Spatial genetic structure in wild cardoon, the ancestor of cultivated globe artichoke: Limited gene flow, fragmentation and population history.

Nuclear and chloroplast markers and phenotypic characters were integrated to analyse the population genetic structure of wild cardoon, Cynara cardunculus var. sylvestris, the ancestor of cultivated globe artichoke, Cynara cardunculus var. scolymus on the island of Sardinia, Italy. The spatial scale ranged from a few metres to ∼200km. Wild cardoon appears to be genetically fragmented, with significant genetic divergence at various scales, indicating that gene flow is insufficient to counterbalance the effects of genetic drift or founder effects. Divergence between populations was higher for chloroplast (40%) than for nuclear markers (15%), suggesting that gene flow via seed was lower than via pollen. Two main genetic groups were detected; these correlated with differences in flowering time, capitula size, glossiness, and anthocyanin pigmentation. A complex population structure of wild cardoon emerged over small spatial scales, likely resulting from the interplay between gene dispersal, colonisation history and selective forces. Indeed, Sardinia appears to be a 'hybrid zone' of different gene pools. The island has unique diverse germplasm that has originated from hybridisation among different gene pools. The sampling of seeds from a few plants but from many sites is suggested as the best strategy to harvest the genetic diversity of wild cardoon.

Effects of forage type, body condition and single-nucleotide polymorphisms in the bovine cytochrome P450 regulatory region on cow productivity.

Single-nucleotide polymorphisms (SNP) in the coding sequence of cytochrome p450 (CYP3A28) have been associated with milk yield and composition, and calving traits in cows. In this study, we aimed to determine whether (i) the CYP3A28 regulatory region was polymorphic and (ii) SNP genotype, forage type, body condition and their interactions affect cow productivity. Primers for CYP3A28 promoter were designed to amplify a 483-bp segment by PCR. Amplicon sequences revealed seven SNP (T-318C, T-113A, C-189T, T-78G, A6G, G17A and T21C) in Brahman (38 cows), Brahman x Angus reciprocal crosses (47 cows) and crossbreds (98 cows). Angus cows (n = 41) appeared to be fixed at those SNP locations. Genotype and forage {endophyte-infected tall fescue [KY+; Lolium arundinaceum (Schreb.) S. J. Darbyshire] vs. bermudagrass [Cynodon dactylon (L.) Pers.]} effects on lifetime (8-years) calving rate, and calf weaning weights and heights were determined in Herd 1 (126 cows); genotype and BC (low vs. moderate) effects on calving date and calving percent were determined in Herd 2 (98 cows). Four SNP (T-318C, T-113A, A06G and T21C) appeared to be related to cattle productivity, CC cows at T-318C having a lower (p < 0.05) lifetime calving rate than TC or TT cows (65%, 85% and 81% respectively). Cows that grazed KY+ and were TT at T-318C produced calves that tended (p < 0.07) to weigh less than their contemporaries. Moreover, calves of TT cows were shorter (p < 0.05) at weaning than calves of CC or TC cows. In Herd 2, moderate-BC cows that were TT or AA at T-318C, T-113A, T-78G, A6G and T21C had greater (p < 0.05) calving rates (74-80%) than heterozygous cows (46-60%), and low-BC cows that were AA at G17A calved at least 6 days earlier (p < 0.05) than heterozygous cows. Our findings suggest that SNP in the CYP3A28 regulatory region of Brahman-influenced cows are associated with cattle productivity.

Effects of bovine cytochrome P450 single-nucleotide polymorphism, forage type and body condition on production traits in cattle.

