J. Sutka, G. Galiba, M. Molnár-Láng, B. Köszegi, G. Kocsy, G. Linc, and A. Vágújfalvi.
Somaclonal variation.
Electrophoretic patterns of seed storage proteins, HMW-glutenins,
and gliadins were studied in 468 plants of the common wheat cultivar
Chinese Spring regenerated from callus culture of immature embryos.
Of the 115 plants grown from seeds treated with nitrosoethylurea
and in 260 control plants, from 5 to 21 single grains were analyzed.
In these three groups, the frequencies of inherited mutations
causing the loss of all proteins controlled by a locus (null-mutations,
probably caused by a chromosomal deficiency) were 0.69 %, 2.07
%, and 0.05 % per locus (the differences were statistically significant),
respectively, whereas frequencies of mutations causing the loss
of a single protein band were 0.11 %, 0.33 %, and 0.05 %, respectively.
The loss of all of the gliadins controlled by Gli-B1 or
Gli-B2 (mutations probably caused by a deletion of the satellites
of the corresponding chromosomes), was significantly higher than
the loss of gliadins controlled by the A and D genomes. Gene mutations
altering the electrophoretic mobility of a single protein band
in the pattern were found only in the second group of plants (0.44
%). Therefore, chemical mutagenesis, which produces not only more
mutations than cultivation of immature wheat embryos in vitro,
but also a higher ratio of mutations with altered DNA sequences,
can be considered an easier and comparatively more promising way
for obtaining new, improved variants of loci controlling biochemical
characteristics in wheat. Somaclonal variation, on the other hand,
probably was caused mainly by chromosomal abnormalities and hardly
can be considered as a useful tool in wheat breeding.
Drought and cold tolerance.
Growth, changes in the total N and P levels, and K+ and Na+ accumulation
under osmotic and salt stress conditions were compared in callus
cultures of several wheat varieties differing in drought and salt
tolerance. Salinity stress initiated a different response than
the mannitol-induced nonionic osmotic stress in the content of
K+ and Na+. Osmotic and salinity-induced polyamine accumulation
were compared in callus cultures of different wheat varieties
and in disomic substitution lines. Mannitol-induced osmotic stress
increased the level of putrescine in all varieties and the level
of cadaverine in two varieties. Salt stress increased spermidine
titer; the accumulation rate was higher in the sensitive than
in the tolerant varieties. The changes in mannitol- and salt stress-induced
free amino acid accumulation in wheat varieties were similar.
To determine whether a genotype possessing only drought
tolerance would have any advantage if drought and salinity stresses
occured consecutively, hydroponically grown seedlings of a drought-sensitive
and a drought-tolerant breadwheat variety were evaluated
for drought (PEG 4000) and salt (NaCl) tolerance under controlled
environmental conditions. Changes in net photosynthesis, stomatal
conductance, specific leaf area, abscisic acid content, and the
water content of shoots and roots showed that the drought-tolerant
variety was more susceptible than the drought-sensitive one with
consecutive occurrence of water and salt stresses.
In addition to other compatible solutes, the levels
of free amino acids, especially proline, increase during drought
and cold conditions as other investigations have shown. Significant
positive correlations have been found between proline levels and
frost tolerance in a wide spectrum of species, e.g., potato, winter
barley, and winter wheat. The fact that limited desiccation induces
frost tolerance is well documented. Moreover, during cold acclimation,
the water content in plain tissue decreases and desiccation tolerance
increases.
Chromosome substitution lines of the wheat variety
Cappelle-Desprez in Chinese Spring were tested for drought tolerance
in growth chambers in the Martonvasar phytotron. Three different
moisture regimes were used: E1, a fully irrigated control; E2,
mid-season water stress (preanthesis); and E3, terminal water
stress during grain filling. Data were analyzed to estimate the
chromosomal location of the genes controlling relative water content
(RWC), relative water loss (RWL), drought-susceptibility index
(DSI), and phenotypic stability in each substitution line. Simultaneous
consideration indicated that most of the genes controlling these
characters are located on chromosomes 1A, 5A, 7A, 4B, 5B, 1D,
3D, and 5D.
Crossability of wheat with rye and other related
species. The recessive crossability
allele kr1 was transferred from the wheat variety Chinese
Spring (CS) into the winter wheat variety Martonvásári
9 (Mv9) by backcrossing the `Mv9 x CS' hybrids with
Mv9. After three backcrosses with Mv9 and two selfings after each
backcross, the selected progenies had 61.6 % seed set when 60
individual plants were crossed with rye. These data confirm that,
after the third backcross, the selected Mv9 kr1 line carries
recessive crossability alleles kr1 and kr2, but
the genotype is 93.75 % Mv9.
Alien gene transfer into wheat from related species.
