Effect of Soil Drought Stress on Selected Biochemical Parameters and Yield of Oat × Maize Addition (OMA) Lines.

Plant growth and the process of yield formation in crops are moderated by surrounding conditions, as well as the interaction of the genetic background of plants and the environment. In the last two decades, significant climatic changes have been observed, generating unfavorable and harmful impacts on plant development. Drought stress can be considered one of the most dangerous environmental factors affecting the life cycle of plants, reducing biomass production and, finally, the yield. Plants can respond to water deficit in a wide range, which depends on the species, genetic variability within the species, the plant's ontogenesis stage, the intensity of the stress, and other potential stress factors. In plants, it is possible to observe hybrids between different taxa that certain traits adopted to tolerate stress conditions better than the parent plants. Oat × maize addition (OMA) plants are good examples of hybrids generated via wide crossing. They can exhibit morphological, physiological, and biochemical variations implemented by the occurrence of extra chromosomes of maize, as well as the interaction of maize and oat chromatin. The initial goal of the study was to identify OMA lines among plants produced by wide crossing with maize. The main goal was to investigate differences in OMA lines according to the Excised Leaf Water Loss (ELWL) test and to identify specific biochemical changes and agronomic traits under optimal water conditions and soil drought. Additionally, detection of any potential alterations that are stable in F2 and F3 generations. The aforementioned outcomes were the basis for the selection of OMA lines that tolerate growth in an environment with limited water availability. The molecular analysis indicated 12.5% OMA lines among all tested descendants of wide oat-maize crossing. The OMA lines significantly differ according to ELWL test results, which implies some anatomical and physiological adaptation to water loss from tissues. On the first day of drought, plants possessed 34% more soluble sugars compared to control plants. On the fourteen day of drought, the amount of soluble sugars was reduced by 41.2%. A significant increase of phenolic compounds was observed in the fourteen day of drought, an average of 6%, even up to 57% in line 9. Soil drought substantially reduced stem biomass, grains number, and mass per plant. Lower water loss revealed by results of the ELWL test correlated with the high yield of OMA lines. Phenolic compound content might be used as a biochemical indicator of plant drought tolerance since there was a significant correlation with the high yield of plants subjected to soil drought.

Genetic melting pot and importance of long-distance dispersal indicated in the Gladiolus imbricatus L. populations in the Polish Carpathians.

The genetic diversity in 11 populations of Gladiolus imbricatus in five mountain ranges, including the Tatra, Pieniny, Gorce, Beskid Niski (Western Carpathians) and Bieszczady Mts (Eastern Carpathians), was studied with inter-simple sequence repeat (ISSR) markers. The species is a perennial plant occurring in open and semi-open sites of anthropogenic origin (meadows and forest margins). We checked a hypothesis on the microrefugial character of the plant populations in the Pieniny Mts, a small calcareous Carpathian range of complicated relief that has never been glaciated. Plant populations in the Tatra and Pieniny Mts had the highest genetic diversity indices, pointing to their long-term persistence. The refugial vs. the non-refugial mountain ranges accounted for a relatively high value of total genetic variation [analysis of molecular variance (AMOVA), 14.12%, p = 0.003]. One of the Pieniny populations was of hybridogenous origin and shared genetic stock with the Tatra population, indicating there is a local genetic melting pot. A weak genetic structuring of populations among particular regions was found (AMOVA, 4.5%, p > 0.05). This could be an effect of the frequent short-distance and sporadic long-distance gene flow. The dispersal of diaspores between the remote populations in the Western Carpathians and Eastern Carpathians could be affected by the historical transportation of flocks of sheep from the Tatra to Bieszczady Mts.

Chlorophyll a Fluorescence Parameters of Hulled and Hull-less Barley (Hordeum vulgare L.) DH Lines Inoculated with Fusarium culmorum.

Barley worldwide is affected seriously by Fusarium seedling blight (FSB) and Fusarium head blight (FHB) diseases caused by the Fusarium species. The objective of this study was to facilitate the resistance of hulled and hull-less barley at different growth stages to F. culmorum according to direct parameters: disease rating (DR), fresh weight of leaves and roots, kernel weight per spike, kernel number per spike, plump kernels, and indirect parameters - chlorophyll a fluorescence (CF). Plate assay, greenhouse and field tests were performed on 30 spring barley doubled haploid (DH) lines and their parents infected with Fusarium culmorum. Direct parameters proved that hulled genotypes show less symptoms. Most studied chlorophyll a fluorescence (CF) parameters (apart from DIo/CS - amount of energy dissipated from PSII for laboratory test, TRo/CS - amount of excitation energy trapped in PSII reaction centers, ETo/CS - amount of energy used for electron transport and RC/CS - number of active reaction centres in the state of fully reduced PSII reaction center in field experiment) were significantly affected by F. culmorum infection. In all experiments, hulled genotypes had higher values of CF parameters compared to hull-less ones. Significant correlations were detected between direct and indirect parameters and also between various environments. It was revealed that ABS/CS, TRo/CS, and RC/CS have significant positive correlation in greenhouse test and field experiment. Significant correlations suggest the possibility of applying the CF parameters in selection of barley DH lines resistant to F. culmorum infection.

