Cotyledon persistence and seedling growth in fluted Pumpkin (<i>Telfairia occidentalis</i> Hook. F.)

Abstract

Photosynthetic activity of exposed cotyledons of Telfairia occidentalis during seed germination and the growth of seedlings with removed or attached cotyledons were investigated. The experiment  investigated how early cotyledon removal affects seedling growth. Seedlings from seeds germinated in light and those  germinated in the dark were compared four weeks after germination. The effects of removal of cotyledons on seedling growth were also investigated with  cotyledons removed at different times and from different seed sizes in order to assess the effect of time of removal and seed sizes on seedling growth. Biomass accumulation of the different plant parts, number of leaves and root/shoot ratio were used to assess the relative importance of cotyledon photosynthesis and  cotyledon storage reserves to seedling growth. The cotyledons which are predominantly for storage were found to have a minimal photosynthetic function. Telfairia seedling biomass was significantly reduced (P<0.05) by removal of the cotyledon. Seed size and morphotype influenced the effect of cotyledon removal on seedling growth. The time of cotyledon removal affected all growth parameters negatively with greatest effect on removal at the first week of growth. Cotyledon reserves  support seedling growth of Telfairia occidentalis, and ability to cope with loss of cotyledon is affected by factors such as seed size, morphotype and time of  removal.

Keywords: Storage reserves, cotyledon removal, hypogeal, morphotype, Telfairia occidentalis.