Heterosis, lipid profile and lignan glycosides assessment in raised inter-varietal promising hybrids of sesame (Sesamum indicum L.; Pedaliaceae)

Abstract

Seven desirable hybrids (based on fatty oil content) namely RTH2, RTH5 and RTH7 (roma × tilottama), SRH1, SRH2, SRH3 (savitri × roma) and STH2 (savitri × tilottama) of Sesamum indicum L. (Family: Pedaliaceae; commonly known as sesame, an important oil seed crop of commerce) are selected from twenty intervarietal hybrids (tilottama — black seed coat; roma — brown seed coat and savitri — white seed coat) raised through natural crossing following interplanting (15 cm and 30 cm between plants and rows respectively). Seed coat color is used as marker trait for hybrid identification. Heterosis (mid parent heterosis, heterobeltosis and standard heterosis) is measured in F1, F2 and F3 (raised following selfing) generations considering seed yield and yield contributing (plant height, number of primary and total branches per plant, capsules per plant and seeds per capsule) traits. Considering heterosis and inbreeding depression it seems that RTH2 is the most promising hybrid. F3 harvested seeds are used to assess fatty acid profile and oil soluble lignan contents (sesamin and sesamolin detected from virgin sesame oil) in the studied hybrids. Result highlights the following: (1) significant enhancement in seed yield across generations in RTH2, RTH5 and SRH3, (2) identification of behenic acid (C22:0) fraction pioneerly in sesame fatty oil (tilottama, roma, savitri, RTH5 and RTH7), (3) SRH2 hybrid shows most promising fatty acid profile comprising of balance proportion of ω-6:ω-9 fatty acid (1:1) and enhance ω-3 fatty acid content desirable for human health and (4) SRH1 hybrid as the most promising germplasm in relation to dietary lignan content. Pure lines of the hybrids in later segregating generation can be more desirable for commercial exploitation.