CEREAL RESEARCH INSTITUTE
Szeged, Hungary.
Inheritance of quality traits in durum wheats (Triticum durum Desf.).
J. Matuz and B. Beke.
The value of durum wheats depends on their quality
traits. The inheritance of some quality traits was studied in
early generations of the following two crosses: `D41/D30,'
and `D42/D30'. The pedigrees of the parental varieties
are D30: `Parus/GK Pannondur'; D41: `BD431//GK
Basa/GK Minaret'; and D42: `BD437//M7793.26/DF407.78.'
The F1 generation was grown in an unreplicated field
trial with low plant density (80 plants/sq m) in 1992. The F2
and F3 generations were grown in a field trial replicated four
times at a normal plant density (500 plants/sq m, 6.5 sq m/plot)
in 1994. The grain yield of the plots was examined for the following
quality traits: semolina yield, pigment content, wet gluten content,
vitreousness of grain, protein content, and cooking value of the
pasta.
Positive, as well as negative, overdominance was
found in the inheritance of semolina yield of the hybrids in F1
generation, but in the F2 and F3 generations the semolina yields
of the hybrids were similar to values of their midparents. The
low pigment content was dominant in the F1 generation, but in
the F2 and F3 generations, the pigment content of the hybrids
was close to that of the midparent. Negative overdominance was
found in the wet gluten content of the hybrids in the F1 generation,
but in the F2 and F3 generations, positive heterosis generally
was observed. The vitreousness of grain was inherited intermediately,
and positive heterosis often was observed. Low protein content
dominated in one hybrid, but in the other combination, it showed
recessive inheritance. The cooking value of pasta made from flour
of the hybrids (measured by aleurograph) after 15 and 30 minutes
cooking time was similar to the value for the poorer parent.
This work was supported by OTKA (National Scientific
Research Fund) grant no. 486.
Evaluation of some aspects of variety maintenance in wheat.
Z. Kertesz, J. Matuz, J. Pauk, and Cs. Kertesz.
Comparison of variety maintenance methods.
Three maintenance systems were evaluated on five cultivars differing
in phenotype, homogeneity, and the rate and capability of open
pollination. Three methods were used. In the `Pedigree 1'
method, single plant progenies were grown in a spaced planting
system (`50 x 10 cm' spacing), and their progenies
were tested in yield trials under normal density. In the `Pedigree
2' method, single heads were selected, head rows were evaluated,
and the progenies of the head rows were tested in yield trials.
In the third (Jensen's bulk method), 1,000 heads were selected
and the blends of the head rows were harvested as breeder's seed.
All these methods were found suitable in achieving adequate homogeneity
during the maintenance process, but Pedigree 1 is the most expensive
and space- and time- consuming. The bulk method is the cheapest,
but can be used in highly uniform varieties. The Pedigree 2 method
can be used widely for maintaining different kinds of wheat varieties.
Study of open pollination.
The rate of open pollination was studied using the blue endosperm
marker line as pollinator. In the middle of a `100 x 100'
meter wheat multiplication, a 200 square meter marker pollinator
was planted. Two ears were emasculated in every meter in four
different directions on the examined variety. To test pollen navigation,
10 heads were harvested at each check point to test the open pollination.
Data showed that the wheat marker pollen navigated at least 20
meters, whereas open pollination took place within a 3-meter distance
in the main wind direction. The study provided valuable data for
seed multiplication work.
Use of doubled haploids in the variety maintenance.
In five model varieties, doubled haploid versions of 12-12
families were produced by anther culture. R0 plants and R1 lines
were grown in the greenhouse and field nurseries, respectively.
The original families and the DH R2 versions were planted together
in yield trials in the fall of 1995. Comparative evaluation of
the families and their DH versions will clarify the usefulness
of doubled haploids in achieving homogeneity during the maintenance
process. (This work was supported by OTKA grant no. 6050)
L. Cseuz.
Genebank activity is continuing in the Wheat Department
of the Institute with the support of the Hungarian Ministry of
Agriculture. The main goal of the genebank program is the preservation
of the local varieties and advanced lines selected by the institute.
Last year, 500 genotypes were included in the active collection,
where they were evaluated according to the International Board
of Plant Genetic Resources (IBPGR) system of characterisation
using descriptors to focus on morphological and highly heritable
agronomic characters. In 200 samples, farinograph values were
calculated to obtain information on breadmaking quality. Resistance
to rusts and powdery mildew was scored by the modified Cobb's
scale at the adult stage and by Stakman's scale at the
seedling stage. All the 500 entries were planted in 5.5 sq m plots
for multiplication of seed and to continue detailed quality studies.
Seed samples are stored in the cold chamber (in glass containers,
at 5_C temperature) of the Institute's breeding station,
Kecskestelep, Szeged.
Response of wheat genotypes to virus diseases under field conditions.
