A field experiment was conducted in the Ridge and Valley region of Virginia near Blacksburg during the 1989 through 1991 corn-rye growing seasons. The treatments in this experiment consisted of varying amounts of ¹⁵N-depleted fertilizer N applied to corn (Zea mays L.) at planting followed by a winter rye (Secale cereale L.) cover crop treatment. The research was divided into four studies. The first study was conducted to evaluate an analytical procedure that could be used for the diffusion of low masses of ¹⁵N-labeled NH₄ in 2M KCI and subsequent analysis for N recovery and ¹⁵N concentrations in soil by direct combustion mass spectrometry. Diffusion was found to be a suitable technique for preparing low-mass N samples for automated ¹⁵N analysis by Automated Nitrogen-Carbon Analysis/Mass Spectrometry (ANCA/MS). Recoveries of low masses of added N were quantitative, and accurate ¹⁵N concentrations were obtained when the results were corrected for isotope dilution due to background or contaminant N. The second study was conducted to determine if ¹⁵N-depleted fertilizer N could be satisfactorily used as a tracer of residual fertilizer N in plant tissue and various soil N fractions through a corn-winter rye crop rotation. Fertilizer-derived N in the soil NO₃-N fraction following corn harvest was clearly detectable and distinguishable from natural abundance to a 90-cm depth. Detection of fertilizer N in the total N pool below the 30-cm depth was not reliable, particularly at the lower N rates. Clay-fixation of fertilizer N measured at corn harvest was not detected by ¹⁵N analysis. Inconclusive results indicate that further research is needed to determine the feasibility of using depleted material for measuring clay-fixation of fertilizer-derived NH₄⁺-N. Nitrogen uptake by a winter rye cover crop reduced soil NO₃-N levels below that required for accurate isotope-ratio analysis. Following winter fallow (approx. 1 yr after fertilizer application) residual ¹⁵N-depleted fertilizer N was still detectable in plant tissue and the soil NO₃-N fraction. The objectives of the third study were to measure plant uptake and soil distribution of fertilizer N applied to corn at varying N rates and to determine the relationships between economic optimum N rate, fertilizer-use efficiency, and potential leaching loss of residual fertilizer N to groundwater. Plant recovery of fertilizer N in 1989 ranged from 33 to 47% even though no grain yield and fertilizer N uptake response resulted from N fertilization. Greatest accumulation of residual fertilizer N was found in the surface 30-cm both years following corn harvest. The economic optimum N rate for 1990 corn planted into a rye mulch (218 kg N ha⁻¹) corresponded closely with the rate (224 kg N ha⁻¹) resulting in the highest fertilizer-use efficiency. Low levels of residual fertilizer-derived NO₃ in the 60-90-cm depth following the 1990 corn harvest provides evidence to support the use of the economic optimum N rate concept from both economic and environmental viewpoints. The fourth study was designed to measure the effectiveness of a winter rye cover crop for recovering residual fertilizer N from the previous application of varying N rates to corn. Recovery of fertilizer N by winter rye increased with increasing N rate applied to the previous corn crop and ranged from 3.5 to 35.9 kg N ha⁻¹ in 1990 and 2.3 to 25.7 kg N ha⁻¹ in 1991. Residual fertilizer N recovery in 1991 was higher in rye plots where the previous corn crop had been planted no-till into rye stubble as compared to corn planted no-till into rye mulch. Little or no fertilizer-derived mineral N was measured in the soil to a final depth of 90-cm following a winter rye cover crop. Amounts of fertilizer-derived mineral N increased with depth and previous fertilizer N rate applied to corn following winter fallow. These results provide evidence to support the use of a winter rye cover crop on a silt loam soil to recover residual fertilizer-derived mineral N that might otherwise be lost to groundwater. / Ph. D.

