High Protein Wheat Research Articles

A selection strategy for combining high grain yield and high protein content in South African wheat cultivars

Grain protein content is a major contributor to nutritional quality of wheat. Due to the negative relationship between yield and protein content, simultaneous improvement of these traits is very difficult. The aim of this study was to identify possible selection criteria to improve protein content and yield simultaneously. Six spring irrigated wheat cultivars were used as parent lines in a half diallel design. The F1 hybrid progeny and parents were used as experimental material. Both high and low protein wheat types translocated equal amounts of nitrogen to the grain. Phenotypic correlations re-emphasised the problems of simultaneous improvement of grain yield and protein content. The use of correlated response gave a better solution. If grain protein yield (highly significantly correlated with grain yield), was used as selection criterion, even protein per kemel showed a correlated response. It also had a relatively high narrow sense heritability. Grain protein yield selection therefore gave the only possible solution towards simultaneous improvement of grain yield, and grain protein content.

Sustaining productivity of a Vertisol at Warra, Queensland, with fertilisers, no-tillage or legumes. 2. Long-term fertiliser nitrogen needs to enhance wheat yields and grain protein

Cereal production in the summer-dominant rainfall region of Australia, especially the north-east, has relied heavily on natural soil fertility. Continued cereal production has so depleted the fertility of some soils that corrective strategies are required to restore the production of high protein wheat needed for domestic and export markets. Application of nitrogen (N) fertilisers, along with other strategies to improve soil N status, was evaluated between 1987 and 1994 on a Vertisol located in an area of unreliable winter rainfall. Responses of wheat grain yield and protein content to applied N (0-150 kg/ha) under zero tillage (ZT) and conventional tillage (CT) were determined each year, except 1991 when severe drought prevented wheat sowing. The ZT practices increased grain yields, particularly in 1988 and 1992-93 when antecedent soil water supplies were moderate (about 1 m wet soil in 1988 and 1992) or low (about 0.6 m wet soil in 1993), apparently due to increased antecedent soil water. Tillage practice had little effect on available nitrate-N (kg/ha) to 1.5 m, but the greater water supply in ZT soil usually benefited the wheat crop when N was applied. Applying N increased returns from 5 of the 7 crops because of grain yield and/or grain protein responses. Grain yield responses were inconsistent in the year of fertiliser application where no N fertiliser had been applied to preceding crops. Nevertheless, grain protein usually increased with increasing N application at sowing, except in 1994, when drought after sowing prevented secondary root development and fertiliser uptake. Where N was applied with each successive crop, the crops receiving small N applications (0, 12.5 or 25 kg/ha.crop) produced grain of a low protein concentration (<10%) and lower yields (<90% maximum yield) than crops which received larger N applications (75 kg/ha.crop). Profits were substantially reduced where the rate of N applied was insufficient to raise grain protein concentration to >11.5%, due to the low market value of low protein wheat, or because of lower grain yields. Routine N application to crops over the period 1987-94, which included the longest drought (1990-94) in the lifetime of most producers, caused similarly inconsistent grain yield increases but increased grain protein concentrations (>11.5%) in all except the first crop (1987). Increased frequency of high protein wheat and a high anticipated market value of the higher protein grain should encourage greater producer confidence with routine application of N throughout this region.

Production practices for high protein, hard wheat in Western Australia

Field experiments were conducted at 18 sites over 4 years in the eastern and north-eastern wheatbelt of Western Australia where average annual rainfall is <400mm, to investigate suitable techniques for the production of high protein (>13%) wheat in an area that traditionally produces grain of a much lower average protein percentage. Wilgoyne yielded as well as, or better than, any of the cultivars accepted into the Special Hard (SH) grade in Western Australia but 5-10% less than cultivars suitable for the Australian Standard White (ASW) grade. Differences between cultivars were greatest at the optimum sowing time in late May. Lower yields in early May were attributed to water stress during early growth or to frost damage during grain filling. The addition of nitrogen (N) fertiliser to crops sown after 1 June was less effective in increasing grain yield and grain protein than N added to earlier sowings. Most crops that produced >13% protein followed medic or field peas. The addition of N fertiliser was seldom required to produce this concentration of protein in crops that followed medic or peas. Crops following pasture with a low legume content or wheat had lower grain protein concentrations. Friable red-brown earth soils in a medic or pea rotation were able to achieve the required grain protein, but other combinations were not extensively tested. From these experiments, cultivars with inherently small grains due to their propensity to produce high levels of small grain screenings (whole grain through a 2-mm, slotted sieve) may be less able to increase yields economically by increasing kernel numbers per unit area under conditions in Western Australia.

