Non structural carbohydrates

SUMMARY–A significant proportion of mariculture is undertaken in Europe under intensive farming conditions in open cage culture. Wastes are dispersed from cage farms in terms of particulate organic carbon and nutrients, dissolved organic carbon and inorganic nutrients. These enrich the surrounding ecosystem and may lead to a stimulation of both primary and secondary production. This pan-European research project will demonstrate the effectiveness of reducing the environmental impacts of inputs from intensive cage ...

The effect of additional dietary fibre on the consistency of faeces was studied in a group of four Francois langurs (Trachypithecus francoisi) kept in Rotterdam Zoo. To increase fibre intake, a diet pellet rich in fibre was offered instead of the usual, commercial primate pellet. This dietary change raised the amounts of hemicellulose and cellulose that were consumed at the expense of non-structural carbohydrates. The experiment had an Al-B-A2 design. Stool quality improved when the high-fibre pellet was fed. The monkeys produced somewhat more faecal dry matter and the faeces contained markedly more nonstructural carbohydrates and less crude fibre when the high-fibre pellet was fed. The percentage of water in the faeces was slightly lower when the high-fibre diet was offered. We speculate that the extra fibre was partly fermented and that the breakdown products were recovered in the carbohydrate fraction of faeces. These breakdown products might have a superior water-binding capacity, leading to well-shaped faeces. This study showed that Francois langurs have the capacity to digest dietary fibre, as has been demonstrated earlier for other species of leaf-eating monkeys.

The presence of significant variation among rice (Oryza sativa L.) genotypes in total nonstructural carbohydrates (TNC) that is related to grain yield should be of interest to rice breeders. The effects of four important yield‐determining traits (maximum number of tillers, grain weight, panicle node number, and panicle size) on the TNC concentrations of plant structures at heading and harvest were determined. Path analysis was used to determine the path coefficients of the effect of changes in TNC content (Δ TNC) in leaves or stems on Δ panicle TNC at various stages of crop maturation. Fifteen rice genotypes were used in this study (‘Lemont’, ‘Teqing’, and 13 inbred lines obtained from a Lemont × Teqing cross) to represent the combinations of low and high levels of the four important yield determinants. Field experiments were conducted during the 1994 and 1995 cropping seasons at the Texas A&M University Agricultural Research and Extension Center, Beaumont, TX. Path coefficients for...

Regeneration capacity of submerged rice (Oryza sativa) seedlings in terms of CO 2 photosynthetic rate, chlorophyll a fluorescence and chlorophyll and carbohydrate content were investigated in three Indica rice cultivars namely FR 13A, Kalaputia and IR 42 that differed in submergence tolerance. Twenty-one day old plants were completely submerged under water for 8 days. Subsequently, plants were kept under normal conditions with 5-10 cm of stagnant water above soil surface for a further period of 15 days. After complete submergence, all genotypes showed inhibition of CO 2 photosynthetic rate. Submergence treatment resulted in a significant reduction of Rubisco activity. Maximal photochemical efficiency (F v /F m ) of PS II and area above the fluorescence curve between F o and F m decreased more under submergence especially in susceptible cultivar IR 42. When re-aerated, the plants recovered to various degrees. The carbohydrate content of plants was found to be significantly and positively associated with submergence tolerance and regeneration growth. The tolerant cultivar (FR 13A) could survive submergence apparently because it possessed 1.9-2.0 and 3.2-3.7-fold more non-structural carbohydrate content before and after submergence compared to the susceptible cultivar (IR 42) and it had a better capability to restore its photosynthetic capacity during post-submergence periods.

With the purpose to know the expected yield of Grindelia pulchella, a potential new resin-producing crop, four plant densities: 29 000, 41 000, 71 000 and 143 000 plants ha -1 were compared in experimental plots during two years. Experiments were established in Buenos Aires, Argentina, under rainfed conditions, during which three successive harvests were performed. Optimum density was near 105 000 plants ha -1 with a biomass yield close to 11 t/ha/2 years, so a crude resin yield of 1089 kg/ha/2 years may be expected.

Knowledge about allocation of carbohydrates among tree organs with different life times and decomposition rates is crucial in determining the residence time of carbon (C) in forests and the overall ecosystem C cycling rate. A new model (named CAF) able to simulate C allocation among fine roots, above-, and belowground wood in deciduous forests was developed and integrated into the net ecosystem exchange model FORUG. CAF draws on growth rules and source-sink relationships. Maintenance and growth of the modelled sinks i.e. fine roots, coarse roots, stems, and branches, are controlled by phenology, environment, and by the reserve of non-structural carbohydrates. CAF was parameterized for 2-y and tested against 6-y observations from a beech (Fagus sylvatica L.) stand in North-East France, experiencing summer droughts of different intensities. The model reproduced well (i) the C fluxes allocated annually to assimilation, respiration and biomass production, and (ii) the interannual pattern of wood biomass accumulation. Seasonality of C reserve and wood growth was captured, but some discrepancies were detected at the onset of the growing season. The allocation pattern differed among years, although the overall net primary production decreased only in case of severe drought. During a year with severe drought, the fraction of C allocated to production of fast-decomposing C pools (e.g. fine roots, C reserve) increased by +13% than years without drought, whereas the same fraction increased on average by +18% in case of low to moderate drought. Carbon invested in biomass during a year with summer drought has therefore a shorter residence time in the ecosystem than the C stored during a year without summer drought.

Dissolved organic carbon (DOC) is an important component in the terrestrial carbon cycle. Yet, the relative importance of different inputs of DOC to the soil solution remains uncertain. Here, we used a large-scale forest girdling experiment to examine how the supply of recent photosynthate to tree roots and their mycorrhizal fungi affects DOC, in particular low-molecular weight organic acids (LMWOA). We also studied effects of tree girdling on non-structural carbohydrates in microorganism, and examined the effects of freezing of soil and the presence of roots in the soil samples on soil solution DOC and LMWOA in this experiment. The concentration of DOC was reduced by 40%, while citrate was reduced by up to 90% in the soil solution by the girdling treatment. Other LMWOA such as oxalate, succinate, formate and propionate were unaffected by the girdling. We also found that girdling reduced the concentrations of trehalose (by 50%), a typical fungal sugar, and of monosaccharides (by 40%) in microorganisms in root-free soil. The effect of freezing on DOC concentrations was marked in samples from control plots, but insignificant in samples from girdled plots. Release of DOC from cell lysis after freezing was attributed equally to roots and to microorganisms. Our observations suggest a direct link from tree photosynthesis through roots and their mycorrhizal fungi to soil solution chemistry. This direct link should impact solute transport and speciation, mineral weathering and C dynamics in the soil compartment. Importantly, our finding of a substantial photosynthate driven production of DOC challenges the paradigm that DOC is mainly the result of decomposition of organic matter.

