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Field pea (Pisum sativum L.) as a cool season legume crop is sensitive to high day time temperature, especially during flowering. A population of 107 recombinant inbred lines (RILs) known as PR-11 was made from the cross of CDC Centennial (heat tolerant cultivar) X CDC Sage (heat sensitive cultivar) with the objectives of screening heat tolerant traits during flowering and subsequent seed development, and to map the quantitative trait loci (QTLs) responsible for these traits. Experiments were carried out in 2012-2014. PR-11 was seeded at normal seeding dates in 2012 and 2013 at Saskatoon (52º12’N, 106º63’W) and Rosthern (52º66’N, 106º33’W) in Canada, and in 2014 PR-11 was seeded at both normal and late seeding (three weeks later than normal) dates at one location, Saskatoon. Correlation analyses demonstrated that the duration of flowering (DOF) was positively associated with final seed yield under both normal and late seeding date conditions. Yield component traits on the main-stem [reproductive node number (Rnode), pod number (Pod), seed number per pod (Seed), single seed weight (SSW)] were significantly associated with main-stem seed yield, among which pod number appeared to be the component most positively associated with seed yield. However, yield on the main-stem was not significantly associated with seed yield at the plot level, which inferred that the contribution of seed yield on side branches was important. A genetic map consisting of 369 SNPs markers with a total coverage of 746 cM was developed using JoinMap 4.0. A total of 14 QTLs were detected under environments with normal seeding date, six for flowering traits, and eight for yield component traits. Eight QTLs were identified at late seeding, four for flowering traits and four for yield component traits. The total variation in days to flowering (DTF), DOF, Pod, Seed, SSW and grain yield that were each explained by the QTLs under normal seeding environments was 24 %, 43%, 15%, 32%, 34% and 21%, respectively. The QTLs together accounted for 43% of DTF variation, 14% of DOF variation, 17% of Pod variation, 12% of SSW variation and 12% of grain yield variation at the late seeding date. Lines PR-11-2, PR-11-88 and PR-11-91 performed as the top yielding lines under both normal and late seeding environments, and could be considered as heat tolerant lines.

The aim was to develop new methods for measuring texture of Atlantic salmon (Salmo salar L.) fillets and investigate the genetic basis of flesh quality traits. Firstly, a new tensile strength method was developed to quantify the force required to tear a standardized block of salmon muscle with the aim of identifying those samples more prone to factory downgrading as a result of gaping. The repeatability, sensitivity and predictability of the new technique was evaluated against other common instrumental texture measurement methods. Data from the new method were shown to have the strongest correlations with gaping severity r=-0.514, P<0.001) and the highest level of repeatability of data when analysing cold-smoked samples. The Warner Bratzler shear method gave the most repeatable data from fresh samples and had the highest correlations between fresh and smoked product from the same fish (r=0.811, P<0.001). It is therefore recommended that the new method be adopted for measuring gaping potential and the Warner Bratzler method become the standard for firmness assessment. Genes associated with post mortem softening in mammals were characterised in Atlantic salmon. A previously unknown ancient paralogue of calpastatin (here named CAST2) was identified. Evidence was provided for the existence of highly homologous recent paralogues of CAST2 and CTSD1. Evidence for the ancestral history of these paralogues was provided by phylogenetic analysis. Recent gene duplicates of 6 further genes were identified. In all cases, homology between recent paralogues was greater than 94%. Analysis of synonymous vs non-synonymous nucleotide substitution between the observed paralogue pairs shows a significant purifying selection in most cases. The CTSD1 gene shows significant purifying selection in a pairwise analysis between 12 teleost species (all cases P<0.0001) but a similar analysis of CTSD2 revealed no significant occurrence of purifying selection. The present study provides further support for the idea of asymmetrical selective pressure on paralogues. Genetic markers were developed that can distinguish individuals with above average fillet yield and texture. A database of firmness, tensile strength and fillet yield was made from 254 individuals from 5 batches of farmed salmon and these fish were genotyped at 7 novel SNP loci. Individuals with the combined favourable genotype at CAPN1a and MYOD1b were associated with an average increase in fillet yield of 2.7% above batch average. A combined genotype of CAPN1a, MYOD1b and MYF5 was significantly associated with an average increase in tensile strength of 9.8% above batch average (P=0.015). In both cases individuals with the combined favourable genotype occurred with a frequency of c. 6% across all batches. The favourable genotypes had no unfavourable effects on other traits. Highly polymorphic microsatellite loci were used to perform tests of assignment, which revealed an overall correct assignment rate of 92.7% to batch of origin and a minimum reference sample number of 25 was empirically determined. A phylogenetic analysis supported the results of the assignment tests. Given that 7 microsatellites is a relatively small number for a study of this nature, these results suggest that reliable assignment of unknown fish to the true batch of origin is potentially rapid and cost effective. Overall, the thesis presents molecular markers for broodstock selection, new genes of relevance to flesh quality, a new method of texture analysis and a proposal for an escapee traceability project.