The Mv9 kr1 line was crossed with
different rye inbred lines and with old Hungarian rye varieties
with the aim of producing new wheat-rye translocations in the
future. Amphiploids were produced in all the combinations. Backcrosses
were initiated on the `Mv9 kr1 x Lovaszpatonai wheat
x rye' amphiploids with the Mv9 kr1 line.
Aegilops species (Ae.
biuncialis, Ae. triuncialis, and Ae. ovata) originating
from the Genetic Resources Unit International Center for Agricultural
Research in the Dry Areas (Aleppo, Syria) were crossed with Mv9
kr1 lines with the aim of producing drought-tolerant lines.
The `Mv9 kr1 x Aegilops ovata', and
Ae. biunciualis hybrids were treated with colchicine to
produce amphiploids.
Molecular cytogenetic analysis (C-banding, in
situ hybridization) of the wide hybrids and derivatives.
C-banding and in situ hybridization (GISH) is used to identify
chromosomes of hybrids and derivatives. The presence of the T1B·1R
translocation in several Martonvásár wheat varieties
(Mv 14, Mv 15, Mv 16, Mv 17, Mv 18, Mv 19, Mv 20, Mv 21, Fatima,
Mv 22, Mv 23, Mv 24, and Mv 25) was demonstrated by C-banding.
In situ hybridization analysis demonstrated that the size of the
translocated rye chromosome arm is the same in the analyzed genotypes
(Fatima, Mv 17, and Mv 23). However, large differences in quality
parameters occurr among these varieties. The barley chromosomes
were detected by genomic in situ analysis (GISH) in the backcross
progenies of the CS wheat x Betzes barley hybrids with the Mv
9 kr1 lines.
Publications.
Farshadfar E, Köszegi B, Tischner T, and Sutka
J. 1995. Substitution analysis of drought tolerance in wheat (Triticum
aestivum L.). Plant Breed 114:542-544.
Farshadfar M, Kissimon J, and Sutka J. 1995. Genetic
distance between Triticum timopheevi Zhuk., T. araraticum
Jakubz. and T. aestivum L. Plant Breed 144:401-405.
Galiba G, Quarrie SA, Sutka J, Morgounov A, and Snape
JW. 1995. RFLP mapping of the vernalization (Vrn1) and
frost resistance (Frl) genes on chromosome 5A of wheat.
Theor Appl Genet 90:1174-1179.
Karimzadeh G, Kovács G, and Barnabás
B. 1995. Effects of cold treatment and different culture media
on the androgenic capacity of two winter wheat genotypes. Cereal
Res Commun 23:223-227.
Karsai I, Mészáros K, Bedő Z,
Hayes PM, and Chen F. 1995. Genetic analysis of the components
of winterhardiness in barley (Hordeum vulgare L.).
Acta Biologica Hungarica (in press).
Kovács M, Barnabás B, and Kranz E.
1995. Electro-fused isolated wheat (Triticum aestivum L.)
gametes develop into multicellular structures. Plant Cell Rep
15:178-180.
Nagy Z and Galiba G. 1995. Drought and salt tolerance
are not necessarily linked: a study on wheat varieties differing
in drought tolerance under consecutive water and salinity stresses.
J Plant Physiol 145:168-174.
Millard MM, Veisz OB, Krizek DT, and Line M. 1995.
Magnetic resonance imaging (MRI) of water during cold acclimation
and freezing in winter wheat. Plant, Cell and Envir 18:535-544.
Szákacs E and Barnabás B. 1995. The
effect of colchicine treatment on microspore division and microspore-derived
embryo differentiation in wheat (Triticum aestivum L.)
anther culture. Euphytica 83:209-213.
Sutka J, Farshadfar E, Köszegi B, Friebe B, and Gill BS. 1995. Drought tolerance of disomic chromosome additions of Agropyron elongatum to Triticum aestivum. Cereal Res Commun 23:351-357.
Szunics L and Szunics Lu. 1995. Race composition
and virulence of wheat powdery mildew (Erysiphe graminis tritici)
and the resistance of wheat varieties in Hungary. Cereal Res Commun
23(1-2):117-125.
Szunics L and Szunics Lu. 1995. Field resistance
of wheat varieties to leaf rust. Növénytermelés
44(2):109-120.
Upelnik VP, Novoselskaya AY, Sutka J, Galiba G, and
Metakovsky E V. 1995. Genetic variation at storage protein-coding
loci of common wheat (cv `Chinese Spring') induced
by nitrosoethylurea and by the cultivation of immature embryos
in vitro. Theor Appl Genet 90:372-379.
Veisz O and Tischner T. 1995. Hardiness of winter
wheat varieties as a function of changes in certain environmental
factors. Biotronics 24:73-83.
Vida G and Jolánkai M. 1995. Studies on wheat
varieties with different breadmaking quality in different years
and under various growing conditions. Növénytermelés
44(1):43-54.
Personnel.
After 37 years in service, Dr. László
Balla retired in February 1996 at the age of 63. See special tribute
to Dr. Balla on p. 2 of this publication.