Thesis (M. Sc.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on June 9, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Animal Science, Department of Agricultural, Food and Nutritional Science, University of Alberta. Includes bibliographical references.

The enormous burning of fossil fuel and deforestation have caused an increase in the atmospheric CO₂ concentration ([CO₂]) during the last century. This will invariably have profound direct and indirect effects on plant carbon metabolism. The majority of research on the effects of CO₂ enrichment on plants are short-term and are done on other crops, but very little have been done on barley. This project aimed to determine the effects of long-term CO₂ enrichment on photosynthesis, growth and grain yield on barley. Hordeum vulgare L. cvs Stirling and Schooner plants were grown from seeds in controlled environment chambers at ambient (350) and elevated (600) μmol molˉ¹ [CO₂]. Measurements of net assimilation rate (NAR), photosynthetic pigments content and growth parameters were started 7 days after germination (DAG) and continued until senescence. The anatomy of matured fully developed leaves was also monitored. Elevated [CO₂l resulted in an increase in NAR in the two cultivars from days 7 until 14, after which the stimulation of NAR of CO₂-enriched plants started to decrease. At the onset of senescence, NAR was almost equal in plants grown under both ambient and elevated [CO₂]. The response of assimilation as a function of internal [CO₂l (C₁) at the end of the experimental period showed a significant decrease in both the initial slope of the A/C₁ curves and the CO₂-saturated photosynthetic rates in the two cultivars. Stirling showed no significant changes in the content of chlorophyll α,chlorophyll б or in total carotenoids. However, Schooner showed a stimulation in chlorophyll α content at day 7, but decreased at day 28. Chlorophyll б and total carotenoids content were not affected by CO₂ enrichment. While total above-ground biomass was not affected by elevated [CO₂] in the two cultivars, total plant height decreased significantly after 14 days in Stirling whereas no significant change occurred in Schooner throughout the experimental period. Leaf area was not significantly affected by CO₂ enrichment in the two cultivars although the leaves in CO₂ enriched plants were slightly shorter. Anatomical studies reveal that leaf thickness was significantly increased by CO₂ enrichment in Stirling, but the increase was not significant in Schooner. Both cultivars did not show any significant effect on chloroplast morphology and ultrastructure as a consequence of elevated CO₂ exposure. No signs of starch accumulation were evident in variety Schooner, but Stirling showed some form of starch accumulation, under increased atmospheric [CO₂]. Elevated CO₂ resulted in a significant reduction by more than 50 % in the number of grain yield per plant in both Stirling and Schooner. Results from this study therefore indicate that CO₂ enrichment will not be beneficial in terms of growth and yield in this important crop.

The linkage relationship and arm location of the gene for greenbug resistance in the variety Will was determined by using primary trisonomics and tertiary trisomic homozygous translocations. The gene for greenbug resistance was found to be on linkage group 1 by using primary trisonomics. The gene was located on the cetromere segment of the Tl-6a translocation by using a tertiary trismoic homozygous for greenbug resistance. The data further substantiates the feasibility of using trisomics in placing genes on proper linkage groups.

No description available.