Desiccation-tolerant (DT) organisms can lose nearly all their water without dying. Desiccation tolerance allows organisms to survive in a nearly completely dehydrated, dormant state. At the cellular level, sugars and proteins stabilize cellular components and protect them from oxidative damage. However, there are few studies of the dynamics and drivers of whole-plant recovery in vascular DT plants. In vascular DT plants, whole-plant desiccation recovery (resurrection) depends not only on cellular rehydration, but also on the recovery of organs with unequal access to water. In this study, in situ natural and artificial irrigation experiments revealed the dynamics of desiccation recovery in two DT fern species. Organ-specific irrigation experiments revealed that the entire plant resurrected when water was supplied to roots, but leaf hydration alone (foliar water uptake) was insufficient to rehydrate the stele and roots. In both species, pressure applied to petioles of excised desiccat...

Objetivou-se a partir desse trabalho apresentar uma revisão da literatura sobre, o processamento de silagem de grão úmido de milho na alimentação animal. Visto que o grão do milho é a principal fonte de energia para ruminantes e monogástricos. O planejamento é o primeiro passo para alcançar a produção de qualidade da silagem. Os mesmo cuidados da ensilagem da planta inteira são imprescindíveis para o processamento da ensilagem apenas de grãos. Na técnica da ensilagem, são adotadas estratégias como o dimensionamento do silo adequado, rapidez no momento da colheita; transporte e moagem; compactação necessária para acomodar com eficiência as partículas do material; agilidade na vedação do silo e seu uso durante o fornecimento aos animais. Cada vez mais pesquisas vêm confirmando utilização da silagem de grão úmido de milho como um importante componente energético da dieta para a maioria das espécies de interesse zootécnico. Considerando que elaboração e processamentos da silagem de grão úmido de milho é uma tecnologia que pode contribuir de forma significativa a fim de melhorar os índices de produtividade dos animais. Entretanto seu uso ainda e considerado incipiente no pais, com necessidade de novos estudos em sua utilização em relação as dificuldades de processamento e fornecimento aos animais.

Avaliou-se o efeito da adição ou não de fontes de carboidratos (milho dentado ou milho duro ou polpa de citros) a forragens (silagem de milho, silagem de sorgo + silagem de resíduo de milho, capim-elefante, cana-deaçúcar, silagem de resíduo de milho sem adição das fontes de carboidratos), pela técnica in vitro semiautomática de produção de gases em função da produção de ácidos graxos voláteis (AGVs) nos tempos de incubação de 2, 6, 12 e 24 horas. Utilizou-se o delineamento inteiramente casualizado em parcelas subdivididas com o fator tempo nas subparcelas. As médias da produção de gases foram tratadas pelos parâmetros de France. O acetato foi o AGV de maior produção. Observou-se correlação alta e positiva entre todos os AGVs no presente estudo. PALAVRAS-CHAVES: Acetato, polpa de citros, subproduto.

The Bossoleto CO2 spring emits CO2 which has a stable carbon isotopic ratio (~5~3C = -8%o). We determined ~3C on leaves of several individual species growing in Bossoleto and in a nearby control site at ambient CO,.. ~5t3C was 6% more negative in leaves of species collected from the grassland community of Bossoleto, indicating increased discrimination (A) against the heavy carbon isotope. No such changes were found in ruderal species growing in the same spring, suggesting that photosynthetic capacity was much less affected. A was substantially increased under elevated CO2 in leaves of Quercus pubescens but not in Quercus ilex, which also did not show any increase in non-structural carbohydrates. Gas-exchange measurements made on Plantago lanceolata, supported the view that photosynthetic capacity is decreased in plants grown under elevated CO: and on poor soils.

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

The lichens Parmelia olivacea and Parmeliopsis ambigua are common epiphytes in subarctic forests in Europe. They differ in abundance and vertical distribution particularly on birch trees, and these differences relate to the level and duration of the winter snow cover. Parmeliopsis ambigua is covered much of the cold season on the lower trunk whereas P. olivacea occurs well above the snow surface. Periods over 6 months under snow have no apparent effect on P. ambigua thalli while much shorter snow cover has been demonstrated to kill P. olivacea. It was hypothesized that the contrasting distributions are due to differences in growth rates and in size and quality of non-structural carbon stores in their tissues affecting their endurance to extended periods of dark respiration. To test these hypotheses, growth measurements were performed on both species and their thalli were sampled for chemical analyses. The results show that the mean annual margin extension growth of P. olivacea thalli was significantly higher than that of P. ambigua, i.e. 1.1 mm and 0.5 mm, respectively. The average nonstructural carbohydrate concentration in the two species did not differ, but the annual concentration of storage lipids (triacylglycerol) in P. ambigua was four times higher than that in P. olivacea, despite a shorter growing season and lower rate of photosynthesis. The proportion of polyunsaturated fatty acids in structural (polar) lipids was high in both species, i.e. 77% in P. olivacea and 64% in P. ambigua, which appears to enable both species to withstand low ambient thallus temperatures. The higher concentration of storage lipids in P. ambigua allows survival in environments where P. olivacea would respire to death, e.g. under a prolonged snow cover. Parmeliopsis ambigua avoids competition by establishing toward the base of the tree trunk, where P. olivacea would not survive.

