AGRICULTURAL RESEARCH INSTITUTE OF THE HUNGARIAN ACADEMY OF SCIENCES
Martonvásár, H-2462, Brunsvik str. 2, Hungary.
www.mgki.hu
The wheat season. The last wheat growing season was
characterized by extreme weather and above-average rainfall. A
mild January was followed by a cold February, although no freezing
out was observed. The abundant rainfall in spring caused frequent
early lodging. After flowering, the weather was unusually hot,
after which cold weather delayed ripening. A long period of wet
weather began just before the harvest, leading to a considerable
deterioration in the wheat quality. Approximately 5 x 106 t of
wheat was produced in Hungary, with a moderate yield average (4.49
t/ha). [p. 27]
Z. Bedö, L. Láng, O. Veisz, G. Vida, I. Karsai, K. Mészáros, M. Rakszegi, D. Pribék, S. Bencze, K. Puskás, and A. Uhrin.
Breeding. One new winter wheat variety was registered in 2005.
Mv Gorsium (Mv 04-02) is an early maturing, high-yielding cultivar with good abiotic stress resistance, selected from the cross 'GT6687-12R/F6038W12-1'. This cultivar has very good frost resistance, a firm stem, and tolerates high temperature during the grain-filling period. Mv Gorsium is moderately resistant to powdery mildew and leaf rust, and resistant to stem rust. This cultivar is a medium quality hard red bread wheat.
MAS selection. The resistance gene Lr37, originating from Ae. ventricosa, has been identified using the SC-Y15 F/R PCR marker in a set of wheat genotypes. From 219 cultivars and lines tested, gene Lr37 was identified in 35 genotypes originating from various countries where its presence was not previously reported. One of them is Vekni, a very promising breeding line from Martonvásár, which confirms year by year the continued effectiveness of resistance against leaf rust under field conditions.
Durum wheat breeding. The most recent success in the winter durum wheat breeding project is the state registration of Mv Gyémánt, a high-yielding winter durum wheat variety with excellent cold tolerance and good technological quality. Two further cultivars are being tested in state variety trials that gave satisfactory results for yield and technological quality in the first year. They have been sown in the second year of the state trials.
Molecular markers linked to the yellow pigment content of durum wheat have been identified using the bulk segregant analysis model. After combining the DNA of the ten lines with the highest and the ten with the lowest yellow index, these two samples were used to look for polymorphism mainly using RAPD primers. The experiment is expected to end in February 2006.
Investigations were made on a combination developed using breeding lines with widely different values of yellow pigment content (the Austrian line PWD1216, which had high pigment content, and MvTD10-98, which had an extremely low pigment content). Based on data for the last two years, ANOVA demonstrated a significant difference between the yellow index values of the families, but the year and 'genotype x year' interaction also were significant. The difference between the yellow index values of the two parents was well in excess of the LSD5% value (1.94). The yellow index was also significantly influenced by the year. The mean value for the families and parents was 25.61 in 2004 and 21.95 in 2005. The order of progeny with values close to those of the parents did not change to any great extent in the two generations, so effective selection for yellow pigment content can be carried out in both the positive and negative direction even in early progeny generations.
Disease-resistance studies. Within the framework of an international (Bioexploit-EU FP6) project, molecular marker selection is being used to incorporate known resistance genes (Lr9, Lr19, Lr24, Lr25, Lr29, Lr35, Lr37, and Lr47) into cultivars adapted to Hungarian conditions as part of a backcross program. Progeny similar to the recurrent cultivar but resistant to leaf rust have been selected from populations sown in field experiments for phenotypic testing.
The degree of infection of genotypes carrying known genes for leaf and stem rust resistance was tested in an artificially inoculated nursery. The resistance genes Lr9, Lr19, Lr24, Lr25, Lr29, Lr35, and Lr37 continued to provide effective protection against leaf rust in Martonvásár, as did gene Lr47, which had not been previously tested. Cultivars with the gene Sr36 were still not infected by stem rust. The resistant reaction type and less than 20 % infection was observed for genotypes carrying genes Sr11, Sr27, Sr30 or SrDr, or the gene combination Sr5+6+8+17.
