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Wheat Information Service
Number 90:45-46 (2000)
Research information
Comparative performance of semi-dwarf wheat
(Triticum aestivum L.) genotypes.
K.D. Jamali, M.A. Arain and M. Ahmad
Nuclear Institute of Agriculture, Tando Jam, Sindh, Pakistan
Plant height in wheat (Triticum aestivum L.) and its
relationship to grain yield has long been of interest to plant
breeders. In wheat the GA-insensitive semi-dwarfing genes Rht-B1b
(Rht1) and Rht-D1b (Rht2) have been successfully utilized
by plant breeders worldwide for more than three decades. The Yield
advantage of wheats carrying the GA-insensitive semi-dwarfing genes
is only partly due to the direct effect of the genes on plant height
and increased lodging resistance (Gale and Youssefian 1985). Field
experiments analyzing near-isogenic lines for GA-insensitive dwarfing
genes clearly demonstrate that positive pleiotropic effects on
increased number of grains per spike result in higher yields under
most environmental condition (Borner et al. 1993; Flintham et al.
1997; Jamali and Ahmad 1998).
To feed the increasing population of Pakistan there is continuous and
perpetual need to evolve new high yielding wheat varieties. The aim
of this study was to compare the semi-dwarf genotypes for their yield
and other agronomic characteristics. The trial was consisted of five
F6 semi-dwarf genotypes with four commercial varieties
viz. Sarsabz, Soghat-90, Anmol and Mehran-89. The genotypes were
planted in six rows, with row length of 4 meters in a randomized
complete block design with three replicates. The pedigree/parentage
of genotypes is presented in Table 1.
The genotypic comparison results are presented in Table
2. In this comparison all the genotypes were not significantly
different from each other for grain yield per plot. The reasons for
the non-significant differences may be due to saline patches in the
experimental area, as we could. not conduct the soil analysis.
However, the line 37-1 and Soghat-90 had the highest yield and the
line 29-2 the lowest yield. The possible reason for the lowest yield
in line 29-2 may be due to reduced number of tillers per unit area.
Number of tillers is one of the important yield components which
affects the final yield. In this comparison, line 25-1 was late in
heading, tallest in plant height and possessed the highest number of
spikelets. Line 9-6 had the highest number of tillers with decreased
main spike yield, grain weight (mg) and number of grains per
spikelet. Final yield is a complex character and depends on its
various components. Genotype, environment and its interaction may
also significantly affect the yield. Each genotype has its own
strategy to produce more yield.
References
Borner A, Worland AJ, Plaschke J, Schumann E and Law CN (1993)
Pleiotropic effects of genes for reduced height (Rht) and
day-length insensitivity (Ppd 1) on yield and its components for
wheat grown in middle Europe. Plant Breed 111: 204-216.
Flintham JEF, Borner A, Worland AJ, Gale MD (1997) Optimizing
wheat grain yield: effects of Rht (gibberellin-insensitive)
dwarfing genes. J Agric Sci 128: 11-25.
Gale MD and Youssefian S (1985) Dwarfing genes in wheat. In:
Russell GE (ed) Progress in plant breeding, 1: 1-35, Butterworths,
London.
Jamali KD and Ahmad M (1998) Evaluation of semi-dwarf wheat
genotypes for high yield. Proc 9th Int Wheat Genet Symp 2:
234-236.
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