HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (20) Citing Articles via Google Scholar Google Scholar Articles by Ross, A. J. Articles by Cianzio, S. R. Search for Related Content PubMed Articles by Ross, A. J. Articles by Cianzio, S. R. Agricola Articles by Ross, A. J. Articles by Cianzio, S. R.

CROP BREEDING, GENETICS & CYTOLOGY

Agronomic and Seed Traits of 1%-Linolenate Soybean Genotypes

^a Dep. of Agronomy, Iowa State Univ., Ames, IA 50011 USA

wfehr{at}iastate.edu

	ABSTRACT

TOP NOTES ABSTRACT INTRODUCTION Materials and methods Results and discussion REFERENCES

 
An oil from soybean [Glycine max (L.) Merr.] cultivars with <20 g kg^-1 linolenate would have a desirable oxidative stability. The objective of our study was to compare the agronomic and seed traits of lines with the genotype fan1(A5)fan1(A5)fan2(A23)fan2(A23)fan3fan3, designated as 1%-linolenate (<20 g kg ^-1) lines, and the genotype fan1(A5)fan1(A5)fan2(A23)fan2(A23), designated as 2%-linolenate lines (>20 g kg^-1). Three backcross populations were developed by crossing three high-yielding, recurrent parents with 25 g kg^-1 linolenate to a donor line with 13 g kg^-1 linolenate. For each population, 27 1%- and 27 2%-linolenate BC₁F_2:4 lines were evaluated at Ames, Grand Junction, and Hubbard, IA during 1998. The mean seed yields of the 1%-linolenate lines were 47 kg ha^-1 lower in Population 1, 65 kg ha^-1 lower in Population 2, and 164 kg ha^-1 lower in Population 3 than the 2%-linolenate lines, but the difference was only significant in Population 3. The maximum mean differences between the 1%- and 2%-linolenate lines in any of the populations for the remaining agronomic and seed traits were 1 d for maturity, 0.1 score for lodging, 2 cm for plant height, 4 mg seed^-1 for seed weight, 5 g kg^-1 each for protein and oil content, 0.6 g kg^-1 for palmitate, 2.2 g kg^-1 for stearate, 16.4 g kg^-1 for oleate, and 6.8 g kg^-1 for linoleate. The lack of major differences between the 1%- and 2%-linolenate lines indicated that it should be possible to develop acceptable cultivars with <20 g kg^-1 linolenate.

	INTRODUCTION

TOP NOTES ABSTRACT INTRODUCTION Materials and methods Results and discussion REFERENCES

 
SOYBEAN OIL with reduced linolenate has oxidative stability superior to that of conventional soybean oil (Liu and White, 1992; Mounts et al., 1994; Shen et al., 1997). The improved oxidative stability of reduced-linolenate oil may diminish the need for partially hydrogenating conventional soybean oil for some food products.

Soybean cultivars with 28 g kg^-1 linolenate in the seed oil have been developed jointly by Iowa State University and Pioneer Hi-Bred International, Inc. The cultivars have the genotype fan1(A5)fan1(A5)fan2(A23)fan2(A23) for reduced linolenate (Hammond and Fehr, 1983; Fehr et al., 1992; Fehr and Hammond, 1996). A fan3 allele for reduced linolenate was developed by treating seeds of the line A89-144003 with ethyl methanesulfonate (Fehr and Hammond, 1998). By hybridization and selection, three alleles for reduced linolenate, fan1(A5), fan2(A23), and fan3, were combined in a line A29 that has 13 g kg^-1 linolenate in the seed oil.

The agronomic and seed traits of soybean lines with the fan1(A5)fan1(A5)fan2(A23)fan2(A23)fan3fan3 genotype have not been evaluated. Wilcox et al. (1993) reported that lines with the fan1 allele and 40 g kg^-1 linolenate did not exhibit negative associations with agronomic and seed traits that would preclude the development of cultivars with reduced linolenate. Walker et al. (1998) evaluated the performance of soybean lines with the fan1(A5)fan1(A5)fan2(A23)fan2(A23) genotype and found that the associations of reduced linolenate with seed yield, seed weight, and palmitate and oleate contents were not consistent among the three populations. The objective of this study was to determine the influence of <20 g kg^-1 linolenate controlled by the genotype fan1(A5)fan1(A5)fan2(A23)fan2(A23)-fan3fan3 on the agronomic and seed traits of soybean.

