Winter Bread Wheat Cultivars Research Articles

Breeding value and homeostaticity of the spike performance and its constituents in medium tall winter bread wheat (Triticum aestivum L.) accessions in relation to resistance to the pathogens of powdery mildew (Blumeria graminis (DC.)...

Identification of sources of group resistance in winter bread to the pathogens B. graminis (DC.) E.O. Speer f. sp. tritici Em. Marchal and S. tritici Rob. et Desm. and of high performance of the spike and its constituents is a necessary and relevant step towards the creation of comprehensively valuable and adaptable genotypes. The paper presents the results of evaluation of the breeding value and homeostaticity of the spike performance and its constituents in medium tall winter bread wheat in relation to resistance to powdery mildew and Septoria leaf blotch. New sources of consistently high group resistance to the powdery mildew and Septoria leaf blotch pathogens have been identified: Kyivska 17, Zorianka, Sicheslava, and Svitiaz (UKR). We have selected accessions with high performance of the spike and its constituents in combination with high breeding value and homeostaticity of these characteristics: the kernel weight per spike (Kyivska 17 (Sc = 1.8; Hom = 21.9) (UKR)); the kernel number per spike (Svitohliad (Sc = 37.8; Hom = 554.1), Stritenska (Sc = 36.4; Hom = 452.5), Svitiaz (Sc = 35.8; Hom = 451.8), MIP Lada (Sc = 33.6; Hom = 572.7) (UKR), and Manella (Sc = 33.1; Hom = 460.8) (NLD)); and the thousand kernel weight (Kyivska 17 (Sc = 42.9; Hom = 1053.7), Sicheslava (Sc = 42.6; Hom = 873.2) (UKR), and Turanus (Sc = 41.3; Hom = 707.5) (AUT)). It was found that the percentage of accessions with high homeostaticity of the thousand kernel weight, the kernel number per spike and the kernel weight per spike was 63.6%, 31.8%, and 22.7%, respectively. In the medium tall winter bread wheat accessions, there were strong positive correlations between the breeding value of the kernel weight per spike and resistance to Septoria leaf blotch (r = 0.77, P < 0.01) and between the kernel number per spike and resistance to powdery mildew (r = 0.71, P < 0.01). Significant positive correlations were observed between the breeding value of the thousand kernel weight and resistance to Septoria leaf blotch (r = 0.61, P < 0.01), between the homeostaticity of the thousand kernel weight and resistance to Septoria leaf blotch (r = 0.51, P < 0.01) and between the breeding value of the kernel number per spike and resistance to Septoria leaf blotch (r = 0.56, P < 0.01). The selected sources of high group resistance to powdery mildew and Septoria leaf blotch, high performance of the spike and its constituents in combination with the breeding value and homeostaticity of these traits are valuable starting materials to create highly promising winter bread wheat cultivars, which would be adaptable to limiting biotic factors.

Differentiation of Triticum aestivum L. genotypes according to combination of yield and flour quality indicators

