The effect of maturity (time to maturity) on seed composition in soybean [Glycine max (L.) Merr.] genotypes is not well understood because maturity is generally confounded with genotypic background. Therefore, the effects of maturity on seed composition were estimated in two sets of near isogenic soybean lines (‘Clark’ and ‘Harosoy’), where the maturity of each line within a set varied, but all had a common genotypic background. There was a positive linear relationship between protein concentration and maturity among isolines of the Clark set in 2004 (r2 = 0.75; P ≤ 0.001) and 2005 (r2 = 0.63; P ≤ 0.001). However, in Harosoy isolines there was no relationship between protein and maturity. There was a negative linear relationship between oil concentration and maturity for Clark (in 2004, r2 = 0.82, P ≤ 0.001; in 2005, r2 = 0.91, P ≤ 0.0001) and Harosoy (in 2004, r2 = 0.19, P ≤ 0.05; in 2005, r2 = 0.36, P ≤ 0.01). Maturity had greater effects on seed composition than maximum temperature. The results indicate that the relationship between seed composition and maturity was different between the Clark and Harosoy sets of isolines. However, the overall mean of protein and oil concentration was not different between genotypic backgrounds. This information will be useful for soybean breeding in developing new germplasm for seed composition.

The genetic linkage map of Prunus constructed earlier and based on an interspecific F2 population resulting from a cross between almond (Prunus dulcis D.A. Webb) and peach (Prunus persica L. Batsch) was extended to include 8 isozyme loci, 102 peach mesocarp cDNAs, 11 plum genomic clones, 19 almond genomic clones, 7 resistance gene analogs (RGAs), 1 RGA-related sequence marker, 4 morphological trait loci, 3 genes with known function, 4 simple sequence repeat (SSR) loci, 1 RAPD, and 1 cleaved amplified polymorphic sequence (CAP) marker. This map contains 161 markers placed in eight linkage groups that correspond to the basic chromosome number of the genus (x = n = 8) with a map distance of 1144 centimorgans (cM) and an average marker density of 6.8 cM. Four more trait loci (Y, Pcp, D, and SK) and one isozyme locus (Mdh1) were assigned to linkage groups based on known associations with linked markers. The linkage group identification numbers correspond to those for maps published by the Arús group in Spain and the Dirlewanger group in France. Forty-five percent of the loci showed segregation distortion most likely owing to the interspecific nature of the cross and mating system differences between almond (obligate outcrosser) and peach (selfer). The Cat1 locus, known to be linked to the D locus controlling fruit acidity, was mapped to linkage group 5. A gene or genes controlling polycarpel fruit development was placed on linkage group 3, and control of senesced leaf color (in late fall season) (LFCLR) was mapped to linkage group 1 at a putative location similar to where the Y locus has also been placed.

The physiological effects of foliar boron application (FB) on nitrogen metabolism and seed composition have not been well established in soybean [(Glycine max(L.)Merr.)]. Therefore, the effect of FB on nitrogen metabolism and seed composition was investigated. Nitrate assimilation was evaluated by measuring nitrate reductase activity (NRA) and nitrogen fixation was evaluated by measuring nitrogenase activity and natural abundance of 15 N/ 14 N. NRA were significantly (P≤0.05) higher in plants that received FB than the control plants. Higher rate of FB (One application of four times of commercial rate) inhibited nitrogen fixation as measured by natural abundance of 15 N/ 14 N ratio, but increased NRA. The higher activities of NR and nitrogenase by FB were accompanied with a higher B concentration in leaves. The significant (P<0.0001) enrichment of 15 N/ 14 N, accompanied with a higher rate of FB, suggested a possible mechanism where nitrate assimilation may compensate for the decrease in nitrogen fixation. FB increased seed protein by 13.7% and oleic acid by 30.9% compared to the control plants. This alteration was accompanied by a higher B concentration in leaves and seed. The results suggest that FB affects nitrogen metabolism and alters seed compositions, especially protein and unsaturated fatty acids.

The objective of this study was to investigate the effects of maturity, genotypic background, and maximum temperature 20 d before maturity on soybean [Glycine max (L.) Merr.] seed mineral concentrations. A field experiment was conducted in Stoneville, MS, in 2004 and 2005, using two sets of near-isogenic soybean lines that differed in maturity genes. One set of isolines derived from cultivar Clark and the other from cultivar Harosoy. The maturity of each line within a set varied, but all had a common genotypic background. For Clark isolines, there were positive correlations (P < 0.05) between maturity and N with r = 0.83 in 2004 and r = 0. 62 in 2005, and between maturity and Ca (r = 0.59 in 2004 and r = 0.89 in 2005). For Harosoy isolines, there were positive correlations (P < 0.05) between maturity and Ca with r = 0.60 in 2004 and r = 0.83 in 2005, and between maturity and B (r = 0.48 in 2004 and r = 0.72 in 2005). There was a highly significant genotypic background effect (P < 0.01) on seed N, S, Ca, K, Mg, P, and B concentrations, and maturity gene (E-gene) effect (P < 0.01) on Ca and B. Generally the contribution of genotypic background or maturity to total variation of nutrient concentrations was greater than that of temperature. This information may be useful when developing soybean germplasm with higher seed mineral content by using genotypes with a higher nutrient uptake efficiency trait as either parental lines or source material to improve existing varieties for the seed nutrition trait.

