Relationship between total sulphur and sulphur amino acids in chickpea (Cicer arietinum L.) and pigeonpea (Cajanus cajan [L.] Millsp.)

Total sulphur was determined in seed meal of 30 chickpea and 24 pigeonpea cultivars by the wet digestion procedure and by using the Leco sulphur analyser. Methionine and cystine were determined after performic acid oxidation in an amino acid analyser. The two methods used for total sulphur determinations were highly correlated (r=0.943). Percent meal protein was significantly correlated (r=0.476) with total sulphur in chickpea but not in the case of pigeonpea. Total sulphur content exhibited a significant positive correlation (r=0.651) with sulphur amino acids of pigeonpea when expressed as percent of protein but not in the case of chickpea. Correlation coefficients between total sulphur and sulphur amino acids when the results were expressed as percent of sample were positive for both chickpea (r=0.494) and pigeonpea (r=0.534). The amount of sulphur in methionine and cystine accounted for 54.8% of the total sulphur in chickpea and for 75.5% in pigeonpea. In both chickpea and pigeonpea, methionine was positively and significantly correlated with cystine when they were expressed either as percent of sample or as percent of protein.Submitted as J.A. no. 159 by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).     

Chemical composition and nutritional quality of five peanut cultivars grown in Pakistan

Four high yielding imported and one local peanut cultivar, grown under local soil and climatic conditions, were compared for their chemical composition and nutritional quality. The local cultivar Kurram contained the maximum protein (28.3%) and the imported cultivar No. 45 contained the maximum oil content (49.5%). K, Mg, P, Fe, Zn, Cu and Mn were present in nutritionally significant and comparable amounts in all the cultivars. Lysine was the first limiting amino acid in all the cultivars. The chemical scores and net protein utilization (operative) values were higher for the imported than local cultivar while net dietary protein calories percent (NDP Cal%) values showed only minor variations among the five cultivars. Significant differences (P<0.05) were observed for protein, oil, Na, K, Ca, P and Zn contents of all the cultivars. Roasting (150°C, 1/2 h) decreased the lysine, threonine, methionine, cystine, arginine, tryptophan and tyrosine contents but increased the protein, oil, ash, fiber, mineral elements (except Na and C1), aspartic acid, serine, glutamic acid, proline and phenylalanine contents.     

The response of a perennial ryegrass (Lolium perenne L.) seed crop to nitrogen fertilizer application in the absence of moisture stress

Responses of perennial ryegrass (Lolium perenne L.) to nitrogen (N) fertilizer application rates and timings vary widely, because water is often limiting. Yield response to N fertilizer application during autumn, late‐winter and spring, and the associated efficiency of use of these inputs, was assessed under conditions of non‐limiting soil moisture during two, one‐year lysimeter studies in Canterbury, New Zealand. There were significant (P < 0·05) increases in seed and herbage yields with increasing N fertilizer application. Seed yields differed with year; greatest yields were 300 g m^?2 in 1996 and 450 g m^?2 in 1997. Seed head numbers (r²=0·77), seeds head^?1 (r²=0·92) and herbage yield (r²=0·92) were the major determinants of seed yield in both years. Irrigation required to maintain the soil between 70% and 90% of field capacity was directly related (r²=0·94 and 0·99 in 1996 and 1997 respectively) to increases in herbage yield. Seed yield, seed quality (thousand seed weight and percentage of seed > 1·85 mg), efficiency of water use, efficiency of N fertilizer use and apparent N fertilizer recovery were greatest when N fertilizer was applied at a rate of 50 kg N ha^?1, 50 or 100 kg N ha^?1 and 150 kg N ha^?1 in autumn, late‐winter and spring respectively; further increases in spring N fertilizer stimulated vegetative growth, but not seed yield. As a management strategy, applying N fertilizer to match the N requirements of the crop during the reproductive stage of growth will result in high yields of high quality seed while minimizing environmental impact.     