To determine the contribution of polar auxin transport (PAT) to auxin accumulation and to adventitious root (AR) formation in the stem base of Petunia hybrida shoot tip cuttings, the level of indole-3-acetic acid (IAA) was monitored in non-treated cuttings and cuttings treated with the auxin transport blocker naphthylphthalamic acid (NPA) and was complemented with precise anatomical studies. The temporal course of carbohydrates, amino acids and activities of controlling enzymes was also investigated. Analysis of initial spatial IAA distribution in the cuttings revealed that approximately 40 and 10 % of the total IAA pool was present in the leaves and the stem base as rooting zone, respectively. A negative correlation existed between leaf size and IAA concentration. After excision of cuttings, IAA showed an early increase in the stem base with two peaks at 2 and 24 h post excision and, thereafter, a decline to low levels. This was mirrored by the expression pattern of the auxin-responsive GH3 gene. NPA treatment completely suppressed the 24-h peak of IAA and severely inhibited root formation. It also reduced activities of cell wall and vacuolar invertases in the early phase of AR formation and inhibited the rise of activities of glucose-6-phosphate dehydrogenase and phosphofructokinase during later stages. We propose a model in which spontaneous AR formation in Petunia cuttings is dependent on PAT and on the resulting 24-h peak of IAA in the rooting zone, where it induces early cellular events and also stimulates sink establishment. Subsequent root development stimulates glycolysis and the pentose phosphate pathway.

The world reserves of petroleum will finish in about 100 years. For a tropical country like Brazil, biomass will be the natural substitute for petroleum. For the best utilization of biomass, it first needs to be separated into its principal components: cellulose, hemicelluloses, lignins, vegetable and essential oils, non-structural carbohydrates, bark and foliage. All feedstocks for the chemical industry can be obtained from these biomass components, as shown in the first part of this paper. In the second part we discuss how the major products from petrochemicals can be obtained from the different biomass components. We show that Brazil can use different strategies, compared to other countries, to obtain petrochemical products, which could result in innovations. However, it is necessary that the government starts to invest immediately in order to keep the petrochemical industries competitive with foreign industries, so that they continue to be one of Brazil's major employers.

In Jalisco, several liquors are extracted from plants of the genus Agave L. Tequila is the most important of these, because of its large national and international market. It is a major Mexican export product. In order to produce the various tequilas, the juices of Agave tequilana Weber are fermented, distilled, and prepared in various forms. The principal plantations are located between 20 °30' and 21°n orth latitude and 102 °30' and 104° west longitude and cover 16,000 hectares of dry-farmed lands with a warm temperate, semi-arid climatic regime. Over 50% of the factories are located in the Tequila region of Jalisco; these account for 80% of the world production.

 Numerous analytical methods are used to measure seagrass non-structural carbohydrates (NSC) content, however, these are non-comparable  Carbohydrates estimates by high performance liquid chromatograph (HPLC) assays are more precise than colorimetric assays (phenol-sulfuric acid)  Solvents used for soluble sugar extraction and starch gelatinization result in significantly different NSC estimations  We present an optimized 5-step protocol for the quantitation of seagrass soluble NSC and starch using HPLC that identifies individual mono-and oligosaccharides

Two-year-old olive trees (Olea europaea L., cv. Coratina) were subjected to a 15-day period of water deficit, followed by 12 days of rewatering. Water deficit caused decreases in predawn leaf water potential (W w ), relative water content and osmotic potential at full turgor (W p100 ) of leaves and roots, which were normally restored upon the subsequent rewatering. Extracts of leaves and roots of well-watered olive plants revealed that the most predominant sugars are mannitol and glucose, which account for more than 80% of non-structural carbohydrates and polyols. A marked increase in mannitol content occurred in tissues of water-stressed plants. During water deficit, the levels of glucose, sucrose and stachyose decreased in thin roots (with a diameter \1 mm), whereas medium roots (diameter of 1-5 mm) exhibited no differences. Inorganic cations largely contribute to W p100 and remained stable during the period of water deficit, except for the level of Ca 2? , which increased of 25% in waterstressed plants. The amount of malate increased in both leaves and roots during the dry period, whereas citrate and oxalate decreased. Thin roots seem to be more sensitive to water deficit and its consequent effects, while medium roots present more reactivity and a higher osmotic adjustment. The results support the hypothesis that the observed decreases in W w and active osmotic adjustment in leaves and roots of water-stressed olive plants may be physiological responses to tolerate water deficit.

Grain yield of rice consists of sink capacity and grain filling. There are some genes known
to contribute to sink capacity, but few genes associated with grain filling are known. We conducted a
genetic analysis on yield-related traits by using a chromosome segment substitution line population
that have introgression from DV85, an aus variety of rice, in the background of T65, a japonica variety.
Refined whole-genome genotypes of the 43 TD-CSSLs were obtained by genotyping-by-sequencing.
The effects of previously detected quantitative trait loci (QTLs), qNSC1 and qNSC2, were confirmed
by the amount of non-structural carbohydrate (NSC) at 5 days after heading (DAH). The CSSL for
qSWTR11, the QTL for decrease in shoot weight during the maturity stage, showed the highest NSC
at 5 DAH and lowest at 35 DAH. The brown rice yield of these lines were not stably significant. Most
of the sink-related traits correlated between the 2 tested years, but most of the grain-filling traits
did not show correlation between the 2 years. Correlation analysis revealed that the sink capacity is
stable and primarily determines the yield, and grain filling is more affected by the environment. In
addition, biomass production before heading and during the maturity stage contributes to higher
yield in TD-CSSLs, and the amount of translocation of stem reserve does not affect much to the yield.
We conclude that higher NSC at the heading stage and rapid decrease in shoot biomass during the
maturity stage did not directly contribute to the yield formation in the japonica genetic background.

The decrease in temperature with increasing elevation may determine the altitudinal tree distribution in different ways: affecting survival through freezing temperatures, by a negative carbon balance produced by lower photosynthetic rates, or by limiting growth activity. Here we assessed the relative importance of these direct and indirect effects of altitudinal decrease in temperature in determining the treeline in central Chile (33°S) dominated by Kageneckia angustifolia. We selected two altitudes (2000 and 2200 m a.s.l.) along the treeline ecotone. At each elevation, leaf non-structural carbohydrates (NSC) and gas exchange parameters were measured on five individuals during the growing season. We also determined the cold resistance of K. angustifolia, by measuring temperatures that cause 50% seedling mortality (LT 50) and ice nucleation (IN). No differences in net photosynthesis were found between altitudes. Although no differences were detected on NSC concentration on a dry matter basis between 2000 and 2200 m, when NSC concentration was expressed on a leaf area basis, higher contents were found at the higher elevation. Thus, carbon sink limitations may occur at the K. angustifolia's upper altitudinal limit. For seedlings derived from seeds collected at the 2200 m, LT 50 of cold-acclimated and non-acclimated plants were)9.5 and)7°C, respectively. However, temperatures as low as)10°C can frequently occur at this altitude during the end of winter. Therefore, low temperature injury of seedlings seems also be involved in the treeline formation in this species. Hence, a confluence of global (carbon sink limitation) and regional (freezing tolerance) mechanisms explains the treeline formation in the Mediterranean-type climate zone of central Chile.

