Amount Of Water-soluble Carbohydrates Research Articles

Селекционна оценка на някои показатели за качеството на фуража при многогодишнишни житни треви – пасищен райграс (Lolium perenne L.)

The chemical composition of 21 accessions of Lolium perenne L. from the collection nursery of Institute of Forage Crops - Pleven, for three cuts each year, for the period 2017-2018, was evaluated as follows: crude protein (CP), % – according to Kjeldahl‘s method; crude fiber (CF), % – by Weende analysis; water-soluble carbohydrates (WSC) – according to Ermakov et al. Statistical processing of the data was performed, which included regression, correlation, two-factor ANOVA a nd cluster a nalyses. There is a t rend i n both years for the first cut to be lowest in crude protein (CP); relatively high in crude fiber (CF) and highest in water soluble carbohydrates (WSC) content. In the second and third cuts, crude protein increases; crude fiber content varies within different limits, but generally decreases; and the amount of water-soluble carbohydrates also decreases. The genotype–environment (accessions x cuts) interaction had insignificant variance in all three studied traits. In terms of CP, the maximum value was reported for the Iljo variety (18.8%) and the minimum for China (14.6%). No significant differences were observed between the check Tetrany (16.1%) and the other accessions. Only two cases of significant differences were observed for CF and WSC between accessions. The cluster analysis arranges the accessions into three groups, with the second cluster of 8 accessions being the most interesting for the selection. The analysis well differentiates the accessions regarding the optimal combination of the three traits in one genotype, as well as their ploidy level. A significant negative correlation was observed between crude protein and crude fiber content (r=-0.744).

Enhanced cellulosic d-lactic acid production from sugarcane bagasse by pre-fermentation of water-soluble carbohydrates before acid pretreatment

After several rounds of milling process for sugars extraction from sugarcane, certain amounts of water-soluble carbohydrates (WSC) still remain in sugarcane bagasse. It is a bottleneck to utilize WSC in sugarcane bagasse biorefinery, since these sugars are easily degraded into inhibitors during pretreatment. Herein, a simple pre-fermentation step before pretreatment was conducted, and 98 % of WSC in bagasse was fermented into d-lactic acid. The obtained d-lactic acid was stably preserved in bagasse and 5-hydroxymethylfurfural (HMF) generation was sharply reduced from 46.0 mg/g to 6.2 mg/g of dry bagasse, after dilute acid pretreatment. Consequently, a higher d-lactic acid titer (57.0 g/L vs 33.2 g/L) was achieved from the whole slurry of the undetoxified and pretreated sugarcane bagasse by one-pot simultaneous saccharification and co-fermentation (SSCF), with the overall yield of 0.58 g/g dry bagasse. This study gave an efficient strategy for enhancing lactic acid production using the lignocellulosic waste from sugar industry.

Upgrading steam pretreatment by converting water-soluble carbohydrates into lactic acid prior to pretreatment

Steam pretreatment is an effective approach to open up the intact lignocellulosic matrix for biofuels and animal feed production. However, crop residues especially corn stover contain certain amounts of water-soluble carbohydrates (WSC), which are easily degraded into toxic 5-hydroxymethylfurfural (HMF) at high temperature and bring negative effects on subsequent utilization of lignocellulose biomass. Few studies have focused on the WSC loss and proposed a corresponding solution to utilize them in steam pretreatment. This study introduced a solid-state fermentation prior to steam pretreatment of corn stover to convert WSC into lactic acid, which could catalyze the hydrolysis of hemicellulose and acetyl groups in pretreatment. Compared to the regular steam pretreatment at the same severity (180 °C for 5 min), the conversion yields of xylan and arabinan in the steam pretreatment were both increased from 9.6% and 37.2% to 28.8% and 69.6%, respectively. Cellulose conversion also increased from 48.1% to 50.7% in the subsequent enzymatic hydrolysis. On the other hand, the generation of the toxic HMF reduced by 42.1% due to the pre-conversion of WSC into the relatively thermal stable lactic acid. This study provided an effective approach to process corn stover with higher hydrolysis yield and lower inhibitor generation.

Physiological and morphological responses of different spring barley genotypes to water deficit and associated QTLs.