Fertilizer effects on yield,mineral and amino acid composition,dietary fibre content and nutritive value of leeks

In pot experiments with greatly differing rates of N, P, S, K and Ca, dry matter (DM) yields of leek stems varied from 25 to 164 g/pot. Total-N and NO₃-N concentrations varied from 1.18 to 3.56% and from 10 to 1515 ppm in DM, respectively. Both N applications and P and K deficiency greatly increased total-N and NO₃-N content. S applications increased total-S content from 0.047 to 0.359% in DM, of which between approximately 100 to 25% were found in methionine+cystine. Total-N/total-S ratios decreased from 57 to 6 with the highest S level. P and K applications increased their respective content in DM two- and threefold. Severe Ca deficiency reduced Ca content from 0.495 to 0.045%. Iron, zinc, manganese and copper contents varied from 33–69, 14–26, 11–34 and 3.1–5.7 ppm in DM, respectively. Increasing N contents, whether due to N applications or P or K deficiency, decreased the content of all essential and some other amino acids in crude protein. Both S and severe P deficiency had a pronounced negative effect on amino acid composition and chemical score. Only glutamic acid (glutamine) and arginine were increased by increasing N contents. However, expressed as g/kg DM the concentrations of all amino acids were positively correlated with protein content. S and P deficiency reduced total dietary fibre (TDF) content of DM from 28.3 to 18.6% and 17.4%, respectively, of which between 53 and 60% were insoluble dietary fibre (IDF). Digestible energy (DE) was positively correlated with protein content (r=0.90**). In N-balance trials with rats, increasing protein concentrations (50% of total protein given as casein and supplemented with 1% methionine) raised the true digestibility (TD) of the protein from 44 to 72%. The biological value (BV) of protein was generally high, with a mean of 91.7 N deficiency tended to increase and S deficiency tended to decrease the BV.     

Dietary fibre,sugar, starch and amino acid content of kale,ryegrass and seed of rape and field beans as influenced by S- and N-fertilization

In pot experiments, S-deficiency decreased the seed weight of rape from 4.30 to 2.44 g/1000 seeds at highest N-level. N/S ratios varied from 5.8 to 45.0 and from 3.7 to 21.6 in ryegrass and kale. S-deficiency tended to decrease the fat(oil) content. In kale and ryegrass, it was increased by N-applications, but decreased in rape. S-deficiency had very little effect on starch and sugar content, whereas N-deficiency in kale greatly increased starch (eightfold) and sugar content. Soluble (SDF) and insoluble dietary fibre (IDF) content was hardly affected by S-deficiency. In kale and ryegrass N-deficiency decreased SDF-content, but increased IDF-content. Cystine and methionine concentrations (g/16 g N) were affected by S-deficiency, most strongly at high N-levels, where decreases in kale, ryegrass, rape and field beans amounted to respectively 18,39,40 and 17% for cystine and 27,59,24 and 6% for methionine. Also, lysine, threonine and tryptophan were decreased. S-deficiency increased aspartic acid (asparagine) content of ryegrass (fourfold) and of arginine in rape and kale. In N-balance trials with rats, S-deficiency reduced the biological value (BV) of the protein of kale from 65 to 40 and of field bean seed from 70 to 61. Corresponding decreases in digestible energy (DE) were from 56 to 48 and from 82 to 78, respectively.     

Responses of Seed Yield and Quality to Nitrogen Application Levels in Two Oilseed Rape (Brassica napus L.) Varieties Differing in Nitrogen Efficiency