Foram avaliados os consumos e as digestibilidades aparentes dos nutrientes de silagens de sorgo dos híbridos AG2006, AGX215, AGX213, AGX202 e AG2002. Utilizaram-se 20 carneiros adultos, sem raça definida, castrados, com peso médio de 50,7 kg, distribuídos EM um delineamento em blocos casualizados, com quatro animais por tratamento. Não houve diferença significativa entre as silagens para o consumo dos diversos nutrientes. Os consumos de matéria seca e nutrientes digestíveis totais expressos em g/dia revelaram valores variando de 936,2 (AGX202) a 1156,4 (AG2006) e de 460,9 (AGX215) a 613,4 (AGX213), respectivamente. Os coeficientes de digestibilidade diferiram entre as silagens, registrando-se maiores coeficientes de digestibilidade aparente da matéria seca e da matéria orgânica para a silagem do híbrido AGX213, em relação às silagens dos híbridos AGX215, AG2006 e AG2002. Com base nos consumos e digestibilidades dos nutrientes, excetuando proteína bruta, os híbridos AGX 213e AGX202 m...

Kenaf (Hibiscus cannabinus L.) is a fibre crop that can be used as a biomass crop. Results of trials conducted in the 90's years by University of Bologna in several places of the Po Valley have shown useful indications about the effects of environmental and agronomic factors on yield and duration of the crop cycle. The year effect seemed to be very important on the life cycle duration, from 85 to 160 days between the sowing and the harvest time. The fresh stem yield ranged from 20 to 80 t ha-1 , seemingly related to the amount of rainfall. The optimal harvest time seemed to be in the end of September for most of genotypes, whereas long cycle varieties harvested twenty days later have increased production. Trials testing several genotypes without water supply have shown that long cycle cultivars were more productive with a field variation from 11.5 to 16.5 t ha-1 of dry matter. In Northern Italy climatic conditions only rescue irrigation seemed to be necessary during dry years. The restoration of 50% of ETM increased the dry biomass yield of 15-25%, but irrigation did not seemed to be economically convenient. The density trials have shown that the limit of 100-120 plants m-2 as the optimal for biomass production.

Parallel with the successful genetic selection for higher milk production in Holstein-Friesian cows, a dramatic decline in fertility rates has been observed around the world. Therefore, to achieve an optimum herd reproductive performance, we must focus on the first 100 days postpartum. During and after calving, a cow overcomes a series of physiological hurdles before becoming pregnant. By selecting accurate diagnostic devices and/or methods, such as predicting the onset of calving, monitoring activity and rumination time to determine cows for early treatment of clinical metritis and/or metabolic diseases, long-term measurement of reticuloruminal pH to monitor subclinical acidosis, perform metabolic profile tests to diagnose subclinical metabolic diseases at the herd level, estrous detectors and/or detection aids, on-farm/in-line P4 test to monitor specific events in the postpartum periods, diagnosis of early pregnancy and pregnancy loss using ultrasonography to correctly identify pr...

Due to the successful genetic selection for higher milk production in Holstein dairy cows, a dramatic decline in fertility rates has been observed around in the world in recent decades. Therefore, herd management should focus the first 100 days postpartum to achieve optimum herd reproductive performance (calving interval less than 400 days). After calving, a cow has to overcome a series of physiological hurdles before becoming pregnant. The selection of timely diagnostic devices and methods, such as the calving alarm vaginal thermometer to predict the onset of calving, electronic hand-held BHBA measuring system to detect subclinical ketosis on the farm, long-term measurement of reticuloruminal pH by an indwelling and wireless data transmitting unit to monitor subclinical acidosis, monitoring rumination time to select cows for early treatment of subclinical metabolic diseases (subclinical ketosis, acidosis and/or hypocalcaemia) and/or clinical metritis, performing metabolic profile t...

Future increases in oceanic carbon dioxide concentrations (CO 2(aq) ) may provide a benefit to submerged plants by alleviating photosynthetic carbon limitation. However, other environmental factors (for example, nutrient availability) may alter how seagrasses respond to CO 2(aq) by regulating the supply of additional resources required to support growth. Thus, questions remain in regard to how other factors influence CO 2(aq) effects on submerged vegetation. This study factorially manipulated CO 2(aq) and nutrient availability, in situ, within a subtropical seagrass bed for 350 days, and examined treatment effects on leaf productivity, shoot density, above-and belowground biomass, nutrient content, carbohydrate storage, and sediment organic carbon (C org ). Clear, open-top chambers were used to replicate CO 2(aq) forecasts for the year 2100, whereas nutrient availability was manipulated via sediment amend-ments of nitrogen (N) and phosphorus (P) fertilizer. We provide modest evidence of a CO 2 effect, which increased seagrass aboveground biomass. CO 2(aq) enrichment had no effect on nutrient content, carbohydrate storage, or sediment C org content. Nutrient addition increased leaf productivity and leaf N content, however did not alter above-or belowground biomass, shoot density, carbohydrate storage, or C org content. Treatment interactions were not significant, and thus NP availability did not influence seagrass responses to elevated CO 2(aq) . This study demonstrates that long-term carbon enrichment may alter the structure of shallow seagrass meadows, even in relatively nutrient-poor, oligotrophic systems.

Two field experiments were conducted in two successive spring-summer seasons at the Newe Ya'ar Research Center (northern Israel) to examine source-sink relationships in 'Noy Amid', a Casaba-type melon. The source and sink were artificially manipulated by removing leaves and fruit shortly after fruit-set. Highest fruit yield and fruit quality were obtained in control plants and any reduction in source size (by leaf removal) resulted in yield decline. In 'Noy Amid' melon, plants with 4-8 leaves could not support more than one fruit and all other young fruits aborted. The weight of mature fruits was reduced with decreasing source size (leaf number). The sink size (number of young fruits) at the beginning of treatment application had a significant effect on assimilate production and translocation to the fruits. Plants with 2 young fruits as compared to a single fruit, and with 4 young fruits as compared to 2 fruits produced larger mature fruits with the same number of leaves. These data strongly support the idea that sink size affects the photosynthetic activity of the leaves, which is increasing by increased demand of the sink organs. Decreased source size had a negative effect not only on fruit yield but also on fruit quality characters. Fruit shape, flesh perfection and total soluble solid content were all adversely affected by artificially reducing leaf number.