Water deficit is one of the major limitations to food production worldwide and most climate change scenarios predict an aggravation of the situation. To face the expected increase in drought stress in the coming years, breeders are working to elucidate the genetic control of barley growth and productivity traits under water deficit. Barley is known as a relatively drought tolerant crop and genetic variability was observed for drought tolerance traits. The objectives of the present study were the quantification of morphological and physiological responses in a collection of 209 spring barley genotypes to drought stress, and the genetic analysis by genome-wide association study to find quantitative trait loci (QTL) and the allele contributions for each of the investigated traits. In six pot experiments, 209 spring barley genotypes were grown under a well-watered and water-limited regime. Stress phases were initiated individually for each genotype at the beginning of tillering and spiking for the vegetative- and the generative stage experiments, respectively, and terminated when the transpiration rates of stress treatments reached 10% of the well-watered control. After the stress phase, a total of 42 productivity related traits such as the dry matter of plant organs, tiller number, leaf length, leaf area, amount of water soluble carbohydrates in the stems, proline content in leaves and osmotic adjustment of corresponding well-watered and stressed plants were analysed, and QTL analyses were performed to find marker-trait associations. Significant water deficit effects were observed for almost all traits and significant genotype x treatment interactions (GxT) were observed for 37 phenotypic traits. Genome-wide association studies (GWAS) revealed 77 significant loci associated with 16 phenotypic traits during the vegetative stage experiment and a total of 85 significant loci associated with 13 phenotypic traits during the generative stage experiment for traits such as leaf area, number of green leaves, grain yield, harvest index and stem length. For traits with significant GxT interactions, genotypic differences for relative values were analysed using one way ANOVA. More than 110 loci for GxT interaction were found for 17 phenotypic traits explaining in many cases more than 50% of the genetic variance.

Влияние углеводного субстрата из крахмалсодержащего сырья на состав глюканов биомассы микромицета Aspergillus niger ВКПМ F-171

The conditions for biocatalytic cleavage of corn starch and rye whole grain flour for the subsequent cultivation of the Asperillus niger strain VKPM F-171 are described. As a result of this procedure, the amount of water-soluble carbohydrates in the substrates increased by 5-6 times in comparison with the initial raw material, and the content of glucan p-form in the hydrolysate of rye whole grain flour grew by 2-3 times. The content of glucans in the biomass by the end of the cultivation of A. niger VKPM F-171 on corn starch hydrolysate was 28±2% of dry matter, while the proportion of glucans after fermentation on the rye whole grain flour hydrolysate was 21±1%, 96-97% of which were β-glucans. The hydrolysis with Trichoderma longibrachiatum β-glucanase and Trichoderma reesei xylanase resulted in a 1.1-1.2-fold increase in the proportion of soluble carbohydrates in microbial biomass. It was found via gas-liquid chromatography that the structural units of carbohydrates in microbial biomass are represented by glucose and its 2- and 6-deoxy derivatives, fructose, fucose, galactose, mannose, xylose, and, to the greatest extent, by the reserve saccharide sedoheptulose. It was established that β-glucans are products of hydrolysis of the chitin-glucan complex and glycopeptides. The molecular weight of the obtained microbial glucan-containing biopolymers ranges from 0.5 to 50 kDa. It was shown that the content of β-glucans in microbial biomass allows the latter to be considered as an alternative to plant sources. biosynthesis, Asperillus niger, biocatalysis, starch-containing raw materials, glucans

Isolation and identification of lactic acid bacteria in fresh plants and in silage from Opuntia and their effects on the fermentation and aerobic stability of silage

AbstractThe current study aimed to select the strains of lactic acid bacteria (LAB) isolated from forage cactus plants and silage and assess their effects on silage fermentation and aerobic stability. Forty wild isolates from plant and cactus silage, classified as LAB, were evaluated for metabolite production and identified by 16S ribosomal DNA sequencing. These wild isolates were identified asLactobacillus plantarum,Weissella cibaria,Weissella confusaandWeissella paramesenteroidesand the LAB populations differed among the silage. The use of microbial inoculants did not influence gas or effluent losses in forage cactus silage. The silage inoculated with the microbial strain GP15 showed the highest number of LAB populations. The amounts of water-soluble carbohydrates (WSC) and ammonia nitrogen differed among the silage. The silage inoculated with the GP1 strain presented the highest WSC. Populations of enterobacteria and yeasts and moulds were below the minimum detection limit (<2.0 log cfu/g silage) in all the silage studied. The predominant action of inoculants was to maximize dry matter recovery of the silage, which could be the criterion adopted to select the strains of LAB for use as inoculants inOpuntiasilage.