	Materials and methods

TOP NOTES ABSTRACT INTRODUCTION Materials and methods Results and discussion REFERENCES

 
Three backcross populations were developed with the donor parent A29 that had the fan1(A5)fan1(A5)fan2(A23)-fan2(A23)fan3fan3 genotype and three high-yielding recurrent parents with the genotype fan1(A5)fan1(A5)fan2(A23)fan2(A23). The recurrent parents YB25K and XB280 of Maturity Group II and 93B52 of Maturity Group III were developed jointly by Iowa State University and Pioneer Hi-Bred International, Inc. and had 25 g kg^-1 linolenate.

The crosses between A29 and the three recurrent parents were made in March 1996 at the Iowa State University–University of Puerto Rico soybean breeding nursery in Isabela, Puerto Rico. The cross YB25K x A29 was designated as Population 1, XB280 x A29 as Population 2, and 93B52 x A29 as Population 3. The BC₁F₁ seeds were obtained for each population at the Agronomy and Agricultural Engineering Research Center of Iowa State University near Ames, IA in July 1996 by crossing the F₁ plants to the recurrent parent. In October 1996, the BC₁F₁ seeds from each population were planted in Puerto Rico and each plant was harvested individually. A total of 1176 BC₁F₂ seeds from Population 1, 398 BC₁F₂ seeds from Population 2, and 545 BC₁F₂ seeds from Population 3 were split into two portions with a razor blade. The one-third portion that lacked the embryonic axis was used for fatty ester analysis by gas chromatography as described by Hammond (1991). The two-thirds portion that contained the embryonic axis was retained for planting. The BC₁F₂ seeds with the lowest and highest linolenate contents from each population were planted in Puerto Rico in January 1997 and the plants were harvested individually. A bulk of five random BC₁F_2:3 whole seeds was analyzed from each plant. The 50 BC₁F₂ plants in each population with the lowest linolenate content were designated as 1%-linolenate lines (9–17 g kg^-1) and the 50 plants with the highest linolenate content as 2%-linolenate lines (19–29 g kg^-1).

In 1997, the 50 1%-linolenate lines and 50 2%-linolenate lines from a population as well as 10 check cultivars and lines were grown as a set in a randomized complete-block design with two replications at two locations near Ames, IA. The entries in each of the three sets were planted in single-row plots 76 cm long with a spacing of 102 cm between rows and a 107-cm alley between the ends of plots. The seeding rate was 20 seeds per plot. Each plot was evaluated for maturity, harvested in bulk, and analyzed for fatty ester content. From the lines with similar maturities in each population, the 27 with the lowest linolenate and the 27 with the highest linolenate content were selected for the experiment.

Each population was evaluated as a separate experiment in 1998 that included 27 1%-linolenate lines, 27 2%-linolenate lines, and six check cultivars and lines. Each experiment was planted in a randomized complete-block design with two replications at Ames, Hubbard, and Grand Junction, IA. The soil types were a Nicollet loam (fine-loamy, mixed, superactive, mesic Aquic Hapludoll) at Ames and Grand Junction, and a Harps loam (fine-loamy, mixed, superactive, mesic Typic Calciaquoll) at Hubbard. The plots were two rows 3.1 m long with a spacing of 69 cm between the two rows of a plot and 102 cm between adjacent plots. The seeding rate was 29 seeds m^-1 of row. Each plot was evaluated for seed yield; maturity; lodging; plant height; seed weight; and protein, oil, and fatty ester content. Maturity was recorded as days after 31 August when 95% of the pods had reached their mature color. Lodging was scored at maturity on a scale of 1 (all plants erect) to 5 (all plants prostrate). Plant height was measured at maturity in centimeters from the soil surface to the terminal node. The plots were harvested with a two-row self-propelled combine to determine seed yield, which was expressed in kilograms per hectare on a 13%-moisture basis. Seed weight, expressed in milligrams per seed, was determined by weighing 200 random seeds per plot. Protein, oil, and moisture content were measured on a seed sample of 300 g with a whole grain near-infrared reflectance analyzer. Protein and oil content were expressed in grams per kilogram on a 13%-moisture basis. Fatty ester content was determined from two random seven-seed bulk samples from each plot by gas chromatography. The mean fatty ester content of the two samples from each plot, expressed in grams per kilogram, was used for data analysis.

