[Resistance of bread wheat (Triticum aestivum L.) to preharvest sprouting: an association analysis].

A statistical analysis of the data about 1422 bread wheat accessions with estimated preharvest sprouting was carried out. Close associations of preharvest sprouting resistance with the grain color and with resistance to Fusarium head blight were revealed, as well as weak, but statistically significant, associations with the type of development, awnedness, and reduced height genes Rht-B1 and Rht-D1 (insensitive to gibberellin GA3). The pedigree analysis showed that the cluster structures of the gene pools of the North American red-grained and white-grained varieties are practically identical. In both groups, varieties that are resistant to preharvest sprouting differ from susceptible ones in the percentage of the contributions of the Crimean and Mediterranean landraces. Resistance is associated with a high contribution by the Crimean landrace and susceptibility is associated with a high contribution by the Mediterranean landrace.

[Analysis of diversity of Russian and Ukrainian bread wheat (Triticum aestivum L.) cultivars for high-molecular-weight glutenin subunits].

The allelic diversity of high-moleculat-weght glutenin subunits (H WIGS) in Russian and Ukrainian bread wheat cultivars was analyzed. The diversity of spring wheat cultivars for alleles of the Glu-1 loci is characterized by medium values of the polymorphism index (polymorphism information content, PlC), and in winter wheats it varies from high at the Glu-A1 locus to low at the Glu-D1 locus. The spring and winter cultivars differ significantly in the frequencies of alleles of the glutenin loci. The combination of the Glu-A1b, Glu-B1c, and Glu-D1a alleles prevails among the spring cultivars, and the combination of the Glu-A1a, Glu-B1c, and Glu-D1d alleles prevails among the winter cultivars. The distribution of the Glu-1 alleles significantly depends on the moisture and heat supply in the region of origin of the cultivars. Drought resistance is associated with the Glu-D1a allele in the spring wheat and with the Glu-B1b allele in the winter wheat. The sources of the Glu-1 alleles were identified in the spring and wheat cultivars. The analysis of independence of the distribution of the spring and winter cultivars by the market classes and by the alleles of the HMWGS loci showed a highly significant association of the alleles of three Glu-1 loci with the market classes in foreign cultivars and independence or a weak association in the Russian and Ukrainian cultivars. This seems to be due to the absence of a statistically substantiated system of classification of the domestic cultivars on the basis of their quality.

[Genealogical and statistical analyses of the inheritance of gliadin-coding alleles in a model set of common wheat Triticum aestivum L. cultivars].

Allelic diversity of the gliadin-coding loci Gli-1 and Gli-2 was compared with the genealogical profiles of common wheat cultivars developed in Saratov. Allele tracking through their pedigrees and hierarchic cluster analysis associated 31 Gli alleles with groups of original ancestors. The cultivars Poltavka (12 alleles of six loci) and Selivanovskii Rusak (six alleles of six loci) were identified as sources of the majority of alleles. The results of the cluster analysis fully coincided with the results of allele tracking for alleles occurring at high frequencies. For rare alleles, the resolution of the cluster analysis was somewhat lower and depended on the similarity/distance measure. Thus, it proved possible to indirectly identify the donors of gene alleles by multidimensional statistics even when data on alleles identified in ancestors are unavailable. This approach to the analysis of inheritance has two limitations: detailed pedigree data should be known, and relatively high frequencies (no less than 15--20%) should be observed for the alleles in a sample under study. Cluster analysis was used to study the association of gliadin alleles with commercial quality classes. The most important gliadin-coding alleles, which mark strong cultivars, were identified. In the Saratov cultivars, such alleles include Gli-A1f, Gli-B1e, Gli-D1a, Gli-A2q, Gli-B2s, and Gli-D2e, which were inherited from the landrace Poltavka, and Gli-A1i, Gli-A2s, and Gli-B2q, which were inherited from the landrace Selivanovskii Rusak.

[Genealogical analysis of the diversity of spring barley cultivars released in former Czechoslovakia and modern Czechia].

