Quality Of Barley Research Articles

Image Analysis of Grain and Chemical Composition of the Barley Plant as Predictors of Malting Quality in Mediterranean Environments

ABSTRACTWe have explored the possibility of predicting the malting quality of barley grain, indicated by malt extract yield, by characteristics measured either on plants at anthesis or in mature dry grain by image analysis. To produce barley samples with varying levels of all the characteristics studied, we used grain from an experiment designed to study the influence of lowinput husbandry practices on malting quality of barley by growing five malting genotypes at each of four environments (site × season) and with two different agronomic treatments (N fertilization and herbicide‐mechanical roguing of weeds). The results showed that nitrogen content in the plant at anthesis was a good predictor of grain protein content, this characteristic in turn being positively correlated with embryo size and grain volume, as estimated by image analysis, and negatively correlated with nonstructural carbohydrate content in the plant at anthesis. Extract yield was positively correlated with Kolbach index (ratio of soluble to total wort protein) and negatively correlated with wort viscosity and barley grain protein content. Thus, the only practical predictor of malt extract was grain protein content.

Growth, yield and grain quality of barley (Hordeum vulgare L.) in response to nitrogen uptake I. A low cost, controlled nutrient supply system

This paper describes the development of an inexpensive, perlite culture system with recirculating nutrient solutions which required simple maintenance and provided aerial conditions approximating those of a crop stand. A range of repeatable nitrogen experiments provided sufficient plant material for sequential, destructive harvests, grown under the same climatic conditions and protected from rainfall by a polythene tunnel. A study of the effects of nitrogen uptake on development, growth, grain yield, and quality was done in two contrasting cultivars of malting barley. Two nitrogen treatments were imposed, High N where nitrogen was supplied to plant demand and Low N where nitrogen supply was restricted to one-third of that demand. The development of the controlled nutrient supply system is described and the possible improvements and test performance according to three criteria is discussed: (1) the uniformity of growth and nitrogen uptake within a treatment bed, (2) the ability to achieve the desired nitrogen uptakes (3:1, High N: Low N) and (3) that the stand of plants behaves as a crop rather than a collection of isolated or semi-isolated plants are discussed. This third criterion was evaluated using Greenwood's (1982) definition of optimal nitrogen uptake for maximal growth and compared with the results obtained in the High N treatments.

Growth, yield and grain quality of barley (Hordeum vulgare L.) in response to nitrogen uptake. II. Plant development and rate of germination

Growth, yield and grain quality of barley (Hordeum vulgare L.) in response to nitrogen uptake. II. Plant development and rate of germination

Growth, yield and grain quality of barley (Hordeum vulgare L.) in response to nitrogen uptake. I. A low cost, controlled nutrient supply system

Growth, yield and grain quality of barley (Hordeum vulgare L.) in response to nitrogen uptake. I. A low cost, controlled nutrient supply system

Growth, yield and grain quality of barley (Hordeum vulgare L.) in response to nitrogen uptake: II. Plant development and rate of germination

modern agricultural systems for use in an ‘industrial process’ such as malting, a wide variability of grain size A nutrient culture system supporting stands of barley and germination rate are unwanted. In the malting process was used to examine the effect of nitrogen supply on the prime requirement is even germination so that grain plant development and germination rate. Two con- modification can be controlled and carried to completion. trasting cultivars of barley were grown for two seasons If a grain sample germinates and modifies unevenly, with nitrogen supplied at an optimal rate and at one- achievement of the malt specification can result in high third that rate. Mature grain was dissected from ears malting losses. In slower germinating grains the failure by grain position; stored until out of dormancy, to convert starch to sugars will reduce spirit yield in weighed, and the time from imbibition to germination distilling malts. estimated for different ear positions. A parallel set of In species of the Hordeae, within-plant variability samples was analysed for grain nitrogen concentra- results from diVerences within the ears and between the tions. A systematic increase in germination time was culms of a plant. The successful malting barley cultivars observed from the bottom to the top of the ear. This most commonly grown in Europe have a two-row ear, effect was in addition to and of the same order as the because the six-row type has unacceptable variation in effect of grain size on germination time. Although there grain size (Riggs and Kirby, 1978). Functionally, the was significant variation in nitrogen concentration by barley plant has two stem types, i.e. the main stem and grain position, these effects were smaller than the its lateral branches or tillers. The later time of apical variations in grain weight within the ear and were not primordium initiation and the tendency for the date of related to germination rate. These results are discus- heading to be synchronous between the ears of a plant sed in relation to plant development and events at the means that the time for development is increasingly onset of germination. compressed with each additional tiller. The number of stems per square metre is influenced by environmental

