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More than 2000 wheat collection samples were studied for seedling resistance to 4 diseases. Noncoincidence of results obtained after inoculation of leaf segments placed on water solution of benzimidazole (60 ppm) and intact plants was found for 3 foliar diseases (leaf rust - Puccinia recondita, dark brown leaf spot blotch - Bipolaris sorokiniana and septoria glume blotch - Septoria nodorum). Sixty-three entries were resistant to leaf rust; 26 of them have gene for resistance Lr26 (non-effective under field condition), 25 - gene Lr24, 4 - gene Lr19, 8 - gene Lr9 and 2 - gene Lr41. Samples 181-5, Fielder, Butte 66, Raj 1972 and Soisson were moderately resistant to spot blotch; 181-5 - to common root rot and Moking and MN 81330 - to glume blotch. Very high level of partial resistance to 3 diseases was found in late generations of somaclonal lines of weakly and moderately resistant initial genotypes: to leaf rust in lines of cv. Spica, to leaf spot blotch - in lines of 181-5, to common root rot - in that of 181-5 and cv. Vera; moderate resistance to glume blotch was identified in lines of cv. Spica.

A genetic linkage map for apricot (Prunus armeniaca L.) has been constructed using amplified fragment length polymorphism (AFLP) markers in 80 BC1 individuals derived from a cross LE-3246 × Vestar. From 26 different primer combinations, a total of 248 AFLP markers were scored, of which, 40 were assigned to 8 linkage groups covering 315.8 cM of the apricot nuclear genome. The average interval between these markers was 7.7 cM. One gene (PPVres1) involved in resistance to PPV (Plum pox virus) was mapped. Two AFLP markers (EAA/MCAG8 and EAG/MCAT14) were found to be closely associated with the PPVres1 locus (4.6 cM resp. 4.7 cM). These markers are being characterized and they will be studied for utilization in apricot breeding with marker-assisted selection (MAS).

Achievements and prospects of wheat breeding for disease resistance in the world and in the Czech Republic are reviewed. Attention is paid to rusts, powdery mildew, leaf blotch, glume blotch, tan spot, fusarium head blight, common and dwarf bunt, eyespot, barley yellow dwarf virus on wheat and wheat dwarf virus. Genes for resistance to rusts and powdery mildew in the cultivars registered in the Czech Republic are listed. Promising resistance genes and sources of resistance to the above mentioned diseases are reviewed. Prospects of resistance breeding including application of methods of molecular genetics and development of synthetic hexaploids are outlined.

For 17 cultivars of winter wheat (Triticum aestivum L.) different vernalization and photoperiod responses were detected. The effect of photoperiod sensitivity was not significantly changed by vernalization; different vernalization responses were probably due to the presence of multiple alleles at Vrn loci. The delay in heading depended on the vernalization deficit exponentially: y = Parameter (1) + (y0 - Parameter (1)) × EXP (Parameter (2) × (x - x0)). The dependence was shown to be general and significant for the given model in all the studied cultivars. Individual regressions characterised responses of cultivars to a deficit of vernalization treatment. Cluster analysis according to the characterisation obtained (full vernalization requirement, minimum vernalization requirement, insufficient vernalization and parameters of the dependence) showed the relationships between cultivars and enabled their grouping by similar profiles of vernalization, and, possibly, of photoperiod response. In individual cultivars, an attempt was made to use the model to predict performance for some agronomic traits.

Genetically modified organisms have become a part of our environment and food chain. Roundup Ready soybean is at the moment the most frequent one that man can meet. National regulations require careful monitoring and detection of GMOs. We present in this investigation comparison of several protocols and individual steps, which are included in the whole detection procedure. Currently used CTAB based protocol is suitable for DNA isolation from the green plant tissue but also from the flour. Lectin coding sequence specific primers were suitable for soybean DNA detection unlike leu-tRNA gene specific primers. Only one of the tested CaMV sequence specific primer pairs did not amplify unspecific products under condition tested. NOS terminator specific primer pair was found suitable for routine screening. EPSPS gene was detected using two different protocols; the same primers did not identify other Roundup Ready GM crops.