Purpose. Hence, the purpose of this study was to identify winter bread wheat (Triticum aestivum L.) cultivars and breeding lines giving high yields, with improved flour quality and with combination of these features.
 Materials and Methods. The study was conducted at the V.M. Remeslo Myronivka Institute of Wheat (MIW) of NAAS of Ukraine in 2019/20–2021/22. Ten new winter bread wheat cultivars and four promising breeding lines were evaluated. Winter wheat was grown in accordance with routine techniques in the Forest-Steppe of Ukraine. The yields were harvested and recorded in accordance with methods of qualification examination of plant varieties for suitability for dissemination in Ukraine. Winter bread wheat grain quality parameters were determined by conventional methods at the Grain Quality Laboratory MIW.
 Results and Discussion. There was a significant variability of yield and flour quality parameters depending on the conditions of the study years. On average across the winter bread wheat cultivars and breeding lines, the highest contents of protein (14.7%) and wet gluten content (31.9%) were recorded in 2019/20, but the lowest yield (3.40 t/ha) was harvested that year. In 2020/21, on the contrary, the yield was higher (6.46 t/ha), while the sedimentation value (59 mL), protein content (11.9%), and wet gluten content (27.4%) were lower. Cv. ‘MIP Aelita’, ‘MIP Vidznaka’ and breeding line ‘Lutescens 37548’ yielded significantly more than the check cultivar (‘Podolianka’; 5.05 t/ha; LSD05 = 0.33 t/ha). We singled out genotypes that on average in 2019/20–2021/22 were significantly superior to the check cultivar (‘Podolianka’) in term of protein content (‘MIP Nika’, ‘MIP Vidznaka’, ‘MIP Dovira’, ‘Lutescens 37548’, ‘Lutescens 60049’, and ‘Lutescens 60400’), sedimentation value (‘MIP Feieriia’, ‘Lutescens 37548’, ‘Lutescens 60049’, and ‘Lutescens 60302’) and wet gluten content (‘Lutescens 375480’). It should be noted that breeding line ‘Lutescens 37548’ significantly outperformed the check cultivar in all measured flour quality parameters. Based on combinations of high yield with several parameters of flour quality, cv. ‘MIP Aelita’ and ‘MIP Vidznaka’ and breeding lines ‘Lutescens 37548’, ‘Lutescens 60049’, and ‘Lutescens 60302’ were distinguished.
 Conclusions. The selected winter bread wheat cultivars and breeding lines can be used in breeding to create starting materials as sources of improved corresponding parameters of flour quality, a set of the investigated characteristics of flour quality and of combinations of high yield and good parameters of flour quality.

Variability of performance and yield constituents in winter bread wheat accessions

This paper is focused on the study of the performance constituent variability in 104 new winter bread wheat cultivars from 10 countries worldwide, which was carried out in 2016-2019 at the Plant Production Institute named after V.Ya. Yuriev of NAAS of Ukraine. Research results revealed that spike length was the least variable parameter depending on the growing conditions (CV = 2.0–19.2%) and that the following characteristics responded most strongly to changes in the growing conditions: kernel number per spike (CV = 3.5–30.6%), spike weight (CV = 2.3–47.1%), and kernel weight per spike (CV = 1.2–55.1%). According to the variability degree, it was established that cv. Ladyzhynka, Polianka, and Apertus were most responsive to changes in the growing conditions, while cv. Dobirna, Darynka Kyivska, MIP Asol, and Cappelle Desprez were stable in terms of expression of the performance constituents and yield.

The Association of Grain Yield and Agronomical Traits with Genes of Plant Height, Photoperiod Sensitivity and Plastid Glutamine Synthetase in Winter Bread Wheat (Triticum aestivum L.) Collection.

The reduction in plant height caused by mutations in Rht-B1 or Rht-D1 (Reduced height-1) genes in combination with day-length-independent early flowering associated with the Ppd-D1 (Photoperiod-D1) gene were the main factors of the drastic yield increase in bread wheat in the 1960s. Increasing nitrogen use efficiency as well as maintaining high yields under conditions of global climate change are the modern goals of wheat breeding. The glutamine synthetase (GS) enzyme plays a key role in ammonium assimilation in plants. In previous studies, the TaGS2-A1 gene, coding the plastid isoform of GS, was shown to be connected with nitrogen use efficiency in wheat. Using the polymerase chain reaction (PCR) markers, the association of yield and agronomical traits with haplotypes of Rht-B1, Rht-D1, Ppd-D1 and TaGS2-A1 genes was studied in a diverse collection of winter bread wheat cultivars grown in Krasnodar (Russia). In the three-year experiment, semidwarfism and photoperiod insensitivity were confirmed to be highly favorable for the grain yield. The TaGS2-A1b haplotype had a tendency for increased grain yield and lodging resistance, but mainly in plants not possessing the ‘green revolution’ alleles. Thus, TaGS2-A1b may have potential in breeding wheat cultivars with alternative dwarfing genes or tall cultivars, which may be optimal for growing under certain environments.