Influence of seed rate and sowing date on the yield and grain quality of Blenheim spring malting barley in the south-east of Ireland

The effect of four seed rates on the grain yield, grain N content and grain size of Blenheim malting barley sown on two dates in the spring was tested on three different soils over a 4-year period (1991–94). The four seed rates (120, 160, 200 and 240 kg/ha) gave mean plant populations of 222, 308, 374 and 430 plants/m2, respectively, for the first sowing date (February to early March) and 235, 340, 405 and 470 plants/m2 for the second sowing date, 3–5 weeks later (late March to mid-April). The earlier-sown crops generally gave greater yield, lower grain N and smaller amount of screenings, but in two of the twelve experiments, the first sowing gave lower yield and greater grain N.The influence of seed rate on yield and quality depended on sowing date. The three higher seed rates (160, 200, 240 kg/ha) had little influence on yield or grain N, irrespective of sowing date, and there was no significant difference in yield between the lowest (120 kg/ha) and the three higher seed rates when the crop was sown in February and early March. But when the crops were sown in April, the lowest seed rate (120 kg/ha) gave the lowest yield in all seven comparisons and gave significantly reduced yield in three of the seven comparisons. There was a significant increase in grain N in three of the comparisons. Seed rate had little effect on grain screenings or 1000-grain weight. Soil differences did not influence the effect of seed rate on the yield and quality of the grain.

The effect of seedbed condition on the grain yield and quality of spring malting barley

The effect of seedbed conditions at the time of sowing on the grain yield and quality ex-farm of spring-sown malting barley was examined in three experiments in the south-east of Ireland in 1993–95. Blenheim malting barley sown in good seedbed conditions gave significantly (P<0·05) greater yields (3·1–9·6% more) than the identically treated crop, sown several days earlier, in less suitable seedbed conditions in all three experiments, but there was no effect on grain nitrogen content or the amount of screenings. The better soil conditions gave significantly (P<0·05) better plant emergence, a greater number of fertile tillers and more grains per ear.

Effects of a period of high temperature during grain filling on the grain growth characteristics and malting quality of three Australian malting barleys

Short periods of high temperatures (up to 35°C) during mid grain filling appear to reduce yield and quality in barley. Plants of 3 malting barley varieties, Schooner, Arapiles, and Sloop (a new South Australian malting variety), were grown under constant environment conditions from germination to maturity and exposed to 5 days of high temperatures (up to 35°C) during mid grain filling. Schooner and Sloop showed similar patterns of accumulation of dry matter under control conditions (21°C/16°C, day/night temperature) and in response to high temperatures. In all varieties, the reduction in starch accumulation represented the most significant detrimental effect of high temperature and made the greatest contribution to the reduction in final grain weight. The reduction in absolute grain nitrogen (N) in heat-treated Arapiles grains represents a potentially important response under high temperature conditions. In this study, water loss did not have a decisive role in the termination of grain filling. Continued accumulation of endosperm dry matter at low moisture levels suggested that water distribution and/or components of water potential may be more important than overall water content in the cessation of grain filling. Final grain composition depended not only on the amount of endosperm storage component present in the grain but also on the contribution of the non-endosperm components (including the embryo and husk) to final grain dry weight. In some cases, changes in the contribution made by the non-endosperm components of the grain to final grain weight masked important high temperature effects on key endosperm storage components. Hot water extract (HWE) values were similar within treatments and ranged from 73% to 78%. High temperature exposure reduced HWE for all varieties. Malt b-glucan was lower in heat-treated grains than in control grains. Despite relatively high malt protein levels in all varieties, higher free amino N levels in heat-treated grains indicated a higher protein modification than in control grains.

