Evaluation Of Slovak Winter Wheat Quality In Terms Of Puroindoline Genes

The grain hardness of 100 current and 24 old superior Slovak winter wheat cultivars was studied at molecular level. Using polymerase chain reactions (PCRs), normal and null alleles of both puroindoline Pina and Pinb genes were identified. Three different genotypes were found: 1) normal allele of both genes (dominant wild type with soft endosperm) − Pina-D1a/Pinb-D1a; 2) normal allele of the Pina gene and null allele of the Pinb gene – Pina-D1a/Pinb-D1b; and 3) null allele of the Pina gene and normal allele of the Pinb gene Pina-D1b/Pinb-D1a. No Slovak current as well as old wheat cultivar had together null allele of both puroindoline genes. The frequencies of wild-type Pinb-D1a and null Pinb-D1b allele in current cultivars were 62.0% and 38.0%, respectively, whilst in old cultivars, 8.3% and 91.7%, respectively. Regarding null allele Pina-D1b of puroindoline Pina gene, only in Rheia current cultivar, one was found. All other cultivars had wild-type Pina-D1a allele. Alacris, Alana, Axis, Balada, Blava, Bona Dea, Bruta, Charger, Hana, Ilona, IS Karpatia, Ludwig and Sulamit current cultivars were selected as donors of the null Pinb-D1b allele for molecular breeding in order to improve the grain hardness as important wheat quality trait. Statistically significant correlations between null Pinb-D1b allele and grain size as well as colour were found. In comparison with wild type, cultivars with this null allele have paler and longer grain with higher length-to-width ratio and lighter grain colour

The Choice of Suitable Conditions for Wheat Genetic Transformation

Wheat is one of three most important cereals worldwide. Its production rises every year. There is a possibility to improve quantitative and qualitative parameters by biolistic method of transformation. The process of introduction of desired gene into the wheat genome and plant regeneration is affected by many factors. To identify the suitable conditions, selection system, the influence of donor, plant environment and the regeneration capacity of wheat genotypes were tested. The scutella of immature embryos served as the initial explants. Plant regeneration was achieved by 6 out of 11 genotypes tested. The highest values were reached by the cultivar Ilias. The effect of donor, plant environment was evaluated by two genotypes. Plants from growth chamber appeared to be better source of explants compared to plants grown in the natural conditions. The selection system was optimized as follows: regeneration medium in the dark and subsequently in photoperiod conditions (DR) with 5 mg/l of phosphinotricin (PPT), shoot induction medium (DS) with 7 mg/l of PPT

Rhizosphere Bacterial Communities of Arundo Donax Grown in Soil Fertilised with Sewage Sludge and Agricultural by-Products

Application of sewage sludge to soil is a potentially inexpensive source of nutrition for plants, but may contain undesirable and toxic substances, e.g. heavy metals. Alterations in microbial communities can serve as an environmental indicator of possible soil contamination. We used two molecular fingerprinting methods (Automated Ribosomal Intergenic Spacer Analysis, ARISA and Terminal Restriction Fragment Length Polymorphism, T-RFLP) to study changes in the genetic diversity of bacterial communities in the rhizosphere of Arundo donax L. cultivated in the soil fertilised with additive based on sewage sludge from wastewater treatment plant and agricultural by-products represented by crushed corn hobs and wastes from grain mill industry. The metagenomic DNA extracted from rhizosphere samples were collected in August and November 2014. The amount of mgDNA was statistically higher in samples with additive than in control samples without it in both dates. The Venn diagrams showed that operational taxonomic units which were common to all samples were represented in 32.8% in ARISA and 43.4% in T-RFLP. However, based on Principal component analysis and subsequent PERMANOVA statistical tests did not confirm significant differences in the rhizosphere of control plants and plants grown in the soil supplemented with sewage sludge in dose 5 and 15 t/ha present in the additive

Anatomy and Histochemistry of Seed Coat Development of Wild (Pisum sativum subsp. elatius (M. Bieb.) Asch. et Graebn. and Domesticated Pea (Pisum sativum subsp. sativum L.)

