摘要:

AbstractThe inheritance pattern of protein content in seeds of two crosses of cowpea (Vigna unguiculata(L) Walp) was studied. It was observed that, in both crosses, inheritance of the character involved both additive and non‐additive gene effects. Heritability in the broad sense was 0·70–0·78. A significant effect of pollen source was detected in one of the two crosses. In both crosses, comparison of seed protein content of reciprocal segregating generations indicated the influence of cytoplasmic fa

ISSN:0022-5142    

DOI:10.1002/jsfa.2740540102

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractCarbon and nitrogen in the soil microbial biomass were measured on eight occasions during a grassland production season, under swards of perennial ryegrass receiving 210 or 420 kg N ha−1per year or of ryegrass/white clover receiving no fertiliser N. The swards were either cut or grazed at monthly intervals. Soil microbial biomass C increased under all treatments in late April before declining until late July and rising slowly towards the end of the season. Values for microbial C under cutting and grazing were not significantly different but were usually larger under grass/clover than under grass. In contrast, the smallest values for soil microbial biomass N were recorded in late April. Larger N values were again recorded under grass/clover, and although values were nearly always smaller under grazing than under the corresponding cut treatment the differences were not significant.Soil biomass N comprised a large reservoir of mobile N, and at any one time contained 11, 3 and 5 times more N than was present in the mineral N component of the soil, the standing crop or excretal returns, respectively. It did not appear to be responsive, within a season, to the considerable returns of C and N from grazing animals or to N fertiliser managemen

ISSN:0022-5142    

DOI:10.1002/jsfa.2740540103

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe degradation of starch from various feedstuffs was investigated with rumen fluid, α‐amylase, pancreatin and a freeze‐dried, cell‐free preparation of rumen fluid. Rumen fluid was taken from either a hay‐fed cow or a concentrate‐fed cow. It was shown that incubations with rumen fluid at a constant pH of 6·5 gave a higher degradation of starch than those with a decreasing pH. The degree of starch degradation varied widely for the 21 feedstuffs investigated. Sorghum, maize and millet degraded slowly whereas tapioca showed fast degradation. Processed feedstuffs showed a higher level of degradation than unprocessed ones. The use of enzymes did not allow an accurate prediction of starch degradation by rumen fluid. However, this was made possible by the use of a freeze‐dried, cell‐free preparation of rumen fluid. Scanning electron microscopic observations showed that for the degradation of starch granules additional enzymes, present in rumen fluid

ISSN:0022-5142    

DOI:10.1002/jsfa.2740540104

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractTwo digalactosyldiacylglycerols (DGDG), galactosyl(α1 → 6)‐galactosyl (β1 → 3′)‐diacylglycerol (A isomer) and galactosyl(β1 → 6)‐galactosyl(β1 → 3′)‐diacylglycerol (B isomer), were found to be commonly distributed in some leguminous seeds. B isomer DGDG was detected in the range 1·9–32·5% of the whole DGDG from four varieties of kidney bean, five varieties of soya bean and adzuki bean, and one variety of pea, broad bean and scarlet runner bean. In kidney bean, the principal molecular species of diacylglycerol moieties in B isomer DGDG were dilinolenin (LnLn), linoleoyllinolenin (LLn) and oleoyllinolenin (OLn), whereas those in A isomer were LnLn, OLn and LLn. The major molecular species of B isomer DGDG from broad bean were predominantly dilinolenin (LL) and LLn which were found to be significantly differen

ISSN:0022-5142    

DOI:10.1002/jsfa.2740540105

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractCoriander (Coriandrum sativumL) is an important spice crop and is used in Indian diets. Physiological characters of plants and biochemical constituents like structural carbohydrate and phytate were studied in developing coriander (var Narnaul and Panth) seeds. Moisture decreased with advancement of seed development. Neutral detergent fibre, acid detergent fibre, hemicellulose, cellulose and lignin levels increased with maturation of seed in both coriander varieties. Significant variations were observed in biochemical constituents between varieties and during different stages of seed development. The presence of phytate did not vary at different stages of seed development. The height of plants varied from 134 to 139 cm with 10 branches. Umbels varied from 89 to 99 with an average of six umbellets. Narnaul seed weight was double that of the variety Panth.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740540106

