Diversity of Ethiopian sweet basil (Ocimum basilicum L.) germplasm for quantitative morphological traits

Abstract

In Ethiopia sweet basil has been used for thousands of years as a culinary and medicinal herb. Although sweet basil is distributed widely throughout the county and boasts of centuries of cultivation and selection, the extent of morphological diversity is not well investigated. Therefore, the objective of this study was to evaluate the morphological variability of sweet basil using quantitative morphological traits. Forty-nine accessions of basil were used in a 7 × 7 simple lattice design. Except for flowering stem length, which was extremely significant (P<0.01), fresh leaf weight, and seed weight, all morphological variables were shown to be very highly significant (P<0.001) by analyses of variance. The first four principal components were able to explain 75.53% of the total variation. Cluster analyses based on quantitative traits revealed four distinct clusters. The first, second, third, and fourth clusters consisted of 2.04, 44.9, 48.98, and 4.08% of the accessions, respectively. The highest inter-cluster distance was recorded between cluster III and cluster IV (351.5). The minimum inter-cluster distance was noted between cluster II and cluster IV (87.21). The maximum and minimum intra-cluster distances were recorded within clusters IV (84.18) and I (0). The intra and inter-cluster distance ranges were 0 to 84.18 and 87.21 to 351.5, respectively. Thus, the current study reveals that Ethiopian basil germplasm exhibits substantial genetic variability for a variety of horticulturally significant features that might be used in future breeding and conservation initiatives to increase the yield of sweet basil's essential oils and herbal products.