Chemical composition and nutritional value of para-rubber seed and its products for chickens

Para-rubber (Hevea brasiliensis) seed and its products were subjected to different methods of processing such as decortication, oil extraction, autoclaving and fermentation and assayed for their chemical composition and nutritional value. Peanut oil meal and yellow maize were also assayed similarly for comparison.

Decortication reduced the crude fibre content, with proportionate increases in other nutrients and energy value. Autoclaving and fermentation failed to improve the nutritional value of undecorticated rubber seed oil meal.

Crude protein content of rubber seed and its products ranged from 11.5% in rubber seeds to 27.4% in commercial decorticated rubber seed oil meal. The oil content of the rubber seeds and kernels was 24.0 and 40.1%, respectively. The available carbohydrate content of rubber seed and its products ranged from 6.3% in rubber seeds to 15.9% in commercial decorticated rubber seed oil meal; these values may be compared with the value of 59.0% for yellow maize.

Both undecorticated and decorticated rubber seed oil meals appeared to be deficient in sulphur-containing amino acids and lysine. The gross protein value of undecorticated and decorticated rubber seed oil meals and peanut oil meal was estimated to be 43.6, 47.0 and 49.7, respectively.

Both undecorticated and decorticated rubber seed oils were rich in oleic and stearic acids, but relatively poor in poly-unsaturated fatty acids, compared with peanut oil.

Determined apparent ME (AME) values were (kcal/g dry matter): rubber seeds, 2.91; kernels, 4.70; undecorticated rubber seed oil meal, 2.00; and decorticated rubber seed oil meal, 2.80. The true ME (TME) values were 3.24, 5.16, 2.22 and 3.00 kcal/g dry matter, respectively. In general, TME values were about 10% higher than the AME values.     

Effects of fat and protein levels on foraging preferences of tannin in scatter-hoarding rodents

Both as consumers and dispersers of seeds, scatter-hoarding rodents often play an important role in the reproductive ecology of many plant species. However, the seeds of many plant species contain tannins, which are a diverse group of water-soluble phenolic compounds that have a high affinity for proteins. The amount of tannins in seeds is expected to affect rodent foraging preferences because of their major impact on rodent physiology and survival. However, variable results have been obtained in studies that evaluated the effects of tannin on rodent foraging behavior. Hence, in this study, we aimed to explain these inconsistent results and proposed that a combination of seed traits might be important in rodent foraging behavior, because it is difficult to distinguish between the effects of individual traits on rodent foraging behavior and the interactions among them. By using a novel artificial seed system, we manipulated seed tannin and fat/protein levels to examine directly the univariate effects of each component on the seed preferences of free-ranging forest rats (Apodemus latronum and Apodemus chevrieri) during the behavioral process of scatter hoarding. Our results showed that both tannin and fat/protein had significant effects on rodent foraging behavior. Although only a few interactive effects of tannin and fat/protein were recorded, higher concentrations of both fat and protein could attenuate the exclusion of seeds with higher tannin concentrations by rodents, thus influencing seed fate. Furthermore, aside from the concentrations of tannin, fat, and protein, numerous other traits of plant seeds may also influence rodent foraging behavior. We suggest that by clarifying rodent foraging preferences, a better understanding of the evolution of plant seed traits may be obtained because of their strong potential for selective pressure.     