Initial developmental rate delay in modern highly productive cultivars of winter bread wheat from West Europe

Aim. To evaluate the vernalization requirement duration and sensitivity to photoperiod in the set of modern high yielding winter bread wheat cultivars from West Europe which are proposed for production in Ukraine. Methods. Planting in natural and shortened photoperiods followed by artificial vernalizing variants of 5-days green seedlings have been used for heading dates registration. Results. Many foreign cultivars revealed the durable vernalization requirement and strong photosensitivity. Few stocks were characterized by the week analogous physiological reactions, which are typical in most modern Ukrainian cultivars and breeding lines. Conclusions. Reveled data confirmed the adaptive value of discussed properties for specific environment which are similar to Ukrainian one in many zones of winter wheat cultivation. And they refute the assertion that strong photosensitivity and durable vernalization requirement limit the improvement of yield potential by selection.
 Keywords: winter bread wheat, vernalization requirement, photosensitivity, modern cultivars from West Europe.

Assessment of potential winter hardiness in winter bread wheat cultivars and genotypes by analyzing autofluorescence in seedling tissues

Background.Winter crops are the most productive component of agricultural biocenoses. In Russia, winter wheat suffers the greatest losses in winter, so a search for traits marking high or low winter hardiness in autumn-sown genotypes, including improved cultivars, is needed to assess their potential for overwintering. One of such markers of high winter hardiness is an increased lignin content in plant tissues. The terminal enzyme in the phenylpropanoid pathway of metabolism, wherein lignin components are formed, is cinnamyl-alcohol dehydrogenase (CAD, EC 1.1.1.195). In plants, the CAD enzyme is one of the links in the aromatic metabolism, which generates, in addition to lignin, a number of aromatic compounds, such as lignans, aromatic glycosides, etc. Many of these compounds, like lignin, contain chromophore groups and are capable of autofluorescence.Correlations of the genotypes that incorporate CAD1-F with overwintering are studied in this work.Materials and methods.The winter bread wheat cultivars ‘Zitnica’ (Yugoslavia) and ‘Novosibirskaya 9’ (ICG SB RAS, Russia), contrasting in winter hardiness and CAD isozyme spectra, their hybrids, and 28 improved winter cultivars developed in Krasnodar were selected for the study. Fluorescence analysis of 28 winter wheat cultivars was also performed. Correlation coefficients between fluorescence and frost tolerance were calculated using the results of the analysis of 7 most contrasting cultivars.Conclusions. The tested winter bread wheat genotypes demonstrated the interplay between CAD1-F and successful overwintering: a correlation was found in the genotypes carrying the 00 CAD1-F allele with higher percentage of overwintered plants. This dependence was not observed in every season. The analysis of seedling sections for fluorescence can also be used for preliminary assessment of winter tolerance in winter bread wheat under laboratory conditions.

Formation the elements of productivity of winter wheat by seed dressing application the slow-acting complex fertilizers

