Seeds are complex biological systems comprising three genetically distinct tissues: embryo, endosperm, and maternal tissues (including seed coats and pericarp) nested inside one another. Cereal grains represent a special type of seeds with the largest part formed by endosperm, a specialized triploid tissue ensuring embryo protection and nourishment. We investigated the dynamics of DNA amount changes of the three major seed tissues from the time of pollination until dry seed. We show that cell cycle is under strict developmental control in different seed compartments. After an initial wave of active cell division, cells switch to endocycle and most endoreduplication events are observed in endosperm and seed maternal tissues. Using different barley cultivars we show that there is natural variation in the kinetics of this process. During the terminal stages of seed development, specific and selective loss of endoreduplicated nuclei occurs in the endosperm. This is accompanied by reduced stability of nuclear genome, progressive loss of cell viability and finally programmed cell death. In summary, our study shows, that endopolyploidization and cell death are linked phenomena that frame the barley grain development.

The purpose of this work was to assess the impact of zearalenone (ZEN) and selected hormone regulators on the effectiveness of microspore embryogenesis in anther culture of wheat. The plant material comprised F1 hybrids of winter and spring wheat. Six combinations of media inducing microspore proliferation and formation of embryogenic structures were investigated: two combinations of growth regulators (D - 2,4-D + dicamba, K - 2,4-D + kinetin), each with three ZEN concentrations (0 mL/L, 0.1 mL/L, 0.2 mL/L). A significant increase in microspore embryogenesis effectiveness on media with the addition of ZEN was observed both at the stages of its induction and the formation of green plants in some genotypes. In case of both combinations of growth regulators, an increased concentration of ZEN resulted in more effective induction of microspore embryogenesis. The most effective induction medium was the D medium supplemented with 0.2 mL/L ZEN. As a result of the use of zearalenone together with two combinations of growth regulators, all genotypes tested produced androgenic structures, which indicates the breakdown of genotypic recalcitrant in the analysed hybrids. In addition, green plants were obtained from 18 out of 19 tested hybrids. The addition of ZEN to the medium did not affect the number of regenerated albino plants nor the number of spontaneous genome doublings proportion.

Solid-stemmed spring wheat cultivars (Triticum aestivum L.) are resistant to the stem sawfly (Cephus cinctus Nort.) and lodging. Anthers of 24 spring wheat cultivars with varying content of pith in the stem were used in the experiment. All were classified into three groups: solid, medium–solid and hollow stems. There was considerable influence of the cultivar on callus formation and green plant regeneration. The highest efficiency of green plant regeneration (24%) was observed for the solid-stemmed AC Abbey cultivar. There was no regeneration from the explants of four cultivars: CLTR 7027, Alentejano, Marquis and Bombona. Principal component analysis showed no differences between the cases under observation (callus induction and green plant regeneration) in their response to pre-treatment temperatures (4 and 8°C). The examination of the effects of various auxin types in the induction medium on callus formation and green plant regeneration revealed that the strongest stimulation of these processes was observed in the C17 medium with 2,4-D and dicamba. The efficiency of callus formation and green plant regeneration was greater in solid-stemmed cultivars than in hollow-stemmed cultivars.

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Diseases caused by fungi from the genus Fusarium constitute a serious problem in spring wheat cultivation. Ear infestation leads reduced yield and plant contamination with mycotoxins. Therefore it is essential to introduce resistance genes to high-yielding cultivars. The generation of double haploid (DH) lines makes it possible to shorten the time required to select favourable genotypes. The aim of this study was to analyze the capacity of plants to regenerate in anther cultures and to generate DH of spring wheat genotypes that potentially constitute germplasm material for resistance breeding, directed against fungi from the genus Fusarium. The plant material comprised wheat cultivars with increased resistance to Fusarium: Sumai 3, Ning 8331, Norin 52, Frontana, as well as line 8475-59 and high-yielding Polish cultivars: Łagwa, Waluta and Zadra. Spikes were subjected to a thermal shock at 4EC. Anthers were placed on the C17 inducing medium. Two combinations of growth regulators, i.e. 2,4-D and kinetin as well as 2,4-D and dicamba were applied. A total of 19,200 anthers were used, resulting in a total of 440 calli from which 352 plants were obtained. Of this number 14% were albino. The regeneration efficiency ranged from 0% to 17.33% depending on the analyzed genotype and the combination of growth regulators in the induction medium. The highest number of green plants and seeds were obtained from cv. Łagwa, Zadra and Sumai 3. Analyses of the regenerants, using a flow cytometer, demonstrated that depending on the genotype, haploids constituted approx 75% of green plants. Doubling of the number of chromosomes at a 40% efficiency rate took place when 0.1% colchicine was used. In the experiment 54 DH lines were obtained from which 283 kernels were collected. The best genotypes for crossing components in terms of their regeneration ability were found to be cultivar Frontana among the cultivars resistant to Fusarium, and cultivar Łagwa from Polish cultivars used in the experiment.