Relating single-nucleotide polymorphisms (SNP) to cows with acceptable productivity could benefit cattle breeders in areas where tall fescue is the predominant forage. This study aimed to (i) identify SNPs in bovine cytochrome P450 3A28 (CYP3A28) and (ii) determine the associations between SNP genotype, forage and cow body condition (BC). Genotype (CC, CG or GG) and forage [Kentucky-31 wild-type endophyte-infected tall fescue (KY+) vs. bermudagrass] effects on milk volume and quality were determined in Herd 1 cows (123 cows); in Herd 2 (99 cows), genotype and BC (low vs. moderate) effects on ovarian follicle size, calving date and calving per cent were determined; and in Herd 3 (114 cows), effects of genotype and fescue cultivar [KY+ vs. non-toxic endophyte-infected tall fescue (HiMag4)] were related to calving per cent, calving date and weaning weights of both cow and her calf. A cytosine (C) to guanine (G) transversion at base 994 (C994G) in CYP3A28 was identified. There was a genotype × forage type interaction (p < 0.05) on milk protein in Herd 1 cows; CC cows grazing bermudagrass had greater milk protein percentage in relation to other cows in the herd. In Herd 2, BC and genotype × BC tended (p < 0.10) to influence follicle size and Julian calving date respectively. Diameter of the largest follicle tended to be larger in moderate BC than in low-BC cows; whereas, CC and CG cows in moderate BC and homozygous (CC and GG) cows in low BC tended to calve 14 days earlier in relation to CG cows in low BC. In Herd 3, there was a genotype × forage type interaction (p < 0.05) on calving per cent, Julian calving date and calf weaning weight. In this study, genetic alterations (G allele at C994G) coupled with nutritional factors (low BC and toxic tall fescue) resulted in overall lower productivity in cows.

Microbial, instrumental color and sensory characteristics of inoculated ground beef produced using potassium lactate, sodium metasilicate or peroxyacetic acid as multiple antimicrobial interventions.

Effectiveness of multiple antimicrobial interventions on ground beef microbial, instrumental color and sensory attributes through display was evaluated. Beef trimmings were inoculated with Escherichia coli (EC) and Salmonella typhimurium (ST) then treated with either: (1) 3% potassium lactate followed by 4% sodium metasilicate (KN); (2) 4% sodium metasilicate followed by 3% potassium lactate (NK); (3) 200-ppm peroxyacetic acid followed by 3% potassium lactate (PK); (4) 200-ppm peroxyacetic acid followed by 4% sodium metasilicate (PN); or control (CON). Trimmings were ground, packaged and sampled on days 0-7 of display for EC, ST, coliforms, aerobic plate count, instrumental color and sensory characteristics. Only PK reduced (P<0.05) all bacterial types evaluated. The PN treatment remained (P<0.05) redder (a*), contained more (P<0.05) oxymyoglobin and had less (P<0.05) discoloration than CON by days 3-7 of display. All treatments maintained or improved odor attributes.

Effects of salt, BHA/BHT, and differing phosphate types on quality and sensory characteristics of beef longissimus muscles.

USDA Select striploins (n = 20) were cut into thirds (anterior, medial, and posterior) and randomly assigned to 1 of 6 treatments. Treatments included: (1) control (C); (2) 0.006% BHA (butylated hydroxyl anisole)/BHT (butylated hydroxytoluene) (70%/30%) (BB); (3) 0.4% trisodiumphosphate (CT); (4) 0.4% sodiumtripolyphosphate with 0.5% salt (BH); (5) sodiumtripolyphosphate, 0.5% salt, and 0.006% BHA/BHT (70%/30%) (SB); (6) 0.2% sodiumtripolyphosphate, 0.2% trisodiumphosphate, and 0.5% salt (STB). Muscle sections were injected to 110% (10% pump) of their weight with their respective treatments. Inclusion of BHA/BHT allowed for lower mean oxidation values. Regardless of phosphate type, muscles treated with both phosphate and salt had lower retail purge (P < 0.05). Sensory panelists rated (P < 0.05) STB, SB, and BH to be juicier than all other treatments. These data suggest that inclusion of both salt and phosphate can enhance palatability, lower cook loss, and retail purge.

Effects of conjugated linoleic acid, salt, and sodium tripolyphosphate on physical, sensory, and instrumental color characteristics of beef striploins.

USDA Select striploins (IMPS 180; n= 24) were cut into thirds (anterior, medial, and posterior) and assigned to 1 of 8 treatments utilizing a randomized incomplete block design. Treatments included (1) control (C); (2) 1.5% conjugated linoleic acid (conjugated linoleic acid = CLA) (CGA); (3) 0.4% sodium tripolyphosphate (PHO); (4) 0.5% salt (SAL); (5) 0.4% sodium tripolyphosphate, 0.5% salt (SPH); (6) 0.4% sodium tripolyphosphate, 1.5% CLA (PCL); (7) 0.5% salt, 1.5% CLA (SCL); and (8) 0.4% sodium tripolyphosphate, 0.5% salt, 1.5% CLA (SPC). Treatments were injected with solutions to 110% (10% pump) of their original weight. Treatments with CLA had higher (P < 0.05) marbling scores than treatments that did not. Not including SAL, treatments with salt, or phosphate or a combination of the two had higher tenderness values when sampled by panelists. Fresh steaks with inclusion of CLA had greater amounts (P < 0.05) of the CLA isomers than steaks not having CLA. Cooked steaks having CLA also had greater amounts (P < 0.05) of CLA, except for SCL, which were not different (P > 0.05) from the non-CLA treatments. Day was a significant source of variability for a*, b*, and saturation index. Treatment x day interactions were significant (P < 0.05) for hue angle and L* values. These data suggest that inclusion of CLA can increase amounts of CLA isomers without major deleterious effects to instrumental, physical, and quality characteristics of beef striploin steaks.