Optimization of plant nutrition in the initial stages of the development is important for the formation of productive elements of the main and additional spikes and grain yield. The article presents the results of the studying of the effect of slow-release chlorine-free fertilizers in seed dressing application at the rate of 100 kg/ha on the formation of productive elements in winter wheat compared with the zone control (nitroammophoska) and a variant without fertilizers. Field research was conducted in 2019–2021 on winter bread wheat cultivars Bohdana and Samurai. The fertilizers produced by FertinAgro were studied: DuraSOP with the content of NPK(S) – 9:20:12:(15), 10:10:17:(20), and 4:26:12:(10). It is established that the influence of weather conditions on the variability of grain weight per spike, grain number per spike, thousand kernel weight significantly exceeded the studied factors in both cultivars. The formation of productivity elements under the impact of the studied fertilizers depended on the cultivars and manifested themselves in different ways in different weather conditions. DuraSOP fertilizers did not have a significant difference in the effect on grain number and weight per spike in cv. Bohdana compared to the control in arid conditions, but grain weight from spike increased to 1.74–1.78 g compared to the application of nitroammophoska, and grain number per spike varied insignificantly under favorable conditions. Application of DuraSOP fertilizers in cv. Samurai allowed to form 1.17–1.21 g of grain in spike under the arid conditions and 1.47–1.49 g – in the favorable conditions, which did not differ significantly from the control. The DuraSOP ActiBION increased the number of productive shoots by 8.4% and DuraSOP Phos – by 7.7% in cv. Bohdana, while only DuraSOP Phos significantly affected the productive shoots in cv. Samurai (an increase of 3.8%). Application of slow-release fertilizers allows obtaining grain yield of 6.58 to 7.03 t/ha in cv. Bohdana and 6.61–6.80 t/ha in cv. Samurai. Fertilizers have higher efficiency in cv. Bohdana, while there was a significant increase in cv. Samurai only when DuraSOP Phos was applied (0.31 t/ha or 4.8%). The application of slow-release fertilizers also increases the protein content in the grain by 0.3-0.5%. Sensitivity of cultivars to different ratios of macronutrients in pre-sowing fertilizers is one of the elements of technology that have a high impact on wheat cultivation, so the use of effective forms can increase yields up to 11.4% compared with typical fertilizers.

YIELD PERFORMANCES OF WINTER WHEAT (T. aestivum) GENOTYPES IMPROVED FOR DRY ENVIRONMENTAL REGION OF TURKEY

This research, to determine the genetic progress in the winter bread wheat cultivars developed with breeding studies in the last 45 years for Turkey's arid environment, in Kirsehir ecological conditions, 2016-2017 and 2017-2018 growing periods were carried out for two years in randomized block design with four replications. In this research, yield and yield components of 24 winter bread wheat cultivars selected according to registration years were examined and genetic progress was evaluated for these properties by regression analysis method. As a result of two years of research, it has been determined that cultivars have a grain yield between 249 kg da-1 (Gun 91) - 362 kg da-1 (Karahan 99) and fertile spikes number per square meter 377 - 552, grain number per spike 28.81 – 41.83, grain weight per spike 1.07 – 1.52 g, harvest index 26.17% - 37.07%. The annual yield increase of the cultivars with genetic progress was found to be 1,029 kg da-1. While it was determined genetic progress in 6 of total 11 traits, was observed negative genetic change in the other traits. Specifically, it was determined that the genetic improvement seen in the grain number per spikelet, grain number per spike, grain weight per spike, biomass yield and harvest index characteristics were found to contribute to the increase in grain yield. Characteristics seen genetic progress, have come to the forefront as selection parameters that wheat breeders working on rainfed conditions should emphasize. In addition, Karahan 99, Nacibey, Bayraktar 2000, Izgi 2001 and Bagci 2002 cultivars were determined as cultivars that could be recommended to be grown in Kirsehir ecological conditions.

Evaluation of yield and agronomic traits of new winter bread wheat cultivars

Yield and quality attributes of 13 bread wheat cultivars registered for Thrace region in 2018 and 5 standard bread wheat cultivars were determined and compared in this study. Tested cultivars are originated from Turkey, Bulgaria, Romania, Croatia, Austria and Ukraine. Experiments were conducted in 2015-2016 and 2016-2017 growing seasons. Since the locations were not equally distributed to growing seasons, statistical analyses for yield and other parameters were performed through assuming each location as an environment. Therefore, assessments were made over 7 environments. Environment (E) explained 54.9% of the total variation (E+G+GEI), genotype (G) and genotype ? environment interaction (GEI) generated 25.6% and 19.5%, respectively. GGE (Genotype + Genotype by environment interaction) biplot analysis was able to explain 78.51% of variation in grain yield. Trial environments gathered under 3 mega-environments. Of the cultivars registered in 2018, Adali, Bc Anica, Topkapi, FDL Miranda, Otilia, ZT Ziyade, Viktoria and Dragana had values larger than the average and thus they had the largest PC1 (Principal component 1) scores. Tested cultivars were also assessed based on vector lengths to average environment coordinate (AEC). Adali cultivar with a high PC1 score and the closest position to AEC apsis was found to be quite prominent for grain yield. In environment-focused assessments, E3, E4 and E5 had the closest position to ideal environment circle. With regard to physical quality attributes, Pehlivan, Bojana and Adali cultivars had high performance values. The cultivar Bojana, Topkapi and Iveta had protein contents above 15%. For Zeleny sedimentation values, Krasunia odes?ka had the best performance.

