Progress 09/15/02 to 09/14/06
Outputs
Low phytic acid (LPA) genotypes of wheat are one approach to improveing the nutritional quality of wheat by reducing the concentration of phytic acid in the aleurone layer, thus reducing the chelation of nutritionally important minerals and improving the bioavailability of phosphorus. Field studies were conducted at Aberdeen and Tetonia, ID in 2003 and 2004 to evaluate the effects of the LPA genotype on the agronomic performance of wheat. These studies included wild-type and LPA genotypes in hard red spring, hard white spring, and soft white spring wheat genetic backgrounds. In the hard red spring genetic background, LPA genotypes had delayed development and reduced grain yield (8 to 25%) in the high yield environment, in part due to reduced kernel size (up to 3 mg/kernel). In the hard white spring genetic background, differences in crop development and grain yield were not observed; however, in the high yield environment LPA genotypes produced smaller kernels (2.0 to
2.4 mg/kernel). In the soft white spring genetic background, LPA genotypes developed earlier, but grain yield of LPA genotypes was reduced 20-24% in the high yield environment. However, LPA kernels, on average, were heavier and larger in diameter than wild-type kernels. The absence of consistent effects of the LPA genotype across the three genetic backgrounds suggests that deleterious effects of the LPA genotype may be mitigated by plant breeding. Mineral concentrations also were determined. LPA selections had elevated concentrations of inorganic P and Mg in flour fractions. The concentration of inorganic P in LPA flour was 3 times the concentration in WT flour, and Mg concentration in LPA flour was 25% greater than in WT flour. Therefore, P and Mg in LPA wheat appear to be redistributed within the kernel. Milling and baking quality evaluations were conducted on hard red, hard white, and soft white spring wheat grain from field trials to evaluate the effects of the LPA genotype on the
end-use quality of wheat. In hard wheat backgrounds, the LPA genotypes were not associated with detrimental effects on flour protein concentration, dough mixing properties, or bread loaf volume. LPA wheats had consistent, substantial increases (up to 0.93 g/kg) in flour ash concentration relative to wild-type wheats. Higher flour ash in WT wheats is often a sign of higher aluerone and bran fragments which are visually evident in dulling of Asian noodles color. However, initial alkaline noodle brightness (L*= 86.8 to 87.5) from hard white LPA flours was at least as high as from hard white wild-type flours (L*= 86.1 to 87.9). LPA genotypes have demonstrated a significant redistribution of minerals from the bran to the endosperm; this redistribution of minerals most likely caused the increase in flour ash, rather than greater partitioning of bran into the flour. In the soft wheat background, LPA genotypes had greater sodium carbonate and sucrose SRC (31 and 43 g/kg greater than
wild-type, respectively), suggesting that LPA wheats milled with greater apparent starch damage and/or pentosan content than WT sib lines.
Impacts
The low phytic acid trait has the potential to improve the phosphorous economy for developed countries and the nutrition of people in the developing countries who have primarily grain based diets. The increased concentration of magnesium in the flour of low phytic acid wheats may be significant for US consumers. Magnesium deficiency in the US is linked to osteoporosis and juvenile onset of Type II diabetes. The positive effects of the low phytic acid trait on hard wheat dough rheology may also have benefits for the milling and baking industry. To meet the USDA recommendations for the daily servings of whole grain in the US diet, it will be increasingly important for industry to address some of the anti-nutritional aspects of bran in food products. Low-phytic acid wheat may be one approach to increasing bio-availability of minerals in the US diet when wheat bran is present.
Publications
- Guttieri, M.J., Peterson, K.M. and Souza, D.J. 2006. Milling and Baking Quality of Low Phytic Acid Wheat. Crop Sci. 46:2403-2408.
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Progress 01/01/05 to 12/31/05
Outputs
Low phytic acid (LPA) wheat is one approach to improving nutritional quality of wheat. LPA and wild-type (WT) sib selections of hard red spring wheat families with the pedigree Grandin*4/Js-12-LPA were grown in replicated field trials in 2003 and 2004. Grain was milled on an experimental mill, and the distribution of phosphorus, phytic acid P, and inorganic P was measured in milling fractions. Mineral concentrations also were determined. LPA selections had elevated concentrations of inorganic P and Mg in flour fractions. The concentration of inorganic P in LPA flour was 3 times the concentration in WT flour, and Mg concentration in LPA flour was 25% greater than in WT flour. Therefore, P and Mg in LPA wheat appear to be redistributed within the kernel. Field studies were conducted to evaluate the effects of the LPA genotype on the agronomic performance of wheat. In the hard red spring genetic background, LPA genotypes had delayed development and reduced grain yield in
the high yield environment, in part due to reduced kernel size. In the hard white spring genetic background, differences in crop development and grain yield were not observed; however, LPA genotypes produced smaller kernels. In the soft white spring genetic background, LPA genotypes developed earlier, but grain yield of LPA genotypes was reduced 20-24% in the high yield environment. However, LPA kernels, on average, were heavier and larger in diameter than wild-type kernels. The absence of consistent effects of the LPA genotype across the three genetic backgrounds suggests that deleterious effects of the LPA genotype may be mitigated by plant breeding.
