| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Dep. of Agronomy, Iowa State Univ., Ames, IA 50011. This journal paper of the Iowa Agric. and Home Econ. Exp. Stn., Ames, IA, Project No. 3732 was supported by the Hatch Act, State of Iowa, Iowa Soybean Promotion Board, Raymond F. Baker Center for Plant Breeding, and the United Soybean Board
* Corresponding author (wfehr{at}iastate.edu).
 |
ABSTRACT |
|---|
 TOPNOTES ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
|---|
Abbreviations: B019, B01769B019 • CX1834, CX1834-1-6 • CZE, capillary zone electrophoresis • LP, low phytate • NP, normal phytate
|
INTRODUCTION |
|---|
|
TOPNOTESABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
|---|
25% phytate P compared with 75% phytate P in normal soybean cultivars (Wilcox et al., 2000). Reducing phytate P and increasing inorganic P would increase the availability of P in the soybean meal fed to monogastric animals, reduce the amount of inorganic P added to their rations, and reduce the amount of P they excrete (Powers et al., 2007). The impact of the LP trait on agronomic and seed traits of soybean was evaluated by Meis et al. (2003). They studied lines with the mips allele that controls reduced phytate and reduced raffinose saccharides. They found that the LP lines had significantly lower seedling emergence than NP lines. The emergence of LP lines was significantly influenced by the environment in which the seed was produced for planting. Seed produced in subtropical environments had significantly lower emergence than seed produced in a temperate environment.
Oltmans et al. (2005) compared LP and NP lines derived from crosses between the LP line CX1834 and three NP cultivars. The LP trait in CX1834 was controlled by the pha1 and pha2 alleles (Oltmans et al., 2004). The LP lines had a mean seedling emergence across three Iowa locations of 45% compared with 68% for the NP lines. They did not find a consistent significant difference between the two types of lines for other agronomic and seed traits. Hulke et al. (2004) evaluated LP lines with the pha1 and pha2 alleles in comparison with NP lines from a backcross population that was developed by crossing CX1834 to the NP line B019 and backcrossing once to B019. They observed a mean seedling emergence of 65% for the LP lines and 87% for the NP lines averaged across three Iowa locations. Despite the lower emergence of the LP lines, their mean yield was not significantly different from the NP lines. They concluded that it should be possible to develop LP cultivars that yield as well as conventional cultivars, particularly if it is possible to minimize the reduction in seedling emergence of LP lines. One objective of our study was to evaluate if LP lines with normal seedling emergence could be obtained by incorporating the LP trait into a NP line through multiple backcrosses.
It would be desirable to be able to predict the seedling emergence of LP lines in the field through one or more laboratory tests. Meis et al. (2003) evaluated the effectiveness of four laboratory tests for predicting the field emergence of LP lines with the mips allele. They reported that the tetrazolium, warm germination, and cold vigor tests were not effective, but the accelerated aging test was useful for predicting field emergence. A second objective of our study was to evaluate the effectiveness of the warm germination, cold vigor, and accelerated aging tests for predicting the field emergence of LP lines with the pha1 and pha2 alleles.
|
MATERIALS AND METHODS |
|---|
|
TOPNOTESABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
|---|
The BC1F1 seeds were planted at Isabela during February 2002 and the plants were harvested individually. The BC1F1 plants had one of four genotypes for the pha alleles: Pha1Pha1Pha2Pha2, Pha1Pha1Pha2pha2, Pha1pha1Pha2Pha2, or Pha1pha1Pha2pha2. The desired genotype was Pha1pha1Pha2pha2 because it was the only one that could produce LP BC1F2 progeny. Eleven seeds from each BC1F1 plant were analyzed to identify those that had at least one LP seed, which indicated that the plant had the Pha1pha1Pha2pha2 genotype. The technique used for phytate testing was a modification of the procedure described by Wilcox et al. (2000). A seed was crushed and placed in a 12 by 75 mm glass tube. An aliquot of 1 mL of 12.5% (w/v) trichloroacetic acid and 25 mM magnesium chloride was added to the test tube to extract the inorganic P from the seed. A volume of 1 mL of Chen's reagent was added about 15 min after the trichloroacetic acid was added. Chen's reagent consisted of 1 vol 3 M sulfuric acid, 1 vol 0.02 M ammonium molybdate, 1 vol 10% (w/v) ascorbic acid, and 2 vol double-distilled water. The samples were allowed to stand for 15 min at room temperature. The solution became dark blue for a LP seed but remained clear or became light blue for a NP seed.