Isolation and characterization of thirteen polymorphic microsatellite loci in the A-genome perennial group of the legume genus Glycine.

Thirteen polymorphic microsatellite loci were developed for the closely related and reproductively compatible species comprising the A-genome perennial group of the legume genus Glycine. Primers developed from the widespread and isozymically differentiated G. canescens amplified successfully across G. clandestina and four other species within the complex. Species were highly polymorphic, and observed heterozygosities were extremely low for all loci, as expected for these predominantly autogamous taxa. These markers will be useful in studying genetic variation, population structure, gene flow, and polyploidy within the A-genome group.

Effects of potassium lactate, sodium metasilicate, peroxyacetic acid, and acidified sodium chlorite on physical, chemical, and sensory properties of ground beef patties.

Beef trimmings were treated with 3% potassium lactate (KL), 4% sodium metasilicate (NMS), 0.02% peroxyacetic acid (PAA) or 0.1% acidified sodium chlorite (ASC) or left untreated (CON). Beef trimmings were ground, pattied, and sampled for 7 days. Under simulated retail display, instrumental color, sensory characteristics, TBARS, pH, and Lee-Kramer shear force were measured to evaluate the impact of the treatments on the quality attributes. The NMS and PAA patties were redder (a(∗), P<0.05) than CON on days 0-3. Panelists found KL, NMS, PAA, and ASC patties to have less (P<0.05) or similar (P>0.05) off odor to CON on days 0-3. The NMS and PAA treated patties had lower (P<0.05) lipid oxidation than the CON at days 0, 3, and 7. Therefore, KL, NMS, PAA, and ASC treatments on beef trimmings can potentially improve or maintain quality attributes of beef patties.

The impact of single antimicrobial intervention treatment with potassium lactate, sodium metasilicate, peroxyacetic acid, and acidified sodium chlorite on non-inoculated ground beef lipid, instrumental color, and sensory characteristics.

The effect of using potassium lactate, sodium metasilicate, acidified sodium chlorite, or peroxyacetic acid as a single antimicrobial intervention on ground beef instrumental color, sensory color and odor characteristics, and lipid oxidation was evaluated. Prior to grinding, beef trimmings (90/10) were treated with 3% potassium lactate (KL), 4% sodium metasilicate (NMS), 200-ppm peroxyacetic acid (PAA), 1000-ppm acidified sodium chlorite (ASC), or left untreated (CON). Ground beef under simulated retail display was measured at 0, 1, 2, 3, and 7 of display for instrumental color, sensory characteristics, TBARS values, and pH to evaluate the impact of the treatments. The KL, NMS, PAA, and ASC were redder (a(∗); P<0.05) than CON. All treatments were scored by sensory panelists to have a brighter (P<0.05) red color than CON during days 1-3 of display. All treatments had less (P<0.05) lipid oxidation than CON on days 0, 3, and 7 of display. These results suggest that the use of these antimicrobial compounds on beef trimmings prior to grinding may not adversely affect, and may improve bulk packaged ground beef quality characteristics.

Phylogeny and evolution of mating-type genes from Pyrenophora teres, the causal agent of barley "net blotch" disease.

