Marker-assisted selection for complex trait in common bean (Phaseolus vulgaris L.) using QTL-based index

A procedure was developed for marker-assisted selection of complex traits for common bean (Phaseolus vulgarisL.) using an index based on QTL-linked markers and ultrametric genetic distances between lines and a target parent. A comparison of the mean seed yields of the top five lines selected by different schemes demonstrated that the highest yielding group was selected on the basis of a combination of phenotypic performance and a high QTL-based index,followed by groups identified by a high QTL-based-index, conventional selection,and a low QTL-based-index. This study demonstrated a simple way to use information obtained from QTL studies to make selection decisions. The study also showed that the use of the QTL-based-index in conjunction with the ultrametric genetic distance to the target parent would enablea plant breeder to select lines that retain important QTL in a desirable genetic background. Therefore, this type of MAS would be expected to be superior to the phenotypic selection. This revised version was published online in August 2006 with corrections to the Cover Date.     

Pharmacokinetics of pentoxifylline and its 5-hydroxyhexyl metabolite following intravenous administration in cattle

This study investigated the pharmacokinetics of pentoxifylline (PTX) and its 5-hydroxyhexyl metabolite (M-I) after single-dose intravenous (IV) administration (10 mg/kg) of PTX in six healthy cattle. The safety of PTX was evaluated by clinical observation and biochemical analysis. Plasma concentrations of PTX and M-I were simultaneously determined by reverse-phase high performance liquid chromatography. Pharmacokinetic parameters were calculated using non-compartmental methods. Salivation and discomfort were observed for 2 h following the drug administration. Serum direct bilirubin, total bilirubin, and phosphorus levels at 24 h following the drug administration were significantly different from the control values (0 h) (P?<?0.05). Pharmacokinetic variables of PTX were characterized by a short terminal elimination half-life (1.05?±?0.19 h), a large volume of distribution (6.30?±?1.76 L/kg), and high total body clearance (5.31?±?1.27 L/h/kg). The mean ratio between the area under the concentration-time curves of M-I and PTX was 1.34. These results indicate that single-dose administration of PTX at 10 mg/kg IV in cattle resulted in therapeutic concentrations similar to those observed in humans and horse. However, further studies are necessary to determine the safety and pharmacokinetics following repeated administrations of PTX.

     

Population structure and association mapping of traits related to reproductive development in field pea

Field pea (Pisum sativum) is an important pulse crop globally for human consumption and livestock feed. A panel of 92 diverse pea cultivars was evaluated across nine environments and genotyped using 1536 single nucleotide polymorphisms (SNPs) arranged in a GoldenGate array. Population structure analysis revealed three subpopulations roughly consistent with the cultivar origin. Phenotyping included days to flowering (DTF), duration of flowering (DOF), number of reproductive nodes, number of pods on the main stem, percentage of pods set, percentage of pods retained with seed and pollen germination reduction due to heat stress. Association analyses identified a total of 60 SNPs significantly associated (?log₁₀ p ≥ 4.3) with these seven reproductive development-related traits. Among these 60 marker-trait associations, 33 SNPs were associated with the onset of flowering, 8 SNPs with pod development and 19 SNPs with the number of reproductive nodes. No SNP marker was significantly associated with in vitro pollen germination reduction caused by high temperature stress. We found that 12 SNPs associated with DTF and 2 SNPs associated with DOF overlapped with the SNP markers associated with the number of reproductive nodes. Genomic regions associated with variation for reproductive development-related traits identified in this study provide grounds for future genetic improvement in pea.     

Characterization of 169 diverse pea germplasm accessions for agronomic performance, Mycosphaerella blight resistance and nutritional profile

Improved agronomic performance and nutritional profile are among the major objectives in pea breeding, but the narrow gene pool available in pea germplasm has slowed progress. Therefore, the objective of this work was to evaluate 169 diverse pea accessions from Eastern Europe, Western Europe, Australia and Canada for agronomic performance, Mycosphaerella blight resistance and nutritional profile under western Canadian growing conditions. In general, eastern European accessions required less days to flower, had higher protein, acid detergent fibre and neutral detergent fibre concentrations in the seeds, compared to western European and Canadian pea accessions, which had better lodging resistance, less days to maturity, higher grain yield and seed weight, greater resistance to Mycosphaerella blight and powdery mildew and higher starch concentration in the seeds. Significant correlations were observed between different traits. Principal component analysis revealed significant variation among traits with the first four principal components explaining 68 % of the total variation. The wide range of variation in agronomic performance, Mycosphaerella blight resistance and nutritional profile detected will provide useful parents for pea breeding.     