Acid soil tolerances of wheat lines selected for high grain protein content

Abstract Literature suggests that nitrogen (N) metabolism is involved in differential acid soil (Al) tolerances among wheat (Triticwn aestivum L. en Thell) genotypes. Atlas 66 wheat is characterized by acid soil and aluminum (Al) tolerance, nitrate (NO3 ‐) preference, pH increase of the rhizosphere, high nitrate reductase activity, and high protein in the grain. Atlas 66 has been used as a high protein gene donor in the development of new high protein wheat lines at Lincoln, NE. The objective of our study was to determine the acid soil tolerances of such lines and to relate such tolerances to their abilities to accumulate grain protein when grown on near‐neutral, non‐toxic soils. Twenty‐five experimental lines, nine cultivars not previously classified as Al‐tolerant or ‐sensitive and three cultivars previously classified according to acid soil tolerance, were grown for 28 days in greenhouse pots of acid, Al‐toxic Tatum subsoil. Relative shoot dry weight (pH 4.35/pH 5.41%) varied from 83.2% for Atlas 66 to...

Protein isolate from an experimental high-protein wheat and flour

An experimental high-protein (25% protein, N×5.1 dry basis) spring wheat (ND 643) and flour from that wheat were used to make protein isolate by alkaline extraction. Optimal extraction of protein was at pH 10.1 in sodium hydroxide. The alkaline extract after centrifugation was adjusted to optimal pH of 6.2 to yield a precipitate and a supernatant. Bran was separated from starch by screening the second alkaline dispersion. The protein contents of the isolates from ground wheat and flour were 90 and 95%, respectively, and accounted for 65 and 68% of the total nitrogen of the starting wheat and flour

EXTRUSION COOKING OF SWEET POTATO ROOTS1

ABSTRACTAn extruded product was prepared using a mixture of sweet potato roots (SP), high protein wheat flour (WF), oil and water. The mixture was extruded in a Wenger X‐5 extruder. The best physical characteristics of the extruded product were obtained using drum dried baked sweet potato powder (DDSPP) and WF in the ratio of 3:1, oil content of 4.0% and an initial moisture content of 12.32%. This combination yielded a 4.33 fold expansion of the product. Physical measurements on the extruded product were: diameter, bulk density, expansion, and percent rehydration. The carotenoid content of the extruded product did not change considerably from that of DDSPP. The use of DDSPP: WF ratio of 3:1 represented 89.86% utilization of raw SP roots on a fresh weight basis.

YIELDS AND PROTEIN TRENDS OF SPRING WHEAT (Triticum aestivum L.) ON THE CANADIAN PRAIRIES, 1961–1982

Mathematical models of hard red spring wheat (Triticum aestivum L.) were used to account for effects of weather on annual variations in yield and protein content on the Canadian prairies. When weather effects were calculated, other relatively slow-changing trends became much clearer. Results indicate that yields in the three major soil zones have increased an average of 806 kg ha−1, while protein contents have decreased (1.0% from 1961 to 1982). Both trends show the largest change at the beginning of the period (1961) with a levelling off at the end (1982). There seems to be an inverse relationship between yield and protein, with technology contributing to yield increases and at the same time decreasing protein content by dilution although this was not conclusively proved. Decreases in soil organic matter or other soil factors may be contributing to the protein decline but these factors were not required to explain the observed patterns in yield and percent protein. The results indicated that the potential to produce high protein wheats has decreased during the period 1961–1982.Key words: Nonlinear fitting, physical model, technology effects, protein dilution

Nitrogenous compounds and protease activity in developing testapericarp and endosperm of high and low protein wheat (Triticum aestivum L.)