Nitrate deposition from anthropogenic activities into nutrient impoverished soils of Mediterranean ecosystems represents a significant income to their N economy, which may potentially increase the sensitivity of those typically UV-B (280 Á/315 nm) resilient plants from these ecosystems with superior photosynthetic rates especially to increases in solar UV-B flux due to ozone depletion. This proposal was examined by exposing nodulated Podalyria calyptrata seedlings for 6-months in nitrate deficient and nitrate replete sand culture to biologically effective UV-B (UV-B BE) supplements approximating 40 and 77% above clear-sky background (control) at an outdoor site. Leaf photosynthesis and chemical composition of purely symbiotic plants were unaffected by increased UV-B BE. Conversely, nodulated plants that received nitrate supplements displayed a linear reduction in stomatal conductance (g S) but non-linear asymptotic reductions in light-saturated net CO 2 assimilation rate (A sat), apparent carboxylation efficiency (ACE) and nitrogen use efficiency (NUE) with increased UV-B BE. RuBP regeneration limitations on CO 2 assimilation were not apparent, since A sat at saturating internal leaf CO 2 concentrations displayed insignificant depressions with increased UV-B BE. Nor was there any suggestion of diminished light absorption capacity of antenna complexes, or of photosynthetic inhibition due to starch accumulation, since leaf chlorophyll and carotenoid contents and non-structural carbohydrate concentrations were insignificantly altered by increased UV-B BE. Also, there seemed unlikely photosynthetic inhibition due to reduced allocation of N to Rubisco with increased UV-B BE in the nitrate-fed plants, since both ACE and A sat were negatively correlated with leaf N content, much of which probably constituted assimilated nitrate according to the less negative d 15 N values. We suggest that the molecular processes that rendered P. calyptrata plants receiving nitrate supplements more sensitive to photosynthetic inhibition by increased UV-B BE may be related indirectly to their more active metabolic state, this apparent from their elevated respiratory and photosynthetic rates, rather than to any direct UV-B effects on CO 2 uptake and fixation.

The lichens Parmelia olivacea and Parmeliopsis ambigua are common epiphytes in subarctic forests in Europe. They differ in abundance and vertical distribution particularly on birch trees, and these differences relate to the level and duration of the winter snow cover. Parmeliopsis ambigua is covered much of the cold season on the lower trunk whereas P. olivacea occurs well above the snow surface. Periods over 6 months under snow have no apparent effect on P. ambigua thalli while much shorter snow cover has been demonstrated to kill P. olivacea. It was hypothesized that the contrasting distributions are due to differences in growth rates and in size and quality of non-structural carbon stores in their tissues affecting their endurance to extended periods of dark respiration. To test these hypotheses, growth measurements were performed on both species and their thalli were sampled for chemical analyses. The results show that the mean annual margin extension growth of P. olivacea thalli was significantly higher than that of P. ambigua, i.e. 1.1 mm and 0.5 mm, respectively. The average nonstructural carbohydrate concentration in the two species did not differ, but the annual concentration of storage lipids (triacylglycerol) in P. ambigua was four times higher than that in P. olivacea, despite a shorter growing season and lower rate of photosynthesis. The proportion of polyunsaturated fatty acids in structural (polar) lipids was high in both species, i.e. 77% in P. olivacea and 64% in P. ambigua, which appears to enable both species to withstand low ambient thallus temperatures. The higher concentration of storage lipids in P. ambigua allows survival in environments where P. olivacea would respire to death, e.g. under a prolonged snow cover. Parmeliopsis ambigua avoids competition by establishing toward the base of the tree trunk, where P. olivacea would not survive.

Various genes which control or affect heading time have been found in rice. Out of them, <em>Se1</em> and <em>E1 </em>loci play important roles in determining heading time by controlling photosensitivity. An isogenic-line pair of late and early lines were developed from progenies of the F<sub>1 </sub>from Suweon 258 × 36U. A lateness gene tentatively designated as "<em>Ex</em>" was found to control the difference in heading time between the early and late lines mentioned above. The present study was conducted to examine the effect of <em>Ex</em> on yield and related traits. <em>Indica</em>-type variety Suweon 258 was crossed with 36U, which is an <em>Ur1</em> (Undulate rachis-1) isogenic line of IR36. In the F<sub>2</sub> population, comparatively early-heading, late-heading and intermediate-heading plants were segregated. Segregation similar to that by the three types of headin...

Objetivou-se avaliar o efeito do uso de aditivo microbiano e de uréia na composição química, digestibilidade in vitro, no desaparecimento ruminal, e na estabilidade aeróbia de silagens de grãos úmidos de milho com adição de soja crua. Um segundo ensaio foi conduzido com o objetivo de avaliar a substituição do concentrado comercial por silagem de grãos de milho com adição de 20% de soja crua na produção e composição do leite de vacas holandesas. Para a avaliação das silagens foram feitos mini silos de pvc arranjados em delineamento inteiramente casualizado com três tratamentos (silagem de grãos úmidos de milho + 20% de soja crua; silagem de grãos úmidos de milho + 20% de soja crua + inoculante microbiano e silagem de grãos úmidos de milho + 20% de soja crua + 1,4% de ureia) e quatro repetições. As silagens apresentaram-se estáveis no período de 96 horas, com perdas de matéria seca de 3,55, 3,32 e 4,39 para silagens sem aditivos, com a adição de inoculante microbiano e com uréia respe...

The underground systems of plants show the most varied structures adapted to survival in unfavorable environmental conditions. For instance, long-term droughts may induce the development of either water and reserve substances or vegetative propagation structures. Since Mandevilla atroviolacea is a species found at high altitudes on rocky outcrops, this study aimed to provide information on the morpho-anatomy of the underground system of this species that may assist in understanding the adaptive strategies at play. Samples from the underground system of three young and two mature plants collected in the field were sectioned and processed according to standard plant anatomical techniques. The upper area of the underground system corresponds to a xylopodium, while the lower is a tuberous stem organ. Tuberous roots account for the majority of the underground system. The increase in tuberous root diameter results from the action of a typical cambium. The high shoot-forming potential and storage of water and reserve substances observed in the underground system of this species are important strategies for it to survive in this habitat.

