Rye Genotype Research Articles

Cocultivating rye with berseem clover affects benzoxazinoid production and expression of related genes

AbstractBenzoxazinoids (BXs) are secondary metabolites synthesized mainly by gramineous plants, including rye (Secale cereale L.), that play an important role in stress resistance and allelopathy. In the present work, the influence of cocultivation of rye with berseem clover (Trifolium alexandrinum L.) on the expression of BX synthesis‐regulating genes (ScBx1–ScBx5, ScIgl, and ScGT) and the content of six BXs (HBOA, DIBOA, GDIBOA, DIMBOA, GDIMBOA, and MBOA) in roots and the aerial portion of three rye inbred lines (ILs) (L318, D33, and D39) was investigated. Cocultivation of rye with berseem clover influenced its gene expression levels and BX contents. The response was strongly affected by rye genotype, plant part, time point, gene, and metabolite. The most frequently observed changes of gene expression concerned IL D33, aerial plant parts, the second time point (4 wk after germination), and ScBx3. For BX synthesis, the most frequently observed changes for IL D33 were in roots, the third time point (6 wk after germination), GDIBOA, and DIBOA. In 18.3% of cases, gene expression was correlated with BX synthesis. The coregulation of gene expression and BX synthesis in roots and aerial parts of rye plants affected by clover was observed relatively rarely. Cocultivation of rye with clover led, after 6 wk, to BX increases in roots of all tested ILs. Despite the lack of clearly universal response, the cocultivation of rye with clover may strengthen rye defense capability, at least against soil pathogens.

Al exposure increases proline levels by different pathways in an Al-sensitive and an Al-tolerant rye genotype

Aluminium (Al) toxicity limits crop productivity, particularly at low soil pH. Proline (Pro) plays a role in protecting plants against various abiotic stresses. Using the relatively Al-tolerant cereal rye (Secale cereale L.), we evaluated Pro metabolism in roots and shoots of two genotypes differing in Al tolerance, var. RioDeva (sensitive) and var. Beira (tolerant). Most enzyme activities and metabolites of Pro biosynthesis were analysed. Al induced increases in Pro levels in each genotype, but the mechanisms were different and were also different between roots and shoots. The Al-tolerant genotype accumulated highest Pro levels and this stronger increase was ascribed to simultaneous activation of the ornithine (Orn)-biosynthetic pathway and decrease in Pro oxidation. The Orn pathway was particularly enhanced in roots. Nitrate reductase (NR) activity, N levels, and N/C ratios demonstrate that N-metabolism is less inhibited in the Al-tolerant line. The correlation between Pro changes and differences in Al-sensitivity between these two genotypes, supports a role for Pro in Al tolerance. Our results suggest that differential responses in Pro biosynthesis may be linked to N-availability. Understanding the role of Pro in differences between genotypes in stress responses, could be valuable in plant selection and breeding for Al resistance.

Grain hardness in triticale: a physical and molecular evaluation

Grain hardness is an important quality trait of cereals. In the present work, the particle size index (PSI) was used to assess the variability in grain hardness of thirteen triticale genotypes, three wheat genotypes and one rye genotype grown in two subsequent seasons. The PSI values of the triticale samples ranged between 7.7 to 19.2%, representing a medium hard to a very hard grain. Moreover, the sequencing of genes in the Hardness (Ha) locus revealed a limited genetic variability in the grain hardness genes, namely secaloindoline-a (Sina) and secaloindoline-b (Sinb). Two possible new allelic variants were identified, one for each of the secaloindoline genes. The existing variability in the grain hardness as well as polymorphisms in its candidate genes are a good starting point for efforts in breeding new varieties of triticale with improved grain hardness.

Obtaining of Winter Rye (Secale Cereale L. ssp. Cereale) Haploid Embryos through Hybridization with Maize (Zea Mays L.)

