The soybean aphid [Aphis glycines Matsumura (Hemiptera: Aphididae)] is an invasive pest of soybean [Glycine max (L.) Merr.]. Since the first report in the United States in 2000 it has become one of the most damaging soybean pests. Three soybean aphid biotypes have been reported to date. The objective of this research was to determine whether an A. glycines field isolate collected near Lomira, WI, was unique from those previously reported. The response of the Lomira isolate was compared to existing soybean aphid Biotypes 1, 2, and 3 by conducting caged and noncaged assays using 10 soybean genotypes. In both the caged and noncaged assays, there were significant effects (P < 0.0001) of soybean aphid isolate, genotype, and soybean aphid isolate × genotype interaction. The Lomira isolate reaction profile was different than those of previously reported biotypes, therefore identifying a new biotype to use in characterization of soybean aphid resistant germplasm.

the -6 position mediated by the enzyme -6 fatty acid desaturase. Okuley et al. (1994) isolated the cDNA en-Soybean [Glycine max (L.) Merr.] oil with elevated oleate content coding the microsomal -6 fatty acid desaturase from would be useful for food and industrial applications that require increased oxidative stability. The first objective of this study was to Arabidopsis thaliana (L.) Heynh. as the Fad2 gene. Hepdetermine if molecular selection for the Fad2-1 deletion associated pard et al. (1996) found two clones encoding -6 fatty with the ol allele in the mid-oleate mutant line M23 could be used acid desaturase in soybean that they designated Fad2-1 to identify mid-oleate individuals in a breeding program. The second and Fad2-2. Heppard et al. (1996) found Fad2-1 to be objective was to determine if modifying genes affect phenotypic exstrongly expressed in developing seeds while Fad2-2 was pression of oleate content in individuals homozygous for the deleexpressed in both vegetative tissue and developing tion from a cross between M23 and Archer, a cultivar with normal seeds. oleate content. The segregation among 88 F 2 plants from the cross Kinoshita et al. (1998) used the cDNA of Fad2-1 and satisfactorily fit a ratio of 1:2:1 homozygous normal (OlOl)/heterozy-Fad2-2 as probes to screen 40 F 2 plants from the cross gous (Olol)/homozygous (olol) for the Fad2-1 deletion on the basis

FA22 and N98-4445A do not have the deletion of Fad2-1 present in M23 (Alt et al., 2005). Increased oleate content of soybean [Glycine max (L.) Merr.] oilThe objective of this study was to determine if the may be useful for food and industrial applications requiring increased alleles conditioning mid-oleate in FA22, N98-4445A, oxidative stability. The objective of this study was to determine if and M23 were sufficiently different to result in transtransgressive segregates for oleate content could be found in crosses between three mid-oleate lines: FA22 from Iowa State University, gressive segregation for the trait. If transgressive segre-N98-4445A from the USDA-ARS/North Carolina State University, gates were found, they could be useful for elevating the and M23 from Saga University, Japan. Single-cross populations of oleate content of soybean in a cultivar development FA22 ϫ M23, FA22 ϫ N98-4445A, and N98-4445A ϫ M23 were deprogram.

Oleic acid is one of the three major unsaturated fatty acids in soybean oil. Expression of the embryo-specific Fad2-1 gene correlates with fatty acid biosynthesis and oil deposition in developing seeds. Elevated levels of oleate in the X-ray-induced mutant line M23 have been shown to be associated with the deletion of a Fad2-1 gene. In soybean, two homologs of the Fad2-1 gene, termed Fad2-1a (L43920) and Fad2-1b (AY611472), presumably encode functional embryo-specific fatty acid desaturase. The objectives of this investigation were to determine which copy of the Fad2-1 gene is associated with the increased oleate content in the mutant line and what is the relative transcript abundance of these two embryo-specific genes. PCR and DNA blot analyses showed that increased oleate content in M23 mutant was associated with the deletion of Fad2-1a. These results were further validated using five independent soybean populations developed by crossing mid-oleate and normal-oleate parents. Investigation of the soybean expressed sequence tag database and reverse transcription PCR analyses revealed that Fad2-1b is the predominantly transcribed copy of the Fad2-1 gene. We hypothesize that null mutation in Fad2-1b in the fad2-1a mutant background should further elevate the oleic contents of soybean oil.Keywords Fad2-1 Á M23 Á Oleic acid Á Oil Á Soybean Electronic supplementary material The online version of this article (

Soybean aphid (Aphis glycines) is an invasive species in North America. For more than a decade, scientists have been working on host plant resistance, but the frequent identification of aphid isolates resistant (virulent) to soybean [Glycine max (L.) Merr.] traits has caused concern amongst stakeholders interested in aphid control. To explore the diversity and distribution of these virulent aphids, we sampled soybean fields throughout the north‐central United States and southern Canada from 2011 through 2013. We evaluated soybean aphid performance on soybean cultivars containing Rag1, Rag2, and Rag3 loci and categorized them per standard biotypes. The soybean aphid biotypes were widely distributed across the sampled region. We also used the performance test scores to study the outliers and unexpected results according to biotype. Intrabiotypic variability is common in North America.