The main aim of this study was to test the patterns of sequence divergence and haplotype structure at the MAT locus of Pyrenophora teres, the causal agent of barley 'net blotch' disease. P. teres is a heterothallic ascomycete that co-occurs in two symptomatological forms, the net form (NF) and the spot form (SF). The mating-type genes MAT1-1-1 and MAT1-2-1 were sequenced from 22 NF isolates (12 MAT1-1-1 and 10 MAT1-2-1 sequences) and 17 SF isolates (10 MAT1-1-1 and seven MAT1-2-1 sequences) collected from Sardinian barley landrace populations and worldwide. On the basis of a parsimony network analysis, the two forms of P. teres are phylogenetically separated. More than 85% of the total nucleotide variation was found between formae speciales. The two forms do not share any polymorphisms. Six diagnostic nucleotide polymorphisms were found in the MAT1-1-1 intron (1) and in the MAT1-1-1 (3) and MAT1-2-1 (2) exons. Three diagnostic non-synonymous mutations were found, one in MAT1-1-1 and two in MAT1-2-1. For comparison with P. teres sequence data, the mating-type genes from Pyrenophora graminea were also isolated and sequenced. Divergence between P. graminea and P. teres is of a similar magnitude to that between NF and SF of P. teres. The MAT genes of P. graminea were closer to those of SF than to NF, with the MAT1-2-1 SF peptide not different from the MAT1-2-1 peptide of P. graminea. Overall, these data suggest long genetic isolation between the two forms of P. teres and that hybridization is rare or absent under field conditions, with each form having some particular niche specialization. This indicates that research on resistance to P. teres should consider the two forms separately, as different species.

Injection of conjugated linoleic acid into beef strip loins.

Beef strip loins (IMPS 180; n=15) were sectioned in thirds and sections (n=45) were left untreated (CNT) or injected with either a commercial powder conjugated linoleic acid (CLA) source (Powder) or a commercial oil CLA source (Oil), whose major isomers were 18:2cis-9, trans-11 and 18:2trans-10, cis-12 CLA isomers. Fresh Oil steaks had 3.20 and 3.15, Powder steaks had 4.67 and 4.62, and CNT steaks had 0.19 and 0.02mg/g muscle tissue (wet basis) of the cis-9, trans-11 and trans-10, cis-12 CLA isomers, respectively. TBARS were similar (Oil) and lower (Powder), compared to CNT. Powder steaks had similar instrumental color, and beef and off flavor characteristics as CNT. Artificial marbling was created with Oil steaks having USDA Small(79) and Powder steaks having USDA Modest(86) marbling scores, while CNT steaks had USDA Slight(94) marbling scores. Injection of CLA can be effective in significantly increasing CLA and potentially creating artificial marbling.

Fatty acid and sensory characteristics of beef from three biological types of cattle grazing cool-season forages supplemented with soyhulls.

Over two consecutive years, the effects of allocating divergent biological types of cattle (n=107) to fescue pasture without supplementation, or fescue or orchardgrass pasture with soyhull supplementation on chemical, fatty acid and sensory characteristics were investigated. Cattle from the two supplemented treatments produced beef that had increased (P<0.05) percentage lipid and decreased (P<0.05) polyunsaturated and n-3 fatty acids compared to the control. However, the n-6 to n-3 ratio was still less than four in beef from the supplemented cattle. Additionally, supplementation did not decrease (P>0.05) the CLA present in the longissimus, which can commonly occur when forage-fed cattle are supplemented concentrates. Although supplementation did not impact (P>0.05) Warner-Bratzler shear force or tenderness, supplementation of soyhulls reduced (P<0.05) the grassy flavor intensity of rib steaks when compared to the control. Biological type did not have a significant influence on most traits analyzed in this study. These results suggest that supplementation of soyhulls to cattle grazing forage can reduce grassy flavor intensity without decreasing CLA proportions, but can reduce the n-3 fatty acid proportions present in the longissimus.

Enhancement with varying phosphate types, concentrations, and pump rates, without sodium chloride on beef biceps femoris quality and sensory characteristics.

Beef biceps femoris muscles (n=45) were used to evaluate the effect of enhancement with solutions containing sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STPP), or tetrasodium pyrophosphate (TSPP) at either 0.2% or 0.4% of product weight, without sodium chloride. All solutions were injected into muscle samples at either 112% (12% pump) or 118% (18% pump) of raw product weight. Muscles enhanced with STPP or TSPP had a higher (P<0.05) pH than SHMP or untreated muscles (CNT), whereas there was no difference (P>0.05) in pH between SHMP and CNT. Muscles enhanced with STPP had less (P<0.05) free water than CNT, whereas SHMP and TSPP did not differ from CNT. However, direct comparison of phosphate types revealed no difference (P>0.05) in free water. Steaks enhanced with SHMP had greater (P<0.05) cooking losses than CNT, whereas steaks treated with STPP or TSPP did not differ (P>0.05) from CNT. Phosphate inclusion at 0.2% allowed for greater (P<0.05) cooking losses than CNT, whereas 0.4% phosphate inclusion exhibited similar (P>0.05) cooking losses as CNT. Although there were no differences (P>0.05) in cooking loss between pump rates, steaks enhanced at an 18% pump rate had greater (P<0.05) cooking losses than CNT, whereas those enhanced at 12% had similar (P>0.05) cooking losses as CNT. Enhancement with any of the three phosphate types or either concentration did not improve (P>0.05) sensory tenderness or juiciness characteristics compared to CNT, but enhancement at an 18% pump rate allowed for improved (P<0.05) overall tenderness, compared to a 12% pump rate. These results suggest that while phosphate enhancement independent of sodium chloride generally did not improve water retention, cooked yields and palatability compared to untreated samples, utilizing higher phosphate concentrations or utilizing STPP or TSPP effectively retained the additional water associated with solution enhancement, allowing for similar free water and cook yields as untreated samples.