The seeds from heterozygous BC1F1 plants were planted at Ames in 2002 and the second backcross was made by crossing B019 as the female parent to BC1F2 plants. The BC1F2 plants used for crossing were identified with a number. At maturity, the BC2F1 seed and each BC1F2 plant used as a male was harvested. To determine the genotype of the BC1F2 plant, one seed from each plant was tested for phytate content. If the seed had LP, three more seeds from that plant were tested for phytate. If the four seeds had LP, the BC1F2 plant was considered to have the genotype pha1pha1pha2pha2 and the BC2F1 seeds that traced to that plant were saved.
The BC2F1 seeds were planted at Isabela, PR, during October 2002 and each plant was harvested individually. All the BC2F2 seeds from each BC2F1 plant were split with a razor blade into two pieces. About one-third of the seed was used for phytate testing and the remaining two-thirds with the embryonic axis was saved for planting. A total of 13 BC2F2 LP seeds and seeds of B019 were planted in January 2003 at Isabela and BC3F1 seeds were obtained.
All the BC3F1 seeds were planted in a greenhouse at Ames in 2003 and the seedlings were transplanted to the field at 6 plants m–1 in rows spaced 1.02 m apart. At maturity, the BC3F1 plants were harvested and threshed individually. The BC3F2 seeds from each plant were split and the part without the embryonic axis was tested for phytate and fatty ester content. The method of fatty ester analysis by gas chromatography was described by Hammond (1991). The LP seeds with low saturates (palmitate + stearate) were planted in October 2003 at the Illinois Crop Improvement Association research station at Ponce, PR. The BC3F2 plants were harvested and threshed individually.
A five-seed bulk from each BC3F2 plant was tested for fatty ester content and those with low saturates had five individual seeds tested for phytate content. A total of 27 BC3F2 plants were selected that had low saturates and LP, and 50 seeds from each of the selected plants were planted during January 2004 at Ponce at 6 seeds m–1. Two plots of 50 seeds each were planted of CX1834 and B019. The seedling emergence in each plot was determined by counting the number of plants that were harvested. All the BC3F3 plants from all the lines were harvested individually. For BC3F2:3 lines that had a seedling emergence of 75% or greater, five individual seeds from five plants were tested for phytate content. The BC3F2:3 lines that were homogenous for LP had five seeds tested from their remaining BC3F3 plants to identify all LP plants. A total of 285 plants that were homozygous for LP were selected for progeny testing.
The progeny test of the LP BC3F3 plants was grown at Ames during 2004. A 20-seed sample from each plant was retained for phytate testing and the remaining seeds were used to plant a two-row plot 2.74 m long at 20 seeds m–1. Seedling emergence was determined when plants were in the V3 stage when there were three nodes on the main stem with fully developed leaves (Fehr and Caviness, 1977). The seedling emergence of CX1834 was 53% and B019 was 80%. Lines that had a seedling emergence of 75% or greater were selected for phytate testing. For each of the 29 selected lines, one of the two rows was thinned to 18 plants to enhance seed production of each plant. To determine the inorganic P content of the selected lines, the 20 reserve seeds and 20 seeds of CX1834 and B019 were analyzed by Victor Raboy, USDA-ARS, Aberdeen, ID. The inorganic P contents were 3.58 g kg–1 for CX1834 and 0.19 g kg–1 for B019. For the 25 BC3F3–derived lines (family) with an inorganic P content of >2.0 g kg–1 and 75% or greater field emergence, six BC3F4 plants were harvested from the row that had been thinned. For each of the six plants, five individual seeds were tested for phytate. All of the BC3F4 plants were homozygous for LP.