Related to Ppd-1 and Vrd gene systems peculiarities of initial development rate in new European winter bread wheat cultivars

Aim. Vernalization response and photosensitivity were evaluated in some new cultivars originating from West European countries. Methods. Vrd and Ppd-1gene effects were measured by comparing numbers of days to heading at planting in natural and 10-hours photoperiods after preliminary green seedling vernalization of various duration. Those genes inheritance was studied under environment combinations securing the division of their effects. Results. Studied gene effects were inherited as partially dominant with additive-epistatic interactions. Evaluated stocks characterized often by durable vernalization requirement and photosensitivity presence differing essentially from modern Ukrainian cultivars. Conclusions. We call in question the assertion of leading Ukrainian breeders that strong physiological reactions of initial development delay are the factors limiting the modern productivity level in winter bread wheat.
 Keywords: winter bread wheat, heading dates, vernalization requirement, photosensitivity, modern cultivars, productivity.

Effects of wheat-rye translocations on the combining ability of winter bread wheatcultivars

The aim and tasks of the study. The purpose was to study the combining ability of winter bread wheat cultivars – carriers of wheat-rye translocations (WRT) for performance elements to determine their breeding values and to simulate selection of high-yielding offspring. Results and discussion. The results of analysis of variance attest to strong effects both of the general combining ability (GCA) and of the specific combining ability (SCA) for performance elements in the cultivars under investigation. At the same time, the mean square variance of the GCA was higher than that of of the SCA. Thus, we can affirm that additive effects dominate in the genetic control of the bread winter wheat performance elements, since the ratio of variances was >1.We distinguished the cultivars with a high GCA in F1for performance elements: Smuhlianka – the spikelet number in the main spike, 1000-grain weight, grain weight per plant; Epokha Odeska – the grain number in the main spike; Kryzhynka – 1000-grain weight; Rozkishna – grain weight from the main spike and grain weight per plant. Smuhlianka was distinguished among the others due to its with high and intermediate effects of the GCA. Kryzhynka, Rozkishna, and Epokha Odeska were some what inferior to it. Estimation of the combining ability suggests Smuhlianka as the best donor of grain productivity elements. According to the SCA constants, all the studied wheat cultivar shad intermediate indices for the most traits in 2014–2015. Cultivars with WRT were not distinguished by stable constants of the SCA and were not inferior tothe other studied cultivars, except Epokha Odeska. High constants of the SCA for some traits in WRT carriers indicate increased variability of the trait under investigation. Therefore, these cultivars may have specific hybrid combinations both with overexpression and with under expression of an inherited trait.Conclusions. Cultivars with wheat-rye translocations – Smuhlianka and Kryzhynka are of the highest value for breeding as components in crossings, providing formation of promising populations for selection of elite plants with increased performance.

Chromosomal localization of aromatic alcohol dehydrogenase fast-migrating isoenzyme Aadh1F (CAD1-F) gene in Triticum aestivum L. bread wheat

Differences in isoenzyme pattern of aromatic alcohol dehydrogenase, NADP-AADH or CAD, were found in the Triticum aestivum L. winter bread wheat cultivars by the method of electrophoresis in the starch gel. A standard three-component spectrum is present in the cv. Zitnica (former Yugoslavia); additional fact-migrating isoenzymes appear in the cv. Novosibirskaya 9 (Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Russia). The presence of fast-migrating CAD isoenzymes is designated as FF phenotype; their absence, as 00 phenotype. Hybridological analysis was carried out; the excess of “null” genotypes was found in F2 progenies. Hybridization with nulli-tetrasomic lines of the chromosomes of the fifth homeologous group was conducted for the gene localization. The segregation analysis demonstrated the most probable localization of the CAD1-F gene in the chromosome 5A. The plants with FF and 00 genotypes differed in a number of chemical and anatomical traits, as well as in grain productivity. The results obtained are discussed in connection with the function of this enzyme in the wheat plant tissues.