Genealogical analysis was employed in studying the time course of changes in genetic diversity of spring barley cultivars released in former Czechoslovakia and the modem Czech Republic. Cultivars from different regions proved to significantly differ in the distribution of dominant ancestor contributions, suggesting a specificity of original ancestors to different cultivation conditions. A comparison of cultivar groups differing in end use showed that the genetic diversity of malting cultivars was significantly lower than that of feed cultivars, although modern malting and feed cultivars of Czechia and Slovakia have virtually the same genetic basis. Temporal analysis showed that diversity tended to increase through decades. While new original ancestors were introduced in pedigrees, especially in the past 30 years, the number of local landraces and old cultivars gradually decreased. The losses accounted for about two-thirds of the local germplasm. Thus, a substantial increase in genetic diversity was accompanied by genetic erosion of the local spring barley gene pool of former Czechoslovakia. A cluster structure was observed for the set of spring barley cultivars released in the postwar period. The coefficient of parentage averaged overall possible pairs of cultivars introduced in the Czech National List was estimated at 0.11. It was concluded that the genetic diversity of modern spring barley cultivars in the Czech Republic is at an acceptable level.

[Dynamics of genetic diversity in winter common wheat Triticum aestivum L. cultivars released in Russia from 1929 to 2005].

Genealogical analysis was used to study the dynamics of genetic diversity in Russian cultivars of winter common wheat from 1929 to 2005. The Shannon diversity index of the total set of released cultivars remained almost unchanged, although the number of original ancestors (landraces and genetic lines) increased almost tenfold in the period under study. This was explained in terms of the dependence of the modified Shannon diversity index on two parameters, the number of original ancestors and the mean coefficient of parentage. Significant direct effects were revealed: a positive effect of the former parameter and a negative of the latter. As a result, the increase in the number of original ancestors was compensated by the increase in relatedness of cultivars. Genetic erosion of realized diversity was observed, as a half of Russian landraces were lost. Although the mean coefficient of parentage did not reach its critical value (R = 0.25), cultivars of some regions (Central and Volga-Vyatka) proved to be closely related. A favorable gradual decrease in the mean coefficient of parentage was observed in the past 15 years. A set of modem winter wheat cultivars, which were introduced in the Russian State Catalog from 2002 to 2005, displayed a cluster structure. The overwhelming majority of cultivars formed two clusters originating from Bezostaya 1 (67% of cultivars) and Mironovskaya 808 (31%).

[Genealogical analysis of resistance to fusarium head blight in Russian and Ukrainian cultivars of common wheat Triticum aestivum L].

The GRIS3.5 information analytical system of wheat genetic resources was used to track the possible ways of the transmission of fusarium head blight resistance from ancestors to progenies in extended pedigrees of 149 Russian and Ukrainian cultivaris of winter common wheat. Analysis of variance was performed for the coefficient of parentage computed for the cultivars under study and the putative sources of resistance and revealed that groups of resistant and susceptible cultivars differed in the distribution of contributions of the sources. In the resistant group, significant results were obtained for the contributions of Odesskaya 16, Gostianum 237, and Frontana. Pedigree analysis showed that fusarium head blight resistance was most commonly transmitted from Gostianum 237 through Odesskaya 16 and its derivatives. The landrace Khar'kovskaya probably served as a source of resistance in the case of Gostianum 237. In addition, the set of resistance sources included Kooperatorka, Hope, San Pastore, Triticum timopheevii Zhuk., and Secale cereale. Some well-known sources of fusarium head blight resistance varying in genetic determinants--Sumai 3, Wangshuibai, Wuhan 1, Nyubay (China), Nobeokabozukomugi, Shinchunaga (Japan), Arina (Switzerland), Fundulea-201R (Romania), and Renan (France)--have so far not being employed in breeding in Russia and provide an important reserve for breeding for resistance.

[Analysis of genetic diversity of spring durum wheat (Triticum durum Desf.) cultivars released in Russia in 1929-2004].

