This study was undertaken to develop a fast and reliable nutrient solution technique to screen grain sorghum genotypes for aluminum (Al) tolerance, and to study the gene system controlling the inheritance of Al tolerance in grain sorghum. Twenty-five sorghum genotypes representing a wide range of environmental adaptation were grown in tanks (120 seedlings/tank, approximately 303.0 ml/seedling) of nutrient solution containing 148 uM liter⁻¹ Al. Relative root lengths (RRL) as well as visual symptoms of injury on roots and leaves were the parameters used in evaluating differential Al response of sorghum genotypes. A highly significant negative correlation coefficient was found between RRL and visual symptoms on roots (r = -0.96). Eleven out of the 25 genotypes behaved as Al tolerant and the remaining behaved as Al sensitive. A half-diallel cross involving three Al-tolerant and three Al-sensitive genotypes as identified through the screening test were used to study the gene system controlling the inheritance of Al tolerance in grain sorghum. The F₁ and parents data were analyzed using both Griffing's and Jinks-Hayman methods of diallel analyses. Highly significant GCA and SCA effects were observed for the Al-tolerance trait. The GCA effects were much more important than SCA effects, with the ratio of GCA:SCA being 9:1. From the Vr, Wr graphs the Al-tolerance trait showed predominantly additive genetic effects with some degree of dominance. The six parents fell into four groups according to the relative level of dominance: (1) highly dominant (AR 3010, CI 182); (2) moderately dominant (NB 9040); (3) moderately recessive (Texas Blackhull); and (4) highly recessive (AR 3001 and AR 3006). The degree of dominance was observed to be partial. F₂ populations screened for Al tolerance showed two distinct classes of tolerance with segregating ratios of tolerant:sensitive seedlings of 3:1. This segregation indicated that the Al-tolerant trait was simply inherited, but a wide range of tolerance for Al observed among the 25 genotypes suggested a more complex gene system. Heritability of Al tolerance was very high. The narrow sense and broad sense heritabilities were 77.69% and 99.54%, respectively. These results suggested that a breeding method emphasizing additive gene effects would be favorable in developing Al-tolerant inbred lines.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/183772 |
| Date | January 1982 |
| Creators | BOYE-GONI, SYLVESTER RUTHERFORD. |
| Contributors | Webster, Orrin J., Voigt, Robert, Bemis, William P., Dobrenz, Albert K., Bartels, Paul G. |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | English |
| Detected Language | English |
| Type | text, Dissertation-Reproduction (electronic) |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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