Among Italian buffalo farmers, it is widely held that administering diets with high energy and protein concentrations is an effective way to increase milk production. In order to assess the validity of this opinion, we verified milk yield and physico-chemical characteristics from buffaloes that, from the 5 th month of lactation, were fed two total mixed rations (TMRs) which, given the same intake, should have led to satisfaction of protein requirements though with a slight energy deficit (diet A) or excessive amounts of energy and protein (diet B). Estimate of the energy and protein value of the diets and that of the corresponding requirements was carried out both by using two software programs derived from the Cornell Net Carbohydrate and Protein System (1992), and with the method set up by INRA researchers (1988). The results obtained show that the two diets administered did not result in significant changes to the quantity of milk produced. However, with Diet B the protein concentration in the milk was significantly (p<0.01) higher, although this was partly offset by the higher concentration (p<0.05) of non-protein nitrogen (NNP). The Group B buffaloes also showed significantly higher blood urea levels (p<0.01), with concentrations exceeding those considered physiological for lactating buffaloes. Finally, while administering Diet A the Body Condition Score (BCS) was close to 6.5 (Wagner et al., 1988), whereas in buffaloes which used Diet B it sometimes increased by over 0.5 points. As regards which of the two methods compared is more suitable for expressing dietary energy and protein value and corresponding requirements, we feel that due to the high variability in the Italian Mediterranean buffalo's milk production aptitude, it would be premature to express a judgement on methods which rest on a common scientific base and do not differ substantially.

Reservas orgânicas são compostos capazes de determinar o vigor e a velocidade da rebrota de plantas forrageiras influenciando sua persistência na pastagem. Dentre os compostos constituintes das reservas orgânicas estão os carboidratos não estruturais (CNE). Os teores e a quantidade de CNE foram avaliados em amostras de pastagens de &#39;Tifton-85&#39;, &#39;Florakirk&#39; e &#39;Coastcross&#39;, estabelecidas em Nitossolo Vermelho eutroférrico, durante as estações de inverno, primavera e verão. Os tratamentos corresponderam a quatro situações de &quot;steady state&quot; do relvado, caracterizadas por alturas de pasto de 5, 10, 15 e 20 cm mantidas por ovinos sob regime de lotação contínua. O delineamento experimental foi em blocos completos casualizados, com um arranjo de parcelas subdivididas e quatro repetições. Os cultivares foram alocados nas parcelas e alturas de pasto nas subparcelas. As coletas das amostras para determinação de CNE foram realizadas mensalmente utilizando-se tu...

Avaliou-se o índice de área foliar, o coeficiente de extinção luminosa e o acúmulo de matéria seca em três cultivares de Cynodon spp. (Tifton 85, Florakirk e Coastcross) submetidas a quatro intensidades de pastejo (5, 10, 15 e 20 cm) por ovinos em regime de lotação contínua. O delineamento experimental utilizado foi o de blocos completos casualizados, com quatro repetições, em parcelas subdivididas, tendo na parcela as cultivares, e na subparcela, as intensidades de pastejo. Os maiores valores de índice de área foliar foram encontrados na cultivar Tifton 85. A extinção de luz dentro do dossel do pasto variou com a cultivar, mês do ano e intensidade de pastejo. Os valores mais elevados de coeficiente de extinção de luz (k) foram observados nos pastos mantidos mais altos, dentro de cultivares, na Florakirk. As taxas de acúmulo de matéria seca foram semelhantes em todas as cultivares avaliadas, independentemente dos regimes de desfolha adotados.

PDO Portuguese cheeses were used as a source of DNA for analysis by the polymerase chain reaction (PCR). Good quality DNA was extracted from all samples of milk and cheese and was suitable for PCR amplification at least of fragments up to 600 bp. The presence of caprine, ovine and bovine DNA was assessed using sets of species-specific primers. Electrophoretic patterns of PCR products were analysed with a computer-based method to obtain mobility values for each sample. These data were subjected to multivariate statistical analysis to evaluate the potential of this approach for authentication of dairy products. This enabled unequivocal discrimination between bovine, ovine and caprine milks and their derived cheeses.

Adventitious root (AR) formation is characterized by a sequence of physiological and morphological processes and determined by external factors, including mineral nutrition, the impacts of which remain largely elusive. Morphological and anatomical evaluation of the effects of mineral elements on AR formation in leafy cuttings of Petunia hybrida revealed a striking stimulation by iron (Fe) and a promotive action of ammonium (NH 4 +). The optimal application period for these nutrients corresponded to early division of meristematic cells in the rooting zone and coincided with increased transcript levels of mitotic cyclins. Fe-localization studies revealed an enhanced allocation of Fe to the nuclei of meristematic cells in AR initials. NH 4 + supply promoted AR formation to a lesser extent, most likely by favoring the availability of Fe. We conclude that Fe acts locally by promoting cell division in the meristematic cells of AR primordia. These results highlight a specific biological function of Fe in AR development and point to an unexploited importance of Fe for the vegetative propagation of plants from cuttings.

Baccharis belongs to the Asteraceae family and comprises a number of medicinal species. Baccharis brevifolia DC., B. microdonta DC., B. pauciflosculosa DC., and B. trilobata A.S. Oliveira & Marchiori, which are popularly known in Brazil as "vassouras" ("broom"), are all found in Southern Brazil. The anatomical features of the leaf and stem were investigated by employing the usual light and scanning electron microtechniques, as a means of differentiating the taxa. The following anatomical characteristics can be considered to be diagnostic: the occurrence and type of stomata, midrib, stem and crystal shapes, and the presence of the petiole.

The effect of 1-methylcyclopropene (1-MCP) at three concentrations (0, 1 and 10 µL L-1) for 24 h (Expt. 1) or 24 and 48 h (Expt. 2) on ‘Granola’ potato (Solanum tuberosum L.) tuber visual quality and sprout growth for 8 weeks under ambient dark conditions (27.4±0.62°C, 84.6±2.75% RH) was evaluated. Weight loss and sprouting (% sprouting and apical sprout length) did not vary with 1-MCP concentration and treatment duration. Visual quality at 8 weeks after treatment was better in tubers treated longer at 48 h due to lesser shriveling and decay. Visual quality, shriveling and decay were similar in tubers treated for only 24 h but not vitamin C content.