Scatter-hoarding rodents prefer slightly astringent food

The mutualistic interaction between scatter-hoarding rodents and their seed plants is highly complex yet poorly understood. Plants may benefit from the seed dispersal behavior of rodents, as long as seed consumption is minimized. In parallel, rodents may maximize foraging efficiency and cache high-quality resources for future consumption. Defensive compounds, such as tannins, are thought to be a major mechanism for plant control over rodent behavior. However, previous studies, using naturally occurring seeds, have not provided conclusive evidence supporting this hypothesis. Here, we test the importance of tannin concentrations on the scatter-hoarding behavior of rodents by using an artificial seed system. We combined feeding trials and field observations to examine the overall impact of seed tannin concentrations on rodent behavior and health. We found that rodents favored seeds with an intermediate amount of tannin (~5%) in the field. Meanwhile, in rodents that were fed a diet with different tannin content, only diets with high tannin content (25%, 15%, and 10%) caused a significant negative influence on rodent survival and health. Significant differences were not found among treatments with tannin levels of 0-5%. In contrast to many existing studies, our results clearly demonstrate that scatter-hoarding rodents prefer slightly 'astringent' food. In the co-evolutionary arms race between plants and animals, our results suggest that while tannins may play a significant role in reducing general predation levels by the faunal community, they have no precise control over the behavior of their mutualistic partner. Instead, the two partners appear to have reached an evolutionary point where both parties receive adequate benefits, with the year-to-year outcome being dependent on a wide range of factors beyond the control of either partner.     

Condensed tannins and sugars in the diet of chimpanzees (Pan troglodytes schweinfurthii) in the Budongo Forest, Uganda

Fruits, leaves and bark forming part of the diet of chimpanzees were collected and it was noted whether samples were of a kind being eaten or not eaten. Samples were dried and analysed for condensed tannin content and for three sugars, glucose, sucrose and fructose. It was found that chimpanzees did not select foods according to the level of tannins but did so according to the levels of sugars, preferring the higher levels. Fig seeds contained higher tannin levels than fig pulp, and the chimpanzees made oral boli (“wadges”) of fig seeds which they spat out. Two fig species were compared: the one with lower tannin and higher sugar content was preferred. The bark of one tree species often eaten contained high levels of tannins but also contained sugars. Young leaves with lower tannin levels were preferred to mature leaves with higher levels. Chimpanzees appear to be able to tolerate higher tannin levels than three monkey species in this forest, and considerably higher levels than marmosets (Callitrichidae). Received: 20 October 1997 / Accepted: 1 March 1998     

Costs and benefits of defense by tannins in a neotropical tree

Summary The costs and benefits of defense by tannins were investigated for a neotropical tree, Cecropia peltata L. (Moraceae). Seedlings of equal age were grown under uniform conditions in a greenhouse for 18 months. Within a plant, leaf tannin concentrations measured in different years were highly correlated. Tannin concentrations differed substantially among individuals; plants with high tannin content had lower damage levels in herbivory experiments. The effects of tannin on herbivory appeared to be dosage dependent. There was, however, a cost associated with tannin production in terms of reduced leaf production.     

种子特征和结实量对啮齿动物取食和扩散种子行为的影响

为了深入了解啮齿动物在不同种子丰富度条件下对不同大小和单宁含量种子的觅食行为策略及其与植物种群更新的关系,在宁夏六盘山区的华北落叶松人工林,研究了不同大小和单宁含量[0%Tannin(T)、2%T、8%T和15%T]的人工种子在模拟结实小年和结实大年对啮齿动物取食和扩散行为的影响.结果表明: 啮齿动物消耗种子速度在结实小年更快,结实大年的种子消耗速度相对缓慢. 种子就地取食率(ISPR)在不同结实年份间无显著差异,扩散后取食率(PRAD)在结实小年显著高于结实大年,但前者的扩散后贮藏率(HRAD)显著低于后者;种子扩散后的取食距离(PDAD)和贮藏距离(HDAD)在结实小年均显著大于结实大年.在结实小年,大种子的PDAD和HDAD均大于小种子,前者在不同大小种子间均差异显著,而后者仅在2%T和15%T的不同大小种子间差异显著;在结实大年,除0%T外的其他单宁含量种子的PDAD和HDAD在不同大小种子间均差异显著.ISPR在中等单宁含量种子最大,高单宁含量种子最小;PRAD分别在结实小年的高单宁含量种子和结实大年的无单宁种子最大;不论在结实大年还是结实小年,HRAD均在高单宁含量种子最大,中等单宁含量种子最小.这说明结实大年可延缓啮齿动物对种子的消耗速率,提高种子的HRAD,但种子扩散距离减小;啮齿动物在结实大年和小年均表现出对大种子的扩散偏好,且大种子被扩散的距离更远;啮齿动物在不同结实年份均偏好于就地取食中等单宁含量种子,而扩散高单宁含量种子.     

