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Wheat Information
Service
Number 75: 26-30 (1992)
An
attempt to transferring stem solidity of Triticum aestivum to
triticale (2n=6x=42). II. Analysis in
F2-F4
S. Tsvetkov
Institute for Wheat and Sunflower, General Toshevo, Bulgaria
Summary
New winter triticale forms with solid stem were found in
F2-F4 generations from the hybridization of the
winter common wheat (solid stem) and triticale (2n=42) with
hollow stem. This new developed triticale (2n=42) showed high
resistance to Cephus pygmaeus L.
Introduction
The possibility of blocking of the parasite penetration to the
hostplant (Wallace and McNeal 1966) is proved by the development of
winter triticale forms derived from a cross of T-AD-592 with a solid
stem. By this breading program, lines with a high ento-immunity to
the wheat stem fly Cephus pygmaeus L. will be bred, and
the costs on the chemical control will be also saved (Tsvetkov
1982).
Materials and methods
One of the basic purposes of the complex cross T-AD-592 (MBX-11-7 x
T-AD-17-B) F1 x AD-No.11 is the acquirement of hexaploid
triticale with a solid stem as well as a short stem and high
productivity at F2 - F4 generations of this
cross. For this purpose the selection in F2 was conducted
on the solid stem.
The methods used to determine the degree of solidness of the stem and
the analyses of the meiosis in PMC were mentioned in the previous
paper (Tsvetkov 1992). All plants at F2 - F4
populations and parents were grown under isolator for guaranteeing
trueness of materials.
Results and discussion
A. Second hybrid generation (F2)
A transfer of the solid stem of Triticum aestivum into
triticale (2n=6x=42) was carried out by interspecific
hybridization (simple and complex cross). An interest in this project
is how to combine the solid stem with plant height and the spike
grain number. A number of F2 plants derived from the
interspecific cross T-AD-592 (MBX-11-7 x T-AD-17-B) F1 x
AD-No.11 had solid stem in all internodes and were from 50 to 110 cm
in plant height (Fig.1).
Most valuable plants are the hybrid with a solid stem and 61-80
grains per spike.
Table1
shows considerable meiosis stability in the F2 hybrid with
a solid stem of the cross T-AD-592 compared in F1. The
average number of meiotic disturbances in F2 were 66.2%,
while those in F1 were 96.8% (Tsvetkov 1992).
B. Fourth hybrid generation (F4)
Table
2 shows that
solid stem of the hybrid studied in F4 is successfully
with major agronomical characters, ie, a comparatively short stem,
large spike, a very good grain formation and heavy grain. The average
grain number of the solid-stemmed hybrid plants varies from 56 to 94
grains and the spike grain weight from 3.2 to 5.4 g, compared to 40
grains and 1.8 g of spike grain weight for Sadovo1 (winter common
wheat).
The breeding value of this solid-stemmed triticale selected from the
cross T-AD-592 will be evaluated against Cephus pygmaeus L.
(Fig.2).
Table
3 indicates that
both Sadovo 1 and all the hollow-stemmed foreign triticale are a high
susceptibility to the attack of Cephus pygmaeus L.
(from 39.0 to 54.0%). Under the same conditions, the
new-developed solid- stemmed triticale showed a high resistance to
this pest, that is, the damaged stem was only 2.6%.
References
Tsvetkov S (1982) Breeding of winter triticale (2n=6x=42) in
Bulgaria. D Sc dissertation, General Toshevo, Bulgaria: 1-602.
Tsvetkov S (1992) An attempt to transferring stem solidity of
Triticum aestivum ssp vulgare to triticale
(2n=6x=42). I. Investigation in F1. Wheat Information
Service 21-25.
Wallance LE and McNeal PH (1966) stem sawflies of economic importance
in grain crops in the United States. Mo Agri Exp St In Technical
Bulletin 1350: 1-49.
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