Growth and Final Weight of Central and Lateral Barley Grains under Mediterranean Conditions as Influenced by Sink Strength

Grain weight largely determines the end‐use quality of barley (Hordeum vulgare L.). In six‐rowed types, central spikelets commonly bear heavier grains than lateral spikelets. However, the extent to which such differences in weight are influenced by source availability remains unclear. Field experiments were carried out in nine rainfed trials of northeastern Spain and showed large variability in grain weight. Three six‐rowed genotypes were used: Barberousse, Orria, and Plaisant. Sink strength of mainstems was decreased by half at anthesis by sterilizing 50% of fertile central and lateral florets. Variation among spikelets in grain growth parameters [maximum grain filling rate (GFR) and grain filling duration (GFD)] and in final grain weight was evaluated in control and sink‐reduced spikes. Central grains outweighed lateral ones in control spikes from 7.3 to 14.8 mg across trials. Absolute differences in weight increased progressively in those trials favoring larger grains, although lateral to central grain weight ratios (L/C) remained fairly constant, with an average value of 0.77. This advantage of central grains was mostly caused by higher GFR values. A 50%‐reduced sink increased grain weight of both central and lateral spikelets similarly and did not diminish the absolute differences in weight found in control spikes. This result suggests that central grains have a greater intrinsic potential weight. While grain yield was partially source limited in all environments, lateral grains exhibited on average a major degree of source limitation (24.2%) than central grains (19.1%). Sink reduction increased grain weight of both central and lateral grains by stimulating GFR in all trials, and also by lengthening GFD in poor rainfed environments.

Relationship between Genotype of Hordein and Malting Quality in Japanese Barley.

ビール大麦種子貯蔵蛋白質ホルデインによる麦芽品質の選抜の可能性を明らかにする目的で、麦芽品質とホルデイン遺伝子型との関係を調査した。日本のビール大麦115品種・系統のホルデインをドデシル硫酸ナトリウム-ポリアクリルアミトゲル電気泳動(SDS-PAGE)により分析し、Cホルデインの遺伝子型を同定した。日本のビール大麦のCホルデインには6種類の遺伝子型があった。そのうち5種類は既知の遺伝子型のBr型、Cl型、Ha型、Ma型、Pr型であり、1種類は新たな遺伝子型(Mi型)であった。日本のビール大麦における遺伝子型の割合は、Br型をもつ品種・系統が最も多く全体の41.7%を占めていた。また、Cl型は福岡島総試および栃木農試栃木分場の近年の育成系統に多くみられた。Cホルデイン遺伝子型と麦芽品質項目との間には、コールバッハ数、ジアスタゼカ、最終発酵度、総合評点に有意差があり、Br型、Cl型をもつ系統が麦芽品質が優れていた。また、Cホルデインの個々のサブユニットと麦芽品質との関係では、Br型、Cl型を構成するサブユニットが麦芽品質が優れる傾向にあった。さらに、Cホルデイン遺伝子型の異なる(Mi型とCl型)品種間F1から bulbosum法により作出した半数体倍加系統(DHLs)37系統を用いて、Cホルデイン遺伝子型と麦芽品質との関係を調べた結果、Cl型をもつ系統はジアスターゼカが高かった。以上の結果がら、CホルデインではBr型、Cl型が麦芽品質に優れ、Cホルデインによる麦芽品質の選抜の可能性が示唆された。

Improved Callus Quality and Prolonged Regenerability in Model and Recalcitrant Barley (Hordeum vulgare L.) Cultivars.

In vitro performance of immature embryo-derived callus of two barley cultivars, the amenable cultivar, Golden Promise (GP) and the recalcitrant commercial cultivar, Galena (GL), was tested on fourteen media containing combinations of two auxins, dicamba and 2, 4-dichlorophenoxyacetic acid (2, 4-D) and two cytokinins, 6-benzylaminopurine (BAP) and zeatin. Generalizations for both cultivars include the fact that callus-induction frequencies on dicamba and 2, 4-D alone and dicamba plus zeatin were nearly 100%. Qualitative appearance for both cultivars was nearly identical on comparable media but markedly better on BAP-containing media. The addition of zeatin with either auxin supported vigorous growth due to the proliferation of nonregenerable callus; the presence of BAP produced higher quality callus although it inhibited the relative growth rate. GP calli grown on 2, 4-D plus 0.01mg/L BAP regenerated the largest number of green shoots at most time points relative to other media, while GL tissue on 2, 4-D plus 0.1mg/L BAP yielded the most green shoots at all but one time point. Over time regenerability was lost more rapidly in GL than GP except on 2, 4-D plus BAP media; GL had a higher propensity toward albinism than GP. In both cultivars, the use of 2, 4-D and BAP yielded tissue that proliferated for prolonged periods in a regenerable state.