Complex characterization of oat (Avena sativa L.) lines obtained by wide crossing with maize (Zea mays L.).

BACKGROUND: The oat × maize addition (OMA) lines are used for mapping of the maize genome, the studies of centromere-specific histone (CENH3), gene expression, meiotic chromosome behavior and also for introducing maize C4 photosynthetic system to oat. The aim of our study was the identification and molecular-cytogenetic characterization of oat × maize hybrids. METHODS: Oat DH lines and oat × maize hybrids were obtained using the wide crossing of Avena sativa L. with Zea mays L. The plants identified as having a Grande-1 retrotransposon fragment, which produced seeds, were used for genomic in situ hybridization (GISH). RESULTS: A total of 138 oat lines obtained by crossing of 2,314 oat plants from 80 genotypes with maize cv. Waza were tested for the presence of maize chromosomes. The presence of maize chromatin was indicated in 66 lines by amplification of the PCR product (500 bp) generated using primers specific for the maize retrotransposon Grande-1. Genomic in situ hybridization (GISH) detected whole maize chromosomes in eight lines (40%). All of the analyzed plants possessed full complement of oat chromosomes. The number of maize chromosomes differed between the OMA lines. Four OMA lines possessed two maize chromosomes similar in size, three OMA-one maize chromosome, and one OMA-four maize chromosomes. In most of the lines, the detected chromosomes were labeled uniformly. The presence of six 45S rDNA loci was detected in oat chromosomes, but none of the added maize chromosomes in any of the lines carried 45S rDNA locus. Twenty of the analyzed lines did not possess whole maize chromosomes, but the introgression of maize chromatin in the oat chromosomes. Five of 66 hybrids were shorter in height, grassy type without panicles. Twenty-seven OMA lines were fertile and produced seeds ranging in number from 1-102 (in total 613). Sixty-three fertile DH lines, out of 72 which did not have an addition of maize chromosomes or chromatin, produced seeds in the range of 1-343 (in total 3,758). Obtained DH and OMA lines were fertile and produced seeds. DISCUSSION: In wide hybridization of oat with maize, the complete or incomplete chromosomes elimination of maize occur. Hybrids of oat and maize had a complete set of oat chromosomes without maize chromosomes, and a complete set of oat chromosomes with one to four retained maize chromosomes.

Conversion of oat (Avena sativa L.) haploid embryos into plants in relation to embryo developmental stage and regeneration media.

Obtaining oat DH lines is only effective via wide crossing with maize. Seven hundred haploid embryos from 21 single F1 progeny obtained from wide crosses with maize were isolated, divided into four groups according to their size (<0.5 mm, 0.5-0.9 mm, 1.0-1.4 mm, and ≥1.5 mm), and transferred into 190-2 regeneration medium with different growth regulators: 0.5 mg L-1 kinetin (KIN) and 0.5 mg L-1 1-naphthaleneacetic acid (NAA); 1 mg L-1 zeatin (ZEA) and 0.5 mg L-1 NAA; or 1 mg L-1 dicamba (DIC), 1 mg L-1 picloram (PIC), and 0.5 mg L-1 kinetin (KIN). Among all isolated embryos, approximately 46.1% were between 1.0-1.4 mm, while the smallest group of embryos (7.1%) were those <0.5 mm. The ability of haploid embryos to germinate varied depending on oat genotypes and the size of embryos. Haploid embryos <0.5 mm were globular and did not germinate, whereas embryos ≥1.5 mm had clearly visible coleoptiles, radicles, and scutella, and were able to germinate. Germination of oat haploid embryos varied depending on growth regulators in the regeneration medium. Most haploid embryos germinated on medium with 0.5 mg L-1 NAA and 0.5 mg L-1 KIN, while the fewest germinated on medium with 1 mg L-1 DIC, 1 mg L-1 PIC, and 0.5 mg L-1 KIN. One hundred thirty germinated haploid embryos converted into haploid plants. Fifty oat DH lines were obtained after colchicine treatment.