INVESTIGATION OF THE EFFECT OF HEAT TREATMENT ON THE QUALITY OF THE FEED ADDITIVE CONTAINING CARROT POMACE

The main task of the compound feed industry is development and introduction of high-performance equipment and technologies, expansion of the resource base and the range of finished products. Along with this, in the canning industry, a lot of by-products are formed. By their chemical composition, they are as good as the main products. However, by-products of the canning industry are characterized by a high moisture content. They deteriorate very quickly and require immediate disposal. That is why, the purpose of the paper was to study the effect of heat treatment on the physicochemical properties and on the quantitative and qualitative composition of the microflora of the feed additive made with the use of carrot pomace. The physical properties, chemical composition, sanitary quality, and permissible shelf life of carrot pomace have been determined. The optimum quantitative and qualitative composition of the feed additive have been reasoned and researched. It has been established that the process of extrusion improves the physical properties and increases the digestibility of nutrients. It also improves the sanitary condition and extends the shelf life of the additive. As a result of extrusion of the feed additive, the moisture content decreased by 32.2%, the angle of repose increased by 11.8%, the flowability decreased by 33.3%, the damaged starch content decreased by 33.2%, and the amount of water-soluble carbohydrates became 5 times as big. Besides, under the influence of high temperature and pressure, the total number of bacteria decreased by 89%, and that of mould fungi by 83%. During storage of the feed additive for 6 months, the QMAFAnM decreased by 32.5%. The resulting feed additive will solve the problem utilizing canning industry by-products, expand the raw material base and reduce feed consumption.

Effect of Oregano, Cumin and Cinnamon Essential Oils on Fermentation Quality in Alfalfa Silages

Objective: The aim of this study was to determine the effects of the oregano (OEO), cumin (CEO) and cinnamon (CINEO) essential oils on fermentation quality, metabolic energy (ME) contents and relative feed value (RFV) of alfalfa silages.Material and Methods: Alfalfa was harvested in the end of April, at the early bloom-stage, was wilted for 3 hours and chopped to approximately to a size of 2.0 cm. OEO, CEO and CINEO essential oils were added as additivies in an amount of 600 mg/kg wet chopped alfalfa, yet no additives were added to the control (CONT) group. The packages of silage were kept in a covered storage (18±4 °C) for 60 days for fermentation.Results: The addition of cumin and cinnamon led to a significant increase in dry matter (DM) (P<0.05). The addition of essential oils at high level caused an increase in lactic acid (LA), while the amount of water soluble carbohydrate (WSC) decreased inversely correlated with LA (P<0.05). The treatment was increased lactic acid bacteria (LAB) numbers, and also caused a decrease in the number of yeast and mould at a significant level (P <0.05). All three essential oils led to a decrease in pH, the amount of weigth loss (WL) and ammonia nitrogen (NH3-N). In the cumin and cinnamon essential oil treatments increased amount of enzimatic solubility organic matter (ESOM) (P<0.05).Conclusion: It was concluded that OEO, CEO and CINEO promote to increase LAB population. In addition, MEESOM content calculated through ESOM was increased in OEO and CINEO treatments.

An Approach of Utilizing Water-Soluble Carbohydrates in Lignocellulose Feedstock for Promotion of Cellulosic l-Lactic Acid Production.

Agricultural lignocellulose biomass generally contains certain amounts of water-soluble carbohydrates (WSC) such as glucose, fructose, or sucrose. These sugars are generally degraded in pretreatment at high temperature or discharged with wastewater in a detoxification process. This study proposed an approach of utilizing frequently ignored water-soluble carbohydrates for promotion of cellulosic l-lactic acid production. A simple solid state fermentation was performed during a corn stover storage period to convert the sugars into l-lactic acid and then a dry biorefining technology was applied to convert cellulose and hemicellulose fractions into the same l-lactic acid product. The 5-hydroxymethylfurfural (HMF) formation in pretreatment was significantly reduced and the consequent biodetoxification time was shortened. l-Lactic acid production was increased from 130.2 g/L to 139.0 g/L, and the minimum l-lactic acid selling price was reduced by 5.9%. This study provided an important option of biorefinery processing technology for production of value added biochemicals.