Biological evaluation of protein quality of barley

Protein quality of barley cultivars, namely BH-331 (hulled), DL-88 (hullless) and Dolma (hullless) having 2.18, 4.60 and 6.23% β-glucan content, respectively, was biologically evaluated by rat growth and nitrogen balance studies. Feeding of BH-331 barley diet resulted in marked decrease of food intake, body weight gain, food efficiency ratio, protein efficiency ratio, nitrogen absorption, biological value, net protein utilization and utilizable protein. The diet containing Dolma cultivar (hullless and high β-glucan) caused by intermediate effect on all the protein quality parameters. DL-88 (hullless) gave better results than BH-331 and Dolma. Therefore, β-glucan content may not be affecting protein quality parameters in barley. However, hulled barley (BH-331) showed adverse effects on biological parameters in which husk seems to contribute towards unpalatability of the diet, thereby leading to a reduced food intake and other related parameters.

Evaluation of a Malting Barley Quality Assessment System

New malting barley varieties are annually tested for their malting and brewing potential according to a field trial set-up combined with quality evaluation on pilot scale. To assess the effects of trial year and location on quality evaluation data, a data base consisting of quality data from Dutch malting and brewing trials of new malting barley varieties during the period 1989–1995 was analyzed using multivariate statistical techniques. It was also determined which parameters gave little or no discrimination among varieties over the years. The analysis showed that strong annual effects occurred over the period observed. A considerable list of 23 analytical parameters from barley, malt, wort, and beer analysis were relevant to explain 50% of the variance in the data set. Seven parameters showed hardly any variation and possessed no discriminative value. This indicated that the number of parameters could be diminished to some extent without losing resolving power with respect to quality evaluation. A further reduction is possible when, of two parameters showing high positive or negative correlations, only one is analyzed. Quality data from different trial locations were prone to annual effects. The trends observed showed clustering of data from particular trial locations with discrimination among locations in certain years. From this evaluation, it could not yet be concluded whether or not a limitation in the number of trial sites is feasible. The evaluation offers an approach towards further increasing the efficiency and cost-effectiveness of existing trial systems.

Impact of Fusarium Head Blight on the Malting and Brewing Quality of Barley

Impact of Fusarium Head Blight on the Malting and Brewing Quality of Barley

Micronutrient concentrations in barley and soybean under minimum tillage on podzolic soils in a cool climate

Micronutrients can be limiting for crop production and quality in fine sandy loam Podzolic soils in the cool, humid climate of Atlantic Canada. This study was conducted to determine the effect of mimimum tillage practices, in three long‐term animal feed crop rotations, on micronutrient (B, Cu, Zn, Mn, Fe and Mo) content and grain quality of spring barley (Hordeum vulgare L.) and soybean (Glycine max L. Merrill). Reductions in soil tillage had various effects on micronutrient concentration in plant parts, especially for Cu, Zn, Mn, and Mo, which were probably related to pH changes at the soil surface. Grain micronutrient concentrations, however, for crop yield potential tended to be in the sufficiency range and were not limiting for crop growth or feed quality. Evidence suggesting a decline in Mo concentration over time underlines the need for periodic assessment of micronutrient assimilation in conservation tillage systems.