Powdery mildew isolates collected in the neighborhood of Martonvásár were used to determine the race composition of the pathogen population, the degree of virulence, and the effectiveness of known resistance genes. The following wheat powdery mildew races were dominant in 2005 (frequency in brackets): 51 (24.4 %), 72 (17.2 %), 76 (14.4 %), and 77 (12.2 %). The number of virulence genes in the pathogen population averaged 5.67. Almost complete protection against the wheat powdery mildew isolates tested was provided by the Pm4a + resistance gene, whereas cultivars with genes Pm1+2+9, Pm3b or Pm3d exhibited less than 20 % infection.
Winter wheat genotypes with adult resistance to powdery mildew were identified in field and greenhouse experiments. For the majority of the genotypes tested, the area under the disease progress curve was similar to that of Massey, the resistant control, but cultivars and lines with significantly better resistance also were found. Among the genotypes in the Martonvásár breeding stock, Mv Táltos, Mv Panna, and line Mv07-03 were found to have excellent adult powdery mildew resistance.
The field FHB resistance of lines developed from populations of old Hungarian cultivars was investigated in an artificially inoculated nursery, together with that of foreign resistance sources. The level of spike infection for 19 of the lines developed from populations of old Hungarian cultivars was less than 10 %. The average spike infection of resistant spring wheat genotypes obtained from the Nanjing partner institute as part of a Chinese-Hungarian project was 16.5 %, the most resistant line being Ning894013. Analysis of the genetic background of FHB resistance using microsatellite markers revealed gene effects on several chromosomes in line Ning8331.
Among the Martonvásár genotypes, a low level of FHB infection was recorded for Mv Emese, while Mv Palotás and line Mv08-03 also performed well in the experiment. The Martonvásár cultivars Mv Táltos, Mv Csárdás and Mv Marsall proved to have above-average resistance to the spread of FHB within the spike.
A survey was made of the virus composition of winter wheat, winter barley, durum wheat, winter oat, and triticale crops. The wheat dwarf virus (WDV) was identified on almost 100 % of plants exhibiting symptoms. Work was begun under field conditions on the elaboration of an artificial inoculation method using Psammotettix alienus Dahl., the vector of WDV.
Abiotic stress-resistance studies. The effect of heat, drought, and combined heat and drought stress was studied in an artificially created environmental system on wheat cultivars with diverse genetic backgrounds. Changes in the photosynthetic processes, chlorophyll content, and chlorophyll fluorescence induction of 12 wheat cultivars grown in phytotron chambers were recorded on the basis of biophysical measurements during 15-day stress treatments starting on the 12th day of heading. Among the 12 cultivars, Fatima 2 and Mv Mambó proved to have good heat tolerance based on changes in the chlorophyll content, whereas Plainsman V gave the most sensitive response. Drought stress also was tolerated best by Mv Mambó. The most sensitive response to heat stress was observed in the photosynthetic processes of Mv Makaróni and Bánkúti 1201.
The wheat cultivars tested could be divided into two groups on the basis of the response of their chlorophyll fluorescence values to drought stress. Mv Mambó, Plainsman V, and Bánkúti 1201 proved to be drought-tolerant, whereas Bezostaya 1, Mv Magma, and Mv 15 were classified in the drought-sensitive group.
High temperature and drought had a negative effect on physiological processes both separately and in combination. Similar reductions, which gradually became more severe, were observed as a response to extreme heat stress, drought stress and combined stress.
Among the abiotic stress factors the cultivars exhibited better tolerance to high temperature in all cases, because the optimum water supplies helped them to avoid becoming stressed. Drought had a greater effect on the biomass production and yield of the cultivars, while a combination of the two stress factors resulted in the most drastic reduction.