Abstract

The relationship between nitrogen efficiency (NE), defined as seed yield per unit nitrogen (N) application, and seed quality was examined in two oilseed rape (Brassica napus L.) varieties at 5 N application levels, 0.6, 3, 6, 12, 15 mmol L?¹, N₁, N₂, N₃, N₄ and N₅, respectively. Seed yield, oil yield and protein content were increased with the increase in N application level, but NE and oil content were decreased, and the fatty acid composition in seed was hardly changed. Analysis of seven fatty acids revealed aslight decrease in the contents of erucic acid and arachidonic acid with the increase in N application level, but no obvious change in the contents of palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid. Compared with the low NE variety H29, the seed yield and contents of erucic acid and arachidonic acid in the high NE variety bin270 were more markedly increased with the increase in N application level, and the oil content was hardly changed. The seed yield, oilcontent and oil yield were higher in the high NE variety than in the low NE variety at all 5 N application levels. There were no significant differences in protein, palmitic acid, stearic acid and oleic acid contents between the varieties at any of the 5 N application levels, but there were slight differences in the linoleic acid and linolenic acid contents between the two varieties. In brief, N application improved oil yield more greatly in the high NE variety than in the low NE variety, but hardly affected the fatty acid composition. Therefore, the seed quality and oil content of oilseed rape may not be decreased by breeding of a high NE variety with a high N absorption efficiency and high N use efficiency.     

Variation of the amino acid scores and of the nitrogen-to-protein conversion factors in barley grain as a function of nitrogen content as compared with wheat and rye

Barley grains (9 samples from 7 cultivars) with nitrogen contents (N) ranging from 1.45 to 4.01% of dry matter were analysed for their amino acid (AA) composition with high accuracy from six different hydrolysates per sample. AA levels in grain increased as linear functions ofN with correlation coefficients close to unity. A comparison with literature data confirmed that the AA composition of any grain sample of normal barley can be predicted from itsN for all phenotypes and genotypes. AAs in grain protein changed as hyperbolic functions ofN which increased for Phe, Pro and Glx but more or less strongly decreased for the other AAs. By plotting AA scores againstN, barley proteins were shown to be always richer than wheat and rye in Val and Phe + Tyr; sometimes richer than both other species forN<2 (Lys); 2.2 (Leu and Ile); 3.4 (Thr); sometimes intermediate to wheat and rye above the latterN values. They were also intermediate in sulphur AAs forN<1.9 and drastically poorer forN>1.9. However, they were richer than both other species in Trp forN>1.6. The hyperbolic variations of non-protein nitrogen and nitrogen-to-protein conversion factors were determined as a function ofN and also compared with those of wheat and rye.     

Use of regrowth for forage in seed crops of meadow fescue(Festuca pratensis Huds.)

Different procedures for autumn management in crops of Festuca pratensis grown for seed, in particular the possibility of combining seed production with the production of forage in autumn, were examined in eleven experiments conducted between 1993 and 1996 at various locations in south-east Norway. Methods without intensive use of regrowth, such a nitrogen (N) fertilizer application (40 Kg N ha^?1) on 10 the September, either separately or preceded by cutting on the same date, generally stimulated the subsequent number of reproductive tillers and seed yield compared with untreated plots (no N, no cuting). However, cutting before N fertilizer application on 10th September tended to have a nagative effect on seed yield in 1995–96, when a mild autumn was followed by a winter with extremely low temp ratures and no, or very little, snow cover. Maximizing regrowth, by the application of 80 kg N fertilizer ha^?1 immediately after seed harvest, never impaired seed yield when a forage harvest was taken on 10 September but did so in 1995–96, when a forage harvest was delayed to 10 October. Additional N (40 kg ^?1) after a forage harvest did not significantly affect seed yield, although negative and positive tendencies were observed after harvesting in September and October respectively. When forage harvesting was delayed from 10 September to 10 October, the average yields of dry matter (DM) increased, but the forage quality, especially the crude protein content, decreased. As a result of the high yields of DM obtained (on average 2250 kg ^?1 in September and 2610 kg^?1 in October), use of regrowth may be of essential economic value for seed growers of Festuca pratensis.     

Chemical analysis and nutritional assessment of the less known pulses,Vigna aconitifolia (Jacq.) Marechal andVigna vexillata (L.) A. Rich.