The data from each 1998 experiment were analyzed with the general linear models procedure (GLM) of the SAS software package (SAS Institute, 1992). Locations and replications were considered random effects and genotypes were considered fixed effects. The check cultivars and lines were excluded from the analyses of variance. A single replication from each experiment at Grand Junction was excluded from the analyses of variance because of flooding. For each trait, the sums of squares for genotypes in the analyses of variance were partitioned into 1%-linolenate lines, 2%-linolenate lines, and the orthogonal comparison. The genotype x location interactions were used to test the significance of each partitioned component by an F test. The phenotypic correlation coefficients between linolenate content and the other traits were calculated with the correlation procedure (CORR) of SAS (SAS Institute, 1992) on the basis of the mean performance of lines across the three locations.

	Results and discussion

TOP NOTES ABSTRACT INTRODUCTION Materials and methods Results and discussion REFERENCES

 
There were significant (P < 0.01) differences among locations for each trait in at least one of the three populations. This indicated that the three locations represented unique environments for comparison of the 1%- and 2%-linolenate lines.

There were significant differences for mean linolenate content between the 1%- and 2%-linolenate lines in the three populations (Table 1) . The significant variation among lines within the 1%- and 2%-linolenate groups was attributed to the segregation of minor alleles that altered linolenate content. Linolenate content of <20 g kg^-1 should be considered a quantitative trait in a cultivar development program because of the three major fan alleles and minor alleles that must be considered in designing an appropriate breeding strategy. The breeding strategies proposed by Horejsi et al. (1994) for developing cultivars with reduced palmitate, which is controlled by major and minor alleles, would apply to the introgression of the 1%-linolenate trait into high-yielding cultivars.

The maximum difference between the mean performance of the 1%- and 2%-linolenate lines was only 1 d for maturity, 0.1 score for lodging, and 2 cm in plant height (Table 1). The ranges among lines for the three traits were similar between the 1%- and 2%-linolenate groups. The phenotypic correlation coefficients between linolenate content and the three traits when all lines were considered together were not significant, except for maturity in Population 2 (Table 3). For the 1%-linolenate lines, the only significant correlation coefficient was for lodging in Population 2. The results indicated that it should be possible to develop 1%-linolenate cultivars with the desired maturity, lodging, and plant height.

The mean seed weight, protein content, and oil content of the 1%-linolenate lines were significantly different from the 2%-linolenate lines in the three populations (Table 1). The maximum difference between the two groups of lines was only 4 mg seed^-1 for seed weight, 5 g kg^-1 for protein content, and 5 g kg^-1 for oil content. Although there were significant negative correlation coefficients between linolenate and protein content in two populations and significant positive correlation coefficients between linolenate and oil content in the three populations when all lines were considered together, the ranges among the 1%- and 2%-linolenate lines for protein and oil content were similar (Tables 1 and 3). Reduction of linolenate to <20 g kg^-1 should not impede selection for the preferred seed weight, protein content, or oil content.

The changes in palmitate and stearate content with the reduction in linolenate content were not consistent among the three populations (Table 1). The mean palmitate content of the 1%-linolenate lines was not significantly different from the 2%-linolenate lines in Population 1, significantly less in Population 2, and significantly greater in Population 3. For stearate, the mean of the 1%-linolenate lines was not significantly different from the mean of the 2%-linolenate lines in Population 1, but was significantly greater in Populations 2 and 3. The maximum differences between the means of the two groups was only 0.6 g kg^-1 for palmitate and only 2.2 g kg^-1 for stearate. None of the phenotypic correlation coefficients between linolenate and palmitate content were significant (Table 3). The direction and magnitude of the correlation coefficients between linolenate and stearate content were inconsistent among the three populations (Table 3).

The mean oleate content was significantly greater in the 1%-linolenate lines than in the 2%-linolenate lines for the three populations (Table 1). The differences between the two groups of lines for mean oleate content were 16.4 g kg^-1 in Population 1, 18.2 g kg^-1 in Population 2, and 8.3 g kg^-1 in Population 3. When all lines were considered together, the phenotypic correlation coefficients between linolenate and oleate content were negative and significant in Populations 1 and 2, but the correlation coefficient was not significant in Population 3 (Table 3).

The mean linoleate content of the 1%-linolenate lines was significantly less than the 2%-linolenate lines in Populations 1 and 2, but no significant difference was observed in Population 3. The maximum difference between the two groups was only 6.8 g kg^-1. When all lines were considered together, none of the phenotypic correlation coefficients between linolenate and linoleate content were significant (Table 3).

