Pollination ecology and flowering rhythm of Gloriosa superba L.: Behavioural insights into principal pollinators

Gloriosa superba L. (Glory lily), is an endangered medicinal plant valued for its high colchicine content. Understanding the floral biology and pollination ecology of G. superba is crucial for identifying factors limiting seed setting. This study was carried out at Dr. YS Parmar University of Horticulture and Forestry, Solan, Himachal Pradesh, India, during 2021-2022, focusing on G. superba’s floral biology and pollinator activity from anthesis to senescence. The scarlet red flowers were born on pedicels, with tepals measuring 6.69 × 1.45 cm tepal and a mean weight of 1.72 ± 0.04 mg. Pollen viability was highest on the one day after anthesis and stigma receptivity peaked on the day of anthesis. Among nine flower stages, nectar volume and nectar sugar concentrations were maximum at 6th and 7th stages, respectively. Three kinds of insect floral visitors viz., allotrophous, hemitrophous and eutrophous from 6 orders, 14 families and 16 genera were recorded. The Shannon, Simpson, dominance and Margalef richness indices during 2021 and 2022 were 2.58, 0.16, 0.83 and 1.3 and 2.15, 0.22, 0.83 and 1.22, respectively. Fruit set (86.45 ± 0.21 %), pod length (7.24 ± 0.23 cm) and colchicine percentage were highest in hand pollination. However, test weight (2.02 ± 0.01 g), germination percentage (77.98 ± 0.26 %) and colchicine percentage in seed under honeybee pollination were statistically similar to blower-assisted pollination.