Effects of enhancement with differing phosphate types, concentrations, and pump rates, without sodium chloride, on beef biceps femoris instrumental color characteristics.

Enhancement of beef biceps femoris muscles (n=45) with solutions comprising sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STPP), or tetrasodium pyrophosphate (TSPP) at either 0.2% or 0.4% of product weight, with the exclusion of sodium chloride, was performed to observe the independent phosphate effects on instrumental color during simulated retail display. All solutions were injected into muscle samples at either 112% (12% pump) or 118% (18% pump) of raw product weight. All three phosphate types maintained higher (P<0.05) L* values than untreated steaks (CNT) through 5 days-of-display, and SHMP had higher (P<0.05) L* values than STPP and TSPP through 7 days-of-display. Additionally, steaks with 0.2% phosphate inclusion were lighter (L*; P<0.05) than CNT throughout display, and were lighter (P<0.05) than steaks enhanced with 0.4% phosphates through 7 days of display. Steaks enhanced with TSPP had higher (P<0.05) a* values than CNT on days 5 and 7 of display, whereas SHMP- or STPP-enhanced steaks generally had similar (P>0.05) a* values as CNT after 3d of display. Direct comparison of phosphate concentrations revealed no differences (P>0.05) in a* values. Only steaks enhanced with TSPP were more vivid (P<0.05) and had higher (P<0.05) proportions of oxymyoglobin than CNT on days 5 and 7 of display. However, direct comparison of phosphate types indicated that TSPP- and STPP-enhanced steaks had similar (P>0.05) oxymyoglobin proportions during display. Phosphate inclusion at 0.4% maintained higher (P<0.05) oxymyoglobin proportions than 0.2% phosphate inclusion through 5 days-of-display. These results indicate that while 0.2% phosphate concentrations maintain lighter color, 0.4% concentrations can more effectively retain oxymyoglobin during display. Additionally, only steaks enhanced with TSPP were redder, more vivid, and had higher oxymyoglobin proportions than untreated steaks during the latter stages of display.

Impact of muscle type and sodium chloride concentration on the quality, sensory, and instrumental color characteristics of solution enhanced whole-muscle beef.

Beef biceps femoris (n=10; muscle sections, n=20; BF), infraspinatus (n=10; muscle sections, n=20; IS), and longissimus (n=10; muscle sections, n=20; LM) muscles were utilized to evaluate the effect of enhancement with phosphate and varying levels of sodium chloride in beef muscles differing in composition and palatability. Muscles were untreated or solution enhanced to 112% of raw product weight with sodium tripolyphosphate at 0.4% of product weight (STPP), or STPP and sodium chloride (NaCl) at 0.5%, 1.0% or 1.5% of product weight. There was a quadratic relationship (P=0.04) for percent free water to decrease and a linear relationship (P<0.01) for cook yield to increase as the level of NaCl increased. The IS steaks required less (P<0.05) shear force than either the BF or LM, with the BF and LM having similar (P>0.05) shear force values. There was a linear relationship (P<0.01) for shear force values to decrease with increasing salt concentration. Steaks from all four enhancement treatments had lower (P<0.05) shear force values than untreated steaks. Sensory overall tenderness ratings revealed that the IS and LM were similar (P>0.05) and superior (P<0.05) to the BF in tenderness. Steaks enhanced with STPP and 0.5%, 1.0%, or 1.5% NaCl all were rated more tender (P<0.05) than untreated or STPP-only treated steaks. The BF exhibited the lowest (P<0.05) L* (lightness) and a* (redness) values, as well as decreased (P<0.05) vividness. The LM generally exhibited superior color to the other two muscle types. There was a linear relationship (P<0.01) for L*, a*, b* (yellowness) values, and vividness to decline with increasing salt concentration, but steaks enhanced with STPP and 0.5% NaCl were similar (P>0.05) in a* values and vividness to untreated steaks. These results suggest that across three different muscles varying in composition and palatability, enhancement with 0.4% STPP and 0.5% NaCl allowed for improvements in palatability while minimizing the color deterioration associated with phosphate/salt enhancement.