Alfalfa (A) was ensiled either wilted (35% dry matter (DM)) (WA) or as a mixture of 55% fresh alfalfa+ 45% conoxyltreated cotton gin trash (A + CT-CGT) (DM basis), and the effects of feeding these silages to growing lambs were examined. Lactic acid concentration was higher in A + CT-CGT than in WA silage, but levels of TCA-N (g per 100 g N) were similar, pointing to equal ability of the two silages to preserve protein. Neutral detergent fiber (NDF) glucose level was unchanged, while neutral detergent soluble (NDS) glucose was extensively fermented in the WA silage. Conversely, in the A + CT-CGT silage there was a drop in NDF glucose and a slight increase in NDS glucose concentration. NDF and NDS arabinose and galactose in both silages were slightly reduced during ensilage. Source materials and corresponding silages had similar in vitro digestibility values, but in vitro digestibility of monosaccharides in WA was 10% higher than that of the A+CT-CGT silage. Twenty lambs of the Assaf breed (average body weight (BW) 29 kg) were divided into two equal groups and fed rations composed of 50% concentrate, 25% poultry litter and 25% of either WA silage or A + CT-CGT silage. The diets were fed ad libitum for 64-67 days until the lambs reached 47-48 kg BW. Voluntary feed intake was 5% higher in the A + CT-CGT group than in the WA group. The average daily gains (ADG) were 284 g and 288 g in the WA and A + CT-CGT groups, respectively, which are considered as the low range of intensive growth. Slaughter data of the two dietary groups were comparable. Therefore CT-CGT can be used successfully as a silage additive for direct ensilage of fresh alfalfa. Intensive growth of lambs can be attained on a ration consisting of agricultural wastes including poultry litter, and CT-CGT used as a silage additive.

Lucerne was ensiled either by the conventional wilting process (WL) or as a mixture of 80% fresh lucerne + 20% ozonated cotton stalks (L+ OCS), and the effect of feeding these silages to dairy cows on performance and on the digestibility of ration carbohydrate constituents was examined. Ten cows in mid-lactation were divided into two equal groups with similar performance data at the onset of the experiment, and fed ad libitum for 28 days total mixed rations composed of 70% concentrate, 15% lucerne hay and 15% of either WL silage or LS OCS silage. Average daily milk yields during the experimental period were 27.1 and 27.6 kg in the WL and L+OCS groups, respectively, and the L+OCS cows gained higher body weight. Milk composition was similar in both treatments. The WL silage had a lower content of neutral detergent soluble (NDS) glucose, neutral detergent fibre (NDF) glucose and NDF xylose, and a higher content of arabinose, galactose and mannose than L+OCS silage. Carbohydrate digestibility was 83 and 85% in the WL and L+OCS rations, respectively. NDF digestibility was similar (45.0%) in both rations; however, digestion of NDF glucose, xylose and total polysaccharides was slightly higher in the L+OCS group than in the WL ration. In both rations, NDF glucose was more digestible than NDF xylose and NDF uranic acid and less digestible than NDF arabinose, galactose and mannose. Digestibility of total NDS carbohydrate was 89% in WL ration and 9 1% in L + OCS ration, and in both groups, digestion of NDS mannose and galactose was lower than that of NDS glucose, arabinose and pectin.

Seventeen herb, shrub and tree species of commercial and ecological importance in southern Africa were exposed at one location to ultraviolet-B (UV-B, 280±315 nm) radiation approx. 35 % above clear-sky background (control). The aims were to assess how UV-B affects canopy area, dry mass, and some biochemical and morphological properties of leaves, and to investigate whether differences between species are related to growth form of the plants. There was no pattern of response to UV-B related to growth form. Leaves of trees had altered chlorophyll a and b, carotenoid and¯avonoid concentrations, but those of shrubs or herbs did not. Nonstructural carbohydrates were unaffected. Smaller canopy areas and dry masses were observed under enhanced UV-B, but these were not statistically different among growth forms. There was a general insensitivity of species to elevated UV-B. Only ®ve species had signi®cantly altered leaf biochemical and morphological properties, canopy area and dry mass, the changes differing in magnitude. There was no consistent pattern of change in leaf thickness or biochemical composition with increased UV-B. Correlation analyses did not support the view that growth is less negatively affected in species with thick leaves or in those where leaf thickness increases, or in species with naturally high leaf¯avonoid contents or that are able to synthesize additional¯avonoids in response to UV-B enhancement. The analyses did not support the hypothesis that growth was inhibited by starch accumulation in leaves under elevated UV-B. However, changes in leaf shape did correlate with canopy area and dry mass, showing the importance of photomorphogenetic changes caused by UV-B which affect species' performance. We conclude that generalizations on plant sensitivity to UV-B based on growth form and functional type could be misleading, and that the great majority of economically important species of the region are likely to be insensitive to future UV-B increases. Notable exceptions include the Colophospermum mopane tree ecotypes chota and leslie and the arable annual Vigna unguiculata, both of which are traditional sources of livelihood to rural African populations and of importance to African industry and agriculture.

High levels of some enzymes involved in proline synthesis and utilization were early found in soybean nodules, and rhizobial knockout mutants were shown to be defective in inducing nodulation and/or fixing nitrogen, leading to postulate that this amino acid may represent a main substrate for energy transfer from the plant to the symbiont. However, inconsistent results were reported in other species, and several studies suggested that proline metabolism may play an essential role in the legume-Rhizobium symbiosis only under stress. Different mechanisms have been hypothesized to explain the beneficial effects of proline on nodule formation and bacteroid differentiation, yet none of them has been conclusively proven. Here, we summarize these findings, with special emphasis on the occurrence of a legume-specific isoform of δ 1-pyrroline-5carboxylate synthetase, the enzyme that catalyses the rate-limiting step in proline synthesis. Data are discussed in view of recent results connecting the regulation of both, the onset of nodulation and proline metabolism, to the redox status of the cell. Full comprehension of these aspects could open new perspectives to improve the adaptation of legumes to environmental stress.