The purpose of this experiment is to test the relative yields of grain from across-bred grains s.s compared with self fertilized seed of the same varieties. It was originally purported to make these tests with both wheat and barley. However, owing to unfavorable greenhouse conditions the wheat plants bloomed very poorly and the crosses made set very little seed so the wheat was dropped and the work done entirely with barley. Before entering into the details of the work conducted, a brief review will be made of small grain breeding work at other places. The Agricultural Experiment Station of Wisconsin has only recently issued a bulletin on barley cultivation. Barley being one of the principal crops of Wisconsin, the Experiment Station has made considerable effort to improve the seed production. Individual selection and crossbreeding have been carried on extensively. Up to the present time no cross-bred varieties have been developed that compare favorably with the pure strains. Their great work has been in individual selection and the production of the so-called pedigree barleys. They started by procuring foundation stock from the best varieties in the United States and Canada. These were planted in small plats and watched carefully during their growth. At harvest time the best heads were selected from the best plants. These were in turn grovm in centgener beds and again selected. After five years of this close selection larger quantities of seed were saved and planted. The sixth year small quantities of this seed were sent out to co-operating students all over the state. In this way the new varieties were disseminated throughout the state and were soon available to every farmer in the state. The Wisconsin station bred for large yields, for resistance to smuts, and for uniformity in size and quality of grain, in length and strength of straw and in time of germination and maturity. In twelve years time sixteen different strains of pedigree barley were developed that were superior to the old strains.The six-row bearded was found to be superior to all other varieties. Minnesota has probably done as much or more work than any other State in breeding and improving wheat. The Experiment station has been working for twenty-five years to produce improved strains for the use of Minnesota farmers and have been well repaid in many cases. Their work has been along the usual lines of cross breeding and selection. Two kinds of cross breeding were practiced - out-crosses and in-crosses. Out-crosses were made between plants of different varieties and in-crosses between plants of the same variety. The seed from these crosses was planted and the best one plant from each arose selected to continue the breeding. This individual selection was continued for several years before it was put out as a new variety. In this way several new varieties were developed that yielded very creditably with the best of the old varieties. However, it was found that large numbers had to be worked with in order to get even one cross that was good. The vast majority of them were no good. While out-crosses were harder to get than in-crosses, they gave more evidence of being crossed than did the in-crosses. Only one of the in-crosses showed enough variation from the parent stock to indicate that it was hybrid. Some of the best known varieties originating from crosses are the Fife and Blue stem wheats. After establishing a new variety it was disseminated throughout the state in much the same way as the barley varieties were in Wisconsin. The gain to the farmers of the state by this practice has been immense. It made available for the farmer pedigreed seed that was far superior to the scrub stock commonly used. The Nebraska Experiment station nas done a great deal of wheat breeding work in last twenty years, mainly along lines of selection. In former years the greater part of the wheat grown in Nebraska was spring wheat. The wields were not what they should be so attention was turned to winter wheats. The experiment station took the matter up and has developed a winter wheat that has increased the yield five bushels and more per acre. The variety found to be best suited to Nebraska was the Turkey Red. Dr. T. L. Lyon undertook to improve this variety by a systematic method of selection. To start with he took one thousand select heads and planted them in separate rows in the nursery. The second year the best heads from these rows were planted. This was continued for three years, some of the poorest being discarded each year. At the end of three years. The seed was planted in thirtieth-acre plats. For five years this was continued until good comparisons could be made of the various strains. Then the wheat was sold in ten bushel lots, in different sections of the state on the condition that the buyer should seed according to instructions and make a report on the results. The reports showed that an average of twenty-one tests in twenty counties gave a net increase of four bushels per acre over the local Turkey Red Wheat. In only three instances did the local wheat excel the improved strains. Dr. Hjalmar Wilssen of the Swedish Experiment Station, has done a great deal of breeding work with small grains. He has made selections tending toward improvement along all lines. In some instances he has been successful and in others very unsuccessful. He found that deficiencies of technical nature could be overcome, such as length of spikelet but where the foundation principles were concerned it was more difficult and sometimes impossible. One of his failures was an attempt to breed few stronger culms in barley. One of the most valuable barleys grown in Sweden was disposed to lodge or fall down. Nilsson tried to remedy this by selection. He spent years of hard work on the problem but never accomplished anything and finally gave it up. He later accomplished his end problem by producing another strain of barley which had as good quality as the old, and at the same time had strong culms. / Master of Science

The impact of rate and timing of spring nitrogen application on yield and composition of barley forage and grain and the fermentation and utilization of barley silage was investigated in a 3-yr study. The use of a growth regulator, ethephon, was also investigated. Nitrogen application at a rate of 135 kg/ha increased forage yields in 1984 and tended to increase yields in 1985 and 1986 though dry conditions existed. Crude protein yield was increased with application of 135 kg N/ha all three years. Major impact of N. fertilization appeared to be associated with an application at Feekes stage 5. Nitrogen treatments had little impact on nitrate, NDF or ADF concentration but higher rates generally lowered forage dry matter. Use of N resulted in increased dry matter intake and increased dry matter, crude protein, NDF, and ADF digestibility of silage when fed to lambs. In 2 of 3 yr grain yield appeared to be lowered as forage yield increased due to N treatment. Grain crude protein and crude protein yields were increased with the use of N. Increases in grain crude protein content were associated with applications of N at Feekes stage 5. Generally, test weight and 1000 kernel weight decreased and the number of tillers increased at rates of N application were increased. Use of Ethephon tended to increase yields in 1984 and increased yields in 1985. / M.S.