Estimation of the Colour Properties of Apples Varieties Using Neural Network

The consumer acceptance and the quality standard of agricultural products such as apple are determined mostly by their colour. Colour is measured with a colorimeter and quantified using the C.I.E. L^*, a^*, b^* colour space system. It is used commonly by researchers for the classification and identification of apple fruit. To the best of our knowledge, the present study is the first study investigating the prediction of some colour properties of six apple varieties through artificial neural networks (ANN). The apple varieties are ‘Amasya’, ‘Starking’, ‘Granny Smith’, ‘Pink Lady’, ‘Golden Delicious’, ‘Arapk?z?’ and the colour properties are L^* (lightness), a^* (redness), b^* (yellowness), C^* (chroma), h^* (hue angle), CI (chroma index). General Regression Neural Networks (GRNN) and Adaptive Neuro Fuzzy Interface System (ANFIS) structures were employed to predict the colour properties. According to the experimental and simulation results, the proposed ANFIS predictor had a superior performance in prediction of these colour parameters.     

Investigation of pharmacokinetic interaction between ivermectin and praziquantel after oral administration in healthy dogs

The purpose of this study was to determine the pharmacokinetic interaction between ivermectin (0.4 mg/kg) and praziquantel (10 mg/kg) administered either alone or co‐administered to dogs after oral treatment. Twelve healthy cross‐bred dogs (weighing 18–21 kg, aged 1–3 years) were allocated randomly into two groups of six dogs (four females, two males) each. In first group, the tablet forms of praziquantel and ivermectin were administered using a crossover design with a 15‐day washout period, respectively. Second group received tablet form of ivermectin plus praziquantel. The plasma concentrations of ivermectin and praziquantel were determined by high‐performance liquid chromatography using a fluorescence and ultraviolet detector, respectively. The pharmacokinetic parameters of ivermectin following oral alone‐administration were as follows: elimination half‐life (t_1/2λz) 110 ± 11.06 hr, area under the plasma concentration–time curve (AUC_0–∞) 7,805 ± 1,768 hr^.ng/ml, maximum concentration (C_max) 137 ± 48.09 ng/ml, and time to reach C_max (T_max) 14.0 ± 4.90 hr. The pharmacokinetic parameters of praziquantel following oral alone‐administration were as follows: t_1/2λz 7.39 ± 3.86 hr, AUC_0–∞ 4,301 ± 1,253 hr^.ng/ml, C_max 897 ± 245 ng/ml, and T_max 5.33 ± 0.82 hr. The pharmacokinetics of ivermectin and praziquantel were not changed, except T_max of praziquantel in the combined group. In conclusion, the combined formulation of ivermectin and praziquantel can be preferred in the treatment and prevention of diseases caused by susceptible parasites in dogs because no pharmacokinetic interaction was determined between them.     

Determination of milk/plasma ratio and milk and plasma pharmacokinetics of amoxicillin after intramuscular administration in lactating cows

This study was conducted to determine the passage ratio of amoxicillin into milk and its pharmacokinetics in milk and plasma after intramuscular administration. Five healthy dairy cows (Holstein, weighing 450–500 kg, aged 2–4 years) were used in this study. They received single intramuscular amoxicillin at a dose of 14 mg/kg body weight. Blood and milk samples were collected prior to drug administration (0); after 15, 30, 45, 60, and 90 min; and 2, 3, 4, 6, 8, 10, and 12 hr after administration. The plasma and milk concentrations of amoxicillin were determined using high‐performance liquid chromatography with ultraviolet detection. The passage ratio of amoxicillin into milk and plasma was determined using both AUC‐based calculation and milk and plasma concentrations at sampling times; it was calculated 0.46 and 0.52, respectively. The terminal half‐life and mean residence time of amoxicillin were 6.05 and 8.60 hr in plasma and 2.62 and 5.35 hr in milk, respectively. The C_max2 levels of amoxicillin in plasma and milk were measured as 1,096 and 457 ng/ml, respectively. It was observed that amoxicillin exhibited a secondary peak in plasma and milk. This study was the first to report on the passage ratio of amoxicillin into milk in lactating cows.