In angiosperms, the mature seed consists of embryo, endosperm, and a maternal plant-derived seed coat (SC). The SC plays a role in seed filling, protects the embryo, mediates dormancy and germination, and facilitates the dispersal of seeds. SC properties have been modified during the domestication process, resulting in the removal of dormancy, mediated by SC impermeability. This study compares the SC anatomy and histochemistry of two wild (JI64 and JI1794) and two domesticated (cv. Cameor and JI92) pea genotypes. Histochemical staining of five developmental stages: 13, 21, 27, 30 days after anthesis (DAA), and mature dry seeds revealed clear differences between both pea types. SC thickness is established early in the development (13 DAA) and is primarily governed by macrosclereid cells. Polyanionic staining by Ruthenium Red indicated non homogeneity of the SC, with a strong signal in the hilum, the micropyle, and the upper parts of the macrosclereids. High peroxidase activity was detected in both wild and cultivated genotypes and increased over the development peaking prior to desiccation. The detailed knowledge of SC anatomy is important for any molecular or biochemical studies, including gene expression and proteomic analysis, especially when comparing different genotypes and treatments. Analysis is useful for other crop-to-wild-progenitor comparisons of economically important legume crops

Virulence of wheat leaf rust (Puccinia triticina Eriks.) and Lr resistance genes in wheat cultivars in the Slovak Republic in the years 2016–2019

In the years 2016 to 2019 the virulence of the wheat leaf rust population in Slovakia was tested on Thatcher near-isogenic lines Lr1, Lr2a, Lr2b, Lr2c, Lr3a, Lr9, Lr10, Lr11, Lr13, Lr15, Lr17a, Lr19, Lr21, Lr23, Lr24, Lr26 and Lr28. A total of 111 rust isolates were analysed. Resistance genes Lr19 and Lr9 were effective to most of the tested isolates. Average virulence frequency to these resistance genes was only 1%. The gene Lr24 conditioned resistance to 92% of the tested rust isolates, gene Lr28 to 86% of the tested rust isolates. Low virulence frequency was also recorded to Lr2a (13%), Lr2b and Lr2c (both 12%). Average virulence to other tested Lr genes exceeded 82%. Thirty-eight winter wheat cultivars registered in the Slovak Republic were tested for the presence of Lr10, Lr19, Lr24, Lr26, Lr28, Lr34 and Lr37 by molecular markers. The gene Lr34 was the most frequent one in the tested cultivars, followed by Lr37 (both genes for adult plant resistance). The most widespread pathotypes in separate years and leaf rust severity in thirty-eight cultivars are also recorded

Molecular Selection Of Tomato And Pepper Breeding Lines Possessing Resistance Alleles Against Tobamoviruses

Molecular selection among newly created tomato and pepper lines was applied for identification of lines possessing DNA markers linked with the resistant loci against tobamoviruses ToMV, TMV, PaMMV, and PMMoV. Only four tomato lines among 184 had DNA marker linked with the resistant allele Tm-2 conferring homozygosity at this locus. Resistance of these four lines was tested and confirmed also by virological testing by inoculation with TMV strain 0. Simultaneously tested lines heterozygous at this locus expressed full or unbalanced resistance. Fifty-eight out of 62 tested pepper lines had only marker linked to susceptible allele of the locus L. Three lines derived from tobamovirus resistant pepper cultivars Brill and Brilliant expressed marker linked to resistant allele L3, and only one line derived from resistant cultivar Hurricane possessed both markers. Four selected pepper lines declared resistance also after artificial inoculation with the TMV P0 pathotype. Molecular selection, both in tomato and pepper breeding lines, may be useful in breeding programs directed to tobamovirus resistance

Superabsorbent Polymer Seed Coating Reduces Leaching of Fungicide but Does Not Alter Their Effectiveness in Suppressing Pathogen Infestation