No description available.

3 pp. / Revised / Weeds can be a problem in wheat and barley especially where crop rotation is not practiced. An integrated approach to weed management can be followed. Chemical treatments are important tools in weed management to maintain yield and quality and prevent proliferation of weeds that could affect future crops.

Plants that are heterozygous for genetic markers but do not produce segregating progeny may be suspected of carrying a mutation conditioning apomixis. Seed stocks in which heterozygous plants could be identified phenotypically were treated with a chemical mutagen. These seed stocks were heterozygous for recessive genetic markers, and/or heterozygous for a chromosome translocation. Spikes from heterozygous M1 plants were harvested and seeded in bulk. Spikes from heterozygous M2 plants were harvested and planted in M3 rows. The M3 rows were observed for the absence of segregating progeny and/or were observed cytologically for the presence of a heterozygous translocation. M3 rows not segregating for the genetic markers were crossed onto plants homozygous for the genetic markers. The F1 progenies were observed for an expected ratio of 1 normal: 1 recessive plant. All nonsegregating lines were found to be non-heterozygous. These lines most likely occurred due to seed and pollen contamination or were the result of crossing over between genetic markers. Fertile M2 plants were harvested from the treated heterozygous translocation seed stock. Normally, barley plants heterozygous for a translocation will produce semisterile spikes. Plants that would normally be semisterile but are fertile could be carrying a mutation conditioning apomixis. Progeny of the fertile M2 plants were examined cytologically for the presence of the heterozygous translocation. All selected lines contained the normal seven pairs of chromosomes and were the result of seed or pollen contamination. Seed stocks which could eliminate the problem of contamination in future experiments were developed and discussed. Haploviable mutants closely linked with the male sterile locus, msg2, were isolated in these seed stocks. Haploviable mutants are recognized by upset genetic ratios of alleles linked with the mutant. Selfed progenies of plants carrying a haploviable mutation contained fertile and male sterile plants in about a 1:1 ratio. Mostly male sterile progenies were obtained when plants heterozygous for the haploviable mutant and the male sterile allele were crossed onto male sterile plants. Four lines containing haploviable mutants were evaluated for their usefulness in producing all male sterile lines for hybrid barley production.

Young barley seedlings (Hordeum vulgare L.) were stressed using nutrient solutions containing NaCl or polyethyleneglycol (PEG) and measurements were made of leaf growth, water status, proline soluble sugar contents of growing (basal) and non-growing (blade) tissues. Leaf growth ceased within seconds following exposure of seedlings to osmotic solutions with water potential values (ψ) = -3 to -11 bars but growth resumed after a lag period. Latent periods were increased and new growth rates were decreased as ψ of nutrient solutions were lowered. Growth ceased before detectable changes occurred in tissue water status but leaf basal tissues began to adjust osmotically, and reductions of 1 to 2 bars in both ψ and osmotic potential (π) usually occurred for the first 1 to 2 hours with lower reduction rates thereafter. After 1 to 3 days exposure of seedlings to solutions with different ψ, cumulative leaf elongation was reduced as the ψ of the root medium was lowered. Reductions in ψ and π of tissues in leaf basal regions paralleled growth reductions, but turgor (P) was largely unaffected by stress. In contrast, ψ, π and P of leaf blades were usually changed little regardless of the degree and duration of stress, and blade ψ were always higher than ψ of basally located cells. It is hypothesized that blades have high ψ and are generally unresponsive to stress because water in most of the mesophyll cells in this area does not exchange readily with water present in the transpiration stream. Measurements of proline contents in different sections of leaf following water stress, showed that in living tissues proline levels are dynamically related to water status of the tissue. In the basal regions where reductions in ψ and π occurred rapidly, proline levels were elevated quickly, whereas, accumulation of proline in mid-blade tissues occurred slowly and in lower concentrations. The combined data of many experiments showed a strong correlation between proline levels and tissue ψ (r = 0.93) and π (r = 0.85). Increase in total soluble sugars (TSS) and ion concentrations, contributed significantly to the stress-induced osmotic adjustment observed in the growing tissue.