Heterosis and combining ability in diallel crosses involving maize (Zea mays) S1 lines
M. M. Muraya A B , C. M. Ndirangu A and E. O. Omolo A
A Department of Agronomy, Egerton University, P.O. Box 536, Njoro, Kenya.
B Corresponding author. Email: email@example.com
Australian Journal of Experimental Agriculture 46(3) 387-394 http://dx.doi.org/10.1071/EA03278
Submitted: 26 December 2003 Accepted: 9 September 2005 Published: 28 March 2006
This study was conducted at Egerton University, Njoro, Kenya for 2 growing seasons, 2001 and 2002. A diallel cross, without reciprocal crossings, involving 7 maize S1 lines: KSTP001, KSTP003, KSTP004, KSTP005, KSTP008, E2 and E3 was used to study the heterosis and inheritance of days to 50% flowering, plant height, ear height, leaf angle, number of leaves per plant, leaf area index, cob length, cob diameter, number of lines per cob, number of seeds per line, 100-grain weight and grain yield. A randomised complete block design with 3 replicates was used. Analysis of variance was conducted on the data generated at 0.05 significant level using MSTAT. The results showed that general combining ability (GCA) and specific combining ability (SCA) was significant (P<0.05) for all traits under study, suggesting existence of both additive and non-additive gene effects for the traits. However, GCA : SCA ratio was >1 for all traits except cob diameter and 100 seed weight, indicating preponderance of additive gene effects for inheritance of these traits. The study identified KSTP003 as the best combiner for most of the traits, while KSTP001 and E3 was the best combination for most traits. KSTP004 and E3 was good combiner for grain yield. Hybrid KSTP005 × E3 was the best cross for grain yield. KSTP003 × E2 was the best cross for reduction of leaf angle thus good source for erectophile canopies in a hybridisation program. Heterosis estimates showed that heterosis was more important in grain yield, yield components, plant height, number of leaves per plant and, leaf area index than other traits studied. Most of traits studied had a positive and significant (P≤0.01), while all traits studied except days to 50% flowering had a positive and significant (P≤0.01) genotypic correlations. It is recommended that based on their combining ability the lines be recombined to form synthetic maize varieties which can be released both as a variety or used for further improvement using recurrent selection. The lines which combine well for reduction in leaf angle from vertical should be utilised to develop erective maize varieties.
Additional keyword: inheritance.
A diallel anaylsis of yield related traits in crosses involving two-row and six-row barleys.
East African Agricultural and Forestry Journal
Gene effects estimated from generation means in four diallel sets of maize inbreds.
Combining ability analysis of resistance of sorghum to shootfly.
Indian Journal of Genetics
Gene effects in corn (Zea mays L.). I. Separation and relative importance of gene effects for yield.
Canadian Journal of Plant Science
Response to S1 selection in flint and synthetic maize populations.
Diallel analysis of resistance to gray leaf spot in maize.
Does over-dominance exist for yield in corn?
Concept of general and specific combining ability in relation to diallel crossing systems.
Australian Journal of Biological Sciences
A generalised treatment of the use of diallel cross in quantitative inheritance.
Hallauer AR, Miranda JB (1988) ‘Quantitative genetics in maize breeding.’ 2nd edn. (Iowa State University Press: Iowa)
Genetic, phenotypic and environmental correlations in black medic, Medicago lupulina L., grown in three different environments.
Theoretical and Applied Genetics
Combining ability for grain weight in cowpea.
Indian Journal of Genetics and Plant Breeding
Combining ability for maize weevil preference of maize grain.
Loomis RS, Connor DJ (1992) ‘Crop ecology: productivity and management in agricultural systems.’ (Cambridge University Press: Cambridge)
Heterosis in inter-varietal crosses in maize and it implication in breeding procedures.
Diallel analysis of maize for leaf angle, leaf area, yield and yield components.
Moll RH, Stuber CW (1974) Quantitative genetics — empirical results relevant to plant breeders. In ‘Advances in agronomy’. (Ed. NC Brady) pp. 277–313. (Academic Press: New York)
Components of yield and over-dominance in corn.
Combining ability analysis and relationship among yield, yield components and architectural traits in dry bean.
Heterosis and combining ability in a diallel among 8 elite maize population.
African Crop Science Journal
Field investigations of the relationship of leaf angle in corn (Zea mays L.) to grain yield and apparent photosynthesis.
Estimates of heritability and the degree of dominance in corn.
A comparison of variance components in corn yield trials. III. General and specific combining ability and their interactions with locations and years.
Shewangizaw A (1983) Heterosis and combining ability in a 7 × 7 diallel cross of selected inbred lines of maize (Zea mays L.). M.Sc. thesis, Addis Ababa University, Ethiopia.
Diallel study of open-pollinated maize varieties in Trinidad.
General versus specific combining ability in single crosses of corn.
Journal of American Society of Agronomy
Evaluation of the performance and combining ability of selected lines derived from improved maize populations.
Inbred lines as testers for general combining ability in maize.
Crop Science Journal