Survival Strategy in the Wetland SedgeCarex brevicuspis(Cyperaceae) in Response to Flood and Drought: Avoidance or Tolerance?

Survival strategies of plants to adapt to environmental stress include avoidance and tolerance. These strategies were investigated in the wetland sedge Carex brevicuspis (Cyperaceae) to determine the plasticity of its response to flood and drought. Individual plants were grown in PVC tubes and subjected to five water levels relative to soil surface: -40 cm, -20 cm, 0 cm, +20 cm, and +40 cm. After 60 days, plants were harvested and their biomass accumulation, number of leaves (a measure of growth), root and shoot elongation, aerenchyma formation (avoidance strategy), amount of malondialdehyde (MDA), amount of water-soluble carbohydrates (WSC), alcohol dehydrogenase (ADH) activity, amount of proline (tolerance strategy), and membrane permeability (a measure of degree of injury) were assessed. Relatively high amounts of MDA and proline and a high level of ADH activity, combined with relatively low aerenchyma area, short leaves, and low amount of WSC in the +20 cm and +40 cm treatments indicated that C. brevi...

Effect of heat treatment on quality of feed additive using tomato pomace

Rapid development of the poultry industry requires solving such problems as expanding the resource base and using alternative sources of raw materials, reducing manufacturing cost of animal feed products and ensuring calcium deficiency in highly productive layers. However, during the production of canned vegetables, there are large amounts of waste in the form of tomato pomace, which are very perishable and require immediate disposal. Therefore, a necessary condition for the development of the poultry industry is to elaborate a method of producing a feed additive using the by-products of the canning industry. The aim of the research is to study the effect of heat treatment, namely the extrusion process on the physicochemical properties and quantitative-qualitative composition of the feed additive microflora using tomato pomace. It is found that the extrusion process not only does not affect the feed additive quality, but also significantly improves the physical properties, increases the digestibility of nutrients by enzymes of the gastrointestinal tract of birds, and considerably enhances the sanitary properties of the additive. During extrusion, the content of solid starch in the feed additive decreases by 33.4% and the amount of water-soluble carbohydrates increases 5 times, which greatly improves its absorption by the body of birds. Conducting the extrusion process has allowed to reduce moisture content in feed additive by 34.5%, which is positive in terms of the perspective of its further processing and storage. In addition, under high temperature and pressure, the total amount of bacteria has decreased by 89%, and mycelium fungi - by 83%, which allows to count on the efficient storage of feed additive and use in the manufacture of animal feeds for poultry. The obtained feed additive will allow to solve the problem of disposal of tomato wastes, and the developed method of their processing will be less expensive as compared to the existing ones. Since the extrusion process is less energy-intensive, using the tomato pomace as a mixture humidifier before extrusion reduces the humidification costs.

Understanding grain yield responses to source–sink ratios during grain filling in wheat and barley under contrasting environments

A better understanding of the effects of different source–sink ratio during the grain filling period on grain growth may be relevant in order to further increase cereal grain yield. The main objective of the present work was to determine the effect of different manipulations of the source–sink ratios in wheat and barley grown at four different environmental conditions on responsiveness of sinks (grain growth and yield) and sources (spike photosynthesis and water soluble carbohydrates in the stems). Four treatments were imposed 7 days after anthesis in two contrasting locations with low- and high-inputs conditions in wheat (cv. Soissons) and barley (cv. Sunrise): they were a control, a treatment removing all the spikelets from the upper half of the spikes (TS), and shadings decreasing incident radiation by 75% on the whole canopy (SW) or only on the leaves (having the top area of the meshes individual holes for each spike to be exposed to solar radiation, SL). As expected grain yield was closely related to grain number per m2. Average grain weight was reduced by shading treatments far more markedly in Sw than in SL. Interestingly, significant amounts of water soluble carbohydrates in the stems remained at maturity in SL and Sw treatments and spike photosynthesis in SL was consistently higher than in the unshaded controls in both species. These results may be an indication that wheat and barley are not source-limited during grain filling and that only when subjected to an extremely severe stress, grain size would be reduced due to lack of enough assimilates available to fill them.