Based on genealogical analysis, the genetic diversity of 78 spring durum wheat cultivars released in Russia in 1929-2004 have been examined. The temporal trends of change in diversity were studied using series of n x m matrices (where n is the number of the cultivars and m is the number of original ancestors) and calculating coefficients of parentage in sets of cultivars released in particular years. The pool of original ancestors of spring durum wheat cultivars includes 90 landraces and old varieties, more than a half (57%) of which originate from European countries, including Russia and Ukraine (45%). The original ancestors strongly differ in the frequency of presence in the cultivar pedigrees. Landraces Beloturka, Sivouska, Kubanka (T. durum Desf.), Transbaikalian emmer, Yaroslav emmer (T. dicoccum Schuebl.), Poltavka (T. aestivum L.), and the original ancestors of cultivars Kharkov 46, Narodnaya, and Melanopus 1932 enter in the pedigrees of more than half of cultivars created within the framework of various breeding programs. At that, their distribution by cultivars from different breeding centers strongly varies. Analysis of temporal dynamics of genetic diversity, based on genetic profiles and coefficients of parentage, has shown that the genetic diversity of Russian durum wheats increased during the period examined. Nevertheless, genetic erosion of the local material-a loss of approximately 20% of the pool of Russian original ancestors-has been found. The contribution of the original ancestors to the pedigrees of different cultivars, constructed in different breeding centers and recommended for cultivation in different regions, has been estimated. The variation of the released cultivars was highest in the Lower Volga region and lowest in the Ural region. In all, the lower threshold of genetic diversity in all regions does not reach the critical level, corresponding to the similarity of half-sibs. The set of modern cultivars included in the Russian Official List 2004 has a cluster structure.

[Trends in genetic diversity change of spring bread wheat cultivars released in Russia in 1929-2003]. / Tendentsii izmeneniia geneticheskogo raznoobraziia sortov iarovoi miagkoi pshenitsy, realizovannykh na teritorii Rossii v 1929-2003 gg.

Using genealogy analysis, we studied genetic diversity of 340 cultivars of spring bread wheat that were released on the territory of Russia in 1929-2003. Trends in the temporal change of genetic diversity were inferred from analysis of a set of n x m matrices, where n is the number of the released cultivars and m is the number of original ancestors. The pool of original ancestors of the spring bread wheat cultivars for the total period of study included 255 landraces, of which 88 were from the former USSR and modern Russia. The original ancestors showed great differences in their presence in the cultivar sets examined and, consequently, in their importance for the gene pool of Russian spring wheats. The distributions of contributions of dominant original ancestors to cultivar diversity were significantly different in different regions, indicating that the ancestors were specific for the cultivation conditions. During the last 75 years, the genetic diversity of the spring bread wheat cultivars has been increasing owing to the wide use of foreign material in Russian breeding programs. However, our analysis showed that about 60 landraces, including the Russian ones, were lost during the studied time period. The lost part makes up 35% of the gene pool of the Russian original ancestors. It is reasonable to assume that the lost landraces carried a gene complex f or adaptation to specific Russian environments. Specificity of the contributions of the original ancestors in the sets of cultivars produced in different breeding centers was established. A comparative analysis of genetic similarity of cultivars was carried out using coefficients of parentage. Significant differences in this parameter between breeding institutes and regions of cultivation were revealed.

[Genealogic analysis of the resistance of winter wheat to common bunt]. / Genealogicheskii analiz ustoiichivosti miagkoi ozimoi pshenitsy k tverdoi golovne.

