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MIDMORE et al. (1984) reported that yield
reduction in wheat in hot environments is due to the
acceleration of all plant developmental phases. FISCHER
& MAURER (1976) reported that yield reduction in
semidwarf wheats under high temperatures was associated with
reduced number of heads per plant and seeds per head.
SISODIA et al. (1978) classified bread and
durum wheats into desirable and undesirable groups
when grown under high temperatures. Genotypes which either
flowered too early (< 45 days), too late (> 120 days),
or never flowered were considered undesirable. In the
present study, days to flowering for the heat-resistant
Aegilops accessions ranged from 70 to 101 days
(Table 3). These accessions also
produced a large number of seed-bearing heads, although the
late tillers produced heads with only a few seeds or no
seeds. Plants of Ae. searsii G3069 were an exception;
they tillered profusely over a short period, and the tillers
produced heads with several seeds.
These heat-resistant Aegilops accessions could be
used to study the inheritance of resistance to heat and to
investigate the mechanisms involved in heat resistance.
References
BAGGA, A.K. & H.M. RAWSON. 1977. Contrasting responses
of morphologically similar wheat cultivars to temperatures
appropriate to warm temperature climates with hot summer: a
study in controlled environment. Aust. J. Plant Physiol.
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FISCHER, R.A. & R.O. MAURER. 1976. Crop temperature
modification and yield potential in a dwarf spring wheat.
Crop Sci. 16: 855-859.
FRIEND, F.D.C. 1966. The effect of light and temperature on
the growth of cereals, In: F.L. MILTHORPE & J.D. IVINS
(Eds.), The Growth of Cereals and Grasses. Butterworths,
London, pp. 181-199.
KANANI, P.K. & B.S. JADON. 1985. Variability for high
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MARSHALL, H.G. 1982. Breeding for tolerance to heat and
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Plants for Less Favorable Environments. Wiley Interscience,
New York, NY, pp. 47-70.
MIDMORE, D.J., P.M. CARTWIRGHT & R.A. FISCHER. 1984.
Wheat in tropical environments. II. Crop growth and grain
yield. Field Crops Res. 8: 207-227.
SISODIA, N.S., K.P. SINGH & R.R. SHEOPURIA. 1978.
Variability for high temperature tolerance in wheat. Proc.
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