Variation of agronomic traits among introduced winter bread wheat cultivars

Variation of agronomic traits among introduced winter bread wheat cultivars

Molecular Detection of the Adult Plant Leaf Rust Resistance GeneLr34in Romanian Winter Wheat Germplasm

Wheat continues to be one of the most cultivated cereals in the world, and also in Romania. Leaf rust caused by Puccinia triticina reduces the wheat yield and grains quality worldwide. In the context of climate change, leaf rust has become a more important problem for both wheat growers and breeders in our country. Use of genetic resources, carrying rust resistance genes, play an important role in breeding programs leading to resistant varieties, which can have positive impact on environment and economy. Therefore, the identification of resistance genes in modern wheat cultivars and breeding lines, and then selection of the best resistance genes combination(s) are the first steps for a successful breeding program. At present, one of the best known and studied adult plant leaf rust resistance gene is Lr34 that contributes significantly to durable leaf rust resistance. The functional markers that enable early detection of this gene are a major advantage in the wheat breeding. The aim of this study was to evaluate the presence of the slow rusting resistance gene Lr34 in Romanian wheat germplasm, using cssfr4 and cssfr5 molecular markers. Screening of 47 winter bread wheat cultivars and 47 breeding lines with these markers showed the presence of the Lr34 resistant haplotype in 62% (homozygous genotypes) of the total genotypes. A high frequency (79%) of Lr34 resistance allele was found among 47 breeding lines, suggesting that maintenance of a high frequency of this allele represents a real advantage for the development of adult plant resistance in Romanian breeding programs.

Flowering time control in European winter wheat.

Flowering time is an important trait in wheat breeding as it affects adaptation and yield potential. The aim of this study was to investigate the genetic architecture of flowering time in European winter bread wheat cultivars. To this end a population of 410 winter wheat varieties was evaluated in multi-location field trials and genotyped by a genotyping-by-sequencing approach and candidate gene markers. Our analyses revealed that the photoperiod regulator Ppd-D1 is the major factor affecting flowering time in this germplasm set, explaining 58% of the genotypic variance. Copy number variation at the Ppd-B1 locus was present but explains only 3.2% and thus a comparably small proportion of genotypic variance. By contrast, the plant height loci Rht-B1 and Rht-D1 had no effect on flowering time. The genome-wide scan identified six QTL which each explain only a small proportion of genotypic variance and in addition we identified a number of epistatic QTL, also with small effects. Taken together, our results show that flowering time in European winter bread wheat cultivars is mainly controlled by Ppd-D1 while the fine tuning to local climatic conditions is achieved through Ppd-B1 copy number variation and a larger number of QTL with small effects.

Changing parameters of Czechoslovak obsolete and modern bread wheat cultivars (Triticum aestivum L.) over 90 years

Differences achieved in 18 selected morphological, phenological and grain parameters attributable to the wheat breeding process were evaluated on the basis of 262 original Czech and Slovak winter bread wheat cultivars (Triticum aestivum L.) developed during 1911–2008 and cultivated in the field and climatic conditions of Crop Research Institute Prague-Ruzyně for 3 years (2010–2012). The wheat breeding process unambiguously has improved grain production parameters, lodging and mildew resistance compared to wheat landraces and obsolete cultivars. Only wheat landrace ‘Visnovska Hustoklasa’ showed a higher resistance to lodging (8 points), no old cultivars registered till 1930 were resistant to mildew. Nevertheless, these economically positive properties of modern wheat cultivars are negatively reflected in lower crude protein content, protein content’s lower stability year to year, and decreased stability of Zeleny sedimentation. The breeding of wheat cultivars during 1961–1990 points to a key period responsible for these parameter changes. At the same time, within this somewhat older wheat group (from 1961–1990), several perspective wheat cultivars with acceptable spike productivity (e.g., ‘Regina’) and high crude protein stability (e.g., ‘Diana II’) were also identified.