Nitrogenous compounds such as total protein, true protein, soluble protein, non-protein nitrogen, total amides, ammonium, nitrate, nitrite, free amino acids and neutral and acid protease activities were estimated in a high protein wheat cv Shera (12·8% protein) and a relatively low protein wheat cv C-306 (10·4% protein) at different stages of grain development. All the nitrogenous compounds studied, as well as protease activities, were located in both testa-pericarp and endosperm. Developmental patterns and relative levels were, more or less, similar when expressed on per organ basis, or on dry weight basis. In the testa-pericarp; dry weight, total protein, soluble protein, true protein, amide, ammonium, nitrate and nitrite contents increased during development, and were higher in Shera, compared with cv C-306. Non-protein nitrogen content decreased during pericarp development, and was higher in cv Shera, compared with cv C-306. Free amino acid content and protease activities decreased in developing pericarp, and were lower in cv Shera, compared with cv C-306. Similar developmental patterns and relative levels of nitrogenous compounds and protease activities were found in endosperm. It is suggested that both testa—pericarp and endosperm make qualitatively similar contributions to the accumulation of nitrogenous compounds in developing wheat grain; higher protease activity in the endosperm of C-306 is not responsible for lower protein accumulation, and nitrate and nitrite are assimilated mainly in the green pericarp of the wheat grain. It appears that differences in protein contents of Shera and C-306 wheat arise primarily from differences in translocation of nitrogenous solutes from the phloem sap to the peduncle and pericarp, enroute endosperm.

Relationship between kernel color and protein content of hard red x hard white winter wheat progeny

Utilization of high-protein hard red wheat germplasm in breeding high-protein hard white winter wheats for the U.S. Great Plains raised concern regarding possible genetic relationships between kernel color and protein content. Segregating F3 and F4 populations from reciprocal crosses and backcrosses involving high-protein hard red winter wheat cultivar Plainsman V and normal-protein hard white winter wheat line KS75216 were examined. Nonsignificant regression and correlation coefficients in the F3 generations of KS75216/Plainsman V, KS75216//KS75216/Plainsman V and Plainsman V//KS75216/Plainsman V indicated the absence of genetic relationships between kernel color and protein content. Therefore, despite the presence of genes for protein content and kernel color on the same chromosomes (3A, 3B and 3D), kernel color and protein content appeared as independent traits. A small but significant negative relationship between white kernel color and high protein in Plainsman V/KS75216 was attributable to the possible presence of alien genetic material in the parentage of Plainsman V. Chi-square tests indicated that Plainsman V is a mixture of genotypes for kernel color; most genotypes carry two dominant genes for red color and a few carry one or three. Genetic control of grain protein appeared to be complex. Partial dominance for high protein was indicated in the F3 generation but a generally continuous distribution and transgressive segregation also suggested other genes functioned additively. Heritability estimates by parent-offspring (F3-F4) regression were sufficiently high to ensure genetic progress in the selection of high-protein lines in the red x white wheat crosses. We concluded that development of high-protein cultivars is as feasible for white wheats as for red wheats.

Increasing grain protein content of hard red winter wheat (Triticum aestivum L.) by mutation breeding

Poor adaptability or functional quality of much germplasm used for breeding high-protein hard red winter wheats prompted mutagenesis as an alternative means of increasing grain protein content. Four hard red winter wheat genotypes - KS644 ('Triumph// Concho/Triumph'), 'Kaw', 'Parker', and 'Shawnee' - were treated with 0.40 M ethyl methanesulfonate (EMS). Advanced lines (M8-M10) were selected that had a 3-year mean grain protein advantage of 0.7% to 2.0% over controls. Increased grain protein content was generally associated with decreased grain yield and kernel weight, but some high-protein mutant lines had yields or kernel weights similar to those of original genotypes. Changes in height and lodging induced by EMS were generally favorable, most mutants being shorter and lodging less than controls, but blooming date was generally delayed, a deleterious change. One line also changed from resistant to segregating for wheat soil-borne mosaic virus. Mutant lines might be utilized in cross-breeding programs, particularly if negative pleiotropic effects and linkages are absent.

