KULDEEP SINGH DANGISANTHOSH KUMAR, B2016-10-102016-10-102015http://krishikosh.egranth.ac.in/handle/1/80322The present investigation entitled “Combining ability studies in new promising hybrids in rice (oryza sativa L.)” was carried out at R.A.R.S, Polasa, Jagtial.With the aim to identify promising hybrids. The main objectives of the investigation were to study the combining ability of parents and the crosses to identify superior parents and hybrids. Besides magnitude of heterosis, heterobeltiosis and standard heterosis, were also estimated. The study also aimed to asses the physical grain quality traits of the hybrids and identification of hybrids with gall midge resistance. Four CMS lines were crossed with nine testers and the resultant 36 crosses along with the parents and two checks viz., Samrat and 27P31 were evaluated for combining ability (Line x Tester design), heterosis and grain quality traits at R.A.R.S, Polasa, Jagtial during kharif, 2014. Combining ability effects were studied and heterosis was estimated for the various characters like days to 50% flowering, plant height, panicle length, number of productive tillers per plant, number of tillers per plant, spikelet fertility, 1000 grain weight, incidence of gall midge, kernel length, kernel breadth, L/B ratio, hulling percentage, milling percentage and head rice recovery. The analysis of variance for yield contributing and physical grain quality characters revealed significant difference among the treatments for all the characters under study. In case of replications, for most of the characters, there were no significant differences except for, panicle length, incidence of gall midge, hulling and milling percentage, which signifies that the differences were mainly due to the genotypes. So, further study of these genotypes for combining ability can be continued. The gca effects of the parents revealed that the lines viz., CMS 46A and CMS 11A and the testers viz., JGL-20779, JGL-18047, JGL-20171 were promising general combiners for single plant yield.Based on significant sca effects, six cross combinations viz., CMS 46A x JGL-20779, CMS 11A x JGL-20779, CMS 11A x JGL-21820, CMS 46A x JGL-18222, CMS 46A x JGL-21820 and JMS-1 x JGL-20779 appeared promising for grain yield. The physical grain quality traits like kernel length, kernel breadth, L/B ratio, hulling and milling percentage, head rice recovery, was studied and it was found that among the lines, CMS 46A line had maximum hulling, milling and head rice recovery. Among the testers, JGL-20779 recorded maximum hulling, milling, head rice recovery percentage. Among the crosses CMS 23A x JGL-20171 was the best hybrid for hulling, milling, and head rice recovery percentage. Heterosis for single plant yield was mainly because of simultaneous manifestation of heterosis for yield component traits. Of the 36 hybrids studied, the significant positive standard heterosis over the best check Samrat, was observed in three hybrids, These hybrids are, CMS 46A x JGL-20779(15.30), CMS 11A x JGL-20779 (13.88), CMS 11A x JGL-21820(11.03). The best hybrid identified was CMS 46A x JGL-20779, which had highest single plant yield of (32.4 g/plant), short duration (123 days) and L/B ratio (3.19) which indicates the fitness of the grain, highly preferred by consumers of Telangana. Further, it showed lower susceptible reaction to gall midge at Jagtial. Another hybrid CMS 11A x JGL- 21820 with short duration (125 days) gall midge resistance and higher single plant yield (31.2 g/plant) and L/B ratio is (2.36) also appeared to be promising. Another hybrid CMS 23A x JGL-21820 with short duration (121 days) gall midge resistance and higher single plant yield (27.7 g/plant) and L/B ratio is (2.67) also appeared to be promising.enhybrids, rice, yields, grain, developmental stages, heterosis, planting, biological phenomena, genes, crossing overThesis