Effects of sodium chloride, phosphate type and concentration, and pump rate on beef biceps femoris quality and sensory characteristics.

Beef biceps femoris muscles (n=45) were used to evaluate the effect of enhancement with solutions comprising 2.0% sodium chloride and either sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STPP), or tetrasodium pyrophosphate (TSPP) at either 0.2% or 0.4% of product weight. All solutions were injected into muscle samples at either 112% (12% pump) or 118% (18% pump) of raw product weight. Muscles treated with all three phosphate types had decreased (P<0.05) free water compared to untreated muscles (CNT), and while TSPP-treated muscles were able to bind greater (P<0.05) additional water than CNT, STPP- and SHMP-treated muscles did not differ (P>0.05) from CNT. Disregarding phosphate type, steaks with 0.4% phosphate inclusion bound more (P<0.05) water than those with 0.2% phosphate inclusion. Steaks treated with STPP or TSPP had decreased (P<0.05) cooking losses than CNT, while SHMP-treated steaks did not differ (P>0.05) from CNT. Steaks injected at 18% pump had greater (P<0.05) percent moisture, and did not differ (P>0.05) in free water, water binding, or cooking losses from steaks injected at 12% pump. Although there were no differences (P>0.05) in Warner-Bratzler shear force in this study, steaks with SHMP, STPP, and TSPP all were rated more tender, and juicier (P<0.05) by sensory panelists than CNT steaks or steaks enhanced only with sodium chloride. Regardless of phosphate type, steaks enhanced with 0.4% phosphate and those steaks at 18% pump received improved (P<0.05) sensory tenderness ratings compared to 0.2% phosphate and 12% pump, respectively. These results suggest that enhancing biceps femoris muscles with STPP or TSPP can improve water retention, yield, and palatability characteristics. Additionally, enhancement with a phosphate/salt solution at an 18% pump rate, compared to a 12% pump rate, can allow for improved sensory tenderness perceptions without decreasing product yields.

Effects of enhancement with varying phosphate types and concentrations, at two different pump rates on beef biceps femoris instrumental color characteristics.

The effect of enhancing beef biceps femoris muscles (n=45) with solutions comprising 2.0% sodium chloride and either sodium hexametaphosphate (SHMP), sodium tripolyphosphate (STPP), or tetrasodium pyrophosphate (TSPP) at either 0.2% or 0.4% of product weight on instrumental color during simulated retail display was investigated. All solutions were injected into muscle samples at either 112% (12% pump) or 118% (18% pump) of raw product weight. Muscles treated with all three phosphate types had lower (P<0.05) L* and b* values compared to untreated muscles (CNT). Steaks enhanced with STPP had similar (P>0.05) a* values as CNT, whereas SHMP- and TSPP-treated steaks generally had lower a* values than CNT. Across phosphate type, excluding day 3 of display, steaks treated with phosphate at 0.4% had similar (P>0.05) a* values as CNT, whereas those with 0.2% phosphate addition had lower (P<0.05) a* values than CNT. Across five days of display, STPP maintained higher (P<0.05) a* values than steaks treated only with sodium chloride, whereas SHMP did not differ (P>0.05) from sodium chloride-treated steaks. While STPP maintained a similar (P>0.05) saturation index as CNT, SHMP and TSPP generally had decreased (P<0.05) vividness during display. Additionally, excluding day 3 of display, phosphate concentration at 0.4% maintained similar vividness as CNT, whereas 0.2% phosphate concentration caused decreased (P<0.05) vividness, compared to CNT. The 630/580nm ratio results indicated that SHMP had less (P<0.05) oxymyoglobin than CNT throughout display. Disregarding day 3 of display, both STPP and TSPP had similar (P>0.05) oxymyoglobin proportions as CNT. These results indicate that STPP was the most effective phosphate type for maintaining color. Additionally, 0.4% phosphate concentrations can maintain color better than 0.2% phosphate concentrations. However, none of the phosphate/salt combinations produced superior color, compared to untreated steaks.

