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Developing of a primary hexaploid
Triticale T-AD (2n=6x=42) through the hybridization
of T. durum DESF. (2n=28) and S. cereale L.
(2n=14)
P.POPOV and S.TSVETKOV
The Institute for Wheat and Sunflower, General Toshevo,
Bulgaria
Nowadays, for the needs of selection and perhaps of practice
many primary and secondary hexaploid lines of
Triticale (2n = 42) are being developed. Of these,
more difficult appears the development of primary
42-chromosome lines of Triticale, as seen from the
scarceness of literature on this subject (DERZHAVIN 1938,
O'MARA 1948, NAKAJIMA 1953, KISS and REDEI 1953,
SANCHEZ-MONGE 1956, SHULlNDIN and NAUMOVA 1965, POPOV and
TSVETKOV 1970).
The first primary hexaploid Triticale (2n = 42) in
Bulgaria was brought forth in 1967 through a hybridization
of T. durum DESF. (2n = 28) and S. cereale L.
(2n = 14), (POPOV and TSVETKOV 1970), namely, variety No. 13
of hard wheat (var. melanopus Al.) and variety No. 59
of rye. The F1 hybrid plants were treated with
colchicine, and the technique of CAUDERON and SAIGNE (1961)
was applied, so that sterility be overcomed. The colchicine
treatment resulted in six amphidiploid plants.
Cytological analyses of mitosis showed that the number of
somatic chromosomes of the arnphidiploid plants turns out 2n
= 42. This proved the development of a new primary hexaploid
Triticale, T-AD (2n = 42) with an AABBss genome
formula, to which a fusion has been accomplished on the part
of the AA and BB subgenomes of T. durum DESF. and of
the as genome S. cereale.
The newly developed primary Triticale, T-AD (2n =
42), characterizes for the intermediate arrangement of its
ears (Fig. 1). It also combines the
hairiness of the maternal variety (female No. 13, var.
melanopus Al.) with the immense length of the ear,
inherited from the fraternal male No. 59 variety (S.
cereale L.).
Mean fertility of the ears of Triticale T-AD (2n =
42) runs up to 64.15 per cent compared to 80.38 per cent for
the hard wheat (female No. 13) and 77.98 per cent for the
rye (No. 59). In spite of the lower fertility with the ears
of Triticale T-AD (2n = 42) the average number of
grains per ear of T-AD (2n = 42) just equalizes to that of
the maternal No. 13 variety (T. durum DESF.), due to
their comparatively bigger length and more florets per
spikelet.
Fig. 2. Seeds
At time of vegetation, Triticale T-AD (2n = 42) sets
up a thick stem with an anthocyanine colouring partly on it,
partly on the leaves. Plants demonstrate high field
resistance to leaf rust and stem rust and powdery mildew, as
seen from Table 1.
For some years at this Institute, an intensive selection
work has been carrying out, aiming at developing of new
dwarf lines of secondary hexaploid Triticale (2n =
42) on the grounds of hybridizing the newly developed
primary Triticale, T-AD (2n = 42), with dwarf
octaploid Triticale (2n = 56) of the Rudorf type as
also with the winter dwarf common wheat Tom Pouce Blanc
(T. aestivum L.).
Literature cited
1. DERZHAN, A. 1938, Izv. Akad. Nauk USSR, ser. biol.,
3: 663-666.
2. CAUDERON, J. and B. SAIGNE 1961. Annale de l'ameration
des plantes, 3: 363-373.
3 KISS, A. and A. G. REDAI 1953. Acta Agron. Hung.,
3: 257-276.
4. NAKAJIMA, G. 1953. Japan J. Breed. 2: 178-184.
5. O'MARA, J. G. 1948. Genet. Soc. Amer. Res. 1:
17-52.
6. POPOV, P. and S. TSVETKOV 1970. Comptes rendus de l'
Academie bulgare des Science, 12:1533-1536.
7. SANCHEZ-MONGE, E. 1956. An. Aula Dei 4:
191-207.
8. SHULINDIN. A. F. and L. N. NAUMOVA 1965. Sel. Semenov.
1:52-55.
(Received February 12, 1973)
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