The seeds ofVigna aconitifolia andVigna vexillata were analysed for proximate composition, minerals, seed protein fractions, amino acids, fatty acids, and antinutritional factors. Both the pulses were found to be rich sources of proteins and minerals like Ca, Mg, Fe, Zn, and Mn.Vigna aconitifolia seeds exhibited fairly high levels of crude lipid. The most limiting essential amino acids in both the pulses were the sulphur-amino acids, cystine, and methionine. Threonine inV. aconitifolia and phenylalanine and tyrosine inV. vexillata occurred in higher quantities when compared with WHO/FAO requirement pattern. Oleic acid and palmitic acid inV. aconitifolia and linoleic acid and palmitic acid inV. vexillata lipids were found to be the predominant fatty acids. The tannin content of both the pulses was negligible compared with the domesticated legumes. The other antinutritional factors like total free phenols, L-DOPA and haemagglutinating activity were also analysed/assayed.     

Amino acid composition of sainfoin forage

The crude protein concentration, amino acid composition and protein quality of sainfoin (Onobrychis viciifolia) forage was compared to that of lucerne (Medicago sativa). The amino acid analyses showed that sainfoin contained higher amounts of lysine, histidine, proline, cystine, glycine, alanine, valine, leucine, tyrosine, phenylalanine and tryptophan than lucerne, whereas lucerne contained more aspartic acid, methionine and isoleucine than sainfoin; the limiting amino acid in both legumes was methionine. The protein score, an estimation of protein quality for nonruminants, was 68 for sainfoin forage and 71 for lucerne forage compared to 100 for an ‘ideal protein’. The similarity of protein quality of sainfoin forage to that of lucerne indicates that, where conditions permit, sainfoin could be grown for the production of protein as an alternative to other crops.     

The effect of dicyandiamide on pasture nitrate concentration,yield and N offtake under high N loading in winter and spring

High nitrate () concentrations in pastures and forages represent a health risk to grazing livestock. A field trial was conducted on the Lincoln University Dairy Farm, New Zealand, to investigate the effects of applying the nitrification inhibitor dicyandiamide (DCD) on soil extractable N and pasture concentrations in winter and spring. Treatments were control (T1), urea (T2), urea + DCD (T3), May urine + DCD (T4), August urine + DCD (T5), May urine (T6) and August urine (T7). Urine treatments were applied to the ryegrass‐white clover pasture in either May or August. The DCD treatments were applied at 10 kg DCD ha^?1 in May and August and urea at 25 kg N ha^?1 at selected intervals. Soil samples (0‐ to 75‐ and 75‐ to 150‐mm horizons) were taken regularly to monitor soil and ammonium () levels. Six pasture harvests were conducted from August 2007 to March 2008 and samples analysed for ‐N concentrations and total N content. Application of DCD significantly (P < 0·001) increased total dry‐matter (DM) production by 39 and 42% for the autumn and spring urine treatments, respectively, compared to the urine‐alone treatments. In addition, the application of DCD also significantly (P < 0·001) increased DM yield by 12% on the urea‐only treatment. DCD significantly (P < 0·001) reduced pasture concentrations in both autumn‐ and spring‐applied urine treatments where DCD was applied. This was directly linked to reductions in soil , and increases in soil , from DCD application. The preferential uptake by pasture for ‐N over ‐N may also have been a contributing factor. DCD application can therefore substantially reduce pasture ‐N concentrations to safe levels under high N‐loading (urine patch) conditions.     

Nutritional improvement of lentils,chick pea,rice and wheat by natural fermentation

Effect of natural fermentation process (4 days) on the non-protein nitrogen, crude and true protein, amino acids content and in vitro digestibility of two kinds of legumes (lentils and chick pea) and two kinds of cereals (rice and wheat) was investigated. Non-protein nitrogen increased significantly (p<0.001) in the fermented products. Little increase has occured in the crude protein while no significant change was observed in the fermented true protein samples. It was observed that methionine and cystine which are considered the limiting amino acids in legume seeds were close to those of FAO/WHO patterns. Also, lysine content (the first limiting amino acid in cereals was higher in fermented rice than that of FAO/WHO pattern. Moreover, fermentation process improved significantly, the in vitro digestibility of both legume and cereal products.     

