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The role of the homeotic gene Ultrabithorax in regulating signaling pathways during haltere development in embryos of Drosophila is studied.

An investigation was carried out to study the narrow sense heritability, correlation and path coefficient analysis for 11 characters on 45 maize hybrids, their 10 parents along with 2 standard checks during Kharif 2011. Analysis of variance revealed that mean sum of squares due to genotypes showed significant differences for all the 11 characters studied. Magnitudes of genotypic correlations were found to be higher than phenotypic correlations. The results indicated that grain yield was positively and significantly associated with 100-seed weight, ear girth, number of kernels per row, ear length, plant height and ear height. Days to silking had largest direct effect on grain yield per plant followed by number of kernels per row, 100-seed weight and ear girth. High narrow sense heritability estimates were recorded in days to tasseling, days to silking, ear height, number of kernels per row, 100-seed weight, ear girth, days to maturity, ear length and grain yield per plant. Thus, these traits are predominantly under the control of additive gene action and hence these characters can be improved by selection. [ABSTRACT FROM AUTHOR]

Combining ability analysis for yield and its component traits in maize was performed with 10 parents and the resulting 45 hybrids using diallel cross analysis (excluding reciprocals) in three locations. The results of combining ability analysis revealed significant mean squares due to general and specific combining ability indicating that both additive and non-additive gene actions were important in the inheritance of characters studied. Variances due to specific combining ability (sca) were larger than general combining ability (gca) for all the characters indicating the predominance of non-additive gene action in the expression of various traits. The parents BML-6, BML-7 and BML-5233-5 were good general combiners for yield and majority of the traits over the locations. Hence, these parents can be used in crossing and further exploited for improvement of traits in the population. BML-5233-5 and BML-2 are good general combiners among the parents for earliness i. e. days to 50% tasseling, days to 50% silking and days to maturity. Whereas the hybrids BML-15 × BML-2910, BML-6 × BML-3044, BML-2782 × BML-7, BML-7 × BML-3044 and BML-2486 × BML-3044 were identified as potential ones for yield and yield components based on high sca effects along with high per se performance. These hybrids may be exploited for commercial cultivation by testing them over locations and years for their yield stability. [ABSTRACT FROM AUTHOR]