M. Papp and A. Mesterhazy.
The severity of a natural virus infection was estimated
in field conditions using 120 wheat cultivars and breeding lines
(T. aestivum and T. durum) in 1995. Each genotype
was sown in three replicates, three weeks before the optimal sowing
time in 30 or 60 cm spaced rows at a density of 10 cm/plant. The
rows were 9 m in length. The autumn was short with early frosts,
so no major aphid population developed on the plants. Therefore,
significant virus infection could not be detected in autumn, only
in spring. The infection severity was expressed as percentage
of the total spring plant numbers. The genotypes showed a significant
difference in the severity of virus infection. The number of infected
plants showing visual symptoms varied from 0 % up to 30 % in the
most susceptible genotypes. Some genotypes (GK Delibab, GK Kunsag,
GK Kende, and GK Cipo) were nearly free of heavily infected plants.
Other genotypes were strongly infected (GK Minaret, GK Barna,
GK Betadur, and GK Orseg). Because visual estimation of virus
infection is unreliable, 119 leaf samples were screened for four
virus species, BSMV, BMV, WSMV, and BYDV, by ELISA to estimate
the applicability of visual ratings. In general, complex viral
infection of diseased wheat plants was observed. The dominant
virus in 1995 was BMV. More than 50 % of the samples contained
more than one virus species, and nearly 10 % were infected by
four species. (This work was supported by OTKA grant no. 6230.).
Effects of heavy metals on somatic tissue culture of wheat.
L. Purnhauser.
Heavy metals, as microelements in the culture medium,
may play an important role in plant regeneration. In this study,
the heavy metals AgNO3, CdCl2, CoCl2, CuSO4, and Ni(NO3)2 were
applied at 1, 10, and 100 µM concentrations in a hormone-free
Murashige and Skoog medium. Another treatment lacked application
of any heavy metal to the medium. Calli of three wheat (T.
aestivum) cultivars initiated from immature embryos were used
as inoculi. Shoot regeneration was enhanced significantly by Ag+
and Cu+2 in all treatments. Co+2 and Cd+2 proved to be inhibitory
at the highest concentration. The order of heavy metals on the
effect of shoot regeneration was Cu+2 > Ag+ > Ni+2 >
Co+2 > Cd+2. Root regeneration was significantly promoted by
Cu+2 in all cases and by Ni+2 at 100 µM. At the highest concentration,
Cd+2, Ag+, and Co+2 had an inhibitory effect on rooting. The order
of heavy metals on the effect of root regeneration was Cu+2 >
Ni+2 > Co+2 > Ag+ > Cd+2. We currently are investigating
the relationship between heavy metal concentrations and ethylene
production or stress protein levels in our cultures. (The research
was supported by OTKA grant no. 6102).
Publications.
Kertesz CS, Matuz J, Proksza J, and Kertesz Z. 1995.
Comparison of variety maintenance methods in wheat. Ann Wheat
Newslet 41:102.
Pauk J, Kertesz Z, Beke B, Bona L, Csosz M, and Matuz
J. 1995. New winter wheat variety: GK Deibab developed via combining
conventional breeding and in vitro androgenesis. Cereal Res Commun
23:251-256.
Papp M. 1995. Insect resistance. Ann Wheat Newslet
41:104-105.
Papp M. 1995. Effects of bird cherry-oat aphid
and cereal leaf beetle on yield of winter wheat varieties. In:
Eur J Plant Path. 13th Inter Plant Protection Cong (Schippers
B ed). July 2-7, The Hague, The Netherlands. p. 1377 (Abstract).
AGHARKAR RESEARCH INSTITUTE
Agarkar Road, Pune 411 004, India.
The wheat program at this Institute is devoted mainly
to breeding durum wheat varieties and conducting basic research
in tetraploid wheats. Limited work is conducted on bread wheat
and dicoccum wheat.
V.S. Rao and S.C. Misra.
A durum wheat variety, `MACS 2694',
from the cross `Mexicali/Raj 1555//MACS 2130' was
accepted by the state of Maharashtra for release under timely
sown, irrigated conditions. In the All-India Coordinated
Trials, this variety yielded 40 q/ha, which is about 7 % more
than the check variety HD 4502 (Malavika), released in 1976. The
additional features of this variety are its quality parameters,
which are superior to those of Malavika, a low or negligible yellow
berry prevalance, better hectoliter weight, and high sedimentation
value. MACS 2694 has good resistance to leaf rust and moderate
resistance to stem rust.
Ditelosomic and trisomic stocks in durum wheat.
V.S. Rao, M.D. Bhagwat, P. Varghese, and S.S. Gandhi.
A program to develop aneuploid lines in durum wheat
was initiated some years back. Initially, the project was undertaken
to develop ditelosomic lines in the durum variety MACS 9, a variety
with good pairing and no structural changes, with `Chinese
Spring'. The ditelosomic lines in `Chinese Spring'
were used as the source of telocentric chromosomes, and successive
backcrosses were made to MACS-9 on the monotelodisomic plants.
In most of the cases, five to six backcrosses were attempted before
selfing to recover ditelosomic lines. Ditelosmics for 1AS, 1AL,
3AS, 3BL, 5AL, 5BL, and 6AL have been recovered so far. To develop
trisomic lines in the same variety, the Chinese Spring tetrasomics
were used as the sources of extra chromosome. At present, the
A-genome lines are in the BC5 generation and the B-genome
lines are in the BC4 generation.