Androgenesis is potentially the most effective technique for doubled haploid production of wheat. It is not however widely used in breeding programmes due to its main limitation: the genotype dependence. Due to genetic differences between spring and winter wheat, it was assumed that both phenotypes are different in their capacity to conduct androgenesis. And so, the aim of this investigation was to verify the effectiveness of androgenesis induction and plant regeneration of spring and winter wheat genotypes while considering varying amounts of growth hormones in the induction medium. Fifteen genotypes of spring wheat and fifteen of winter wheat were used in the experiment. Six hundred anthers of each of the 30 genotypes were plated and analysed. Previous studies have allowed selection of the best medium for wheat androgenesis and a combination of growth hormones that are the most effective in stimulating microspore proliferation. Therefore, C17 induction media with two combinations of growth hormones were used: I—supplemented only by auxins (2,4-D and dicamba), and II—supplemented by auxin and cytokinin (2,4-D and kinetin). Data was recorded according to the efficiency of androgenic structure formation (ASF), green plant regeneration (GPR), and albino plant regeneration (APR). The results showed that the induction and regeneration of androgenesis in the spring wheat were more efficient than in the winter ones. The spring genotypes formed more androgenic structures and green plants on anthers plated on the medium supplemented only by auxins, in contrast to the winter genotypes which were better induced and regenerated on the medium supplemented by auxin and cytokinin. The study showed that to increase the efficiency of androgenesis, it is necessary to select appropriate factors such as concentration and type of hormones in medium composition, affecting the course of the culturing procedure according to the winter or spring phenotype of donor plants.

Leaf rust pathogens are able to overcome plants' resistance by the appearance of new races. Therefore, an introduction of leaf rust resistance genes into highyielding wheat genotypes is essential. One of such genes is Lr19 (leaf rust resistance gene) that could be a source of resistance in polish breeding programs. The aim of this study was to obtain doubled haploid lines of the Lr19 gene in anther cultures of winter wheat genotypes. In the experiment, F 3 generation plants from two cross-combinations were used: genotype T39 × Ozon and genotype T36 × Hondia (T36 and T39 lines carry Lr19 gene). Three combinations of growth regulators such as 2,4-D; 2,4-D and dicamba; and 2,4-D and kinetin were applied. A total of 13,550 anthers were tested. The embryo-like structures were formed at an average frequency of 9.95% and were mainly influenced by the genotype, not by the composition of hormones in induction media. Regeneration frequency of green plants was recorded to be 1.45%. The highest frequency of green plant regeneration was observed on induction media supplemented with 2,4-D and dicamba reaching 1.79%. Spontaneous doubled haploids tested by laser flow cytometry were detected in 33.95% of plants. The frequency of the formation of embryo-like structure was mainly influenced by the genotype, not by the composition of hormones in induction media.

There are many reports describing chromosome structure, organization and evolution within goatgrasses (Aegilops spp.). Chromosome banding and fluorescence in situ hybridization techniques are main methods used to identify Aegilops Linnaeus, 1753 chromosomes. These data have essential value considering the close genetic and genomic relationship of goatgrasses with wheat (Triticumaestivum Linnaeus, 1753) and triticale (× Triticosecale Wittmack, 1899). A key question is whether those protocols are useful and effective for tracking Aegilops chromosomes or chromosome segments in genetic background of cultivated cereals. This article is a review of scientific reports describing chromosome identification methods, which were applied for development of prebreeding plant material and for transfer of desirable traits into Triticum Linnaeus, 1753 cultivated species. Moreover, this paper is a resume of the most efficient cytomolecular markers, which can be used to follow the introgression of Aegilops chromatin during the breeding process.