Soybean cultivars with 25 g kg^-1 are grown commercially to obtain oil that is superior in oxidative stability to conventional soybean oil. Our study indicated that it should be possible to develop cultivars with lower linolenate that are similar to 2%-linolenate cultivars for agronomic and seed traits. The major challenge in developing cultivars with <15 g kg^-1 linolenate would be the quantitative inheritance associated with the three major fan alleles and minor alleles that control the trait. Our experience has indicated that <2% of the lines derived from crosses between high-yielding parents with normal linolenate and parents with <15 g kg^-1 linolenate will have linolenate as low as the parents. For backcrossing the 1%-linolenate trait into high-yielding cultivars with normal linolenate, it would be necessary for each backcross generation to self-pollinate the F₁ plants and select the F₂ seeds and plants with the lowest linolenate for crossing. It would be advantageous to evaluate lines with the 1%-linolenate trait for agronomic and seed traits from each backcross generation and discontinue backcrossing as soon as possible. Minimizing the number of backcross generations would reduce the amount of time for cultivar development and would minimize the possibility of losing desired minor alleles for reduced-linolenate content.

An alternative strategy for the initial development of 1%-linolenate cultivars would be to select in populations developed from crosses between high-yielding 2%-linolenate parents with 1%-linolenate parents. Only one major gene for linolenate would be segregating in such crosses, and the frequency of progeny with the desired linolenate would be much higher than in populations derived from crosses between normal and 1%-linolenate parents. Our study demonstrated that it is possible to backcross the F₁ plants from a 2%-linolenate x 1%-linolenate cross directly to the 2%-linolenate recurrent parent and recover lines with <15 g kg^-1 linolenate and yield similar to the recurrent parent (Table 2). This strategy would only be useful as long as 2%-linolenate cultivars and lines with high yield were available as parents.

	NOTES

TOP NOTES ABSTRACT INTRODUCTION Materials and methods Results and discussion REFERENCES

 
Journal Paper no. J-18402 of the Iowa Agric. and Home Econ. Exp. Stn., Ames, IA, Project no. 3107, and supported by the Hatch Act, State of Iowa, and Pioneer Hi-Bred International, Inc.

Received for publication May 17, 1999.

	REFERENCES

TOP NOTES ABSTRACT INTRODUCTION Materials and methods Results and discussion REFERENCES

 

• Fehr, W.R., and E.G. Hammond. 1996. Soybeans having low linolenic acid content and method of production. U.S. Patent 5534425. Date issued: 9 July.
• Fehr, W.R., and E.G. Hammond. 1998. Reduced linolenic acid production in soybeans. U.S. Patent 5850030. Date issued: 15 Dec.
• Fehr W.R., Welke G.A., Hammond E.G., Duvick D.N., Cianzio S.R. Inheritance of reduced linolenic acid content in soybean genotypes A16 and A17. Crop Sci. 1992;32:903-906.[Abstract/Free Full Text]
• Hammond E.G. Organization of rapid analysis of lipids in many individual plants. In: Linskens H.F., Jackson J.F., eds. Modern methods of plant analysis. Vol. 12. Berlin, Germany: Springer-Verlag, 1991:321-330.
• Hammond E.G., Fehr W.R. Registration of A5 germplasm line of soybean. Crop Sci. 1983;23:192.[Free Full Text]
• Horejsi T.F., Fehr W.R., Welke G.A., Duvick D.N., Hammond E.G., Cianzio S.R. Genetic control of reduced palmitate content in soybean. Crop Sci. 1994;34:331-334.[Abstract/Free Full Text]
• Liu H., White P.J. Oxidative stability of soybean oils with altered fatty acid compositions. J. Am. Oil Chem. Soc. 1992;69:528-532.[ISI]
• Mounts T.L., Warner K., List G.R. Performance evaluation of hexane-extracted oils from genetically modified soybeans. J. Am. Oil Chem. Soc. 1994;71:157-161.
• SAS Institute. SAS guide for personal computers, 6th ed Cary, NC: SAS Inst, 1992.
• Shen N., Fehr W., Johnson L., White P. Oxidative stabilities of soybean oils with elevated palmitate and reduced linolenate contents. J. Am. Oil Chem. Soc. 1997;74:299-302.[ISI]
• Walker J.B., Fehr W.R., Welke G.A., Hammond E.G., Duvick D.N., Cianzio S.R. Reduced-linolenate content associations with agronomic and seed traits of soybean. Crop Sci. 1998;38:352-355.[Abstract/Free Full Text]
• Wilcox J.R., Nickell A.D., Cavins J.F. Relationships between the fan allele and agronomic traits in soybean. Crop Sci. 1993;33:87-89.[Abstract/Free Full Text]

