Indian Society of Genetics & Plant Breeding

Inheritance of angled spikelet arrangement in Triticum durum Desf.

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The genus Triticum includes diploid (2n=2x=14),
tetraploid (2n=4x=28) and hexaploid (2n=6x=42)
species. The phylogenetic relationships among different
Triticum species has been largely clarified [1]. The spike
or head size in wheat varies from 2-8 inches or more.
The number of spikelets in each spike usually varies
from 10-30 and are arranged at nodes on the rachis of
spike. The shape of spike varies within as well as
between the species. Normally, the shape of spike is
tapering, parallel, clubbed or fusiform. The spikes of
common wheat, T. aestivum are long, slender and
somewhat flattened, whereas T. durum has somewhat
shorter and flattened spikes. T. aestivum ssp.
compactum possesses short spikes, about 2-3 inches
in length, very compact and flattened. The density of
spikelet also varies in different species as well as in the
varieties of the same species, depending on the relative
length of internode on the rachis. In dense spikes, the
internode or the rachis segments are relatively short
resulting in the dense arrangement of spikelets on the
spike. In lax or very lax spikes, the internode length is
more. Compact spike has not been reported in tetraploid
wheat [2] and only compactoid spike is found. However,
even the compactoid spikes of tetraploid wheat are not
so dense. There are a few reports of dense spike in Ae.
squarrosa (syn. T. tauschii) and T. sinskajae [3]. Besides
the normal spikes, several other non-standard
morphological forms of spikes are known [4]. In this
paper, we report a nonstandard morphological form of
spike in tetraploid wheat Triticum durum which to the
best of the knowledge of authors has not been reported
earlier. Normally arrangement of the spikelets on the
spike is such that when seen from side, it appears
smooth, may be parallel, tapering or fusiform. However,
we came across two genotypes of T. durum where the
arrangement of spikelets in the spike were irregular, as
some spikelets tilted towards one side whereas others
get angled in opposite direction. The present paper
describes the inheritance of this peculiar morphology
of spike.

Keywords: N/A


Year: 2009
Volume: 69
Issue: 3
Article DOI: N/A
Print ISSN: 0019-5200
Online ISSN: 0975-6906



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