Inheritance of seed condensed tannins and their relationship with seed-coat color and pattern genes in common bean (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> L.)

Condensed tannins are major flavonoid end products that affect the nutritional quality of many legume seeds. They chelate minerals and interact with proteins, thus reducing their bioavailability. Tannins also contribute to seed coat color and pigment distribution or intensity. The objective of this study was to analyze the relationship between quantitative trait loci (QTL) for seed tannin concentration in common bean and Mendelian genes for seed coat color and pattern. Three populations of recombinant inbred lines, derived from crosses between the Andean and Mesoamerican genepools were used for QTL identification and for mapping STS markers associated with seed color loci. Seed coat condensed tannins were determined with a butanol–HCl method and a total of 12 QTL were identified on separate linkage groups (LGs) in each of the populations with individual QTL explaining from 10 to 64% of the phenotypic variation for this trait. Loci on linkage groups B3 and B10 were associated with the Mendelian genes Z and Bip for partly colored seed coat pattern, while a QTL on linkage group B7 was associated with the P gene which is the primary locus for the control of color expression in beans. In conclusion, this study found that the inheritance of tannin concentration fits an oligogenic model and identifies novel putative alleles at seed coat color and pattern genes that control tannin accumulation. The results will be important for the genetic improvement of nutritionally enhanced or biofortified beans that have health promoting effects from higher polyphenolics or better iron bioavailability.     

Aging of Soybean Seeds in Relation to Metabolism at Different Relative Humidities

The present study was carried out to clarify the relationshipsbetween respiration, moisture content and the aging of dry soybean(Glycine max) seeds under different storage conditions. Ethanolicfermentation increased with increasing relative humidity (RH)during storage. However, at 75% RH which corresponded to a watercontent of 15.2% in seeds, the production of ethanol ceasedafter one month of storage. The ethanol that had accumulatedwithin the container was re-absorbed by the seeds themselvesand disappeared entirely within 3 months, unless the seeds wereexposed to HCN gas. Similar changes were also found for methanol.The activity of mitochondria increased only in seeds storedat 75% RH, it reached a maximum after the third month of storageand then rapidly declined. The amounts of both CoA and acetylCoA in seeds that had been stored for 4 months were far lowerat 75% RH than at 53% RH, and the viability of soybean seedsstarted to decrease after the fourth month at 75% RH. Therefore,a major cause of the rapid deterioration of seeds at 75% RHat room temperature seems to be the rapid development of mitochondrialrespiration, which is accompanied by the consumption of CoAand its acetyl derivatives. By contrast, the slow deteriorationof seeds during long-term storage at 33% to 68% RH and/or atsubzero temperatures seems to be due to the toxic action ofacetaldehyde, an intermediate in ethanolic fermentation, whichcan slowly occur. (Received April 10, 1995; Accepted July 10, 1995)     

The challenge of interpreting primate diets: mangabey foraging on Blighia unijugata fruit in relation to changing nutrient content

Primates often make foraging selections that are not apparent. For example, they may eagerly consume a particular plant part and species in some instances, but reject it at other times. Blighia unijugata (Baker) fruit is one of the most frequently eaten foods of mangabeys (Lophocebus albigena) in Lwamunda Forest Reserve, Uganda; however, its use varies strikingly depending on the fruit's developmental stage. We conducted feeding observations to investigate the nutritional criteria that mangabeys may have used for the consumption of specific fruit parts by conducting analysis of fruit parts eaten and rejected at different developmental stages. When seeds had low condensed tannins, mangabeys ate them, but seeds were rejected when tannin levels increased. In the first five stages of fruit development, tannin levels in arils declined and the frequency of consumption of the aril increased. Although fat content in seeds increased with maturity, it did not appear to influence seed consumption, but fat content was related to frequency of consumption of the aril. Considering that primates are often making food selections among many species/part combinations, our results illustrate the value of using nutritional analyses to understand foraging decisions. Furthermore, they demonstrate how very specific trade‐offs between consumption of critical nutrients and antifeedants can drive which foods and parts are eaten.     

