D.K.GanguliSurya Prakash2024-07-102024-07-102000https://krishikosh.egranth.ac.in/handle/1/5810211759The present investigation was aimed to evaluate nine white flint inbred lines with the objective of genetical enhancement of maize breeding stock in respect of grain yield and important yield contributing characters. Thirty six crosses were thus developed in half diallel fashion and were evaluated in completely randomized block design with three replication for nine quantitative characters against three check (BM-1, Suwan and Pioneer hybrid-4210) during kharif 98 (Griffing, 1956, method-2) and rabi, 1998-99 (method-4). The F₂ generation along with the parental lines were also evaluated simultaneously during rabi, 1998-99. The analysis of variance revealed highly significant differences among the parental inbred lines for all the characters except for ear length and number of kernel row per ear. However, among the crosses, treatments differences were highly significant for all the characters. The cross mean was more than the parental mean for all the characters except for days to 50 per cent tasseling and moisture percentage. The mean performance of plant characters was observed to be different between kharif and rabi grown crop. The phenotypic and genotypic coefficient of variation (PCV & GCV) were higher in parent than in the crosses for all the characters, except for ear length. A considerable extent of PCV was observed for ear height, grain yield, number of kernels per row and ear length. Heritability estimate (broad sense) was greater in parents than in the crosses for most of the characters except ear length, number of kernel rows per ear and number of kernels per row where reverse was true. Moderate heritability together with high genetic advance was observed in plant height, ear height and 500-kernell weight. A number of crosses showed highly significant positive heterosis over early check variety, BM-1 for grain yield. The cross Dh-539 x Dh-3119 was most heterotic for grain yield over better parent (71.84 %) while Dh-539 x CML-49 was most heterotic over BM-1 (69.40 %) and Suwan (42.68 %). Most of the crosses exhibited negative heterosis over check variety, Suwan, for majority of the characters viz, days to 50 per cent tasseling, plant height, ear height, moisture percentage, ear length and number of kernels per row. The mbining ability studies during kharif revealed preponderance of non-additive gene action for almost all characters except for days to 50 per cent tasseling and ear height (method-2). Through both the method of analysis the character 500-kernel weight and grain yield revealed similar gene effect (non-additive) due to over dominance. Among the parental lines, CML-49 was adjudged to be best general combiner for grain yield while, Dh-3117 for most of the plant characters. The best specific cross combiner for grain yield during kharif were Dh-539 x CML-49, Dh-539 x Dh-3119 and Dh-539 x Dh-3345 and during rabi Dh-541 x CML-49, Dh-543 x Dh-3347 and Dh-534 x Dh-3119 were the best. The estimates of inbreeding depression studied during rabi found to be very low for majority of the characters. However, the performance of F₂'s were found greater than the F₁'s in some crosses for all the characters indicating the presence of additive gene action.EnglishThesis