Influence of exogenously applied paclobutrazol on some physiological traits and growth of Stevia rebaudiana under in vitro drought stress

AbstractThis investigation was carried on to find out the changes occurred in Stevia rebaudiana in response to paclobutrazol (PBZ; 0–4 mg L−1) treatment and drought stress. Polyethylene glycol (PEG; 0–6 % w/v) was used to stimulate drought stress. Drought stress reduced fresh and dry weight, water content, chlorophylls, carotenoids, anthocyanins, water soluble carbohydrates, reducing sugar and proline amounts. Electrolyte leakage, MDA, α-tocopherol and glycine betaine contents increased in drought-stressed plants. The activity of P5CS and PDH enzymes and protein content showed no significant changes under drought stress. PBZ (with or without PEG) treatments decreased fresh and dry weight and water content. In PBZ-treated plants, less pigments was damaged by drought stress. PBZ treatment reduced the negative effect of drought stress on lipid peroxidation which resulted in lower electrolyte leakage and MDA content, compared to the same PEG level without PBZ. PBZ (with or without PEG) treatments increased glycine betaine, α-tocopherol, proline and protein contents. The amount of water soluble carbohydrates, reducing sugar and activity of P5CS and PDH were not affected by PBZ treatments. SDS-PAGE analysis revealed that drought stress increased a 25 kD protein with a critical function in plant development under stresses. According to the results, PEG provoked a severe drought stress in S. rebaudiana that could partly be restored by PBZ treatment.

Graminan breakdown by fructan exohydrolase induced in winter wheat inoculated with snow mold

Fructan structures vary widely among plant species. Graminan-type fructans, extensions of sucrose through β-(2,6)-linked fructosyl units with branches of β-(2,1)-linked fructosyl units, accumulate in tissues of winter wheat ( Triticum aestivum) during cold hardening and are metabolized under persistent snow cover. Snow molds such as Typhula ishikariensis and Microdochium nivale opportunistically infect wheat under snow cover. Snow mold-resistant wheat cultivars tend to heavily accumulate and slowly metabolize water-soluble carbohydrates including graminans in comparison with snow mold-susceptible cultivars. We observed time-dependent changes in the amounts of water-soluble carbohydrates in snow mold-inoculated wheat tissues, and accumulated fructan levels significantly decreased as a result of snow mold inoculation and incubation under snow cover, especially in a snow mold-susceptible wheat cultivar. Three candidates for fructan exohydrolase (FEH) cDNAs with high homology to cell wall invertases were isolated from wheat leaf tissues inoculated with snow mold and incubated under snow cover. The substrate specificity of enzymes encoded by the isolated clones was analyzed by recombinant proteins expressed in Pichia pastoris. The recombinant protein (Wfh-sm3m) encoded by one ( Wfh-sm3) of the isolated clones preferentially degraded 6-kestotriose and possessed minor hydrolase activity to 1-kestotriose and 1,1-kestotetraose. Moreover, Wfh-sm3m hydrolyzed almost all graminans that accumulated in hardened wheat tissues. Wfh-sm3 transcripts increased in wheat leaf tissues inoculated with snow mold and incubated under snow cover. These results suggest that Wfh-sm3 encodes a 6-FEH with minor 1-FEH activity and is associated with degradation of fructans in wheat leaf tissues during inoculation and incubation under snow cover.

Grain Filling Mechanisms in Two Wheat Cultivars, Haruyutaka and Daichinominori, grown in Western Japan and in Hokkaido

Wheat cultivar Haruyutaka, bred in Hokkaido, as a cultivar with improved genetic traits for production in western Japan, had a lower grain yield when grown in Yamaguchi in western Japan than Daichinominori, native to Yamaguchi. We examined the yield and grain growth of these two cultivars in the two areas in 2005/2006, 2006/2007 and 2007/2008 to elucidate theirgrain filling mechanisms under the two environments. When grown in Yamaguchi, Haruyutaka had a lower grain yield due to smaller grains than Daichinominori and when grown in Hokkaido, Daichinominori had a lower grain yield due to smaller grainsthan Haruyutaka. The slower grain growth, especially, at the later period of grain filling was considered to be the major cause of smaller grain in both cultivars, but it was more pronounced in Haruyutaka grown in Yamaguchi. Haruyutaka and Daichinominori ceased total dry mass production earlier when grown in the non-native area, Yamaguchi and Hokkaido, respectively, resulting in less supply of current assimilation products to grain growth. When grown in Yamaguchi, the amount of post-anthesis culm reserves, water soluble carbohydrate (WSC), was smaller in Haruyutaka than in Daichinominori, while they accumulated a similar amount of WSC in Hokkaido. The pattern of remobilization of WSC to grains was similar in both areas. However, the grain filling period was significantly shorter in the non-native area. These results suggested that in the non-native environment, the grain size is decreased due to slower grain growth, mainly due to less current assimilation, and shorter grain filling period.