This article has been cited by other articles:

				S. L. Naeve and S. C. Huerd Year, Region, and Temperature Effects on the Quality of Minnesota's Soybean Crop Agron. J., May 7, 2008; 100(3): 690 - 695. [Abstract] [Full Text] [PDF]

				W. R. Fehr Breeding for Modified Fatty Acid Composition in Soybean Crop Sci., December 18, 2007; 47(Supplement_3): S-72 - S-87. [Abstract] [Full Text] [PDF]

				G. E. Byfield and R. G. Upchurch Effect of Temperature on Microsomal Omega-3 Linoleate Desaturase Gene Expression and Linolenic Acid Content in Developing Soybean Seeds Crop Sci., November 7, 2007; 47(6): 2445 - 2452. [Abstract] [Full Text] [PDF]

				A. J. Cardinal and J. W. Burton Correlations between Palmitate Content and Agronomic Traits in Soybean Populations Segregating for the fap1, fapnc, and fan Alleles Crop Sci., September 1, 2007; 47(5): 1804 - 1812. [Abstract] [Full Text] [PDF]

				P. S. Baenziger, W. K. Russell, G. L. Graef, and B. T. Campbell Improving Lives: 50 Years of Crop Breeding, Genetics, and Cytology (C-1) Crop Sci., September 8, 2006; 46(5): 2230 - 2244. [Abstract] [Full Text] [PDF]

				K. Bilyeu, L. Palavalli, D. A. Sleper, and P. Beuselinck Molecular Genetic Resources for Development of 1% Linolenic Acid Soybeans Crop Sci., July 25, 2006; 46(5): 1913 - 1918. [Abstract] [Full Text] [PDF]

				C. W. Scherder, W. R. Fehr, G. A. Welke, and T. Wang Tocopherol Content and Agronomic Performance of Soybean Lines with Reduced Palmitate Crop Sci., April 25, 2006; 46(3): 1286 - 1290. [Abstract] [Full Text] [PDF]

				P. R. Beuselinck, D. A. Sleper, and K. D. Bilyeu An Assessment of Phenotype Selection for Linolenic Acid Using Genetic Markers Crop Sci., February 24, 2006; 46(2): 747 - 750. [Abstract] [Full Text] [PDF]

				K. Bilyeu, L. Palavalli, D. Sleper, and P. Beuselinck Mutations in Soybean Microsomal Omega-3 Fatty Acid Desaturase Genes Reduce Linolenic Acid Concentration in Soybean Seeds Crop Sci., August 1, 2005; 45(5): 1830 - 1836. [Abstract] [Full Text] [PDF]

				A. Nabloussi, J. M. Fernandez-Martinez, and L. Velasco Spatial and Temporal Expression of Mutations for High Oleic Acid and Low Linolenic Acid Concentration in Ethiopian Mustard Crop Sci., January 1, 2005; 45(1): 202 - 208. [Abstract] [Full Text] [PDF]

				K. L. McCord, W. R. Fehr, T. Wang, G. A. Welke, S. R. Cianzio, and S. R. Schnebly Tocopherol Content of Soybean Lines with Reduced Linolenate in the Seed Oil Crop Sci., May 1, 2004; 44(3): 772 - 776. [Abstract] [Full Text] [PDF]

				K. D. Bilyeu, L. Palavalli, D. A. Sleper, and P. R. Beuselinck Three Microsomal Omega-3 Fatty-acid Desaturase Genes Contribute to Soybean Linolenic Acid Levels Crop Sci., September 1, 2003; 43(5): 1833 - 1838. [Abstract] [Full Text] [PDF]

				V. S. Primomo, D. E. Falk, G. R. Ablett, J. W. Tanner, and I. Rajcan Inheritance and Interaction of Low Palmitic and Low Linolenic Soybean Crop Sci., January 1, 2002; 42(1): 31 - 36. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (20) Citing Articles via Google Scholar Google Scholar Articles by Ross, A. J. Articles by Cianzio, S. R. Search for Related Content PubMed Articles by Ross, A. J. Articles by Cianzio, S. R. Agricola Articles by Ross, A. J. Articles by Cianzio, S. R.