Current interest in cover cropping is focused on enhancing ecosystem services beyond soil conservation. Cover crop (CC) species function uniquely in their effects on ecosystem services when grown in monoculture or mixtures. This research integrated field experiments and a literature synthesis to evaluate the role of cover crops in improving nitrogen (N) management and simultaneously providing multiple ecosystem services. Legume CC fertilized with poultry litter (PL) could replace 101 to 117 kg N ha-1 of fertilizer in corn (Zea mays L.) production. Rye (Secale cereale L.) CC fertilized with PL had a negligible effect on corn production. Biculture fertilizer equivalence ranged between -12 to +75 kg N ha-1. Fertilizer equivalence of legume-containing treatments increased across time. Without CC, fall-applied PL failed to supply N to corn. Ecosystem services of CC and PL illustrate complex species functions. Bicultures produced more total biomass than monocultures in year 1 but less than rye in year 2. Bicultures were as effective in suppressing weeds as rye, produced corn yield similar to legume, and by the second year had similar amounts of available soil N as the legume. Poultry litter effects and interspecific effects cover crop species biomass differed. Rye yield increased, while legume yield decreased slightly in biculture. Poultry litter increased legume N content and a decrease in legume C:N, while rye N content and C:N were unaffected. The synthesis corroborates that mixed and biculture cover crops yield more than the individual component species. Overyielding was transgressive in 60% of cases studied. Mixture effects varied by species: rye and brassica yield increased, while legume decreased in mixtures. The effect of mixed CC on crop yields varied by crop species and management practices, though generally crops increased 8 to 18% overall. This work can be applied to the design of complex CC and PL systems that optimize individual species functions to enhance ecosystem services. / Ph. D.

<p></p><p>It is estimated that in the United States, agronomic weeds are responsible for about 50% of crop yield loss, costing nearly $27 billion each year. As interest in cover crops across the Midwest increases, so does the need to understand when to terminate cover crops for maximum weed control while still maintaining crop yield. Field experiments were conducted in 2017 and 2018 in Indiana to evaluate the effect of cover crop termination timings on weed control, and corn and soybean yield. Cereal rye (<i>Secale cereale </i>L.) and canola (<i>Brassica napus </i>L.) were subjected to early- or late- termination utilizing glyphosate-, saflufenacil- or glufosinate-based burndown herbicide programs. In corn, cereal rye and canola reduced early season weed biomass by 58 to 67% compared to fallow (no cover crop) plots. Cereal rye and canola reduced horseweed (<i>Erigeron canadensis </i>L.) and giant ragweed (<i>Ambrosia trifida </i>L.) emergence by 42 to 50% compared to fallow plots. Early- and late- terminated cereal rye reduced corn yields by 55 to 67% (5,173 to 7,116 kg ha^-1) compared to canola or fallow plots. In soybean, cereal rye and canola reduced early season weed biomass by 73 to 88% compared to fallow plots. Cereal rye and canola reduced horseweed emergence in 2017 and 2018 by 16 to 67 % compared to fallow plots. In 2017, both cover crop and termination timing influenced giant ragweed emergence. Early- and late- terminated cover crop plots reduced giant ragweed emergence by 50 to 76% compared to fallow plots. In 2018, cover crop termination timing influenced soybean yield. Late-terminated plots reduced yields by 48% compared to early-terminated plots. Results from this study suggest that cereal rye and canola planted at these rates can be effective for weed suppression prior to corn and soybeans, however, yield loss in both corn and soybean is expected. </p><p>Reports from Indiana in 2015 suggested that growers planting canola as a cover crop were experiencing difficulties when terminating with glyphosate prior to corn and soybean production. This suggests the utilization of inadequate herbicide programs, or perhaps a seed contamination event containing glyphosate resistant canola. Field experiments were conducted in 2016 and 2017 to determine the most effective herbicide treatment for terminating glyphosate resistant canola in Indiana, and to quantify how these herbicide programs influence corn yield. Canola was planted in early September and herbicide treatments were applied in the spring three weeks before corn planting. Visual ratings of control and above-ground biomass reduction were collected 21 days after treatment (DAT). The highest control of canola occurred following the application of paraquat + saflufenacil + 2,4-D or metribuzin, resulting in 88 to 94% control. These control ratings are supported by applications with paraquat + saflufenacil + 2,4-D or metribuzin resulting in 88 to 97% biomass reduction. Auxin herbicides alone provided very poor control, less than 41% at both locations. In general, saflufenacil-containing herbicide treatments provided the highest control of canola compared to mesotrione or atrazine. Herbicide treatments had no effect on corn grain yield.</p><br><p></p>

