Heterosis and inbreeding depression in forage sorghum (Sorghum bicolor (L.) Moench)

The present investigation in forage sorghum [Sorghum bleolor (L.) Moench] was carried for studying the magnitude of heterosis and inbreeding depression of fifty hybrids (F1s) and their F2s made by crossing of ten sudan grass restorer lines and 5 cytoplasmic male sterile lines in Line x Tester mating design. Observations were recorded on quantitative and qualitative traits viz., plant height, leaf length, leaf width, fifth ieaf area, stem diameter, total soluble solids (T.S.S.%), protein %, digestibility %, shootfly Infestation, green and dry fodder yield. Variable magnitude of three types of heterosis (better parent, mid-parent and standard) were observed for different cross combinations for all the traits. Based on per se performance and heterotic response for green and dry fodder yield, the best crosses were viz., ICSA 94 x Pant Chari-4, ICSA94 x SDSL92111, ICSA94 x SDSL92113, ICSA94 x SDSL92140, ICSA94 x Selection 984, ICSA95 x ICSV96062 and 296A x SDSL92111. Response of inbreeding depression for these traits was significant in positive direction except T.S.S.%, protein % and shootfly infestation.