COMPARISON OF TOWER RAPESEED MEAL AND SOYBEAN MEAL IN DIETS BASED ON CONVENTIONAL AND HIGH-PROTEIN WHEAT WITH AND WITHOUT SUPPLEMENTAL LYSINE FOR BROILER CHICKS

Body weights and feed-to-gain ratios of chicks fed diets that contained Tower rapeseed meal or soybean meal with conventional (13.5%) or high-protein (21.0%) wheats with and without supplemental lysine were compared. High-protein wheat-rapeseed meal diets required lysine supplementation for optimal gain, whereas conventional protein wheat-rapeseed meal diets did not. However, with equal energy in the diets, the rapeseed meal diets did not support as low a feed-to-gain ratio as the soybean meal diets. Key words: broiler chicks, diets, rapeseed meal, soybean meal, wheat, lysine

Nitrogen uptake and redistribution in Karamu and other spring wheats

Abstract The growth and nitrogen status of Karamu wheat, a semi-dwarf breeding line, and two standard height cultivars were studied at three levels of applied nitrogen in controlled-environment rooms. Total grain N and grain N concentration were lower in Karamu than in the other cultivars at all levels of applied N. Both semi-dwarf wheats had smaller vegetative bulk and contained less herbage N at anthesis than the two standard height cultivars. The level of vegetative N at anthesis directly influenced the level of total protein accumulated in the grain, which suggested that the size of the vegetative bulk at anthesis could provide a possible criterion in breeding high yielding, high protein wheats.

Developmental Differences in Embryos of High and Low Protein Wheat Seeds during Germination

Developmental patterns of embryos from high and low protein wheat (Triticum aestivum) grain produced under varied fertilizer conditions were compared. High protein grain produced seedlings 25% heavier with 25% more total RNA, 30% more DNA, 40% more amino acids, 60% more ribosomes, and 80% more soluble protein content than that of low protein seed. Consistently higher glutamine synthetase and alpha-amylase and lower acid phosphatase activities were observed in high protein seeds, though the isozyme pattern of alpha-amylase was not different in the two kinds of seeds. The high total ribosomes and particularly, polysome content observed in high protein seeds may be responsible for the rapid growth and high yield of these seeds.

Protein and Lysine Contents of Endosperm and Bran of the Parents and Progenies of Crosses of Common Wheat1

Grain samples from parent and progeny rows of the common wheat (Triticum aestivum L.) crosses, ‘Nap Hal’/ ‘Atlas 66’ and Nap Hal/‘Super X’, were fractionated into their starchy endosperm and bran components to determine the within‐kernel site of their variation in protein and lysine concentration. Nap Hal and Atlas 66 are highprotein wheats. Nap Hal also has elevated grain lysine content. Super X has average protein and lysine content. Transgressive segregation existed both for high and low endosperm protein concentration among the F5 progeny rows of Nap Hal/Atlas 66. Low‐protein progeny rows had endosperm protein percentages that were 3 to 5 percentage points lower than the parental mean (19.5%). High‐protein progeny lines were 2 to 4 percentage points higher than the parental mean. Nap Hal and some of the progeny rows were 5 percentage points higher in bran protein content than Atlas 66. Endosperm and bran protein percentages of Nap Hal/Super X F4 progeny were within the parental range. Some progeny rows had endosperm and bran protein concentrations equal to those of Nap Hal. Variation among the progeny rows for endosperm and bran lysine (% of protein) concentrations was within the range of variability of the replicated parental rows. Variation for grain protein content among the progeny rows of both crosses was due to variation for both endosperm and bran protein content. Variation for grain lysine (% of sample) among the Nap Hal/Atlas 66 progeny rows was due primarily to variation in endosperm and bran protein content with endosperm and bran lysine (% of protein) being of lesser importance.