Activities on plant genetic resources in the Czech Republic are concentrated in the National Programme on Conservation and Utilisation of Plant Genetic Resources. Eleven institutions maintain 51,000 accessions, of which 17.3% belong to vegetatively propagated species. Research Institute of Crop Production (RICP) Prague has the responsibility for the coordination of the Programme; it holds more than half of all accessions in collections of genetic resources, runs the national information system and provides long-term storage for all seed-propagated species. All Czech collections are fully documented in passport data. Evaluation data (based on National descriptor lists for 29 crops) are available for 33% of the accessions. Much work is currently spent to the description and evaluation of collections, to facilitate their utilisation in breeding and agricultural practice. Also collecting missions on the Czech territory, conservation and monitoring of valuable resources maintained in situ contributeto the maintenance and evaluation of local resources. Landraces are considered a valuable part of the collections. Suitable ways of "on farm" conservation are investigated for selected accessions, to support their utilisation in agricultural practice and to enrich the existing diversity of crops and cultivars. Cultivars and landraces of neglected crops (buckwheat, millet, hulled wheat species) were successfully used to enrich the agro-biodiversity and for specific purposes of human nutrition. Close collaboration with producers (often organic farms) and processing industry has been established. Selected alternative crops and catch crops were studied as potential new crops.

In our previous study of Claviceps purpurea three populations were found: G1 on open localities, G2 from shady or wet habitats and G3 on Spartina stands of coastal salt marshes. The latter two are also chemoraces. In the Czech Republic, isolates of G1 and G2 were found. The ability of four isolates representing these populations to infect and develop sclerotia on different host species (Holcus lanatus, Helictotrichon pubescens, Phalaris arundinacea, Dactylis glomerata, Arrhenatherum elatius, Bromus inermis, Bromus erectus, Elytrigia repens, Avenella flexuosa, Lolium perenne, Poa nemoralis, Poa annua, and different cultivars of Poa pratensis) was studied along with their alkaloid production. P. pratensis and D. glomerata were infected by all the isolates and sclerotia were formed by isolates 207 (G1) and 434 (G2), and on two P. pratensis cultivars even by 481 (G3). Infection ability (formation of sphacelial stage and honeydew) was less host-restricted than formation of mature sclerotia. G2 and G3 strains infected A. flexuosa without sclerotia formation. L. perenne was infected only once by strain 207 (G1) without sclerotia formation. P. annua (natural host of G2), was infected by all isolates, but no sclerotia were formed even with G2 strains. From the two G2 isolates, strain 434 from Dactylis formed sclerotia on five host species, whereas isolate 475 originating from Phragmites stand formed only sphacelia. Composition of alkaloid mixture produced in sclerotia of the same strain from various hosts confirmed that host plant does not influence the type of alkaloids produced, only their ratio.

Substitution lines with the chromosome 3B of the Czech alternative cultivar Česká Přesívka (CP) in the genetic background of the wheat cultivars Zdar, Vala, Košutka, Jara and Sandra, differing in their requirements of vernalisation and photoperiod, were compared with the original cultivars under short and long photoperiod, to evaluate the effects of genes, located on the chromosome 3B of CP, on earliness and the response to photoperiod and vernalisation. The results suggest that these genes have only a small effect upon the vernalisation requirement, but are more related to the response to photoperiod. However, the genes on the substituted chromosome appear to influence the earliness per se and very likely interact also with the photoperiodic response.

A survey of development and prospects of the utilisation of doubled haploid techniques in rapeseed breeding in the world and in the Czech Republic is presented. The first utilisation of spontaneously occurred haploids from Brassica napus inbreeding programmes is described. The development of techniques of anther and later microspore culture is outlined. Special emphasis is given to the practical use of doubled haploids for the improvement of the effectiveness of breeding new productive cultivars. Some partial results of evaluation of yield parameters and resistance to important diseases in the obtained doubled haploid lines of winter oilseed rape are shown. The literary review and present results indicate, that the doubled haploid technique can be effectively used for the development of homozygous oilseed rape lines as an alternative to conventional methods.

The relationship between gliadin alleles, known to mark frost tolerance, and actual frost tolerance was investigated in 52 doubled haploids (DH) from the cross Florida× Vlada. Frost tolerance was expressed as percentage of plant winter survival in pots placed at different heights above the ground. Gliadin allelic blocks (GLI) were determined by starch electrophoresis. From the six GLI, known as frost tolerance markers, the GLI 1B1, GLI 1D5 or GLI 6D2 was present in 27, 27 or 31 DH, respectively. A weak, but significant correlation of r = 0.29 was found in the DH between their survival and frost tolerance prediction values based on the presence of the gliadin frost tolerance markers. The average survival of DH with gliadin frost tolerance marker GLI 1B1 or GLI 6D2, but not with GLI 1D5, was significantly higher than the survival of DH without this block. The DH without any gliadin frost tolerance marker had the lowest survival. Some gliadin genes thus can be used as frost tolerance markers for preliminary selection of frost tolerant lines and for the study of physiological and genetic constitution of frost tolerance in common wheat.