The purpose of this research is to develop a dataset for some of the most important fire characteristics, namely CO2 yield, CO yield, HCN yield, soot yield and heat of combustion for probabilistic analysis and modelling. Raw data in time series are required to mechanically reduce experimental data into yields (kg/kg) and effective heats of combustion (MJ/kg), which are expressions for the amount of products generated per unit mass of fuel. Mass loss rate thresholds were applied to all tests to define the beginning and end of tests. These species yields and heat of combustions were then grouped by material compositions and fitted with distribution functions to produce distributions curves. As fire species productions and heat of combustions are dependent on the fire conditions as it develops, different yields are expected at different fire stages. These have been identified as the growth (G), transition (T), and smouldering (S) stages in this research. These values are also compared against, and are generally in agreement with, other research data. Nonetheless, some discrepancies have occurred and require further information to ascertain the material characteristics and combustion conditions. In conclusion, design recommendations for these fire characteristics have been made for several material groupings and verified against other research results. Certain physical and chemical limitations exist for combustions and have not been reflected in the fitted distribution, including stoichiometric yields and unlimited air yields. As such, species yields and heat of combustions beyond these values should not be considered in fire engineering design and analysis. Research results on HCN including all required data parameters for yield conversions were difficult to obtain and require further research efforts. Tube furnace results were initially investigated. Unfortunately, without a continuous mass record, has proved to be challenging in producing reliable mass loss rate profiles for yield conversions. A semi-automated data reduction application UCFIRE was also used. However, certain technical difficulties were encountered and require modifications to broaden its applicability.

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Urea was applied uniformly inside alfalfa hay bales at baling or on top of bales subjected to rain and weather damage. Hay temperature, color, mold retardation and chemical composition were measured. Also, 24 lactating cows were used to test acceptability of the urea-treated hays. Cows were blocked for 14 d pre-treatment milk production and randomly assigned to one of six treated hays for 3 wk (4 cows/group). Cows were then reassigned at random to another hay for an additional 3 wk. Addition of 1% or more urea to high moisture alfalfa hay resulted in higher nutritional quality through reducing bale temperatures, non-enzymatic browning, and moldiness, compared to high moisture untreated hay. Urea treatment of high moisture hay decreased ADF and NDF content, while increasing digestibility of their fiber components. Urea treated hays were readily eaten by cows with no significant differences (P>.05) between treatments in DM intake, milk production, milk composition, or DM, ADF, and NDF digestion coefficients. Five types of alfalfa hay varying in % ADF were fed to 40 lactating cows. Cows were divided into 10 groups of 4 each based on 14-d pre-treatment milk. Each hay was mixed in TMR diets with 50 or 65% concentrate. In vivo and in situ trials were conducted to determine DM, ADF and NDF digestion. Results indicated that DMI, 3.5% FCM, cows body weight, body score, rectal temperature, and milk composition except milk fat were not affected by type of hay or level of concentrate. Milk fat was affected by level of concentrate (P<.16) while milk production was affected by type of hay (P<.01). Dry matter digestion coefficients for the complete rations showed no change with increased ADF in hay. Large decreases were noted in in situ DM, ADF, and NDF digestion as hay ADF increased. In another experiment, 32 mid to late lactation cows were used in a 41 d production trial. Cows were fed 2 levels of concentrate (25 vs. 50%) with alfalfa hay. Data indicated that DMI, milk yield, 3.5% FCM, milk composition, and other parameters did not differ between treatments. This might be due to the lack of response to higher concentrate level.

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No description available.