Agro morphological and phenotypic variability of sweet basil (Ocimum basilicum L.) genotypes for breeding purposes

Abstract

The genus Ocimum is very complicated due to the presence of huge morphological variability along with genetic diversity. Basil (Ocimum basilicum L.) has pharmacological properties like headaches, coughs, diarrhea, constipation, warts, worms, kidney malfunction, and its potential as a therapeutic agent in treating various age-related diseases. The present investigation comprised of sixty-one genotypes of basil was undertaken to characterize the genotypes based on morphological and phenological features, herbs and essential oil yield of genotypes. A wide range of variations for traits like days to first cutting (56.92-101.6), plant height (13.67-71.90 cm), branch number (3.28-19.43 number/plant), fresh herb yields (12.94-274.11 g/plant), and essential oil yield (0.04-1.71%) were observed and can be useful for breeding purposes. PI 652070 and PI 296391 genotypes were found superior in case of the highest herbs yield as compared with other genotypes. Overall, in PI 358469 and Ames 32309 genotypes exhibited the highest essential oil content. The constellation analysis was conducted to investigate the genetic diversity of basil genotypes. According to the constellation plot analysis, leaf shape and color were evaluated in 2017 and most of the basil genotypes located in the same main group. In 2018, moonlight and dino cultivars located in the same cluster 1 (C1) with PI 141198 (US/Maryland) genotype and Georgia genotypes located in the same main group and they also took place in the sub-main group except Ames 32314 genotype depending on UPOV criteria. Each two years, Bolu genotype and midnight were found in the same main group.