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I. Research Notes
An induced mutant type sphaerococcoid in T. durum
K.P. DJELEPOV and G.A. CHAVDAROV
Dobrudja Agricultural Research Institute, Gen. Toshevo, Bulgaria
In the last years were obtained experimentally sphaerococcum type
mutations in Triticum aestivum ssp. vulgare, which confirms
the idea for mutation orgin of this species (now subspecies) from the
hexaploid group of the genus Triticum-SWAMINATHAN, JAGATHESAN and
CHOPRA (1963), MAKAROVA and ZOZ (1965), CHAVDAROV and DJELEPOV (1968).
Mutations type sphaerococcoid were experimentally induced in the tetraploid
group, namely in Triticum durum by BOZZINI (1965) and in Triticum
dicoccum by GUPTA and SWAMINATHAN (1967). In this contribution we
like to inform of an induced mutant type sphaerococcoid of durum wheat.
Seeds of the variety Apulicum 233-II were irradiated with X-rays in doses
of 10, 15 and 15 kr in 1964. Part of the seeds of M2 were treated
with EMS of 0.2 and 0.4% concentrations at 25C during 24 hours. Immediately
after the treatment and washing in running water, the seeds were sown
in the field.
In the progeny of one of the plants from the variant 15 kr X-rays plus
0.2% EMS (in the second year after the treatment-1968) were found four
plants simulating morphological features found in the hexaploid Triticum
sphaerococcum. From the sown and germinated 20 seeds, 14 plants survived
the winter of which 10 were normal (type durum) and four type sphaerococcoid.
The established plants were considerably shorter than the normal ones
which can seen from Table 1. Essential differences
were observed in the form and arrangement of the leaves. The changed plants
were with shorter, pointed and standing ones. The hairiness of the glumes
were more pronounced but ears were shorter and more compact with smaller
average number of spikelets. The mutant is characterised by hemispherical
glume and strongly suppressed awns which was well developed in the initial
variety. The grain was considerably smaller and spherical, the weight
of 1,000 kernels was 32 g, and 52 g for the durum plants. Chromosome number
was 28 for sphaerococcoid and normal forms. From Table
1 can also seen that all elements connected with the yield was lower
in values for the mutant compared with durum plants. It should be noted
that the fertility of the changed form was entirely normal, on the average
35.5 grains per ear, which does not correspond with the results obtained
by BOZZINI, and BAGNARA 1965 with some of the mutants type sphaerococcoid.
The above described mutant induced in Triticum durum, shows that
the factor for sphaerococcum is not limited only in D genome (3P-XVI
chromosome) but probably is found also in A or B genome. It appeared very
interesting from both a practical and a theoretical point of view. It
is considerably valuable with its spherical grain and with short culms
resistant to lodging
Literature
BOZZINI, A. and D. BAGNARA 1965. Genetica Agraria 19: 209-223.
BOZZINI, A. 1965. Radiation Botany, Suppl. 5: 525-535.
CHAVDAROV, G. and K. DJELEPOV 1958. WIS 27: 5-6.
GUPTA, N. and M.S. SWAMINATHAN 1967. Current Science 36: 19.
MAKAROVA, S.I. and N.N. Zoz 1965. Genetika 1(2): 113-118.
SWAMINATHAN, M.S., D. JAGATHESAN and V.L. CHOPRA 1963. Current Science
32: 539-540.
(Received February 17, 1969)
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