Evaluation of tolerance to osmotic stress of winter bread wheat genotypes using indirect physiological method

Fifteen winter bread wheat cultivars from Romania and Serbia were evaluated with regard to their tolerance to osmotic stress. Evaluation was made by applying the indirect physiological method, recognizing the growth depression seedling, cultivated in solution with increased osmotic pressure (Atm). Water deficit in most of the genotypes suppresses to a great extent the growth of roots compared to that of the shoot. The average coefficient of root growth depression was 55.77% during the moderate osmotic stress trial and 55.83 % during the strong osmotic stress trial, while with shoots the percentage was 35.76 % and 50.12 %, respectively. The average root length / shoot length ratio (R/Sh ratio) for all genotypes in the control was 1.70; in the 0.5 M and 1 M sample solution sucrose it was 1.14 and 1.55, respectively. In genotypes most tolerant to osmotic stress as Renesansa, Dragana, Izvor and Faur the root/ shoot length ratio is decreased in the highest degree. It was established there is negative regression dependence between the growth of the root/shoot and the solution with increase of osmotic pressure. The equations showed the strong limitation role of osmotic pressure for the growth of the seedling. The results of this study showed that the varieties Renesansa, Dragana, Izvor and Faur had the best ability of osmotic regulation.

Yield Stability Of Some Turkish Winter Wheat (Triticum aestivum L.) Genotypes In The Western Transtional Zone Of Turkey

The purpose of the study was to evaluate the yield performance and stabilities of certain winter bread wheat cultivars grown widely in the winter wheat regions of Anatolian peninsula. Eight varieties were grown at 10 locations between 2007 and 2011 cropping seasons, in a field trial arranged in Randomized Complete Block Design with 4 replications. The combined analysis of variance was performed for the data obtained. The significant genotype x environment interactions were further investigated by the regression and the ecovalance analyses. It was concluded that cultivars Kate A1 and Mufit bey were found to be the most stable genotypes for all the environments whereas cultivar Gerek-79 was found to be the best performer for under poor soil and weather conditions.

Inheritance of resistance to two Septoria tritici isolates in spring and winter bread wheat cultivars

All possible crosses (including reciprocals) were made among four winter bread (Aurora, Bezostaya 1, Kavkaz, and Trakia) and two Israeli spring wheat cultivars (spring x winter diallel), and among two South American spring wheats (Colotana and Klein Titan) with the same Israeli cultivars (spring x spring diallel) to study the inheritance of resistance to septoria tritici blotch. Parents, F1, F2 and backcrosses were grown in two separated blocks in the field over two years. One block was inoculated with isolate ISR398A1 and another with ISR8036. Each plant was assessed for plant height (cm), days to heading (from emergence or transplanting), and percent pycnidia coverage on the four uppermost leaves. Plant height and maturity had insignificant effects on pycnidia coverage. No cytoplasmic effects could be detected. In the spring x winter diallel general combining ability (GCA) was the major component of variation. Significant specific combining ability (SCA) was present in all cases. Partial dominance was operative in populations inoculated with ISR398A1. Resistance in the winter wheats was controlled by a small number of genes (usually two). The four winter wheats derive their resistance to ISR398A1 from their common parent Bezostaya 1 which lacks the 1B/1R wheat-rye translocation. Their resistance is readily overcome by ISR8036. Inheritance of the South American wheats can be explained by additive effects, with a small number of genes of recessive mode affecting resistance to both isolates. Breeding strategies that favor additive, and additive x dominance gene action should be pursued.