Traditional knowledge and field marker development for essential oil content using peltate gland trichome and leaf colour in basil (Ocimum basilicum L.)

Abstract

Twenty-six accessions of sweet basil collected from different parts of the country were observed for morphological and quantitative parameters. These accessions were recorded for oil gland type, size of peltate gland (PG), sepal, flower colour, stem girth, branching pattern, growth habits and leaf colour. In addition to that, accessions were observed for herbage parameters viz., maximum plant height, plant spread, stem girth, fresh leaf, dry leaf, herbage and oil yield, and DOB-8W was found superior as compared to checks. Maximum number of PGs on abaxial leaf as compare to adaxial leaf surface were recorded at all the three stages (young, mature and old based on leaf position on axis). Though, formation of PGs takes place in younger leaves only. Number of PGs on abaxial surface of young leaf, green leaf colour and oil content in leaf has positive relationship. The leaf colour intensity (purple) is to be marker character for evaluation of large number of accessions for oil content.