Bibliography: leaves 93-114. / 114, [43] leaves, [30] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis investigates genome analysis of wheat, rye and barley. The objective is to evaluate the feasibility of using polymerase chain reaction (PCR) as a tool for studying cereal genomes. Results are compared for PCR and RFLP (restriction fragment length polymorphism) / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1994

Bibliography: leaves 93-114. This thesis investigates genome analysis of wheat, rye and barley. The objective is to evaluate the feasibility of using polymerase chain reaction (PCR) as a tool for studying cereal genomes. Results are compared for PCR and RFLP (restriction fragment length polymorphism)

<p>Several plant defense systems consist of enzymes that act on glucosides and produce a toxic compound. In the intact plant tissue the substrate and enzyme are kept apart. The system studied here consists of the substrate 2-O-β-D-glucopyranosyl-4-dihydroxy-1,4-benzoxazin-3-one and the enzyme glucan 1,3-β-glucosidase in rye. The aim was to determine the properties of a cell wall β-glucosidase. Two different systems for expression and purification of β-glucosidase fused to a tag were used: a 6xHistidine tag system and a thioredoxin tag system. The sequence of the β-glucosidase had previously been determined so now the gene was subcloned into E.coli. A direct PCR on colonies, a test expression, a restriction digestion of plasmids and sequencing was made to analyze the transformation, which all turned out successful. Then the β-glucosidase solubility was determined. Finally a purification of the β-glucosidase from E.coli under native conditions and a pNPG assay was carried out. For the (His)6-tagged protein, the recombinant β-glucosidase tended to end up in the insoluble pelleted fraction which indicated formation of inclusion bodies. The cell wall 1,3-β-glucosidase was soluble with the thioredoxin system, but the percentage of soluble protein fraction was around 5% only of the total protein. In eluates from a nickel-nitrilotriacetic acid column the presence of recombinant protein was confirmed with Western blot, but contaminating bands were also present. Purified elauted fractions did not exhibit detectable β-glucosidase activity. It was not possible to purify active enzyme. From a BLAST search it was clear that the most similar enzymes all had putative glycosylation sites and lack of glycosylation could be a reason for the protein not to fold properly.</p>

Several plant defense systems consist of enzymes that act on glucosides and produce a toxic compound. In the intact plant tissue the substrate and enzyme are kept apart. The system studied here consists of the substrate 2-O-β-D-glucopyranosyl-4-dihydroxy-1,4-benzoxazin-3-one and the enzyme glucan 1,3-β-glucosidase in rye. The aim was to determine the properties of a cell wall β-glucosidase. Two different systems for expression and purification of β-glucosidase fused to a tag were used: a 6xHistidine tag system and a thioredoxin tag system. The sequence of the β-glucosidase had previously been determined so now the gene was subcloned into E.coli. A direct PCR on colonies, a test expression, a restriction digestion of plasmids and sequencing was made to analyze the transformation, which all turned out successful. Then the β-glucosidase solubility was determined. Finally a purification of the β-glucosidase from E.coli under native conditions and a pNPG assay was carried out. For the (His)6-tagged protein, the recombinant β-glucosidase tended to end up in the insoluble pelleted fraction which indicated formation of inclusion bodies. The cell wall 1,3-β-glucosidase was soluble with the thioredoxin system, but the percentage of soluble protein fraction was around 5% only of the total protein. In eluates from a nickel-nitrilotriacetic acid column the presence of recombinant protein was confirmed with Western blot, but contaminating bands were also present. Purified elauted fractions did not exhibit detectable β-glucosidase activity. It was not possible to purify active enzyme. From a BLAST search it was clear that the most similar enzymes all had putative glycosylation sites and lack of glycosylation could be a reason for the protein not to fold properly.