假酸浆种子发芽特性研究

在不同温度、不同贮藏时间和方法下,对来源于印度尼西亚的假酸浆种子发芽特性进行研究。结果表明:不同温度对假酸浆种子萌发的影响差异极显著,在15/25℃变温条件下种子发芽率最高,为84.3%,发芽快且整齐;假酸浆种子采收后立即播种其发芽率非常低,室温下贮藏6～9个月时在25℃恒温或15/25℃变温条件下均有较高发芽率,说明假酸浆种子有休眠性,通过延长贮藏时间能打破休眠,促进种子发芽;但室温贮藏15个月后,种子活力下降非常明显。低温冷藏在一定条件下能提高假酸浆种子萌发能力,能延长种子寿命。     

Dormancy and viability of Ferocactus peninsulae (Cactaceae) seeds

Knowledge on seed dormancy is crucial for the understanding of plant population dynamics, as it controls seed germination and seed bank formation. Dormant seeds have high potential to establish in soil seed banks, but such information within Cactaceae is scarce, although it is essential for conservation programs. The aim of this study was to determine if seeds of Ferocactus peninsulae showed any kind of dormancy and to test their germination capacity after storage. This was assessed with 15 seed sowing experiments done over 4 years with seeds stored under room conditions (20 ± 2°C). We demonstrated the existence of physiological dormancy in F. peninsulae seeds that is broken with an after-ripening period. Germination was low during the first 3 months of storage (d = 0.206) but increased after 10 months of storage (d = 0.654), and seeds maintained their viability at 48 months (d = 0.707). Also, their speed of germination increased with storage time. Ferocactus peninsulae seeds are positively photoblastic, and the requirement for light for germination persisted over all experiments. The results provide crucial information for propagation and conservation research and may allow us to infer that F. peninsulae seeds are able to form a persistent soil seed bank, as they maintained their viability after dormancy is released.     

Effects of osmotic priming and ageing on the germination and emergence of carrot and leek seed

Carrot and leek seed was osmotically primed in polyethylene glycol solution (273 g/kg water and 342 g/kg water respectively) for 10, 14 or 17 days before accelerated ageing for 0, 24, 48, 72 or 96 h. Priming reduced the germination time compared with non-primed seed. Accelerated ageing increased germination and emergence times and decreased percentage germination and emergence to a greater extent for the primed seeds than for non-primed seeds in both species. Primed and dried but non-aged seed from both species was stored at 10°C for 12 months. There was no loss of viability and improvements in germination time due to priming were maintained throughout the storage period for all the priming treatments in leek, and for the 10 and 14 day priming treatments in carrot. Carrot seed primed for 17 days lost some viability after 12 months storage compared with non-stored seed.     

Germination of Cistus ladanifer seeds in relation to parent material

Variability in seed germination behaviour of Cistus ladanifer L. (rockrose), a Cistaceous species widely distributed in the Mediterranean Basin, was studied in a central Spanish population under controlled conditions. No correlation between seed moisture content and germination was found. Great variability in germination was found among seeds of the population studied, not only between seeds belonging to different mother plants, but also between those collected from different capsules on the same plant. In most cases, seeds preheated at 100 °C for 30 minutes showed a significant increase in germination. This germination behaviour is related to fire regimes as this plant is a typical shrubby element of the mediterranean shrublands. Percent germination did not vary significantly after several months of seed storage at room temperature. In the same way, no difference was found in final germination percentage of seeds stored under room temperature vs. seeds stored under cold conditions.     