The aim of this study was to determine the effect of selected factors on rye (Secale cereale L.) haploid embryo production by the wide crossing method. The study was performed on fifteen winter rye genotypes. This is the first time for rye when besides the genotype, on the enlargement of ovaries and haploid embryo production, such factors as: type of auxin analogues 2,4-dichlorophenoxyacetic acid (2,4-D), 3,6-dichloro-2-methoxybenzoic acid (dicamba) and 4-amino-3,5,6-trichloropyridine-2-carboxylic acid (picloram), and the time between florets emasculation and pollination were investigated. All factors had a significant impact on rye ovary enlargement, however the haploid embryo formation depended only on rye genotype, not on kind of auxin and days between emasculation to pollination. In total, twenty one haploid embryos were formed by six genotypes of fifteen tested. On average, 13.86% (after 2,4-D treatment) to 20.05% (after dicamba treatment) enlarged ovaries per emasculated florets were obtained. Most of the ovaries enlarged when florets were pollinated 4 and 6 days after emasculation. Most of the haploid embryos formed when florets were pollinated 6 days after emasculation. The obtained haploid embryos did not germinate.

Detection genetic variability of secale cereale L. by scot markers

Rye (Secale cereale L.) is our traditional cereal used for baking. The genetic variability of grown rye has been reduced by modern agronomic practices, which subsequently prompted the importance of search for species that could be useful as a gene pool for the improving of flour quality for human consumption or for other industrial uses. Therefore, the aim of this study was to detect genetic variability among the set of 45 rye genotypes using 8 SCoT markers. Amplification of genomic DNA of 45 genotypes, using SCoT analysis, yielded 114 fragments, with an average of 14.25 polymorphic fragments per primer. The most polymorphic primer was SCoT 36, where 21 polymorphic amplification products were detected. In contract the lowest polymorphic primer was SCoT 45 with 5 polymorphic products. Genetic polymorphism was characterized based on diversity index (DI), probability of identity (PI) and polymorphic information content (PIC). The hierarchical cluster analysis showed that the rye genotypes were divided into 2 main clusters. One rye genotype Motto, origin from Poland formed a separate subcluster (1b). Subscluster 2a included only genotype Valtické (CSK). In this experiment, SCoT proved to be a rapid, reliable and practicable method for revealing of polymorphism in the rye cultivars.

Oxidative Metabolism of Rye (Secale cereale L.) after Short Term Exposure to Aluminum: Uncovering the Glutathione-Ascorbate Redox Network.

One of the major limitations to plant growth and yield in acidic soils is the prevalence of soluble aluminum ions (Al3+) in the soil solution, which can irreversible damage the root apex cells. Nonetheless, many Al-tolerant species overcome Al toxicity and are well-adapted to acidic soils, being able to complete their life cycle under such stressful conditions. At this point, the complex physiological and biochemical processes inherent to Al tolerance remain unclear, especially in what concerns the behavior of antioxidant enzymes and stress indicators at early plant development. Since rye (Secale cereale L.), is considered the most Al-tolerant cereal, in this study we resort to seedlings of two genotypes with different Al sensitivities in order to evaluate their oxidative metabolism after short term Al exposure. Al-induced toxicity and antioxidant responses were dependent on rye genotype, organ and exposure period. Al affected biomass production and membrane integrity in roots and leaves of the sensitive (RioDeva) genotype. Catalase was the primary enzyme involved in H2O2 detoxification in the tolerant (Beira) genotype, while in RioDeva this task was mainly performed by GPX and POX. Evaluation of the enzymatic and non-enzymatic components of the ascorbate–glutathione cycle, as well the oxalate content, revealed that Beira genotype coped with Al stress by converting DHA into oxalate and tartarate, which posteriorly may bind to Al forming non-toxic chelates. In contrast, RioDeva genotype used a much more ineffective strategy which passed through ascorbate regeneration. So, remarkable differences between MDHAR and DHAR activities appear to be the key for a higher Al tolerance.