Dietary factors may affect development and progression of prostate cancer. Experimental and epidemiological studies have suggested an effect of phytoestrogens on prostate cancer. Lignans are the predominant phytoestrogen in a Western diet. The effects of a diet rich in phytoestrogens and in particular lignans, as compared to a control diet, were assessed in several prostate cancer models. In paper I, 70 athymic nude mice with transplanted subcutaneous LNCaP tumours, an androgen sensitive human prostate cancer cell line, were fed one out of six phytoestrogen rich diets or a control diet after tumour injection. The rye diet, with high lignan content, decreased tumour take and growth, decreased secretion of prostate specific antigen and increased apoptosis. Addition of fat to the rye diet decreased the beneficial effects. In paper II, transgenic mice designed to develop prostate cancer (TRAMP) were fed rye bran or a control diet from the age of four weeks. Rye bran decreased prostate epithelial cell volume by 20%, and increased cell apoptosis by 31% as compared to the control diet. In paper III, we examined the effects of 7-hydroxymatairesinol (HMR), a purified lignan, in nude mice with subcutaneous LNCaP tumours in two different concentrations as compared to a control diet. Mice on the HMR diets had a reduced tumour take rate, lower total tumour volume, increased proportion of non-growing tumours, and increased apoptosis as compared to the control diet. Paper IV was a three week intervention study exploring the effects of rye bran bread vs. a control diet in men with prostate cancer. The men in the rye group had increased levels of plasma enterolactone and in biopsies from the prostate after the intervention an increase in apoptosis was observed in comparison with biopsies obtained before the intervention. In paper V, we examined the association between plasma levels of enterolactone, and risk of prostate cancer in a nested case control study. In the Northern Sweden Health and Disease Cohort, enterolactone concentrations were measured in plasma obtained at a mean time of 5 years before diagnosis from 265 cases of prostate cancer, and from 525 matched controls. We found no significant association between plasma enterolactone and risk of prostate cancer. Men with very low enterolactone levels (bottom decile) however, had significantly higher risk of prostate cancer. Phytoestrogen rich diet including soy, rye bran, substances purified from rye, and a purified lignan (HMR) all inhibited prostate tumour growth. However, it cannot be concluded that the effects observed were due solely to lignans as other components in rye grain such as tannins, phytic acid, ferulic acid, vitamins and minerals may have contributed to the beneficial effects. Thus, additional studies are needed to further elucidate the effects of phytoestrogens on prostate cancer development and progression.

Winter rye produces ice-modifying antifreeze proteins upon cold treatment. Two of these antifreeze proteins are members of the large, highly conserved, β-1,3-endoglucanase family. This project was designed to identify glucanase genes that are expressed during cold acclimation, wounding, pathogen infection, drought or treatment with the phytohormones ethylene and MeJa. Additionally, a more detailed proteomic analysis was to be carried out to evaluate the glucanase content of the apoplast of cold-acclimated (CA) winter rye. Results of 2D SDS-PAGE analysis revealed that non-acclimated whole leaf protein extracts contain at least two β-1,3-endoglucanses while CA whole leaf protein extracts contain at least three β-1,3-endoglucanses. Subsequent 2D SDS-PAGE analysis was conducted on the apoplast extracts of NA and CA winter rye plants revealed the limitations of standard 1D SDS-PAGE. The 2-dimensional gel analysis revealed that there is a minimum of 25 proteins within the apoplast of CA winter rye, including at least 5 β-1,3-endoglucanases. Genome walking was used to isolate cold-responsive glucanase genes. The five genes isolated were designated scGlu6, scGlu9, scGlu10, scGlu11 and scGlu12. The cis-element pattern within the promoter of each gene was evaluated using online databases of documented plant cis elements. As expected, all of the promoters contained elements associated with cold, biotic and abiotic stresses, light regulation, and development. The expression patterns predicted by the cis elements in each promoter were compared to the mRNA abundance produced by each gene as detected by semi-quantitative reverse transcriptase PCR. In most cases, the abundance of transcripts arising from each gene loosely corresponded to the expression pattern predicted by the cis elements the corresponding promoter. Transcripts of scGlu9, 10 and 11 were present in cold-treated tissues and are candidates for β-1,3-endoglucanases with antifreeze activity. The results presented in this thesis provide additional insight into the apoplast proteome of CA winter rye plants as well as the complexity of the signals controlling the proteins that reside there. Although there are still a number of unresolved questions, this research opens new directions for future studies in the cold acclimation process in winter rye and specifically for the contribution of β -1,3-endoglucanses.