Distribution of seed protein fractions and amino acids in different anatomical parts of chickpea (Cicer arietinum L.) and pigeonpea (Cajanus cajan L.)

Studies on protein fractionation in seed coat, embryo, cotyledons and whole seed were made to observe the differences, if any, between chickpea and pigeonpea. Results indicated that globulin was the major fraction of embryo and cotyledons of these legumes. Seed-coat nitrogen was observed to be mostly comprised of nonprotein nitrogen and glutelin fractions and thus differed from other components in both chickpea and pigeonpea. The albumin fraction of cotyledons of both crops had the highest concentration of sulphur amino acids, methionine and cystine. Glutelin contained a considerably higher concentration of methionine and cystine than did globulin in chickpea and pigeonpea. This suggests that lines with higher glutelin should be identified to improve their protein quality. The amino acid compositions of different seed components did not show large differences between these two pulse crops.Submitted as JA no. 180 by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).     

Effects of sulphur,nitrogen, phosphorus,potassium, and water stress on dietary fibre fractions,starch, amino acids and on the biological value of potato protein

In pot experiments with greatly differing rates of N, P, K, and S, and 3 levels of water, dry matter (DM) yields of tubers varied from 28 to 454 g/pot. Especially P-, K- and S-deficiency reduced the starch content of boiled potatoes, from P from 74 to 59% in DM. S-deficiency increased soluble, insoluble and total digestible fibre (TDF) from about 9 to 12.4% TDF in DM of boiled potatoes. Lignin content of fresh potato DM was increased from 0.7 to 2.0 and from 0.8 to 3.7% by P- and K-deficiency. P-deficiency considerably increased arabinose, galactose, and uronic acid, and decreased glucose content. N-application and P-, K- and S-deficiency increased total- and NO₃-N concentrations which varied from 1.32 to 3.67% and from 17 to 400 ppm in DM. Water stress slightly decreased total-N content. Increasing N in DM, due to high N-rates or P- or K-deficiency, decreased concentrations in crude protein (CP) of all essential amino acids, whereas aspartic acid (asparagine) increased. S-deficiency caused particularly strong decreases in concentrations of essential amino acids from 1.28 to 0.49, 1.62 to 1.10, 5.24 to 3.68, and 5.59 to 2.57 g/16 g N of cystine, methionine, lysine and leucine, respectively. Glutamic acid (glutamine) content was increased from 15.7 to 27.6 g/16 g N by S-deficiency. Expressed as g amino acid/kg DM, all amino acid concentrations increased with increasing % N in DM. In N-balance trials with rats, increasing crude protein concentrations in DM of boiled potatoes increased the true digestibility (TD) of the protein from 72 to 90 but decreased the biological value (BV) from 89 to 65. S-deficiency caused a further reduction of the BV to 45. Excluding S-deficiency treatments, linear regression equations between CP concentrations and BV and TD gave correlation coefficients r of –0.94*** and 0.82***, respectively. There was close agreement between changes of BV and concentrations of first limiting amino acids (chemical score), with r=0.96***.     

Studies on samh seeds (Mesembryanthemum forsskalei Hochst) growing in Saudi Arabia, 1: Anatomy of Samh Seed

The seeds of Samh (Mesembryanthemum forsskalei) are Ostensibly Campylatropous as they seem externally anatropous but internally they have a curved embryo and both the seed body and the funicle exchange shapes. The embryo occupies a cylindrical seed body and is surrounded by a thin layer of endosperm; the major part of the endosperm occupies an ovoid bulge resembling a seed body.     