HIGH-PROTEIN WHEAT IN DIETS FOR LAYING HENS

High-protein wheat (21.0%) and regular-protein wheat (14.5%) were compared at two dietary protein levels with and without supplementary L-lysine. The diets were fed to White Leghorn laying hens maintained in floor pens for 44 wk. The addition of 0.3% L-lysine increased egg production from all diets, although the increase with the 17.4%-protein diet was not significant. L-lysine supplementation increased egg weight with the high-protein wheat diets but not with the regular wheat diets. Feed consumed per dozen eggs was lowest when hens were fed regular-protein wheat supplemented with L-lysine. L-lysine supplementation of the high-protein wheat in the 16%-protein diet reduced the amount of feed required per dozen eggs. Body weights of hens were not affected by L-lysine supplementation of the regular wheat diet; however, supplementation of the high-protein wheat diets resulted in increased body weights. The use of high-protein wheat in the diets that were not corrected for protein (i.e., 17.4%-protein diet) did not support high rates of lay, egg size, and body weight unless supplemented with L-lysine.

Completion of the set of amino acids contained in high-protein wheat through the addition of protein feeds and L-lysine to rations fed to laying hens

2 types of chick rations were fed to 8100 birds. A commercial type of food prepared on the basis of state-controlled standard formulas was used as control ration. The experimental food contained 84% of wheat; the proportion of protein feed in this ration had been reduced by 30%. The chick period was taken to last 8 weeks (controls and half of the experimental groups) or 12 weeks. Until the age of 8 weeks the growth rate of the control birds was by no means better than that of the experimental chicks (8.6 and 8.3 g per bird/day) although the control birds consumed more food (but same level of EFh consumption). At the age of 8 weeks the experimental birds were adjusted to a type of food fed to young hens. The apparently stress-induced lower level of food consumption of the experimental chicks in the period between the 9th and 12th week decreased the rate of weight gains and affected the whole analysis of data for the entire chick period ranging from 0 to 12 weeks (9.0 g per bird per day as compared to 9.6 g). This difference was compensated for in the further course of rearing. No significant differences in the demands for food, energy and crude protein were noticed until the age of 8 weeks. The mortality rates were the same in both groups (2.4% and 3.1%, alphaless than0.05). With regard to the criteria investigated the two rations appear to be equivalent. The 30% decrease in the proportion of protein feed may be regarded as being justified.

PERFORMANCE OF BROILER CHICKS FED TWO DIETARY PROTEIN LEVELS (18 AND 22%), TWO NEEPAWA WHEATS (14.5 AND 21.0% PROTEIN), AND SIX L-LYSINE LEVELS

Day-old male broiler chicks were fed 14.5 and 21.0% protein Neepawa wheats as ingredients in broiler diets to 4 wk of age. Two levels of dietary protein (18 and 22%) and six levels of added L-lysine HCl (L-lysine) (0.0, 0.06, 0.12, 0.18, 0.24, and 0.30%) were used with each wheat. The desired dietary protein contents were obtained by varying the proportions of the wheats and soybean meal. Body weights and feed-to-gain ratios were significantly affected by the three variables. Within the 18% protein diets, the diet containing 14.5% protein wheat and supplemented with at least 0.18% L-lysine gave maximal growth and most efficient feed conversion. Maximal growth was not obtained on any of the 18% protein diets with 21.0% protein wheat, regardless of L-lysine supplementation. With the 22% protein diets, L-lysine supplementation up to 0.24% of the diet improved the body weight and feed conversions of the chicks when the diet contained 21.0% protein wheat, and generally the results were not different from those obtained when the diet contained the 14.5% protein wheat. L-lysine supplementation of the 22% protein diet containing the 14.5% protein wheat did not significantly affect growth or feed conversion. High-protein wheat supplemented with adequate L-lysine can be fed to chicks and thereby substantially reduce the amount of supplemental protein required.

