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Ear development in spring wheat

Published online by Cambridge University Press:  27 March 2009

E. J. M. Kirby
E. J. M. Kirby
Affiliation:
Plant Breeding Institute, Trumpington, Cambridge CB2 2LQ
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Summary

Data from experiments with spring wheat, variety Kolibri, were used to examine size gradients within the mature ear in relation to ear development. The greatest number of grains and florets per spikelet, and the heaviest grains, occurred in the lower-mid part of the ear. Within the spikelets in this region grain 2 > grain 1 > grain 3.

It is proposed that the timing and period of ear development and the number of spikelets can be described quantitatively in terms of (1) the rate of leaf initiation, (2) the number of leaves, (3) the rate of spikelet initiation and (4) the total number of primordia. Both leaf and spikelet initiation proceeded at more or less constant rates, but spikelet initiation was about three times as fast as leaf initiation. Differentiation of the spikelet primordia started at about the time the terminal spikelet was initiated, occurring first in the spikelets in lower-mid part of the ear. The rate of floret initiation was lower than that of spikelet initiation, but did not differ between spikelets. A maximum of nine florets per spikelet was formed and then, in all spikelets, some of the last-formed primordia died, leaving two to four potentially fertile florets.

Morphologically, primordia in the lower-mid part of the ear were always the most advanced. The more rapid development of the terminal primordia tended to synchronize events such as meiosis and anthesis, thus shortening the development period of the later formed florets. Changes in meristem size were such that both length and diameter were the greatest when the primordia of the lower-mid part of the ear were initiated.

The statistical model to describe primordium initiation and ear size is compared with other models describing primordium initiation rates. The analysis of ear development in quantitative terms is discussed in relation to analyses of ear development by morphological stages. A correlation between grain size and time of floret initiation is demonstrated and the significance of the size changes in the meristem is discussed.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 82 , Issue 3 , June 1974 , pp. 437 - 447
Copyright
Copyright © Cambridge University Press 1974

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References

REFERENCES

Bennett, M. D., Finch, R. A., Smith, J. B. & Rao, M. K. (1973). The time and duration of female meiosis in wheat, rye and barley. Proceedings of the Royal Society of London B 138, 301–19.Google Scholar
Bonnett, O. T. (1966). Inflorescences of maize, wheat, rye, barley and oats: their initiation and development. University of Illinois College of Agriculture, Agricultural Experimental Station. Bulletin 721.Google Scholar
Evans, L. T., Bingham, J. & Roskams, M. A. (1972). The pattern of grain set within ears of wheat. Australian Journal of Biological Sciences 25, 1–8.CrossRefGoogle Scholar
Felippe, G. M. & Dale, J. E. (1971). Effects of shading the first leaf of barley plants on growth and carbon nutrition of the stem apex. Annals of Botany 37, 45–56.CrossRefGoogle Scholar
Friend, D. J. C., Fisher, J. E. & Helson, V. A. (1963). The effect of light intensity and temperature on floral initiation and inflorescence development of Marquis wheat. Canadian Journal of Botany 41, 1663–74.CrossRefGoogle Scholar
Hanif, M. & Langer, R. H. M. (1972). The vascular system of the spikelet in wheat (Triticum aestivum). Annals of Botany 36, 721–7.CrossRefGoogle Scholar
Holmes, D. P. (1973). Inflorescence development of semidwarf and standard height wheat cultivars in different photoperiod and nitrogen treatments. Canadian Journal of Botany 51, 941–56.CrossRefGoogle Scholar
Kirby, E. J. M. (1973). Effect of temperature on ear abnormalities in uniculm barley. Journal of Experimental Botany 24, 935–47.CrossRefGoogle Scholar
Lucas, Daphne (1972). The effect of day length on primordia production of the wheat apex. Australian Journal of Biological Sciences 25, 649–56.CrossRefGoogle Scholar
Rawson, H. M. (1970). Spikelet number, its control and relation to yield per ear in wheat. Australian Journal of Biological Sciences 23, 1–15.CrossRefGoogle Scholar
Rawson, H. M. (1971). An upper limit for spikelet number per ear in wheat, as controlled by photoperiod. Australian Journal of Agricultural Research 22, 537–46.CrossRefGoogle Scholar
Rawson, H. M. & Evans, L. T. (1970). The pattern of grain growth within the ear of wheat. Australian Journal of Biological Sciences 23, 753–64.CrossRefGoogle Scholar
Sharman, B. C. (1947). The biology and developmental morphology of the shoot apex in the Gramineae. New Phytologist 46, 20–33.CrossRefGoogle Scholar
Thorne, G. N., Ford, M. A. & Watson, D. J. (1968). Growth, development and yield of spring wheat in artificial climates. Annals of Botany 32, 425–46.CrossRefGoogle Scholar
Walpole, P. R. & Morgan, G. D. (1970). A quantitative study of grain filling in Triticum aestivum L., Cultivar Maris Widgeon. Annals of Botany, 34, 309–18.CrossRefGoogle Scholar
Zee, S.-Y. & O'Brien, T. P. (1971). Vascular transfer cells in the wheat spikelet. Australian Journal of Biological Sciences 24, 35–49.CrossRefGoogle Scholar