The leaf nitrogen content of winter wheat cultivars Mv 15 and
Alba was found to decrease in response to a rise in the atmospheric
CO2 level, but this decline was smallest when the soil N content
was around optimum. The effect of doubling the CO2 level was greatest
in the suboptimum and supraoptimum ranges. At low nitrogen supplies,
this difference could be attributed to the C surplus, and at high
N levels to the excess of nitrogen. At low soil nitrogen levels,
the nutrient uptake of the plants was unable to keep up with the
increase in nitrogen requirements even when the root mass increased.
At high nitrogen levels, however, the plants were unable to prevent
the uptake of excess nitrogen, so the dilution of the toxic level
could be attributed to greater C incorporation. The results proved
that high CO2 level only caused substantial dilution of the nitrogen
content in plant tissues in the suboptimum and supraoptimum N
ranges.
B. Barnabás, M. Molnár-Láng, G. Linc, É. Szakács, K. Jäger, I. Molnár, F. Bakos, H. Ambrus, A. Schneider, A. Sepsi, and A. Fábián.
Effect of aluminium stress on the androgenic development of wheat microspores. Wheat anther culture is a feasible system for the in vitro selection of aluminium-tolerant plants. However, no detailed investigation has yet been reported on the effect of aluminium on the sporophytic development of microspores. In this study, the cell division pattern and viability of microspores, embryoid formation, and green plant regeneration were monitored in the control and in cultures given a single or repeated aluminium treatment.
Although the free Al concentration was higher than 20 mM during the first week of the incubation period, no cytological effect of Al could be detected during the first week irrespective of the Al treatments. By the 14th day, when the anther walls were extensively necrotized, microspore embryogenesis were affected in both cases. In cultures treated with aluminium only at the beginning of the incubation period, the number of nuclei was lower and their distribution in the multinucleate structures was more heterogeneous than in the control cultures. The microspore embryogenesis and plant regeneration were possible, but were delayed and occurred with lower frequency. In the cultures treated repeatedly with Al (weekly), the aluminium toxicity was much more severe, resulting in very few viable microspores. The cells were highly vacuolated, frequently contained micronuclei, and had unusually thick walls. These cells were unable to develop further. These results indicate that the anther walls may delay the manifestation of the effects of Al on microspore development. Microspores can survive a single Al treatment, but perish when they are exposed to Al toxicity for a long time.
Molecular cytogenetic characterization of Ae. biuncialis and its use for the identification of 5 derived wheat/Ae. biuncialis addition lines. The aim of the experiments was to produce and identify different T. aestivum-Ae. biuncialis disomic addition lines. To facilitate the exact identification of the Ae. biuncialis chromosomes in these T. aestivum-Ae. biuncialis disomic additions, we analyzed the FISH pattern of Ae. biuncialis (2n=4x=28, UbUbMbMb), comparing it to the diploid progenitors (Ae. umbellulata 2n=2x=14, UU, and Ae. comosa 2n=2x=14, MM). In order to identify the Ae. biuncialis chromosomes, FISH was done using two DNA clones (pSc119.2, pAs1) on Ae. biuncialis and its two diploid progenitor species. Differences in the hybridization patterns of all chromosomes were observed between the four Ae. umbellulata accessions, the four Ae. comosa accessions, and the three Ae. biuncialis accessions analyzed. The hybridization pattern of the M genome was more variable than that of the U genome. Five different wheat-Ae. biuncialis addition lines were produced from the wheat-Ae. biuncialis amphiploids produced earlier in Martonvásár. The 2M, 3M, 7M, 3U, and 5U chromosome pairs were identified with FISH using three (pSc119.2, pAs1, and pTa71) repetitive DNA clones in the disomic chromosome additions produced. Genomic in situ hybridization was used to differentiate the Ae. biuncialis chromosomes from wheat, but no chromosome rearrangements between wheat and Ae. biuncialis were detected in the addition lines.
Ability of chromosome 4H to compensate for 4D in response to drought stress in a newly developed and identified wheat-barley DS4H(4D) line. A spontaneously produced wheat-barley DS4H(4D) line was identified cytogenetically using GISH, multicolor FISH, and microsatellite markers. The ability of the barley 4H chromosome to compensate for wheat 4D in response to mild drought stress also was investigated.