An undescribed wet rot of roots was observed in surveys of recently harvested sugar beet roots in Idaho and eastern Oregon in 2004 and 2005. Microorganisms isolated from 287 roots fell into the following groups: A (41% of strains), B (29%), C (17%), D (11%), E (2%), and F (1%). Groups A, B, C, and F were composed of bacteria while groups D and E were yeasts. Subgroup A1 (80% of group A strains) included Leuconostoc mesenteroides subsp. dextranicum strains and subgroup A2 (20%) contained Lactobacillus strains. Group B was dominated by subgroup B1 (92% of strains), which included Gluconobacter strains. When only one organism was isolated from rotted roots, strains from subgroup A1 were isolated most frequently. Group C was composed of enteric bacteria. Strain B322 of L. mesenteroides subsp. dextranicum caused the most severe rot on root slices and produced symptoms similar to those in harvested roots. Results suggest that L. mesenteroides subsp. dextranicum is among the first bacterial species to enter sugar beet roots, closely following fungal infections or entering directly through openings such as growth cracks. The bacterial rot leads to yield loss in the field but likely also leads to storage and factory-processing problems.

S oybean seed is a major source of protein, oil, carbohydrates, isofl avones, and other nutrients for humans and animals (Hou et al., 2009). Soybean seed contains approximately 40% protein, 20% oil, and 33% carbohydrates (Hymowitz and Collins, 1974). Half of the carbohydrates are insoluble polysaccharides, which include pectin, cellulose, hemicellulose, and starch (Liu, 1997). The other half are soluble carbohydrates, which include monosaccharides (glucose and fructose), disaccharides (sucrose), and raffi nose oligosaccharides (raffi nose and stachyose) (Liu, 1997). The average soybean seed contains 9 to 12% total soluble carbohydrates, of which 4 to 5% are sucrose (C 12 H 22 O 11 ), 1 to 2% are raffi nose (C 18 H 32 O 16 ), and 3.5 to 4.5% are stachyose (C 24 H 42 O 21 ) (Wilson, 1995).Raffi nose oligosaccharides (RO) are a group of D-galactosecontaining oligosaccharide derivatives of sucrose that are widely distributed in plants. Galactosyltransferases (raffi nose synthase and stachyose synthase) are involved in the biosynthesis of raffi nose family oligosaccharides (Peterbauer and Richter, 2001). Galactinol synthase catalyzes the synthesis of galactinol (O-α-D-galactopyranosyl-[1 1]-L-myo-inositol) from UDP-D-Gal and myo-inositol (Sprenger and Keller, 2000). Biosynthesis of RO starts with the ABSTRACT The objective of this study was to investigate the effect of maturity and fi eld temperature on the concentration of sucrose, raffi nose, and stachyose in soybean seed in two sets of near-isogenic lines of Clark and Harosoy. The maturity of each line within each set varied, but all lines from each set shared a common genotypic background. The results showed that in the Clark isoline set, maturity had a negative linear relationship (sugars decreased as days to maturity increased) with the concentration of sucrose (r 2 = 0.83 in 2004; r 2 = 0.94 in 2005), stachyose (r 2 = 0.51 in 2004; r 2 = 0.51 in 2005), and combined sugars (sucrose+raffi nose+stachyose) (r 2 = 0.83 in 2004; r 2 = 0.91 in 2005). In the Harosoy set, there were signifi cant negative relationships between maturity and sugars only in 2005 for sucrose, stachyose, and combined sugars. In the Clark set, temperature had a signifi cant positive relationship with sugars in 2004 (sugars increased as temperature increased), but signifi cant negative relationship in 2005. In the Harosoy set, there was a signifi cant negative relationship between fi eld temperature and sugars only in 2005. The contribution of maturity to the total variation in sugars was signifi cantly higher than temperature. It was concluded that the effect of genotypic background and maturity genes on sugar concentration depended on the type of sugar.

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Curly top in sugar beet continues to be a challenging disease to control in the western United States. To aid in development of host resistance and management options, the curtovirus species composition was investigated by sampling 246 commercial fields along with nursery and field trials in the western United States. DNA was isolated from leaf samples and the species were identified using species-specific polymerase chain reaction primers for the C1 gene. Amplicons from 79 isolates were also sequenced to confirm identifications. Beet severe curly top virus (BSCTV) and Beet mild curly top virus (BMCTV) were widely distributed throughout the western United States, while only a few isolates of Beet curly top virus (BCTV) were found. In phylogenetic analysis, BSCTV, BMCTV, and BCTV isolates formed distinct groups in the dendrogram. Seven isolates not amplifiable with species-specific primers did amplify with curly top coat protein primers, indicating novel curtovirus species or strains may be present. Given the wide host range of the viruses responsible for curly top, frequent co-infections, and genetic diversity within and among species, establishing better host resistance, and controlling curly top will continue to be a challenge.