (57.56) and shoot dry matter (56.28). Broad-sense heritability for all of the characteristics studied was moderate to high, and varied from 0.41 to 91% with the exception of the number of branches, length and ripening period, which had low broad-sense heritability. Cluster analysis using Ward’s method classified ten populations of Ajwain into four groups. Principal Component Analysis (PCA), using 18 agronomical and morphological characteristics, indicated that the first two principal components (PCs) with eigenvalues of more than one, accounted for 74.5% of the total variance. The results of the PCA were consistent with those of the cluster analysis. The present study demonstrates that populations of Ajwain from Iran displayed a considerable diversity of agronomical and morphological characteristics that are useful in germplasm management and for utilisation in improvement programs.