The conversion of RFLP markers to allele specific amplicons linked to QTLs governing malting quality in barley

Application of marker-assisted selection with RFLP based markers has been constrained by high cost and time requirements in situations involving a large number of plants. RFLP markers mapped on a Harrington/TR306 population have been identified elsewhere as linked to quantitative trait loci (QTL) governing malting quality. The probes ABG610, ABC622, as well as probes for the Nar1, Amy1 and Nar7 were sequenced and locus specific primers developed. These locus specific primers were applied to genomic DNA from both Harrington and TR306. Sequence analysis of the resultant monomorphic fragments revealed sequence divergence for the Xabg610, Xabc622, Amy1 and Nar1 loci, but not for the Nar7 locus. Application of a set of Hor2 primers to genomic DNA from the barley lines Harrington and TR306 led to the direct amplification of codominant alleles. Allele-specific primers were designed based on the sequence divergence identified among the Xabg610, Xabc622 and Nar1 alleles. Amplification conditions were optimized for each of these alleles such that only the favourable allele from Harrington was amplified. The usefulness of these primers for selecting Harrington alleles was demonstrated by their failure to amplify the corresponding alleles from the lines, Sterling, Stella and WM872. The Amy1 allele-specific amplicon was only capable of differentiating this locus between Harrington and TR306. The conversion of these markers into PCR amplifiable, allele-specific amplicons would greatly facilitate their application to barley breeding programs.

Grain growth and malting quality of barley. 2. Effects of temperature regime before heat stress

Short periods of very high maximum temperature (>35°C) during grain filling appear to reduce grain yield and quality in barley. Tolerance of grain yield and quality to heat stress may be increased when acclimation to high temperature occurs. Two experiments were performed to test the hypothesis that a gradual (or stepped) increase to very high temperature reduces the impact of that stress on grain growth and quality of barley, compared with a sudden increase over the same temperature range. Plants experiencing either a sudden or a gradual increase did not exhibit any differences in grain weight or malting quality, but increasing the temperature in 2 steps (so that plants were exposed to 30 or 34°C for 2 h before a 40°C heat stress) appeared to have produced acclimation, since the reduction in grain weight under the 2-step treatment was about half that of either a sudden or gradual increase in temperature. Heat stress altered grain composition in various ways. The reduction in final grain weight was strongly and linearly related to the reduction in starch content. Grain β-glucan was 4·5 ± 0·5% across treatments and experiments and was significantly reduced in the glasshouse but not in the phytotron experiment. However, β-glucan degradation was similar between treatments in both experiments. Grain nitrogen concentration was very high and similar between treatments. Consequently, diastatic power was high and there was a trend towards a reduction under heat stress. Free amino nitrogen was higher under heat stress, indicating a higher protein modification than in the controls. Malt extract was significantly reduced by heat stress in the glasshouse experiment.

Effects of Temperature, Moisture and Cellulases on the Fermentation Quality and Chemical Composition of Naked Barley (Hordeum vulgare L. emand Lam) Straw Silage

Effects of Temperature, Moisture and Cellulases on the Fermentation Quality and Chemical Composition of Naked Barley (Hordeum vulgare L. emand Lam) Straw Silage

Effects of Additives of Lactic Acid Bacteria and Cellulases on the Fermentation Quality and Chemical Composition of Naked Barley (Hordeum vulgare L. emand Lam) Straw Silage

Effects of Additives of Lactic Acid Bacteria and Cellulases on the Fermentation Quality and Chemical Composition of Naked Barley (Hordeum vulgare L. emand Lam) Straw Silage

Grain growth and malting quality of barley. 1. Effects of heat stress and moderately high temperature

In this study, controlled-environment conditions were used to compare the effects of moderately high and very high temperatures during grain filling on grain growth and malting quality of barley. Heat stress applied from 15 to 20 days after anthesis (DAA) reduced grain weight by about 35%, whereas longer periods (15–20 days) of moderately high temperature applied from 20 DAA to maturity reduced grain weight by about 6%. Both heat stress and moderately high temperature resulted in reduced grain weight through a reduction in the duration of grain filling. Grain composition was altered by both moderately high and very high temperatures, although the changes were larger under very high temperatures. In general, there was a decrease in starch content, resulting from the reduction in both volume and number of A- and B-type starch granules. Nitrogen concentration was significantly increased only in the 30/25°C treatments, and changes in diastatic power were only minor. There was a reduction in β-glucan content, together with an increase in β-glucan degradation. However, malt extract was not significantly affected by these stresses.