Impacts
The low phytic acid trait has the potential to improve the phosphorous economy for developed countries and the nutrition of people in the developing countries who have primarily grain based diets. The increased concentration of magnesium in the flour of low phytic acid wheats may be significant for US consumers. Magnesium deficiency in the US is linked to osteoporosis and juvenile onset of Type II diabetes. The positive effects of the low phytic acid trait on hard wheat dough rheology may also have benefits for the milling and baking industry.
Publications
- No publications reported this period
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Progress 01/01/04 to 12/31/04
Outputs
The purpose of this grant was to evaluation the field and quality performance of paired wheat genetic stocks containing a low phytic acid trait using three sets of populations, hard red spring, hard white spring, and soft white spring wheat. We completed the second year of yield testing and quality evaluations of the first year of trials. In all populations we found a slightly delayed plant development in the low phytic acid genotypes, approximately 1 to 2 Zadoks stage at any given point in the development prior to anthesis. Plants mature at a similar time for both genotypes in all backgrounds. In the Grandin hard red spring wheat populations a 10% yield decrease was observed with the low phytic acid trait. In the hard white and soft white populations no yield decrease was observed. Two levels of expression were observed for the low phytic acid trait. We hypothesized from previous work that a minimum of two genes controls the trait. The presence of one gene for low
phytic acid conditions approximately 0.5 mg/g reduction in seed phytic acid. Two genes condition approximately 1.5 mg/g reduction. The low phytic acid trait does not seem to affect bread quality characteristics, but may elevate water absorption in soft wheat backgrounds. We are completing the analysis on the quality of the grain from the second year trials and will summarize them in the next year.
Impacts
We expect this work to lay the groundwork for feeding and genetic trials that will ultimately result in the use of low phytic acid wheat by US agriculture as one tool to manage animal nutrition and agricultural environmental impacts.
Publications
- No publications reported this period
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Progress 01/01/03 to 12/31/03
Outputs
The low phytic acid trait in wheat is designed to elevate the usable levels of phosphorous in the grain by suppressing the synthesis of low phytic acid. We have planted and harvested the first year of field trials to answer three hypotheses: I. That the lpa1-1 gene does not have detrimental effects on wheat yield. II. That the lpa1-1 gene does not have detrimental effects on milling into flour or on the flour quality. III. That the lpa1-1 gene does not alter the mineral composition of wheat and wheat flour. Field trials with three sets of genetic materials were used to test Hypothesis I. Milling and baking quality data from grain produced from the field trials be used to test Hypothesis II in the next year. Elemental analyses of milling streams from the Hypothesis II experiments will be used to test Hypothesis III. The three sets of genetic materials represent diverse genetic backgrounds: rain-fed hard red spring wheat, irrigated hard white spring wheat, and soft
white spring wheat.
Impacts
The first year of yield testing suggests that the first cycle of breeding materials carrying the low phytic acid trait have approximately 10% lower yield. This is similar to observations in other crops. However, subsequent selection has reduced the yield penalty for this trait. This suggest that the benefits of this trait will require one to two cycles of breeding to bring a commercially viable cultivar to the marketplace with the low phytic acid trait.
Publications
- Guttieri, M.J., Bowen, D., Raboy, V. and Souza, E. 2003. Low phytic acid wheat. Abstracts of the Annual Meeting of the Amer. Assoc. of Cereal Chem. Abstract No. 51, http://www.aaccnet.org/meetings/2003/abstracts/a03ma51.htm.
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Progress 01/01/02 to 12/31/02
Outputs
We have begun work on this project this fall by completing the characterization of genetic stocks to be used in field experiments. The segregation and characterization of the low phytic acid genetic stocks confirmed earlier segregation studies suggesting that the original phenotype obtained through mutagenesis is conditioned by two independent loci that act additively. The original mutation is transmitted to progeny and produces suppressed levels of phytic acid in the grain, elevating inorganic phosphorous levels in the endosperm and bran. We have completed the first steps of the grant to prepare material for planting in the spring 2003.
Impacts
This grant seeks to explore the utility of mutations that improve the level of phosphorous available to humans and most livestock. We anticipate the results of this research facilitating the use of this mutation in commercial production by American agriculture.
Publications
- No publications reported this period
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