The effect of different height reducing genes on the early growth of wheat
Marc H. Ellis A B C , Greg J. Rebetzke A , Peter Chandler A , David Bonnett A B , Wolfgang Spielmeyer A B and Richard A. Richards AA CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia.
B Graingene, 65 Canberra Avenue, Griffith, ACT 2603, Australia.
C Corresponding author; email: marc.ellis@csiro.au
Functional Plant Biology 31(6) 583-589 https://doi.org/10.1071/FP03207
Submitted: 30 October 2003 Accepted: 13 February 2004 Published: 23 June 2004
Abstract
Genes that reduce height without compromising seedling vigour or coleoptile length have great potential for wheat improvement. We therefore investigated the effects of various reduced height (Rht) genes on the early stages of plant development, using a combination of near isogenic, recombinant, mutant and wild type comparisons. Gibberellin (GA) insensitivity caused by Rht-B1b or Rht-D1b was associated with reduced leaf elongation rate and coleoptile length. Similar results were found for two other sources of dwarfing, Rht11 and Rht17. We found one class of Rht genes (e.g. Rht8) which had no effect on coleoptile length, leaf elongation rate or responsiveness to GA, indicating that these dwarfing genes may act later in wheat development to reduce height and increase harvest index, without affecting early growth. A third class of Rht genes was found in three durum backgrounds. These had reduced coleoptile lengths and leaf elongation rates, but had a greater response to GA than the corresponding tall varieties. We discuss these results in relation to the possible mechanisms underlying the reduction in height and the suitability of the different Rht genes for wheat improvement.
Keywords: coleoptile length, dwarfing genes, GA response, gibberellins.
Acknowledgments
We thank Jen Price for technical support. This work is supported by Graingene, a research joint venture between AWB limited, CSIRO, GRDC and Syngenta seeds.
Allan RE
(1989) Agronomic comparisons between Rht1 and Rht2 semi-dwarf genes in winter wheat. Crop Science 29, 1103–1108.
Bonnett DG, Ellis MH, Rebetzke GJ, Condon AG, Spielmeyer W, Richards RA
(2001) Dwarfing genes in Australian wheat — present and future. ‘Proceedings 10th Australian Wheat Breeders Assembly, 16–21 September, 2001’. Mildura.
Chandler PM, Robertson M
(1999) Gibberellin dose-response curves and the characterisation of dwarf mutants of barley. Plant Physiology 120, 623–632.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Ellis MH,
Spielmeyer W,
Rebetzke GJ, Richards RA
(2002) ‘Perfect’ markers for the Rht-B1b and Rht-D1b dwarfing genes in wheat. Theoretical and Applied Genetics 105, 1038–1042.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Evans, LT (1993).
Gale MD, Youssefian S, Russell GE
(1985) Dwarfing genes in wheat. ‘Progress in plant breeding 1’. pp. 1–35. (Butterworths: London)
Konzak CF
(1982) Evaluation and genetic analysis of semi-dwarf mutants of wheat. ‘Semi-dwarf cereal mutants and their use in cross-breeding’. Research coordination meeting 1981. (International Atomic Energy Agency: Vienna, Austria)
Konzak CF
(1988) Genetic analysis, genetic improvement and evaluation of induced semi-dwarf mutants in wheat. ‘Semi-dwarf cereal mutants and their use in cross-breeding III’. Research coordination meeting, 1985., pp. 39–50. (International Atomic Energy Agency: Vienna, Austria)
Konzak CF, Wilson MR, Franks PA
(1984) Progress in the evaluation, use in breeding, and genetic analysis of semidwarf mutants of wheat. ‘Semi-dwarf cereal mutants and their use in cross-breeding II’. Research coordination meeting, 1982., pp. 39–50. (International Atomic Energy Agency: Vienna, Austria)
Lorenzetti, R (2000).
Peng J,
Richards DE,
Hartley NM,
Murphy GP, Devos KM ,
et al
.
(1999) ‘Green revolution’ genes encode mutant gibberellin response modulators. Nature 400, 256–261.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Pinthus MJ, Gale MD
(1990) The effects of ‘gibberellin-insensitive’ dwarfing alleles in wheat on grain weight and protein content. Theoretical and Applied Genetics 79, 108–112.
Rebetzke GJ,
Richards RA,
Fischer VM, Mickelson BJ
(1999) Breeding long coleoptile, reduced height wheats. Euphytica 106, 159–168.
| Crossref | GoogleScholarGoogle Scholar |
Rebetzke GJ,
Appels R,
Morrison AD,
Richards RA,
McDonald G,
Ellis MH,
Spielmeyer W, Bonnett DG
(2001) Quantitative trait loci on chromosome 4B for coleoptile length and early vigour in wheat (Triticum aestivum L.) Australian Journal of Agricultural Research 52, 1221–1234.
| Crossref | GoogleScholarGoogle Scholar |
Rebetzke GJ, Richards RA
(2000) Giberellic acid-sensitive dwarfing genes reduce plant height to increase kernel number and grain yield of wheat. Australian Journal of Agricultural Research 51, 235–246.
| Crossref | GoogleScholarGoogle Scholar |
Richards RA
(1992) The effect of dwarfing genes in spring wheat in dry environments. I. Agronomic characteristics. Australian Journal of Agricultural Research 43, 517–527.
SAS Institute Inc. (1990).
Spielmeyer W, Bonnett D, Ellis M, Rebetzke G, Richards R
(2001) Implementation of molecular markers to improve selection efficiency in CSIRO wheat breeding program. ‘Proceedings 10th Australian Wheat Breeders Assembly, 2001’. (Wheat Breeding Society of Australia)
Spielmeyer W,
Ellis MH, Chandler PM
(2002) Semidwarf (sd-1), ‘green revolution’ rice, contains a defective gibberellin 20-oxidase gene Proceedings of the National Academy of Sciences USA 99, 9043–9048.
| Crossref | GoogleScholarGoogle Scholar |
Worland AJ,
Law CN, Shakoor A
(1980) The genetical analysis of an induced height mutant in wheat. Heredity 53, 61–71.
Worland AJ,
Sayers EJ, Börner A
(1994) The genetics and breeding potential of Rht12, a dominant dwarfing gene in wheat. Plant Breeding 113, 187–196.