Comparative genealogical analysis of North American (the United States and Canada) and Eastern European (Russia and Ukraine) winter wheat cultivars resistant and susceptible to common bunt has been performed. Analysis of variance applied to North American wheats has demonstrated that resistant and susceptible cultivars significantly differ from each other with respect to the contributions of common ancestors. The contributions of Oro (Bt4 and Bt7), Rio (Bt6), White Odessa (Bt1), and Florence (Bt3) to the resistant cultivars are significantly higher than their contributions to the susceptible ones. This demonstrates that the use of these resistance donors in wheat breeding for several decades has been effective. The contribution of PI-178383 (Bt8, Bt9, and Bt10) is considerably higher in the group of resistant cultivars bred after 1965. The mean contributions of Federation (Bt7) and Nebred (Bt4) are significantly higher in the group of resistant cultivars obtained before 1965; however, the differences in the contributions of these donors between new resistant and susceptible cultivars became nonsignificant. Among the Russian and Ukrainian cultivars, there are differences between groups of resistant and susceptible cultivars from different regions determined by the differences between the regional populations of the pathogen in racial composition. In the northern region, the contributions of the wheat grass (Agropyron glaucum) and the rye cultivar Eliseevskaya are significantly higher in the resistant cultivars; in the southern region, a local cultivar of the Odessa oblast is the prevalent resistant cultivar. In addition, cultivar Yaroslav Emmer is likely to be effective in the northern region; and foreign sources (Oro, Florence, Federation, and Triticum timopheevii), in the southern region. Very few sources of vertical resistance to common bunt are used for winter wheat breeding in Russia and Ukraine. The decrease in genetic diversity in favor of a few identical genes may cause adequate changes in the pathogen population and subsequent proliferation of the pathogen on the genetically identical substrate. A new interpretation of the resistance of line Lutescens 6028 as a source of new genes, Bt12 and Bt13, is suggested. Both genealogical and segregation analyses have shown that the genes determining the resistance of this line may be identical to those described earlier (Bt1, Bt3, Bt4, Bt6, and Bt7); and the high resistance of this line is determined by a combination of these genes.

[Genealogical approach to the formation of the winter wheat core collection]. / Genealogicheskii podkhod k formirovaniiu sterzhnevoi kollektsii ozimoi pshenitsy.

The correctness of the genealogical approach to the estimation of genetic diversity has been substantiated. The approach implies a comparison of the estimates of similarity based on genetic markers and coefficients of parentage. A method of the application of the genealogical approach to the formation of the core collection has been developed. The adequacy of the core set has been estimated using Shannon's diversity index adapted for genetic profiles and the correlation between the distributions of ancestors' contributions. A core collection has been formed. This collection contains 25% of the accessions of the original winter wheat (Triticum aestivum L.) collection from the Czech Genebank and represents 70-76% of the intracluster diversity. A decrease in intercluster diversity has not been found in the core collection.

[Genealogy-based comparative analysis of loose smut resistance of spring common wheat cultivars]. / Sravneitel'nyi analiz ustoichivosti iarovoi miagkoi pshenitsy k pyl'noi golovne, osnovannyi na genealogicheskom podkhode.

Comparative genealogical analysis was conducted for loose smut-resistant and susceptible common wheat cultivars of three regions: Russia, Canada, and India. Pedigree analysis of differentiator varieties revealed several sources of the Ut1, Ut3, and Ut4 genes. Tracking resistance transmission in extended pedigrees allowed identification of resistance donors, sources, and, in some cases, putative genes in Russian, Canadian, and Indian cultivars. A contingency table was constructed with the data on resistance or susceptibility of 839 common and durum wheat cultivars and demonstrated a significant association for resistance to two, loose and stinking, types of smut.

[Analysis of genetic diversity of wheat using genetic resources information system GRIS]. / Analiz geneticheskogo raznoobraziia pshenitsy s pomoshch'iu informatsionno-analiticheskoi sistemy geneticheskikh resursov GRIS.

The possibilities of using the Genetic Resources Information and Analysis System (GRIS) 3.2, a database and software package, in studies of various aspects of genetic diversity in wheat are demonstrated. A model of genetic diversity was analyzed; diversity levels were estimated in wheat from various regions at different times. The genetic basis of Russian winter and spring common wheat cultivars was investigated. Transmission of powdery mildew resistance genes was traced in cultivars with identified Pm genes. For some genes, patterns of geographical distribution were characterized. Description of GRIS 3.2 is given: the package consists of a database on the global gene pool of wheat and software on genealogical and statistic analyses of genetic diversity.