Polyphenol contents and antioxidant activity of soybean seed extracts

The antioxidant activity and contents of various polyphenol classes in the seeds of 20 soybean hybrids were evaluated. Total polyphenols, tannins and proanthocyanidins were determined after extraction of plant material with 70% aqueous acetone. In addition, flavonoid content was determined. Antioxidant activity of seed extracts was evaluated by DPPH free radical scavenging activity assay. A positive linear correlation between antioxidant activity and contents of total phenols, tannins and proanthocyanidins was established. The highest antioxidant activity was observed in the extracts of hybrids which have higher levels of all polyphenol classes examined. The most of the single-cross hybrids were poor in tannins which recommend them as good source for ensiled livestock feed. Results suggested that polyphenol content should be considered as an important feature of the soybean seed.     

Effect of peanut tannins on percent seed colonization and in vitro growth by aspergillus parasiticus

The relationship between tannin content of mature, intact, cured peanut seed and percent seed colonization byAspergillus parasiticus was examined. Tannin content in 9 cultivars, 7 of which were grown in both Tifton, Georgia and Puerto Rico, was significantly correlated with percent seed colonization. For data expressed as mg tannin/g intact seed and mg tannin/g seed coat, correlation coefficients with percent colonization were 0.74 and 0.76, respectively.Seed coat tannin, methanol-extracted, water-soluble material from peanut seed coats, was testedin vitro for effects on growth ofA. parasiticus. As concentrations of tannins were increased to 7.5%, inhibition of fungal growth increased linearly to 88%; a concentration of 20% produced over 96% inhibition.     

Determination of Lignin and Tannin Contents of Cowpea Seed Coats

Tannins in the seed coats of cowpea cultivars interfere withthe determination of lignin by the acetyl bromide method butthe tannins can be removed by extraction with acetone:water(70:30) allowing a direct determination on the residue. Furthermore,the difference between the absorbance values determined by theacetyl bromide method before and after the removal of tanninscan be used as a measure of tannin content in cowpea seed coats.Copyright1995, 1999 Academic Press Cowpea, Vigna unguiculata, lignin, tannin, acetyl bromide     

Phenolic synthesis and phenylalanine ammonia-lyase activity in suspension cultures of Acer pseudoplatanus L.

Summary Phenolic metabolism is influenced by the levels of sucrose, nitrogen and 2,4 dichlorophenoxyacetic acid (2,4-D) in the growth medium. Chromatographic evidence suggests that the principle products are polymers of leucocyanin, (-) epicatechin and (+) catechin, constituting condensed tannins. Comparison of ethanolic cell extracts with extracts from plant organs shows that although these compounds are present in parts of the plant they are not the major phenolics.Cells maintained in a modified Heller's medium containing 9.0×10^–7 M 2,4-D produce increased levels of tannins from mid passage (day 12) onwards. The presence of 2,4-D at 9.0×10^–6 M supresses this response and increased initial sucrose levels cause the amount of tannins to be greater. At the period when tannin levels increase the standard medium is exhaused of its nitrogen sources, urea and nitrate. Increased initial nitrogen levels delay the beginning of increased tannin production and the addition of urea or 2,4-D to cultures already containing high levels of tannins causes the tannin content per gram fresh weight and per culture to decline. These results indicate an antagonism between tannin synthesis and nitrogen metabolism. The activity of phenylalanine ammonia-lyase EC 4.1.1.5. (PAL) estimated by a spectrophotometric method in acetone powders derived from Acer cells increases three to four fold at the onset of increased tannin synthesis and then declines sharply. The phase of high PAL activity correlates with the exhausion of the medium nitrogen sources.Abbreviation 2,4-D 2,4-dichlorophenoxyacetic acid One of the authors (R.J.W.) was supported by a Science Research Council Studentship during the course of this work.     