In the barley cultivar Betzes and the DS4H(4D) line mild osmotic stress induced intensive stomatal closure, resulting in reduced water loss through transpiration and unchanged RWC in the leaves. Because the CO2 assimilation rate remained relatively high, the water use efficiency, which is an important factor associated with drought tolerance, increased intensively under mild osmotic stress in these lines. In the case of the parental wheat genotypes, however, mild drought stress induced less intense stomatal closure and a greater decrease in the CO2 assimilation rate than in barley or in the substitution line, resulting in unaugmented or reduced water use efficiency. The results demonstrate that genes localized on the 4H chromosome of barley were able to increase the water use efficiency of the wheat substitution line, which is suitable for improving wheat drought tolerance through intergeneric crossing.
G. Galiba, G. Kocsy, A. Vágújfalvi, V. Szilágyi, A. Soltész, and T. Kellcs.
Gene expression studies in cold-treated wheat. An international effort (Hungarian - Italian - American) has shown that the expression of three cold-inducible cbf genes have a positive correlation with the freezing tolerance of wheat. These genes were mapped to a QTL region (Fr-A2) on chromosome 5A of wheat that determines freezing tolerance. In a German-Hungarian joint research project, (Plant Resource) the comparison of cold-induced changes in the transcript profile of wheat chromosome substitution lines having different freezing tolerances showed which genes exhibited a change in expression as the result of the 5A chromosome.
G. Kovács.
Evaluation of selected genetic resources and breeding lines of T. monococcum subsp. monococcum and T. turgidum subsp. dicoccum under organic farming conditions. The growing interest in hulled wheat cultivation has been stimulated, no doubt, by the increasing demand for traditional foods with a natural image, especially in the organic market. The new economic situation could stimulate the breeding and production of emmer and einkorn as the source of an especially valuable foodstuff. Based on intensively growing market needs, the establishment of organic breeding procedures was initiated for einkorn and emmer. Several hundred genebank accessions of these two species have been characterized in recent years. The results suggest that their direct use in breeding is greatly hindered, however, by the fact that the genebank accessions are very heterogeneous populations. In recent years, several pure lines have been produced using the single-seed descent, and the lines obtained have been agronomically described. Genetically extreme genotypes were crossed to produce mapping populations for further molecular studies. The best lines were used in organic breeding. In the case of einkorn, the lines obtained were tested under low-input conditions, and their yielding capacity has found to be already higher than 3 t/ha. During the einkorn improvement procedure, a new semidwarf genotype was identified and genetically analyzed. According to the results of a recent experiment, this genotype carries a recessive monogenic dwarf gene, which should be highly useful in producing semidwarf einkorn cultivars.
Organic wheat and einkorn breeding. Organic farming differs from conventional agricultural practices in that it aims to maximize dependence on naturally occurring biological systems. Such systems are less important in conventional agriculture, which is highly dependent on synthetic, external inputs. Our comparative experiments underlined that there is a significant difference between the agronomic performance and adaptability of conventionally bred cultivars under organic and conventional growth conditions and only a few of them are really useful in organic farming. Therefore, developing cultivars and populations that are bred and selected under organic conditions is essential to ensure good performance and quality for organic production.
During the last 3 years, new einkorn breeding lines have been produced using organic-breeding techniques, which resulted in very good adaptability, weed competitive ability, stable quality parameters, and acceptable yield. Meanwhile, einkorn lines selected under conventional conditions, which had very good agronomic performance and productivity (but unstable quality parameters) under conventional conditions, were not at all competitive with the organically bred lines under organic conditions.
In the case of bread wheat, a new project was initiated on the basis of evolutionary breeding theory. In these experiments, different composite cross populations were produced using 4, 6, and 7 parents. The F2 generations were grown at a range of organic and nonorganic sites and compared with conventionally bred cultivars. The results suggest that genetically diverse populations have better adaptability, especially in the case of low-input, organic conditions, whereas under high-input, conventional growth conditions, they cannot compete with conventionally bred cultivars.