Tiriamojo darbo objektas – žieminiai javai išauginti ekologinės ir intensyvios žemės ūkio gamybos ūkiuose Raseinių raj. Girkalnio ir Nemakščių seniūnijose. Tyrimo tikslas - ištirti javų žiemojimo ypatumus ekologinės ir intensyvios žemės ūkio gamybos ūkiuose. Tyrimo metodika. Tyrimas buvo atliktas 2008 – 2009 m. Raseinių rajono Girkalnio ir Nemakščių seniūnijos ūkiuose. Tyrimų dirvožemis – išplautžemis. Buvo pasirinkti 2 intensyvios ir 2 ekologinės žemės ūkio gamybos ūkiai. Šiuose ūkiuose buvo auginami žieminiai javai (rugiai, kviečiai ir kvietrugiai). Augalų skaičiavimo vietų skaičius buvo nustatomas pagal lauko dydį. Javų lauke atsitiktinai išskiriamos vietos po 0,25 m2 tyrimo laukelius kiekvieno lauko pradžioje, viduryje ir gale. Kiekvienoje vietoje suskaičiuojami augalai vegetacijos pradžioje ir prieš derliaus nuėmimą. Gauti duomenys perskaičiuojami į 1 m2. Pasinaudojant rudens ir pavasario augalų tankumo duomenimis buvo apskaičiuotas žiemojimo procentas. Tarp augalų skaičiaus rudenį ir peržiemojimo procento apskaičiuoti koreliaciniai ryšiai. Taip pat apskaičiuoti koreliaciniai ryšiai tarp augalų tankumo ir oro temperatūros. Tyrimo rezultatai. Atlikus tyrimus minėtuose laukuose suskaičiuota, kad ekologinės žemės ūkio gamybos ūkiuose tankiausi buvo žieminiai rugiai. Jų augalų skaičius įvairavo nuo 344 iki 580 vnt. m2, o intensyvios – žieminiai kvietrugiai, kurių priskaičiuota nuo 380 iki 568 augalų. Pavasarį tiek žieminių rugių, tiek ir žieminių kvietrugių išliko... [toliau žr. visą tekstą] / The study objective – to explore the characteristics of organic winter cereals and intensive agricultural production on farms. Objective – winter crops have been grown in organic and intensive agricultural production on farms Raseiniu region. Method of the work. The study was carried out in 2008 - 2009 on Raseiniu Girkalnio district and parish Nemakščių farms. Soil surveys - Luvisol. It was choice two and two intensive organic agricultural production of farms. These holdings have grown winter cereals (rye, wheat and triticale). Plant counting the number of sites were determined by field size. Cereal field identifies the local random 0.25 m2 for each field of study in the fields early, middle and rear. Each site counted at the beginning of vegetation and plants before harvest. The data obtained are converted into 1 m2. Through the autumn and spring plant density was estimated wintering percent. Among the number of plants in autumn and peržiemojimo calculate percent correlation. Also calculate the correlation between plant density and air temperature. The results of the work. After research in these fields has been calculated that organic agricultural farms were densest winter rye. Their number of plants varied from 344 to 580 units. m2, and intense - winter triticale, which counted from 380 to 568 plants. In spring and winter rye and winter triticale, and remained the least. Among the studies found an average variation - from 10 to 20 percent.Cereal hibernation depends on... [to full text]