Effect of N rate,timing and splitting and N type on bread-making quality in hard red spring wheat under rainfed Mediterranean conditions

Three different experiments were designed to study the effects of N fertilizer rate, timing and splitting, and the response to combined application of N and S fertilizer on the bread-making quality of hard red spring wheat (Triticum aestivum L.) over a 3-year period in Vertisols under rainfed Mediterranean conditions. The following parameters were analyzed: grain yield, test weight, grain protein content, gluten index and alveograph parameters (W: alveogram index; P: dough tenacity; L: dough extensibility; P/L: tenacity–extensibility ratio). The N rate experiment included rates of 0, 100, 150 and 200 kg N ha⁻¹ applied on four different sites. The experiment was designed as a randomized complete block with four blocks. For the experiment on N timing and splitting, a single rate of 150 kg N ha⁻¹ was used, different fractions being applied at sowing, tillering and stem elongation, at a single site; again, experimental design was a randomized complete block with four blocks. Finally, for the experiment on the response to combined application of N and S fertilizer, a single fertilizer dose of 150 kg N ha⁻¹ was applied in two forms (urea+ammonium nitrate and urea+ammonium nitrosulfate) with one leaf application at ear emergence (zero, 25 kg S ha⁻¹, 25 kg N ha⁻¹, $\text{25}\text{kg}\text{S}\text{ha}{}^{\mathrm{-1}}\text{+25}$ kg N ha⁻¹ and 50 kg N ha⁻¹), also at a single site, using a split-plot design with four replications. Year-on-year variation in rainfall led to marked variations in wheat yield, grain protein content and bread-making quality indices. A close correlation was observed between rainfall over the September–May period and both grain yield and grain protein content (optimum values for both being recorded in the rainfall range 500–550 mm) as well as the alveogram index. A negative correlation was observed between mean maximum temperatures in May and both test weight and alveogram index (W). N fertilizer rate had a more consistent effect on bread-making quality than on grain yield. The highest values for grain yield were recorded at an N rate of 100 kg ha⁻¹, while maximum grain protein content values were recorded at 150 kg ha⁻¹. Application of half or one-third of total fertilizer N at stem elongation improved grain yield and grain protein content with respect to applications at sowing alone or at both sowing and tillering. Increased N rates led to a considerable increase in W values and to a reduction in the P/L ratio, thus improving dough balance, with a negative effect on the gluten index. Leaf application of N at ear emergence only affected grain protein content and the W index. Soil or leaf application of S had no effect on protein quality indices. The response of grain yield and grain protein content to fertilizer N differed from that reported for temperate climates.     

Chemical composition and content of antinutritional factors in Polish cultivars of peas

The seeds of 15 Polish pea varieties contained from 221 to 281 g/kg crude protein with a mean of 240.2±3.5 g/kg dry matter (DM). The weight of 1000 pea seeds, depending on cultivar, ranged from 209.4 to 280.4 g. No interactive effect between the seed mass and the crude protein content was detected. The highest significant negative correlation between weight of seeds and dietary fiber content wasr=−0.815^XX. The content of dietary fiber ranged from 161.5 to 209.9 g/kg with a mean of 187.9±3.8 g/kg. The mean gross energy of seeds was 18.1±0.28 MJ/kg. Amino acid composition of all the cultivars was similar, which was indicated by a similar index of essential amino acids (EAAI) of about 69.7±0.25. Trypsin inhibitor content in seeds was from 2.83 to 7.32 TIU/mg and the content of phytates ranged from 6.32 to 13.36 mg/g DM. The mean content of polyphenols and flavanols in analysed pea cultivars was 0.92 amd 0.46 mg/g, respectively. In the seeds of most cultivars little or no pyrimidine glucosides, i.e. vicine and convicine, were found. The overall mean oligosaccharide content was 64.3±1.8 g/kg, of which α-galactosides were 46.8±2.0 g/kg. The antinutritional factor content was not significantly correlated with protein content. No statistical relationship was found between crude protein and dietary fiber content. It was observed that pea cultivars with higher trypsin inhibitor activity contained significantly less flavanols (r=−0.607^X) and α-galactosides (r=−0.617^X). The varieties with higher seed content of dietary fiber contained the highest amount of α-galactosides (r=0.514^X).     

