KULDEEP SINGH DANGICHANDRESH SINGH GAUTAM2016-08-042016-08-042009http://krishikosh.egranth.ac.in/handle/1/70775The present investigation on “Heterosis and combining ability studies in castor (Ricinus communis L.)” was carried out using 39 hybrids generated in a line x tester design using three lines (DPC-9,DPC-17 and M-568) and 13 testers (DCS-9, DCS-92, DCS-93, DCS-94, DSC-96, DCS-97, DCS-98, DCS-103, DCS-104, DCS-106, KIRAN, RG-1582-1 and RG-1582-2) in rabi 2007-08. All the 39 hybrids along with two standard checks-DCH-177 and DCH-519 were evaluated in a RBD with two replications at Directorate of Oilseeds Research, Rajendranagar during kharif, 2008-09. The genotypes were evaluated for 13 characters viz., number of nodes to primary spike, number of nodes to secondary spike-1 (S1), number of nodes to secondary spike-2 (S2), plant height (cm), total length of primary spike (cm), effective length of primary spike (cm), number of capsules per primary spike, number of effective spikes per plant,100- seed weight (g), cumulative seed yield at first, second and final picking (kg/ha) and oil content (%). The data were analysed for estimation of combining ability, heterosis, correlation and path analysis using standard statistical procedures. Combining ability analysis revealed DPC-9 a good general combiner for final seed yield, and short plant height. The line M-568 was a good general combiner for plant height, total and effective length of primary spike, number of capsules per primary spike and seed yield in first picking. Eight hybrids viz., DPC-9 x DCS-92, DPC-9 x DCS-94, DPC-9 x DCS-104, DPC-9 x Kiran, DPC-17 x DCS-98,DPC-17 x DCS-106, M-568 x DCS-93 and M-568 x DCS-103 were good specific combiners for seed yield in all the three pickings. Five hybrids viz., M-568 x DCS-96, DPC-9 x DCS-94, DPC-9 x DCS-104, DPC- 17 x DCS-91 and DPC-9 x DCS-97 were significantly superior over the checks for cumulative final seed yield. The hybrid M-568 x DCS-96 with maximum standard heterosis over both the checks DCH-177 (20.9) and DCH-177 (30.6%) was also heterotic for number of capsules per primary spike and oil content. Other heterotic hybrids viz., DPC-9 x DCS-104, DPC-17 x DCS-91 were also superior to the hybrid DCH-177 for oil content. In the present investigation, oil content (%) was negatively correlated with seed yield in all the three pickings but had positive association with other yield contributing characters. The path coefficient analysis revealed that total spike length, number of capsules per primary, seed yield in second picking were direct contributors to final seed yield. Indirect effects were indicated by total spike length, through number of nodes to secondary spike1, secondary spike 2, plant height, effective spike length, number of capsules and oil content; number of capsules per primary through number of nodes to primary, plant height, total and effective spike length, seed yield in first, second picking and oil content; oil content through number of effective spikes, 100- seed weight, seed yield at first and second picking to the final seed yield. The traits number of nodes to secondary spike 1, secondary spike 2, seed yield in first and second picking had net significant positive genotypic effect on final seed yield while, number of effective spikes per plant and oil content was having significant negative genotypic effect on final seed yield. Based on per se performance, sca effect and standard heterosis over the checks, five hybrids viz., M-568 x DCS-96, DPC-9 x DCS-94, DPC-9 x DCS-104, DPC-17 x DCS-91 and DPC-9 x DCS-97 can be identified for commercial exploitation of heterosis in castor after confirmation in multilocation trials.enHETEROSIS, COMBINING, ABILITY, STUDIES, CASTORThesis