RESUMO-Dentre outros mecanismos, a presença de determinados açúcares solúveis na semente parece estar envolvida na aquisição e manutenção da tolerância à dessecação. Nesse trabalho foi pesquisado a composição de açúcares solúveis em sementes de milho híbrido com diferentes níveis de tolerância à alta temperatura de secagem, assim como a relação entre o conteúdo desses açúcares e a tolerância à dessecação. Foram utilizadas sementes de dez cultivares de milho híbrido que apresentavam efeito recíproco para a tolerância à alta temperatura de secagem. As sementes foram colhidas com teor de água de aproximadamente 35% e secadas a 45°C. A qualidade fisiológica das sementes foi avaliada por meio do teste de germinação, teste frio sem solo e de envelhecimento acelerado. Os açúcares glicose, frutose, sacarose, rafinose e estaquiose foram extraídos dos embriões na presença de metanol e separados por meio da técnica de Cromatografia Líquida de Alta Eficiência (HPLC). Foi observada variação na composição dos açúcares entre as sementes dos híbridos e as de seus recíprocos. Uma maior concentração de sacarose foi verificada nas sementes dos híbridos tolerantes à alta temperatura de secagem. Não foi possível estabelecer uma relação entre a sacarose e rafinose que pudesse servir de parâmetro para a tolerância à alta temperatura de secagem em sementes de milho. Maior tolerância das sementes foi associada com uma maior relação da sacarose, rafinose e estaquiose/glicose e frutose. Termos para indexação: Zea mays, tolerância à dessecação, açúcares solúveis, qualidade fisiológica SUGARS AND TOLERANCE TO HIGH DRYING TEMPERATURE IN CORN SEEDS ABSTRACT-Among other mechanisms, the presence of certain soluble sugars in seed seems to be involved in the acquisition and maintenance of desiccation tolerance. In this study, the composition of. soluble sugars in hybrid corn seeds with different levels of tolerance to high drying temperature as well as the relationship between the content of those sugars and desiccation tolerance was researched. Seeds of ten hybrid corn cultivars presenting reciprocal effect to the tolerance to high drying temperature were employed. The seeds were harvested with a water content of about 35% and dried at 45°C. The physiological quality of the seeds was evaluated by means of the germination test, cold test without soil and accelerated aging test. The sugars glucose, fructose, sucrose, raffinose and stachiose were extracted from the embryos in the presence of methanol and separated by means of the High Performance Liquid Chromatography (HPLC) technique. Variation in the presence of sugars among the hybrid seeds and those of their reciprocals was detected. A higher concentration of sucrose was verified in hybrid seeds tolerant to high drying temperature. It was not possible to establish a ratio between sucrose and raffinose which could serve as a parameter of the tolerance to high drying temperature in corn seeds. Increased tolerance of the seeds was associated with a greater ratio of sucrose, raffinose and stachiose/ glucose and fructose.

Nonstructural carbohydrate (NSC) 4 fractions found in forage may play a role in equine diseases that involve carbohydrate intolerance, such as laminitis. Starch in seed grains such as oats (Avena sativa L.), barley (Hordeum vulgare L.), wheat (Triticum aestivum L.), and corn (Zea mays L.) has been used to induce equine laminitis in clinical studies (1). Sugars in forage may adversely affect equines with dysfunctions of glucose metabolism. Insulin resistance has been associated with laminitis in equines (2), although the mechanisms by which excess sugars can trigger an episode are not yet understood. French and Pollitt (3) were the first to experimentally induce laminitis using fructans. Much of the existing data on NSC concentrations in forage use analytic methods that extract and quantify sugars and fructans collectively as water-soluble carbohydrates. In this study, purified hydrolytic enzymes were used in the analytic procedures to separate starch, fructan, and sugars, thereby facilitating quantification of individual carbohydrate fractions. High concentrations of NSC, including sugars (glucose, fructose, and sucrose-GFS), fructan, and starch, must be considered in developing feed rations for horses and ponies prone to laminitis. Numerous factors are known to influence NSC concentrations in various plant parts. Nonstructural carbohydrate content and type depends on the plant species, plant part, stage of development, and environmental conditions such as root and shoot temperatures during growth as well as light intensity and duration, plant nutrient availability, and water

The objective was to quantify the flow of intestinal nutrients and nitrogen excretion and retention in sheep receiving isoproteic diets. Eight Texel × Lacaune wethers (average body weight = 25±2.5 kg) were fitted with duodenal cannula and housed in metabolic cages. Wethers were assigned to the treatments in a crossover design with two periods of 20 days each, and all feces and urine produced by the wethers were collected. The treatments consisted of two isoproteic (160 g kg −1 of crude protein on dry matter basis) diets composed of red clover (RC) or lucerne (LU; Medicago sativa) silages plus corn silage and concentrate feed. The digestible organic matter and metabolizable energy intake did not differ between treatments. The intestinal nonammonia N (NAN) flow was 5.9 g day −1 (37%) higher in RC wethers than in those of the LU treatment. This result was a consequence of both an increase in the efficiency of microbial protein synthesis (12.7% higher) and a decrease in ruminal degradable protein (RDP) content (20% lower) of the diet. However, the increase in the intestinal NAN flow was accompanied by a reduction in intestinal digestibility of N, resulting in similar daily N retention between treatments. The reduction of RDP content was probably the main reason for reductions in N urinary excretion in RC wethers compared with those in the LU treatment, showing that RC silage may be a tool for mitigating the impact of N excretion in ovine production systems, without changes in N retention.

Studies were designed to determine if colored callas (Zantedeschia sp.) can be successfully grown as a spring color crop under field conditions in the Southeastern United States without substantial modification of greenhouse culture protocols and if yield of clean stock from tissue culture can be improved. Results indicate colored calla lily production in containers in hardiness Zone 8B can be successful, without making significant modifications to either existing greenhouse production guidelines or the environment used for woody plant container culture. Neither fiber nor deeper containers improved overall calla performance over traditional plastic pots. ‘Garnet Glow’ and ‘Pink Persuasion’ produced the most blooms over 6 weeks of evaluation and would be better adapted for the spring color market than ‘Florex Gold’ or ‘Mango’ which bloomed heavily for only two weeks. The disease index developed for this study indicated ‘Mango’, ‘Florex Gold’, ‘Rubylite Pink Ice’ and ‘Majestic Red’ su...