During October 2004, each of the 25 BC3F3–derived families were planted in an experiment at Ponce to evaluate seedling emergence and to obtain seed for subsequent tests. CX1834, B019, and ‘IA3023’ were included in the experiment. IA3023 was used as a conventional NP cultivar with a maturity similar to that of the BC3F3–derived families. The experimental design was a randomized complete-block design with five replications. Each replication of the BC3F3–derived families was planted with 100 seeds from a different BC3F4 plant that traced to that family. Each plot was a single row 3.66 m long. The percentage of seedling emergence of all plots was determined 14 d after planting. The mean seedling emergence was 90% for CX1834, 91% for B019, and 87% for IA3023. The reduction in seedling emergence observed for CX1834 at Ames did not occur in this environment. Only the 18 BC3F3–derived families that had a mean seedling emergence of 86% or greater were selected for harvest. For each selected family, the two replications of their BC3F4:5 progeny with the highest emergence were threshed individually with a stationary bundle thresher. The plots of CX1834, B019, and IA3023 also were harvested. For each BC3F4:5 line, five individual seeds were tested for phytate content and a five-seed bulk was tested for fatty ester content to confirm that they had LP and low saturates.
Field Test
The 36 BC3F4:6 lines were evaluated at six locations for seedling emergence and at five locations for seedling emergence and agronomic and seed traits. The experiment had 40 entries, which included the 36 lines, two entries of CX1834, and one entry each of B019 and IA3023. All of the locations used for the experiment were planted with the seed harvested from the October 2004 planting at Ponce. A randomized complete-block design with two replications was used for each location.
The first field test was planted at Ponce on 28 Jan. 2005. The soil type is a San Antón sandy clay loam (fine-loamy, mixed, superactive, isohyperthermic Cumulic Haplustoll). For each entry, 200 seeds were planted in a single row 7.62 m long. Seedling emergence was determined 21 d after planting. Yield, maturity, lodging, and plant height were not measured because growth of plants at Ponce is not representative of that in Iowa. At maturity, each plot was harvested in bulk with a stationary bundle thresher.
In the summer of 2005, the experiment was planted at Ames, Carlisle, Lewis, Osceola, and Ottumwa, IA. The soil type at Carlisle is a Tama silty clay loam (fine-silty, mixed, superactive, mesic Typic Agriudoll), at Ames is a Nicollet loam (fine-loamy, mixed, mesic Aquic Hapludoll), at Lewis is a Marshall silty clay loam (fine-silty, mixed, mesic Typic Hapludoll), at Osceola is a Grundy silty clay loam (fine, smectitic, mesic Aquertic Arguidoll), and at Ottumwa is a Coppock silt loam (fine-silty, mixed, mesic Mollic Endoaqualf). The plots were two rows 3.05 m long with spacing of 0.69 m between rows within a plot and 1.02 m between rows of adjacent plots. The seeding rate was 30 seeds m–1. The planting dates were 2 May at Ames, 3 May at Carlisle, 4 May at Ottumwa, 6 May at Lewis, and 10 May at Osceola.
Data were collected on all plots at all locations for seedling emergence, plant height, lodging, seed yield, seed size, and protein, oil, and fatty ester content. Maturity was recorded at Ames and Carlisle. Seedling emergence was determined by counting the number of plants in each plot at the V3 stage. Maturity was recorded as days after 31 August when 95% of the pods in a plot had reached their mature color. Plant height was measured as the distance from the soil surface to the terminal node on the main stem. Lodging was determined at maturity on a scale of 1 (all plants erect) to 5 (all plants prostrate). The plots were harvested with a self-propelled plot combine (Almaco, Nevada, IA) at all of the locations, except Ames. A stationary bundle thresher was used at Ames to avoid any seed mixture among plots. The weight and moisture content of the seed was determined and seed yield was expressed on a 13% moisture basis. Seed size was obtained by weighing 200 random whole seeds from each plot. Protein, oil, and moisture were measured on a 300-g sample with a near-infrared transmission spectrometer (Tecator AB, Hooganas, Sweden). Protein and oil content was determined on a 13% moisture basis. Fatty ester content was measured on a five-seed bulk sample by gas chromatography.
The data for each trait at the Iowa locations were analyzed as a randomized complete-block design by the linear model procedure of the SAS statistical software (release 8.02) (SAS Institute, 2001). The field emergence in Puerto Rico was 85% for CX1834, 74% for B019, and 92% for IA3023. The normal emergence of CX1834 prevented any meaningful assessment of differences in field emergence among the backcross lines in that environment and the data were not included in the analysis of variance. Environments and replications within environments were considered random effects and genotypes were considered fixed effects. An F-test was used to determine significance of main effects. The environment x main effect interactions were used to test the main effects across environments. The CORR procedure of SAS statistical software was used to calculate phenotypic correlations among traits.