The effect of environmental factors and plant genotype on the severity of Claviceps purpurea in winter rye

Claviceps purpurea causes ergot, a serious disease of rye and grasses. Resistance genes to the pathogen have not been found in the genome of rye so far. Therefore we evaluated 90 rye genotypes in two seasons at three locations and analyzed the ergot incidence. In one location (Smolice) the same genotypes were also used to assess the influence of water spraying during rye flowering on ergot occurrence. Moreover, 29 cytoplasmic male-sterile genotypes of rye were used in Poznan, where within a 5 km distance there were no rye plants. In the first two experiments the source of the pathogen consisted of its sclerotia introduced into the soil, whereas in the third experiment a suspension of conidiospores was used to spray the plants from the moment of first flowering. Percentage of sclerotia in grain by weight in the first two experiments and sclerotia weight per ear in the third experiment were used as a measure of rye susceptibility to C. purpurea. Both rye genotype and location (weather conditions) showed significant variation for both traits. Low temperature and rainfall during rye flowering increased the occurrence of ergot. Water spraying of rye during flowering also boosted the occurrence of ergot. In another experiment, with sclerotia of C. purpurea used as inocula, ergot occurrence varied from 0 to 4.73 % in 2011/12 and from 0 to 5.22 % of sclerotia in grain yield in 2012/13. Cytoplasmic male-sterile rye inoculation with conidia of C. purpurea resulted in sclerotia presence which ranged from 0.10 to 0.26 g per ear.

Effect of elevated carbon dioxide on nitrogen assimilation and mobilization in wheat and rye genotypes of different ploidy levels

Two wheat genotypes differing in ploidy level viz. PBW 343 (hexaploid) and PDW 274 (tetraploid), and rye genotype WSP 540-2 (diploid) were grown under elevated CO2 (EC: 550 ± 50 ppm) and ambient CO2 (AC: 380 ppm) to study the changes in nitrogen assimilatory pathway enzymes. Elevated CO2 increased nitrate reductase (NR) activity in flag leaves of the three genotypes at milk stage, and activity was highest in rye (diploid). At dough stage, hexaploid and tetraploid genotypes showed higher NR activity in plants grown under EC. Elevated CO2 resulted in higher expression of NR gene (NIA1). Activity of glutamine synthetase (GS) in flag leaves was higher in all the three genotypes under EC at milk stage but the activity declined at dough stage. The expression of GS1 increased in flag leaves of plants grown under EC at both milk and dough stages, while the expression of GS2 declined during the reproductive stages, especially in ears of EC grown plants. Nitrate content decreased in leaf tissues of all the three genotypes by 90 DAS in EC grown plants. This indicated enhanced nitrate assimilation in leaves by NR under EC at reproductive stage. However, lower GS2 expression and lower GS activity during late reproductive phase (dough stage) indicated inhibition of consequent steps.

Mode of endosperm and wholemeal arabinoxylans solubilisation during rye breadmaking: Genotypic diversity in the level, substitution degree and macromolecular characteristics

Insight into solubilisation mechanisms of rye arabinoxylans during breadmaking is important for understanding the biochemical processes that affect bread attributes. Purified ethanol precipitated water-extractable arabinoxylans (WE-AX) and residual unextractable counterparts (WU-AX) were isolated from rye flours and resulting breads. While the endosperm flours had lower endoxylanase activities and higher arabinose-to-xylose ratios of WU-AX than those of corresponding wholemeals, there were not any significant differences between them in the mean amounts of WU-AX hydrolysed during breadmaking. Nevertheless, they were highly affected by rye cultivar used for breadmaking. On average, 42% and 36% of WU-AX were recovered in bread WE-AX fraction, causing its 11% and 8% increase, respectively for endosperm and wholemeal breads. Bread WE-AX, however, had lower molecular weights than those of starting flours, implying chains depolymerisation. Degree of AX solubilisation depends mainly on rye genotype used, determining combined effect of enzymatic and acid hydrolyses, associations and fine structure of AX.