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractSamples of sorghum (Sorghum bicolorMoench ×Sorghum sudanenseStapf, cv ‘P 988’) were harvested at five growth stages. Quantitative methylation and acetalation–methylation methods were used to examine changes during growth of cell‐wall polysaccharides, their association with phenolic compounds and the effects of changes on rumen degradability. Cellulose degradability, as measured by a nylon‐bag method, decreased from 82·5% at the youngest stage to 36·5% at the milk‐ripe stage, at a greater rate of change than degradability of dry matter. Among the monosaccharides contributing to cell‐wall polysaccharides, the degradabilities of arabinose and uronic acid residues were consistently higher than those of xylose and glucose, the main components of structural carbohydrates. Recovery of parent neutral sugars from cell wall polysaccharides, calculated as the sum of partially methylated alditols, was in good agreement with the values obtained by direct estimation of individual sugars as their alditol acetate derivatives. Total non‐starch polysaccharide content increased from 31·1% to 45·1% between the first two growth states, with little change evident thereafter. The relative proportion of individual to total sugars remained consistent throughout growth. The values for arabinose, xylose and glucose residues accounted for 4·9%, 27·9% and 63·0% of total neutral sugars, respectively. The pattern of glycosidic linkages detected could be mainly ascribed to the presence of (1–4)‐β‐D‐glucans (cellulose), arabinoxylan, (1–3)(1–4)‐β‐D‐glucans, (1–4)‐β‐D‐galactan, (1–3)(1–6)‐β‐D‐galactan, rhamnogalacturonan and, possibly, xyloglucan. The cellulose content of the five sorghums was, in order of growth, 14·3%, 21·8%. 22·3%, 21·2% and 22·0% of dry matter.The ratio of the mixed‐linked g1ucan:cellulose decreased during growth. Arabinoxylan, the predominant hemicellulosic polysaccharide, was estimated to comprise about 33% of total neutral sugars consistently for all sorghum samples. Arabinose, found largely as terminal residues in the cell walls, carried various amounts of alkali‐labile substituents, particularly at position 0–5, depending on the growth stage of sorghum. The extent of 0–5 substitution was closely correlated with both the lignin content (total phenolic

ISSN:0022-5142    

DOI:10.1002/jsfa.2740540107

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractStraw residues can reduce the yield of a following cereal crop, perhaps through an effect on tillering. Over two years we measured tillering of winter wheat on a clay soil where straw was either burnt or chopped and returned. Seed was direct drilled in the first year and direct drilling was compared with conventional sowing after ploughing in the second year. Straw had no marked effect on the production per plant of the first three main tillers. Direct drilling resulted in earlier tillering and more tillers per plant than conventional sowing after ploughing, but this was not reflected in grain yields calculated from components of yield. Part of the tillering effect may have been caused by differences in sowing depth.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740540108

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractRecent studies have shown that the compound imazethapyr (5‐ethyl‐2‐(4‐isopropyl‐4‐methyl‐5‐oxo‐2‐imidazolin‐2‐yl)nicotinic acid) possesses growth regulatory activity and can be used to enhance nutritive value of grasses. However, little is known about possible effects of this material on fibre composition or potential fibre utilisation by ruminants. The objective of this research was to examine imazethapyr‐treated cocksfoot (Dactylis glomerataL), ryegrass (Lolium perenne L ×L multiflorumLam), and timothy (Phleum pratenseL) for possible treatment‐induced changes in in‐vitro digestibility and in concentrations of selected fibre constituents. Replicated field plots treated with imazethapyr at 0 (control) or 100 g ai ha−1during the vegetative (pre‐elongation) stage of growth were harvested when controls were in the early stage of inflorescence emergence. Samples taken from treated plots 4 weeks post‐treatment had higher in‐vitro dry matter disappearance (IVDMD), lower neutral detergent fibre (NDF), lower acid detergent fibre (ADF), lower cellulose, lignin, and higher hemicellulose concentrations compared with controls. Imazethapyr treatment also reduced the concentration ofp‐coumaric acid in NDF, but had no effect on ferulic acid. The treatment effect on in‐vitro NDF disappearance, however, was inconsistent among the grass species and was statistically non‐significant (P= 0·10), implying that, under the conditions of this study, imazethapyr‐related enhancements in IVDMD can be attributed primarily to a reduction in the amount of NDF and its associated constituents, as oppose

ISSN:0022-5142    

DOI:10.1002/jsfa.2740540109

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe trace metals (Mn, Cu, Zn, Fe, Cd, Pb and Ag) have been determined in various tissues of raw and cannedLoligo opalescenssquid. As a consequence of processing whole squid, highly elevated levels of cadmium, and to a lesser extent of the other trace metals investigated, were found in the edible parts of canned whole squid.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740540110

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractA high protein, groundnut‐based powder reconstitutable into a milk‐like beverage was packed in polyethylene bags and in lacquered tin cans, and stored at both room temperature (25 ± 2°C) and in a domestic refrigerator (5 ± 2°C) for 60 days. Storage stability was evaluated by analysing periodically for changes in physical characteristics, proximate composition, and development of browning and rancidity, and assessing moisture sorption characteristics. Protein, lipid, total soluble sugars, peroxide value, total carbonyls and extinction values of the ethanolic extract remained practically constant during storage. The isotherm curves exhibited the characteristic sigmoidal shape typical of high protein foods. There was a greater increase in density, hygroscopicity and wettability in polyethylene‐packed samples at both temperatures suggesting that the lacquered tin can leads to better keeping quality for thi

ISSN:0022-5142    

DOI:10.1002/jsfa.2740540111

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY