Abstract
Earlier studies showed that the ratio of the weight of the wheat ear to stem at anthesis (ear:stem ratio) may give a better indication of potential yield than harvest index because it is determined early in the life cycle and is not affected by post anthesis stress. These studies concluded that selection for high ear:stem ratio at anthesis may lead to further improvement in grain yield of wheat. The present work was undertaken in the field to identify lines varying in ear:stem ratio in breeding populations and to study its implications for yield improvement.
At anthesis stem length, ear length, tiller number, dry weight of stem and ear and ear:stem ratio were measured in 14 crosses on F2 single plants and F2 derived lines grown in the F3, F4, and F5 at three locations in Western Australia over four seasons. In addition, biomass, grain yield and yield components were measured on selected crosses at two locations on F2 derived lines grown in the F4 and F5. There was a considerable range of ear:stem ratio between and within the crosses studied. Although ear:stem ratio was strongly correlated with stem length, there was substantial variation within stem length classes. Ear:stem ratio had a high mean broad sense heritability (82%), whereas HI, grain yield and above ground biomass had lower heritabilities, 68, 55 and 35% respectively. Ear:stem ratio was strongly correlated between generations and sites indicating stability of this character. Ear:stem ratio had a significant positive correlation with grain yield, HI, grains per ear and per m2. The correlation of grain yield with HI was equal or slightly higher than that of grain yield with ear:stem ratio.
Ear:stem ratio offers promise as a predictor of HI and yield potential where post-anthesis moisture stress can influence HI. Ear:stem ratio measurement is unlikely to be adopted for selection purposes in routine breeding programs, as it is laborious and time consuming. However, ear:stem ratio could be used to identify superior parental genotypes and early generation selections from special crosses in terms of its ability to partition assimilate.
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References
Austin R.B., 1989. Genetic variation in photosynthesis. J. Agric. Sci. 112: 287–294.
Austin R.B., J. Bingham, R.D. Blackwell, L.T. Evans, M.A. Ford, C.L. Morgan & M. Taylor, 1980. Genetic improvements in winter wheat yields since 1900 and associated physiological changes. J. Agric. Sci. 94: 675–689.
Bhatt G.M., 1977. Response to two-way selection for harvest index in two wheat (Triticum aestivum L.) crosses. Aust. J. Agric. Res. 28: 29–36.
Brooking I.R. & E.J.M. Kirby, 1981. Interrelationships between stem and ear development in winter wheat: the effects of a Norin 10 dwarfing gene, Gai/Rht 2. J. Agric. Sci. 97: 373–381.
Donald C.M. & J. Hamblin, 1976. The biological yield and harvest index of cereals as agronomic and plant breeding criteria. Adv. Agron. 28: 361–405.
Evans L.T., 1987. Opportunities for increasing the yield potential of wheat, pp. 79–96. In: The future development of maize and wheat in the third world. CIMMYT, Mexico, D.F.
Evans L.T. & R.L. Dunstone, 1970. Some physiological aspects of evolution in wheat. Aust. J. Biol. Sci. 23: 725–741.
Fischer R.A. & F. Kertesz, 1976. Harvest index in spaced populations and grain yield in microplots as indicators of yielding ability in spring wheat. Crop Sci. 16: 55–59.
Fischer R.A. & Y.M. Stockman, 1986. Increased kemel number in Norin 10-derived dwarf wheat: evaluation of the cause. Aust. J. Plant Physiol 13: 767–748.
Gleeson A.C. & B.R. Cullis, 1987. Residual maximum likelihood (REML) estimation of a neighbour model for field experiments. Biometrics 43: 277–288.
Hadjichristodoulou A., 1991. The relationship of grain yield with harvest index and total biological yield of barley in drylands. Technical Bulletin No. 126. Agricultural Research Institute, Nicosia, Cyprus.
Passioura J.B., 1977. Grain yield, harvest index and water use of wheat. J. Aust. Inst. Agric. Sci. 43: 117–120.
Patterson H.D. & R. Thompson, 1971. Recovery of interblock information when block sizes are unequal. Biometrika 58: 545–554.
Perry M.W. & M.F. D'Antuono, 1989. Yield improvement and associated characteristics of some Australian spring wheats introduced between 1860 and 1982. Aust. J. Agric. Res. 40: 457–472.
Regan K.L., K.H.M. Siddique, N.C. Turner & B.R. Whan, 1992. Potential for increasing early vigour and total biomass in spring wheat. II. Characteristics associated with early vigour. Aust. J. Agric. Res. 43: 541–553.
Robinson D. & P.G.N. Digby, 1987. REML-Residual maximum likelihood program. Edinburgh: Scottish Agricultural Statistics Service.
Rosielle A.A. & K.J. Frey, 1975a. Estimates of selection parameters associated with harvest index in oat lines derived from bulk population. Euphytica 24: 121–131.
Rosielle A.A. & K.J. Frey, 1975b. Application of restricted selection indices for grain yield improvement in oats. Crop Sci. 15: 544–547.
Rosielle A.A. & K.J. Frey, 1977. Inheritance for harvest index and related traits in oats. Crop Sci. 1117: 23–28.
Sharma R.C. & E.L. Smith, 1986. Selection for high and low harvest index in three winter wheat populations. Crop Sci. 26: 1147–1150.
Siddique K.H.M., E.J.M. Kirby & M.W. Perry, 1989a. Ear:stem ratio in old and modern wheat varieties. Relationship with improvement in number of grains per year and yield. Field Crops Res. 21: 59–78.
Siddique K.H.M., R.K. Belford, M.W. Perry & D. Tennant, 1989b. Growth, development and light interception of old and modern wheat cultivars in a Mediterranean-type environment. Aust. J. Agric. Res. 40: 473–487.
Siddique K.H.M., D. Tennant, M.W. Perry & R.K. Belford, 1990a. Water use and water use efficiency of old and modern wheat cultivars in a Mediterranean-type environment. Aust. J. Agric. Res. 41: 437–447.
Siddique K.H.M., R.K. Belford & D. Tennant, 1990b. Root:shoot ratios of old and modern, tall and semi-dwarf wheats in a Mediterranean environment. Plant and Soil 121: 89–98.
Slafer G.A., F.H. Andrade & E.H. Satorre, 1990. Genetic-improvement effects on pre-anthesis physiological attributes related to wheat grain yield. Field Crops Res. 23: 255–263.
Slafer G.A. & F.H. Andrade, 1993. Physiological attributes related to the generation of grain yield in bread wheat cultivars released at different eras. Field Crops Res. 31: 351–367.
Waddington S.R., J.K. Ransom, M. Osmanzai & D.A. Saunders, 1986. Improvement in the yield potential of bread wheat adapted to Northwest Mexico. Crop. Sci. 26: 698–703.
Whan B.R., A.J. Rathjen & R. Knight, 1981. The relation between wheat lines derived from the F2, F3, F4 and F5 generations for grain yield and harvest index. Euphytica 30: 419–429.
Whan B.R., G. Knight & A.J. Rathjen, 1982. Response to selection for grain yield and harvest index in F2, F3 and F4 derived lines of two wheat crosses. Euphytica 31: 139–150.
Whan B.R., G.P. Carlton & W.K. Anderson, 1991. Potential for increasing early vigour and total biomass in spring wheat. I. Identification of genetic improvements. Aust. J. Agric. Res. 42: 347–361.
Whan, B.R., G.P. Carlton, K.H.M. Siddique, K.L. Regan, N.C. Turner & W.K. Anderson, 1992. Integration of breeding and physiology: Lessons from a water limited environment. In: Proceedings of the International Crop Science Congress, Ames, Iowa, USA (in press).
Youssefian S., E.J.M. Kirby & M.D. Gale, 1992. Pleiotropic effects of GA-insensitive Rht dwarfing genes in wheat. 2. Effects on leaf, stem and floret growth. Field Crops Res. 28: 191–210.
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Siddique, K., Whan, B. Ear:stem ratios in breeding populations of wheat: significance for yield improvement. Euphytica 73, 241–254 (1993). https://doi.org/10.1007/BF00036703
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DOI: https://doi.org/10.1007/BF00036703