Characterisation of Several Rye Cultivars with Respect to Arabinoxylans and Extract Viscosity

Arabinoxylans are considered as the major limiting factor for use of rye in animal feeding. In this study, four selected winter rye cultivars were grown at nine locations and tested for arabinoxylans including total (TAX), soluble (SAX) and insoluble fractions (IAX), extract viscosity, falling numbers and crude protein contents. Amounts of TAX ranged on average between 89 and 103 g/kg wholemeal flour, and the extract viscosity between 2.6 and 5.1 cSt. The extract viscosity was significantly correlated with falling numbers and all three arabinoxylan fractions. Arabinoxylan contents and extract viscosity were influenced by the rye genotype. The anthocyanin free hybrid cultivar Helltop combined reduced TAX, SAX and IAX levels with low extract viscosity and high crude protein contents and seems to be more suitable for use in animal feeding than the other three cultivars tested in this respect.

Antioxidant Activity of Alkylresorcinols from Rye Bran and Their Protective Effects on Cell Viability of PC-12 AC Cells

Alkylresorcinols (ARs) are phenolic lipids that are present in high amounts in the bran layer of different cereals. Rye samples, cultivar Hazlet, and a white rye genotype, RT202, were analyzed for their antioxidant properties and AR content and composition, based on six fractions of the bran, where 1 was the outermost fraction and 6 was the bran fraction closest to the endosperm. Gas chromatography-mass spectrometry (GC-MS) analysis demonstrated that the most commonly found AR homologue in Hazlet rye is C19:0 and that the total amount of ARs decreases from the outermost to innermost fractions. The antioxidant activity using oxygen radical absorbance capacity (ORAC) for both white rye genotype RT202 and Hazlet brans was determined to decrease from the outermost fraction (136.05 μmol TE/g for Hazlet fraction 1 and 186.57 μmol TE/g for white rye genotype RT202 fraction 1) to the innermost fraction (9.84 μmol TE/g for Hazlet fraction 6 and 78.75 μmol TE/g for white rye genotype RT202 fraction 2). A positive relationship was seen with GC-MS results. Treatment of PC-12 AC cells with Hazlet fraction 1 increased mitochondrial biogenesis as determined using mitochondrial fluorescent dyes. In the presence of a prooxidant (AAPH), PC-12 AC cells were better protected from free radical attack when treated with Hazlet fraction 1 than with all other bran fractions. The results suggest that higher AR content in bran fractions confers antioxidant protection against free radical damage.

Analysis of the effects of parental genotypes of rye lines on the development of quantitative traits in primary octaploid triticale. Plant height

When breeding the primary spring octoploid triticale derived from crosses of various inbred rye lines to wheat Chinese Spring, the effects of the rye genotype and growth conditions on the plant height and proportion of the first, second, and final (pedicle) internodes to the entire stem length were studied. Two triticale groups were examined: homozygotes for the dominant (Ddw1) and recessive (ddw1) alleles of the gene responsible for short stem in rye. In the short stem triticale lines carrying the Ddw1 alleles, the plants were 20 cm shorter on average than those in the ddw1-carrying lines, and the distribution of the two triticale groups overlapped significantly. In both groups, the lines significantly differing in plant height could be differentiated, because of allelic diversity of the additional genes controlling this trait along with the Ddw gene. In most triticale lines, especially in the Ddw1-carrying ones, the plant height was much reduced under unfavorable growth conditions. At the same time, a short-stem line was isolated, which is characterized by ecological plasticity, like the maternal wheat cultivar. In the triticale studied, the stem structure depended on the short-stem rye genotype. The two-year study showed that in the triticale carrying the dominant allele of this gene, the first internode is significantly extended, whereas the upper (pedicle) internode is reduced, which increases plant lodging resistance. The differences revealed between the rye lines as well as their effect on the quantitative triticale traits are discussed in view of a variant of the hybridological analysis, which had been previously proposed for identification and mapping of the correspondent rye genes.