Phytate Phosphorus and Inorganic Phosphorus Tests
Phytate P and inorganic P content were analyzed in duplicate with the seed harvested from the two replications at Ames in 2005. A sample of 100 seeds was ground to pass through a 1-mm screen using a UDY Cyclone sample mill (UDY Corporation, Fort Collins, CO). Phytate P was determined by capillary zone electrophoresis (CZE) as described by Nardi et al. (1992) and refined by Joel D. Nott of the Protein Facility at Iowa State University. A 20-mg sample of ground seed was weighed, placed in a scintillation vial, and extracted in 10 mL of 0.5 mM L-aspartic acid. The solution was stirred at room temperature for 20 min with a magnetic stir plate. Following extraction, a 750-µL sample was placed in a 0.22 µm Spin-X centrifugal filter (Costar Corning, NY), and centrifuged with a benchtop microfuge for 10 min. A 250-µL aliquot of the filtered sample was loaded on a 96-well plate and analyzed with a Beckman-Coulter P/ACE MDQ capillary electrophoresis system (Fullerton, CA).
Capillary zone electrophoresis was performed with a fused silica FS-175 capillary (31.2 cm by 75 µm i.d., capillary length to detector of 21.0 cm) obtained from Upchurch Scientific (Oak Harbor, WA). The chemicals used were benzoic acid, phytic acid, phosphoric acid, and hexadecyltrimethylammonium bromide (CTAB) from Sigma-Aldrich (St. Louis, MO) and L-aspartic acid, L-histidine, potassium phosphate, sodium hydroxide, and hydrochloric acid from Fisher Scientific (Fair Lawn, NJ).
Capillary zone electrophoresis was run using reverse polarity (detector side was positive) at ambient temperatures with indirect UV detection at 254 nm. To overcome the electroosmotic flow, a 1.0 mM solution of CTAB was used to coat the capillary before running the samples (Janini et al., 1993). The running buffer–background electrolyte used was 50 mM benzoic acid adjusted to pH 6.3 with 90 mM of L-histidine (Schöppenthau et al., 1996). The run conditions for the CZE were as follows. The capillary was rinsed with 1 mM CTAB for 1 min at 20 psi followed by a 1-min rinse at 20 psi with running buffer. Samples were injected using reverse polarity at 7 kV for 5 s. The ions were separated using reverse polarity at 14 kV for 5 min. Detection of the ions was done indirectly at 254 nm by reversing the polarity of the detector. After every 20 injections, the capillary was regenerated by rinsing it with 1 M hydrochloric acid for 5 min, distilled water for 2 min, 0.1 M sodium hydroxide for 10 min, distilled water for 3 min, 1 mM CTAB for 5 min, and background electrolyte for 5 min. All rinses were done at 20 psi.
The internal calibrant used for CZE was 0.5 mM L-aspartic acid. From the CZE data, a ratio of phytic acid to L-aspartic acid was determined by dividing the corrected peak area for phytic acid by the corrected peak area for L-aspartic acid. Standards of phytic acid (0 mM to 0.020 mM) were run and a standard curve of phytic acid/L-aspartic acid was generated. From this curve, the phytic acid of all the test samples was determined.
The method used to quantify inorganic P was a modification of the technique described by Chen et al. (1956). A 0.5-g sample of ground seed was extracted in 20 mL of 12% trichloroacetic acid that contained 0.2 M magnesium chloride. The samples were stirred overnight at 4°C. Following extraction, the samples were centrifuged for 20 min. A volume of 100 µL of the aqueous solution was added to 3.9 µL of double-distilled water and 4 mL of Chen's reagent was added to the solution. Samples were allowed to stand for 2 h at room temperature and were analyzed at 820 nm on a Varian Cary 50 Bio UV-Visable spectrophotometer (Palo Alto, CA).
The data for phytate P and inorganic P were analyzed as a randomized complete-block design by the linear model procedure of the SAS statistical software (release 8.02) (SAS Institute, 2001). Replications were considered random effects and genotypes were considered fixed effects. An F-test was used to determine the significance of the main effects. The CORR procedure of SAS statistical software was used to calculate phenotypic correlations between the traits.