Superabsorbent polymers (SAPs) applied to soil have been recognized as water reservoirs that allow plants to cope with periods of drought. Their application as a seed coat makes water available directly to the seeds during their germination and early growth phase, but on the other hand, it can affect the efficiency of plant protection substances used in seed dressing. In our experiments, we evaluated the effect of seed coating with SAP on fungicide leaching and changes in their effectiveness in suppressing Fusarium culmorum infestation. Leaching of fungicide from wheat seeds coated with SAP after fungicide dressing, as measured by the inhibition test of mycelium growth under in vitro conditions, was reduced by 14.2–15.8% compared to seeds without SAP coating. Germination of maize seeds and growth of juvenile plants in artificially infected soil did not differ significantly between seeds dressed with fungicide alone and seeds treated with SAP and fungicide. In addition, plants from the seeds coated with SAP alone grew significantly better compared to untreated seeds. Real-time PCR also confirmed this trend by measuring the amount of pathogen DNA in plant tissue. Winter wheat was less tolerant to F. culmorum infection and without fungicide dressing, the seeds were unable to germinate under strong pathogen attack. In the case of milder infection, similar results were observed as in the case of maize seeds

Responses of Rhizosphere Fungal Communities to the Sewage Sludge Application into the Soil

Due to the increasing sewage sludge production in the world and problems with its disposal, an application of sludge to the soil appears to be a suitable solution considering its fertilizer properties and ability to improve the soil physical conditions. On the other hand, the sludge may also contain undesirable and toxic substances. Since soil microorganisms are sensitive to environmental changes, they can be used as indicators of soil quality. In this study, we used sewage sludge (SS) from two municipal wastewater treatment plants (SS-A and SS-B) in the dose of 5 t/ha and 15 t/ha in order to determine possible changes in the fungal community diversity, especially arbuscular mycorrhizal fungi (AMF), in the rhizosphere of Arundo donax L. Rhizosphere samples were collected in summer and autumn for two consecutive years and the fungal diversity was examined using terminal restriction fragment length polymorphism and 18S rDNA sequencing. Fungal alpha diversity was more affected by SS-A than SS-B probably due to the higher heavy metal content. However, based on principal component analysis and ANOSIM, significant changes in overall fungal diversity were not observed. Simultaneously, 18S rDNA sequencing showed that more various fungal taxa were detected in the sample with sewage sludge than in the control. Glomus sp. as a representative of AMF was the most represented. Moreover, Funneliformis in both samples and Rhizophagus in control with Septoglomus in the sludge sample were other representatives of AMF. Our results indicate that the short-term sewage sludge application into the soil does not cause a shift in the fungal community composition

Biosynthesis of Essential Polyunsaturated Fatty Acids in Wheat Triggered by Expression of Artificial Gene

The artificial gene D6D encoding the enzyme ∆6desaturase was designed and synthesized using the sequence of the same gene from the fungus Thamnidium elegans. The original start codon was replaced by the signal sequence derived from the wheat gene for high-molecular-weight glutenin subunit and the codon usage was completely changed for optimal expression in wheat. Synthesized artificial D6D gene was delivered into plants of the spring wheat line CY-45 and the gene itself, as well as transcribed D6D mRNA were confirmed in plants of T0 and T1 generations. The desired product of the wheat genetic modification by artificial D6D gene was the γ-linolenic acid. Its presence was confirmed in mature grains of transgenic wheat plants in the amount 0.04%–0.32% (v/v) of the total amount of fatty acids. Both newly synthesized γ-linolenic acid and stearidonic acid have been detected also in leaves, stems, roots, awns, paleas, rachillas, and immature grains of the T1 generation as well as in immature and mature grains of the T2 generation. Contents of γ-linolenic acid and stearidonic acid varied in range 0%–1.40% (v/v) and 0%–1.53% (v/v) from the total amount of fatty acids, respectively. This approach has opened the pathway of desaturation of fatty acids and production of essential polyunsaturated fatty acids in wheat