Effects of genotype and harvest year on content and composition of dietary fibre in rye (Secale cereale L) grain

AbstractThe aim of this study was to measure the variation in dietary fibre (DF) content and composition among different rye varieties grown in the same location in three successive years and to estimate the contributions of genotype and harvest year to this variation. The study included grain from 19 different varieties of rye, of which seven varieties were analysed in all three years. The content of total DF in all samples ranged from 147 to 209 g kg−1 dry matter (dm), with 34–66 g kg−1 being water‐extractable (WE) DF and 108–159 g kg−1 being water‐unextractable (WUE) DF. The main DF component was arabinoxylan (AX) with a content of 80–121 g kg−1 dm, of which 26–41 g kg−1 dm was WE AX. The ratio of arabinose to xylose (ara/xyl) of total AX ranged from 0.59 to 0.69. The content of β‐glucan was 13–22 g kg−1 dm and that of fructan was 45–64 g kg−1 dm. Analysis of the data from seven varieties and three harvest years showed a highly significant influence of harvest year on most DF components. Significant genotype effects were found for the contents of total DF, total AX, β‐glucan and fructan and for the ara/xyl ratio of total and WUE AX. Estimation of variance components showed that yearly variations in the contents of total DF, total AX, WUE DF, WUE AX and β‐glucan were generally higher (27–55% of total variance) than genotype effects (14–19%). The ara/xyl ratio of total and WUE AX showed a high influence of genotype (46 and 43% respectively). Non‐adapted rye varieties with small kernel size had the highest contents of total DF and total AX. The content of β‐glucan was positively correlated with kernel weight (r = 0.68), whereas no overall correlation was found between kernel size and the content of DF. As a conclusion, the variation in DF content and composition in this study was significantly influenced by both harvest year and rye genotype.© 2002 Society of Chemical Industry

Wheat genotypes differ in growth and phosphorus uptake when supplied with different sources and rates of phosphorus banded or mixed in soil in pots

The growth response of wheat genotypes supplied with phosphorus fertiliser at different rates (banded or mixed throughout the soil) and sparingly soluble phosphorus sources (aluminium phosphate and iron phosphate) is not known. Eleven wheat genotypes and 1 rye genotype were tested at 3 rates of phosphorus fertiliser application (5, 10 and 20 mg P/kg soil) in a pot study. Another experiment compared 4 wheat genotypes at 2 rates of phosphorus application (deficient and sufficient) and 2 application methods (banding and mixing throughout the soil). The selected wheat genotypes were also used to investigate growth and root exudation response to iron phosphate and aluminium phosphate supply. Banding of phosphorus fertiliser increased the uptake of phosphorus and wheat growth compared with mixing phosphorus throughout the soil. Wheat genotypes did not differ significantly in growth and phosphorus uptake at the low rate of application. With increasing rates of phosphorus supply, the 2 phosphorus-fertiliser-responsive wheat genotypes (Wawht 2074 and Aroona) had significantly increased phosphorus uptake and root and shoot weights. When supplied with aluminium phosphate and iron phosphate, the 2 phosphorus-fertiliser-responsive genotypes had larger roots and higher concentration of phosphorus in the shoots and roots, while the phosphorus utilisation-efficient wheat genotypes (Westonia and Gutha) had higher shoot weights than phosphorus fertiliser-responsive ones. All wheat genotypes produced quantitatively and qualitatively similar root exudates in the iron phosphate, aluminium phosphate and zero-phosphorus treatments. The aluminium phosphate treatment caused genotypes to increase root exudation of oxalic anions, uptake of phosphorus and growth, compared with the iron phosphate treatment. It was concluded that the choice of genotypes for achieving increased wheat growth would depend on the phosphorus source in soil and the rate of application of phosphorus fertiliser.