Changes in germinability,lipid peroxidation,and antioxidant enzyme activities in pear stock (<Emphasis Type="Italic">Pyrus betulaefolia</Emphasis> Bge.) seeds during room- and low-temperature storage

The aim of this study was to determine if loss of germinability in Pyrus betulaefolia seeds stored at 4°C and at room temperature is associated with a loss of membrane lipid peroxidation or changes in antioxidant enzyme activities. The results indicated that germination percentage clearly decreased when seeds were stored at room temperature rather than at 4°C from 6 to 12 months. Room-temperature storage of the pear stock seed for 12 months decreased germination to 15.52%, but germination percentage was not changed when seed was stored at 4°C for 12 months. MDA, a marker for membrane lipid peroxidation, increased significantly under room-temperature storage conditions. Antioxidant enzyme (SOD, POD, and CAT) activities were a good indicator of germination percentage in pear stock seeds. Antioxidant enzyme activities of pear stock seeds at 4°C were higher than antioxidant enzyme activities in seeds stored at room temperature from 6 to 12 months. Antioxidant enzyme activities of the pear stock seed decreased markedly under conditions of room-temperature storage from 6 to 12 months. The results of this study showed that long-term room-temperature storage was detrimental for maintaining the vigor of P. betulaefolia seeds. The mechanisms responsible for this outcome are a higher level of membrane lipid peroxidation and a lower level of activity of antioxidant enzymes.     

African rainforest vegetation and rumen microbes: Phenolic compounds and nutrients as correlates of digestibility

Summary In order to refine hypotheses concerning food selection by generalist herbivores with ruminant-like digestive systems the chemical correlates of digestibility in such a system have been studied. Samples of seeds and leaves from tree species growing in two African rainforests (Douala-Edea Forest Reserve, Cameroon, and Kibale Forest, Uganda) were assayed for phenolic content and nutrient content, and in-vitro dry matter digestibility was analysed utilizing rumen inoculum from a fistulated steer. Both forests studied carry populations of colobine monkeys with ruminant like digestive tracts. Content of condensed tannins and, to a lesser extent of total phenolics, was found to be negatively correlated with digestibility; a result that may be attributable to the inctivation of microbial enzymes by tannins. The negative association of tannin content and digestibility was stronger in material from the Cameroon site, the vegetation of which contains considerably higher concentrations of tannins and is generally less digestible than that from the Ugandan site. Gross energy content of leaves was also found to be persistently negatively correlated with digestibility. The interpretation of this result is uncertain; however, gross energy yield may well reflect variation in content of cell wall polymers, especially lignin. For the complete set of data, tannins presented the strongest observed correlation with digestibility, but when only mature leaves were considered the relationship with gross energy appeared stronger. No strong association was noted between high nutrient content and high digestibility. This was attributed to the fact that the assay measured the extent of digestion under standardised and very favourable conditions of nutrient supply. The results obtained are discussed in relation to observations of leaf and seed selection preferences of Colobus spp. in these two forests.Publication 19-013 of the Wisconsin Regional Primate Research Center     

Bimodal changes in germinability of pea seeds under the influence of low doses of gamma-radiation

Pea seeds (cv. 'Nemchinovskii-85', harvest of 2002, 80%-germination percentage) were exposed to gamma-radiation with doses ranging from 19 cGy to 100 Gy. One week after the irradiation with doses of 19 cGy and 3 Gy. the germination percentage decreased to 58 and 45%, respectively; at doses of 7 and 10 Gy it was 73 and 70% respectively. At greater doses (25, 50, and 100 Gy), germination percentage decreased in proportion. Anomalous changes in seed germination percentage (as a function of irradiation dose) were caused by the redistribution of irradiated seeds between fractions I and II. The measurements of room temperature phosphorescence in air-dry seeds and the phosphorescence of endogenous porphyrines of imbibing seeds showen that the germination decrease after the irradiation with low doses (19 cGy and 3 Gy) was caused by the increase in the number of weak seeds of fraction II, which had high rates of water uptake and suffered from hypoxia under seed coat. Some of these seeds suffocated from hypoxia, and other seeds produced seedlings with morphological defects (such seeds were considered incapable of germination). During storage of seeds irradiated at doses 19 cGy-10 Gy, the recovery of germination percentage (after its initial decrease) was caused by the decrease in seed number in fraction II. The subsequent germination decrease was caused by seed death. The higher was the irradiation dose, the faster were changes in germination percentage during storage of irradiated seeds. Bimodal changes in pea seed germination with the increase of y-irradiation dose has apparently the same origin as the changes in seed germination during accelerated ageing.