The substitution of protein feed by lysine supplemented high protein wheat during the rearing and laying period in hens. 9. True amino acid digestibility of rations with varying lysine levels in hens who had a colostomy

24 experimental birds were fed the same basal ration containing 74% high-protein wheat, 4% extracted soya bean meal, 7% extracted groundnut meal, 2% feed yeast, 1.75% dried green meal, 1.25% mixed vitamins and 10% of a mineral mixture. The birds were placed in 4 groups each comprising 6 hens. The first two groups received an optimum of lysine (0.68%) added to the ration. The rations for the two other groups contained 0.55% lysine. 6 birds of each group receiving either the lysinesupplemented or the unsupplemented rations were colostomated to investigate in which way the hydrolysed urine would affect the true amino acid digestibility. 8.3% of urinary N from the total amount of faecal N were precipitated as uranyl acetate in the faeces of hens fed the lysine-supplemented ration as compared with 7.3% urinary N in birds receiving the unsupplemented ration. The corresponding figures for non-precipitable faecal N were 8.9% and 8.2%. A comparison was made between the levels of amino acids excreted by colostomated and non-colostomated hens showing that 12.4% +/- 3% and 11.7% +/- 3% more amino acids (figures for the supplemented and unsupplemented rations) were excreted in the presence of urine. On the basis of these results the authors recommend that only colostomated hens should be used in digestibility and total metabolism trials.

Die Substitution von Eiweißfuttermitteln durch lysinergänzten proteinreichen Weizen während der Aufzucht und Legeperiode von Hennen

Digestibility trials were performed with laying hens receiving 3 types of rations containing equal proportions of the same dietary components. The percentage of high-protein wheat in these rations was 74%. Ration I was supplemented with 0.12% lysine while 0.06% lysine was added to ration II; ration III remained unsupplemented. The crude protein content of rations 1 to 3 was 16.1%, 16.5% and 16.6%, respectively. The corresponding lysine percentages were 0.66, 0.62 and 0.56. Studies were made to investigate the influence of different lysine levels on the rate of N excretion and various amino acid data. These studies were carried out during two successive laying periods. Only random differences between the data for urinary N excretion and N balances per kg liveweight were obtained in the two laying periods and for the different lysine levels. The true lysine digestibility was significantly lower in the poor-lysine ration as compared with the ration with 0.66% lysine. Moreover, the absorptive capacity for thio-amino acids is influenced by the lysine level of the ration. The proportion of lysine contained in faecal crude protein increased with the decreasing lysine content of the ration. Similarly, the total number of amino acids present in faecal crude protein increased with the declining supply of lysine. These findings suggest that relatively more NPN compounds are excreted in the faeces if adequate amounts of amino acids are supplied rather than when one amino acid is deficient.

FEEDING VALUE OF PURPLE 606-A, C. W. RED SPRING AND WHITE 607-A WHEAT CULTIVARS COMPARED TO CORN IN BROILER RATIONS

A factorial experiment (3 × 5) lasting 8 wk was conducted with Hubbard male broiler chicks to compare the nutritive value of rations containing three wheat cultivars, namely Purple 606-A, C. W. Red Spring and White 607-A, in five corn:wheat combinations in the respective proportions of 100:0, 75:25, 50:50, 25:75 and 0:100. Although the calculated crude protein and energy content of the rations were similar, body weight and feed efficiency of chickens were markedly influenced by two of the wheat cultivars studied and by the proportions of these cultivars in the rations. Performance of birds fed the rations based on White 607-A was similar to that of birds fed corn, even when wheat constituted the sole feed grain. By contrast, birds fed the rations based on Purple 606-A and C. W. Red Spring had significantly [Formula: see text] lower body weight and feed efficiency than those fed rations containing high proportions of corn or any of the rations based on White 607-A. The concentration of lysine and methionine in the high protein wheat cultivars (Purple 606-A and C. W. Red Spring) was markedly lower than that in White 607-A. Furthermore, amino acid analyses showed a greater content of nonprotein nitrogen in Purple 606-A and C. W. Red Spring as compared to White 607-A and corn. These observations suggest that the lower performance of chicks fed the high protein wheat rations may have been related to their amino acid profile as well as the greater amount of soybean meal needed to make the rations of equal crude protein content.