Effects of Application of N,P And K Alone Or In Combination on Growth,Yield And Curcumin Content of Turmeric(Curcuma Longa L.)

Abstract

The effect of nitrogen (N) application rates at active tillering and anthesis on grain yield and protein content of a bread wheat cultivar, ‘Minaminokaori’, was examined in the field study conducted in Fukuoka, Japan. Number of spikes, leaf area index (LAI), and SPAD value at anthesis increased significantly (P < 0.05) with increasing N application rate at active tillering. Grain yield also increased significantly (P < 0.05) because of the increased number of spikes. However, grain yield did not increase significantly (P > 0.05) with increasing N application rate at anthesis. The slope of the relationship between N application rate at active tillering and grain yield was about 3 times that of the relationship between N application rate at anthesis and grain yield. These results indicate that N application at active tillering is more effective than N application at anthesis for increasing grain yield. Increasing N application rate at active tillering and anthesis generally increased grain protein content. However, the slope of the relationship between N application rate at anthesis and grain protein content was about 2 times that of the relationship between N application rate at active tillering and grain protein content. These results indicate that N application at anthesis is more effective than N application at active tillering for increasing grain protein content. The interaction between N application rates at active tillering and anthesis was significant (P < 0.05) for grain protein content. With the application of 4 g N m^–2 at active tillering, grain protein content increased linearly at a rate of about 0.5% per 1 g N m^–2 (from 10.9% to 14.0%) with increasing N application rate (from 0 to 6 g N m^–2) at anthesis. However, the rate of increase in grain protein content with increasing N application rate at anthesis was greater with 0 g N m^–2 at active tillering than that with 4 g N m^–2 at active tillering, whereas that with 8 g N m^–2 at active tillering was smaller than that with 4 g N m^–2 at active tillering. Application of 8 g N m^–2 at tillering resulted in the highest SPAD value at anthesis; this was followed by the results for 4 and 0 g N m^–2. Therefore, the SPAD value may be an important trait to decide N application rate at anthesis.     

Elevated methionine content in soybean seed by overexpressing maize β-zein protein

Soybean provides superior and readily available protein for human and livestock. However, nutritional value of soybean is limited due to the deficiency of an essential amino acid, methionine. To improve total methionine content of soybean, a methionine-rich seed storage protein, β-zein, was introduced into soybean cultivar ’Jack’ under the control of legumin B4 promoter or CaMV 35S promoter. Totally 4 T₃ transgenic lines exhibited higher expression levels of foreign genes, and legumin B4 promoter directed a stronger accumulation of β-zein protein than CaMV 35S promoter. Compared to wild type plant, total methionine content in transgenic soybean seeds significantly increased by up to approximately 15%. Although the introduction of β-zein gene improved total methionine content, the level was negligible compared to native soybean storage proteins, implying that the inadequate soluble methionine is the limiting factor. Based on these observations, a new strategy for simultaneously increasing the “source” and “sink” of methionine metabolism is proposed to further improvement of total methionine content in soybean seed.     

Soybean inoculation: Dose, N fertilizer supplementation and rhizobia persistence in soil

The effect of rate of application of Sinorhizobium (Ensifer) fredii SMH12 or Bradyrhizobium japonicum USDA110 inoculants on grain yields of soybean [Glycine max (L.) Merrill] cv. Osumi was studied in a field experiment laid out in Southern Spain. All inoculant doses tested (10⁴, 10⁵, 10⁶ and 10⁷ rhizobia/seed) produced higher seed yields than those obtained in un-inoculated plots. Increments in nodule dry weight, seed yield and seed N content were observed when the number of rhizobia applied to seed increased from 10⁴ up to 10⁷. The addition of N fertilizer to inoculated soybean plants (50 kg N/ha applied at R1 or R4 stage) did not increase seed yields in comparison with treatments that were only inoculated. Survival of strains SMH12 and USDA110 was monitorized for three years in two different soils of Southern Spain after soybean inoculation. Rhizobia survival was varied dependent on the soil and the rhizobia strain used.