Carbohydrate dynamics during reproductive growth and seed yield limits in perennial ryegrass

Forage grass seed yields are often low and variable with only 10–20% of the above ground matter harvested as seed. Seed yield is affected by the amount of carbohydrate transported to the seed. However, information regarding the storage and mobilisation of carbohydrates during reproductive development in forage grasses is limited and the contribution of stored and current assimilate to seed yield from vegetative tissues is equivocal. To identify whether the total amount of carbohydrate in the plant might be limiting seed yield, and the contribution of vegetative and reproductive tissues to seed yield, the pattern of accumulation of water-soluble carbohydrates (WSC) and their remobilisation was investigated in field-grown perennial ryegrass ( Lolium perenne L.) plants. Tillers were sampled from early head emergence through to harvest. Amounts of WSC in leaf blades, leaf sheaths, internodes and reproductive heads of the tillers were measured in two ways. Firstly, WSC were estimated indirectly by changes in tissue dry weight. These changes were then used to determine any apparent translocation of WSC from vegetative tissues to the developing seed. Secondly, WSC concentration was measured directly. Low molecular weight (LMW) and high molecular-weight (HMW) WSC were extracted from vegetative and reproductive tissues and the concentrations quantified using a colorimetric anthrone assay. The seed yield of the crop was high (2950 kg h −1) and the dry weights and the amount of LMW and HMW WSC in vegetative and reproductive tissues changed significantly during reproductive development. High concentrations of HMW WSC were found in the internodes post head emergence and these concentrations continued to increase during seed fill through to harvest. Total dry weight of the internodes also increased over the same period. In contrast, in the leaf blades and leaf sheaths, total dry weight decreased only slightly while the initial low concentrations of WSC steadily declined. In the heads, WSC increased significantly during seed fill and subsequently declined while the dry weight continued to increase through to harvest. The ratio of LMW and HMW WSC also changed during development depending on the tissue type and growth stage. The present study indicates that the seed head itself maybe an important factor driving seed fill. Knowledge of the mechanisms that underlie carbohydrate partitioning to the seed could in future result in significantly higher yields.

Changes in physical, mechanical and chemical properties of wood during sterilisation by gamma radiation

Abstract Gamma irradiation, which is an easy, fast and effective method for wood sterilisation, changes molecular structures not only in pest cells, but also in wood cell walls. Radiation-induced depolymerisation causes significant changes in some properties of wood crucial for restoration and for laboratory testing of wood-preservative effectiveness, as demonstrated by experimental data. The influence of gamma radiation on maximum swelling (αMAX), resistance to impact milling (RIM), and the total amount of water-soluble carbohydrates (TSC) was investigated. Cobalt (60Co) was used as a gamma source and Scots pine wood (Pinus sylvestris L.) was irradiated at doses of 30, 90 and 150 kGy. A strong linear correlation was found between TSC and radiation dosage. Leached irradiated specimens showed significantly greater TSC content than non-irradiated controls. RIM decreased significantly and linearly with increasing radiation dosage. After leaching, the linearity between these parameters improved. Gamma radiation had no significant effect on αMAX and the time elapsed after irradiation did not influence αMAX, RIM or TSC.

Contribution of storage and structural polysaccharides to the fermentation process and nutritive value of lucerne ensiled alone or mixed with cereal grains