Germination Tests
The lines used to evaluate the effectiveness of laboratory germination tests for predicting field emergence included the eight BC3F4–derived lines with a mean field emergence equal to or greater than B019 at the five Iowa locations, seven BC3F4–derived lines with lower field emergence than B019, two entries of CX1834, and one entry each of B019 and IA3023. The 19 entries were evaluated with a warm germination, cold vigor, and accelerated aging test at the Iowa State University Seed Science Center. Each test was conducted with two replications of 100 seeds for each entry in a randomized complete-block design. Each replication of a test was conducted in a separate germination cart. The seed used for the study was from one replication of the entries harvested at Ames in 2005.
The warm germination test was conducted by planting each entry on a fiberglass food service tray that measured 45 by 66 cm. Two sheets of 12-ply Versa-Pak (National Packing Services Corp., Green Bay, WI) were moistened with 825 mL of water and placed on a tray (AOSA, 2004). The 100 seeds of four entries were planted on top of the Versa-Pak and the trays were placed in a germination cart. The germination cart was 0.5 m wide by 0.7 m deep by 1.6 m high. The cart was made of aluminum, except for the back that was made of Plexiglas to allow light penetration. Each cart was placed in a growth room at 25°C for 7 d. The evaluation of seeds for germination was based on standards provided by the Association of Official Seed Analysts (AOSA, 2005).
For the cold test, one sheet of 12-ply Versa-Pak was placed on a tray, moistened with 1.1 L of water, and placed in a growth room overnight at 10°C. The 100 seeds of each of four entries were planted on a tray. After planting, each tray was covered with a mixture of 1:4 soil/sand to a depth of 2.54 cm and placed in a germination cart. The carts were placed in a growth room at 10°C for 7 d, after which the carts were moved to a growth room at 25°C for 7 d (AOSA, 2002). Germination percentages were determined based on standards provided by the Association of Official Seed Analysts (AOSA, 2005).
The accelerated aging test began by placing 42 g of seed from each entry in a wire basket. The wire basket was placed over 40 mL of distilled water in an acrylic box and covered. The boxes were placed in a chamber at 41°C for 72 h (AOSA, 2005). After 72 h, the 100 seeds of each of four entries were planted on two layers of Versa-Pak that had been moistened with 825 mL of water and placed on a tray. After planting, each tray was covered with 13 mm of moist sand and placed in a germination cart. The carts were put in a growth room at 25°C for 7 d, after which germination was evaluated as described by the Association of Official Seed Analysts (AOSA, 2005).
The data for each germination test were analyzed as a randomized complete-block design by the linear model procedure of the SAS statistical software (release 8.02) (SAS Institute, 2001). Replications were considered random effects and genotypes were considered fixed effects. An F-test was used to determine significance of main effects. The CORR procedure of SAS statistical software was used to calculate phenotypic correlations among traits.
|
RESULTS AND DISCUSSION |
|---|
|
TOPNOTESABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
|---|
|
Warm germination, cold vigor, and accelerated aging tests were conducted to determine their effectiveness in predicting the field emergence of LP lines. All of the tests were effective in predicting the reduced emergence of CX1834. The reduced germination of the line was associated with seed decay due to infection of seed storage fungi. The same infection was not observed for B019 and IA3023 when planted on the same germination trays. Seeds of backcross lines that failed to germinate also were infected by seed storage fungi. The susceptibility of CX1834 to infection by seed storage fungi may account in part for its reduced field emergence.
The three tests differed in the mean germination percentages of the backcross lines and their phenotypic correlations with field emergence (Table 1). The backcross lines had a mean germination of 79% in the warm germination test, 72% in the cold vigor test, and 65% in the accelerated aging test. The phenotypic correlation of field emergence with the warm germination test of 0.49 was not significant (P > 0.05), but the correlation of 0.82 for the cold vigor test and 0.66 for the accelerated aging test was significant (P < 0.01). Of the four lines with <60% field emergence, two were among the five lines with the lowest percentages in the warm germination test, all of them were included in the poorest five lines for the cold vigor test, and two of them were the poorest in the accelerated aging test. The three tests were equal for identifying the lines with the best field emergence. Of the four lines with >70% field emergence, only two of them were among the best lines in each of the three tests. The results indicated that either the cold vigor or accelerated aging tests could be used to discard inferior lines, but neither test could replace field evaluation for identifying the lines with the best emergence.