Evolutionary dynamics and preferential expression of homeologous 18S-5.8S-26S nuclear ribosomal genes in natural and artificial glycine allopolyploids.

Polyploidy is an important evolutionary process in plants, but much remains to be learned about the evolution of gene expression in polyploids. Evolution and expression of the 18S-5.8S-26S ribosomal gene family was investigated at homeologous loci in the Glycine subgenus Glycine perennial soybean polyploid complex, which consists of several diploid genomes that have formed allopolyploids in various combinations, often recurrently. A semiquantitative PCR method targeting the internal transcribed spacer (ITS) of the 18S-5.8S-26S nuclear ribosomal DNA (nrDNA) was used to survey the ratio between homeologous repeats in polyploid genomes and to test for preferential expression of homeologous nrDNA loci. Most natural polyploids possess one predominant nrDNA homeolog in their genome. Analysis of F2 segregation in an artificial cross suggested that in some plants, most or all repeats at one homeologous locus have been lost, whereas in other plants two loci remain, but both have been homogenized by concerted evolution. In most natural allopolyploids harboring a relatively balanced ratio of homeologs, one homeolog was expressed preferentially, but in the majority of plants, low levels of transcription could be detected from the other homeolog. Individuals within some tetraploid taxa varied as to which homeolog was expressed preferentially. In some plants, the degree of preferential expression also varied among tissues. Preferential expression was absent in synthetic polyploids and in some artificial diploid hybrids, suggesting that nucleolar dominance is not necessarily a direct result of hybridization or polyploidization. The establishment of preferential expression in Glycine allopolyploids appears to be either stochastic within lineages or genotype specific.

Multiple origins and nrDNA internal transcribed spacer homeologue evolution in the Glycine tomentella (Leguminosae) allopolyploid complex.

Despite the importance of polyploidy in the evolution of plants, patterns of molecular evolution and genomic interactions following polyploidy are not well understood. Nuclear ribosomal DNA is particularly complex with respect to these genomic interactions. The composition of nrDNA tandem arrays is influenced by intra- and interlocus concerted evolution and their expression is characterized by patterns such as nucleolar dominance. To understand these complex interactions it is important to study them in diverse natural polyploid systems. In this study we use direct sequencing to isolate and characterize nrDNA internal transcribed spacer (ITS) homeologues from multiple accessions of six different races in the Glycine tomentella allopolyploid complex. The results indicate that in most allopolyploid accessions both homeologous nrDNA repeats are present, but that there are significant biases in copy number toward one homeologue, possibly resulting from interlocus concerted evolution. The predominant homeologue often differs between races and between accessions within a race. A phylogenetic analysis of ITS sequences provides evidence for multiple origins in several of the polyploid races. This evidence for diverse patterns of nrDNA molecular evolution and multiple origins of polyploid races will provide a useful system for future studies of natural variation in patterns of nrDNA expression.

Carcass and beef color characteristics of three biological types of cattle grazing cool-season forages supplemented with soyhulls.

Soyhull supplementation to divergent biological types of cattle on forage-based systems was studied to determine the impact on carcass and color characteristics. Weaned calves (n=107) biologically classified as large-, medium-, or small-framed and intermediate rate of maturing were allocated to three cool-season grazing systems consisting of either orchardgrass pasture or fescue pasture, each with soyhull supplementation, or fescue pasture with no supplementation as a control. Supplementing cattle with soyhulls allowed for heavier (P<0.05) live and carcass weights, larger (P<0.05) longissimus muscle area, increased (P<0.05) backfat, kidney, pelvic and heart fat (KPH), and yield grades, and improved (P<0.05) marbling scores and quality grades. Utilizing cattle biologically classified as large- or medium-framed allowed for heavier (P<0.05) carcass weights without reducing (P<0.05) marbling scores or quality grades when compared to small-framed cattle. Instrumental color analysis of lean and adipose tissue revealed improved (P<0.05) lightness (L (∗)) in lean color for supplemented carcasses as compared to the control. There were no differences (P<0.05) between dietary treatments for L (∗), a (∗) or b (∗) values of adipose tissue. These results indicate that supplementing forage-grazing cattle with soyhulls can improve carcass merit, and utilizing large- or medium-framed cattle can allow for increased carcass weights without decreasing carcass quality.