The low content of water soluble carbohydrates (WSC) and the high buffering capacity usually constrains lucerne ( Medicago sativa) ensilability. However, there are other sources of readily fermentable substrate and positive effects of adding cereal grains to wet silages have been reported. An experiment was carried out to study the contribution of hemicellulose, cellulose and natural or added starch to the silage fermentation process, and in vitro digestibility and gas production. A crop of lucerne (10% blooming) was chopped, inoculated with lactic acid bacteria, and ensiled in microsilos with four treatments: alone (T0), or with 50 kg/t of sucrose (SU), barley (BRL), or maize (MZ). Microsilos were incubated for 47 days. Polysaccharide recovery was determined by the mass balance technique, and starch by dacron bag. Except for SU, all treatments were apparently limited by the amount of WSC needed to sustain good silage fermentation. As expected, SU produced an excellent fermentation but despite initial WSC differences, there were no significant differences with BRL for total fatty acids, lactic and acetic acid, total acidity, pH and NH 3-N. Fermentation characteristics of MZ were generally worse than BRL’s and similar to T0’s ones. Hemicellulose was extensively hydrolysed (T0: 59.5%; MZ: 38.1%; BRL: 48.8%; and SU: 46.8%). Cellulose was almost quantitatively recovered and starch recovery averaged 70% for T0 and BRL, and approximately 100% for MZ and SU. The type of cereal added affected starch recovery using the dacron bag technique (MZ: 77%; BRL: 47%; P<0.05). True dry matter digestibility was the same for all treatments (fresh lucerne: 81.3%; T0: 80.7%; MZ: 81.8%; BRL: 80.5%; and SU: 82.1%), and neutral detergent fibre digestibility (NDF-D) of silages was reduced in relation to the fresh material (fresh lucerne: 55.1%; T0: 48.8%; MZ: 51.9%; BRL: 45.3%; and SU: 46.7%). Although all silages showed a rapid in vitro fermentation pattern, gas production (48 h) of SU and BRL (265.4 and 260.5 ml/g DM) was greater than T0 and MZ (246.0 and 244.6 ml/g DM) ( P<0.05). It can be concluded that starch hydrolysis depends on the type of grain, and that starch from barley and legume cell wall components could supply additional fermentable substrate to the ensiling process. These data also showed that ensiling reduced NDF-D and suggest that labile NDF fractions removed during the ensiling process were later accessible during the in vitro fermentation.

Comparison of Assimilation Rates in Leaves at Various Nodes in Canopies of Three Spring Wheat Cultivars with Different Plant Forms

This study was conducted to reveal the ideotype of wheat (Triticum aestivum L.) canopy structure for high yield and biornass productivity. The assimilation rate and nitrogen contents of the flag, second, third and lower leaves and the ear of the main stem were measured in three spring cultivars with different plant forms (figures), Haruyutaka, Norin 61 and Selpek, under field conditions. The assimilation rate was evaluated based on the amount of water-soluble carbohydrate accumulated during the day (WSC/day). Surface area indexes of the ear and flag leaf in Haruyutaka and Selpek were larger than those in Norin 61. In Haruyutaka and Selpek, the amount of WSC/day was larger in the flag leaf than in the second or third leaf, which had a sufficiently high nitrogen content. On the contrary, in Norin 61, the amount of WSC/day in the flag leaf was similar to that in the second and third leaves during the grain-filling period. The amount of WSC/day in the flag leaf during the last half of the grain-filling period was much higher in Selpek than in Haruyutaka and Norin 61. This may be one of the reasons why Selpek had a heavier total dry weight than Haruyutaka and Norin 61 in 1993 and 1995.

The Effect of New Tiller Growth on Carbohydrates, Nitrogen and Seed Yield per Ear in Lolium perenneL.

To clarify whether new vegetative tillers that develop around anthesis in a Lolium perenneseed crop can depress seed yields, the possible competition for carbohydrates or nitrogen between the seeds and new tillers that develop after the onset of anthesis was investigated. In two greenhouse experiments the number of tillers per plant was varied by a combination of cutting, nitrogen supply, light quality and light intensity treatments. Two genotypes with different tillering rates were used. Seed yield per ear was largely independent of the number of tillers and regrowth of cut tillers after the onset of anthesis. It increased in one genotype, but only under low light and a reduced nutrient availability, and no new tillers were produced. The amount of water-soluble carbohydrates in the reproductive tillers increased in both clones under these conditions. Under more favourable conditions the increased tillering rate and regrowth of tillers after cutting did not adversely affect seed yield per ear in either clone, although carbohydrate reserves in the flowering tillers were sharply reduced. Tiller removal increased the concentration and amount of nitrogen in the remaining flowering tillers, irrespective of the amount of regrowth. It is concluded that competition for carbohydrates or nitrogen between the seeds and new vegetative tillers that develop after the onset of anthesis, is not a major cause of the low and variable seed yields in L. perenneseed crops. Processes within the ear itself are probably limiting.