There were 34 of the 36 backcross lines not significantly different than B019 in seed yield. Of the eight lines with field emergence equal or better than B019, none of them were significantly different than B019 in yield. This result supported the conclusion of Hulke et al. (2004) that the LP trait per se when controlled by the pha alleles does not adversely affect seed yield.
The majority of the backcross lines were not significantly different than B019 in maturity, lodging, height, seed weight, protein content, and oil content (Table 1). The results indicated that the LP trait should not adversely affect the development of cultivars comparable to conventional ones for those traits.
The majority of the backcross lines had significantly higher saturates than B019 (Table 1). The increased saturates were due to greater palmitate and stearate in the backcross lines than in B019, which can be attributed to the significantly greater content of the two fatty acids in CX1834. The saturate content of the oil is critical if the intent is to label it as low in saturated fat in accordance with requirements of the U.S. Food and Drug Administration. A liquid oil must have <1.25 g in a 14-g serving (<89 g kg–1) to be designated as a low-saturate oil (U.S. FDA, 1999). Soybean oil contains 10 g kg–1 of saturated fatty acids other than palmitate and stearate (Hulke et al., 2004). Consequently, the content of palmitate and stearate should not exceed 79 g kg–1 and preferably should be less than 75 g kg–1 to take into account possible environment effects on fatty acid content and the possibility of comingling with conventional soybeans during commercial production. There were 13 of the backcross lines that had 75 g kg–1 or less saturates. This was an improvement over the LP lines evaluated by Hulke et al. (2004) that had a mean of 83 g kg–1 saturates, with the best line containing 78 g kg–1 saturates. Our results indicated that it should be possible to develop LP lines with acceptable saturate content. The low-saturate lines used for crossing in the breeding program should contain as little palmitate + stearate as possible to maximize the frequency of acceptable segregates.
There was significant variation among the backcross lines for oleate, linoleate, and linolenate content (Table 1). It should be possible to develop LP cultivars that are similar to low-saturate cultivars for these fatty acids.
|
ACKNOWLEDGMENTS |
|---|
|
NOTES |
|---|
|
TOPNOTESABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
|---|
Received for publication September 20, 2006.
|
REFERENCES |
|---|
|
TOPNOTESABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTS AND DISCUSSIONREFERENCES |
|---|
This article has been cited by other articles:
|
|
 |
|
  J. D. Gillman, V. R. Pantalone, and K. Bilyeu The Low Phytic Acid Phenotype in Soybean Line CX1834 Is Due to Mutations in Two Homologs of the Maize Low Phytic Acid Gene The Plant Genome, July 1, 2009; 2(2): 179 - 190. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A.M. Scaboo, V.R. Pantalone, D.R. Walker, H.R. Boerma, D.R. West, F.R. Walker, and C.E. Sams Confirmation of Molecular Markers and Agronomic Traits Associated with Seed Phytate Content in Two Soybean RIL Populations Crop Sci., March 17, 2009; 49(2): 426 - 432. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Gao, R.M. Biyashev, M.A. S. Maroof, N.M. Glover, D.M. Tucker, and G.R. Buss Validation of Low-Phytate QTLs and Evaluation of Seedling Emergence of Low-Phytate Soybeans Crop Sci., July 1, 2008; 48(4): 1355 - 1364. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. P. Anderson and W. R. Fehr Seed Source Affects Field Emergence of Low-Phytate Soybean Lines Crop Sci., May 1, 2008; 48(3): 929 - 932. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. D. Bilyeu, P. Zeng, P. Coello, Z. J. Zhang, H. B. Krishnan, A. Bailey, P. R. Beuselinck, and J. C. Polacco Quantitative Conversion of Phytate to Inorganic Phosphorus in Soybean Seeds Expressing a Bacterial Phytase Plant Physiology, February 1, 2008; 146(2): 468 - 477. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Vadose Zone Journal | |||
| Journal of Natural Resources and Life Sciences Education |
Soil Science Society of America Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||