Effects of genotype and genotype—environment interaction on deoxynivalenol accumulation and resistance to Fusarium head blight in rye, triticale, and wheat

Abstract Fusarium culmorum is one of the most important Fusarium species causing head blight infections in wheat, rye, and triticale. It is known as a potent mycotoxin producer with deoxynivalenol (DON), 3‐acetyl deoxynivalenol (3‐ADON), and nivalenol (NIV) being the most prevalent toxins. In this study, the effect of winter cereal species, host genotype, and environment on DON accumulation and Fusarium head blight (FHB) was analysed by inoculating 12 rye, eight wheat, and six triticale genotypes of different resistance levels with a DON‐producing isolate at three locations in 2 years (six environments). Seven resistance traits were assessed, including head blight rating and relative plot yield. In addition, ergosterol, DON and 3‐ADON contents in the grain were determined. A growth‐chamber experiment with an artificially synchronized flowering date was also conducted with a subset of two rye, wheat and triticale genotypes. Although rye genotypes were, on average, affected by Fusarium infections much the same as wheat genotypes, wheat accumulated twice as much DON as rye. Triticale was least affected and the grain contained slightly more DON than rye. In the growth‐chamber experiment, wheat and rye again showed similar head blight ratings, but rye had a somewhat lower relative head weight and a DON content nine times lower than wheat (3.9 vs. 35.3 mg/kg). Triticale was least susceptible with a five times lower DON content than wheat. Significant (P = 0.01) genotypic variation for DON accumulation existed in wheat and rye. The differences between and within cereal species in the field experiments were highly influenced by environment for resistance traits and mycotoxin contents. Nevertheless, mean mycotoxin content of the grain could not be associated with general weather conditions in the individual environments. Strong genotype‐environment interactions were found for all cereal species. This was mainly due to three wheat varieties and one rye genotype being environmentally extremely unstable. The more resistant entries, however, showed a higher environmental stability of FHB resistance and tolerance to DON accumulation. Correlations between resistance traits and DON content were high in wheat (P = 0.01), with the most resistant varieties also accumulating less DON, but with variability in rye. In conclusion, the medium to large genotypic variation in wheat and rye offers good possibilities for reducing DON content in the grains by resistance selection. Large confounding effects caused by the environment will require multiple locations and/or years to evaluate FHB resistance and mycotoxin accumulation.

Interaction between different genotypes of allogamous and autogamous rye and the homoeologous pairing control of wheat

In this study, we have analysed meiotic pairing in wheat-rye intergeneric hybrids obtained by crossing T. aestivum cv. Chinese Spring with two cultivars of S. cereale (Elbon and Ailes, respectively) and S. vavilovii. The results have shown that meiotic behaviour of hybrids is different in relation to the type of rye utilised. This has been interpreted as being due to the different effect of each particular rye genotype on the homoeologous pairing in relation with the reproductive systems (allogamy or autogamy) of the particular rye.

The effect of rye genotype on wheat–rye crossability and on the development of F1 seed

Five inbred lines of rye (Secale cereale L.) and an open-pollinated rye cultivar were used to pollinate wheat (Triticum aestivum L.) cultivars of differeing crossability. No hybrid seed was produced with the cultivar of low crossability, but with the highly crossable cultivar an average seed set of 65% was obtained. Significant differences in terms of seed set and weight of F1 seed were detected among the inbreds.

Influence of parental rye on the development of embryos and endosperm of wheat–rye hybrids

Seven lines of rye (Secale cereale L.), six inbred (S9) and one open-pollinated, were used as pollen parents in crosses with two tetraploid wheat strains (Triticum turgidum var. durum cvs. 'Jori' and 'Langdon'). The rye lines were of diverse genetic background and exhibited significant differences in meiotic stability as measured by frequencies of chiasmata and univalent formation. The rate and extent of development of the embryo and endosperm tissue of hybrid ovules were not influenced by the level of meiotic stability of the rye parent, but rather by a genetic interaction between a specific rye genotype and wheat. This was indicated by the significant differences obtained in the frequency of normal embryo formation when different rye lines were used as parents in crosses to a common wheat cultivar. The specific effect of the wheat genotype on the mean seedset was shown by the significant differences obtained when different wheat cultivars were crossed with a given set of rye genotypes under the same environmental conditions. The prevailing ambient temperature significantly affected hybrid embryo and endosperm development in vivo.