This study was conducted to investigate the possible contamination
of foreign pollen at different stages of a wheat breeding
program. These included spaced planted F₂ segregating populations,
replicated yield trials and seed multiplication. The experimental
wheat materials consisted of four different F₂ populations, four
cultivars and two experimental lines.
Two...
Pre-harvest sprouting in wheat costs farmers millions of dollars every year. Pre-harvest sprouting tolerance (PST) has minimized this problem, but improvement of PST is still necessary. Synthetic hexaploid wheats (synthetics) have been used as sources of
genes coding for many useful traits. Two studies evaluated the PST of a synthetic...
Extensive research has been devoted to evaluating potential
genotype-environment interactions. However, plant breeders are still in
need of a simple way to describe how genotypes respond to different
locations and years. In an environmentally diverse state like Oregon,
significant genotype-environment interactions do occur The resulting lack
of association between actual...
Until recently, the viscoamylograph had been the primary method for
measuring starch as it relates to noodle quality in wheat. This method
requires a large sample of flour and is time consuming. With the introduction
of the rapid visco-analyser (RVA) in 1986 and the more recent flour swelling
volume procedure,...
To remain competitive in the international marketplace,
soft white wheat cultivars grown in the Pacific Northwest
must have consistent and predictable flour properties
including kernel texture. As a consequence, there is a need
to develop wheat cultivars for specific end uses. Wheat
cultivars with very soft kernels are used largely...
The Asian noodle market is responsible for the increased volume of wheat
imported to that region in recent years. Soft white wheat produced in the Pacific
Northwest is mainly used for baked products, whereas an Australian wheat,
Australian Standard White, is preferred for noodles. To enter this market soft
white-wheat...
Durum wheat cultivars for North-Eastern Oregon have to be competitive
in terms of their yield potential with soft white winter wheat cultivars and meet
strict quality requirements of the milling industry. Combining the high yield
potential of fall planted durum wheat cultivars which have an acceptable level of
winter hardiness...
The success of a plant breeding program depends upon the availability of
useable genetic diversity. Such diversity may be enhanced depending on the type of
hybridization strategy employed. Segregating progenies resulting from F2
populations, a double cross, and a top cross were compared for the amount of
useable genetic diversity...
Crosses between four near isogenic lines for height reducing genes
Rht₁ and Rht₂ and one agronomically superior dwarf line, including
generations through F₃ with reciprocal backcrosses constituted the
experimental materials. Mean, range and standard deviation values for
eleven traits pertaining to the different generations were obtained.
Heterosis and inbreeding depression...
The objective of this study was to compare three genetically
different groups of winter wheat for their grain yield. Experimental
material consisted of parental lines grown in pure stands, hybrids, and
1:1 mixtures of the parental combinations. Three sites were employed to
evaluate possible interactions between the different groups across...
Grain yield and grain protein are often negatively associated in
wheat. When yield increases and grain protein decreases, there can be
an adverse effect on the milling and baking quality if the desired end
product is bread flour. It has been suggested that this inverse
association is the result of...
Effective chemical control of pollination would
provide an alternative to the cytoplasmic male-sterile
system in hybrid wheat (Triticum aestivum L.) production.
The objective of this study was to determine
concentration, formulation, growth stage of application
and genotypic effects on levels of induced pollen
suppression and subsequent natural out-crossing from
foliar...
Parents and progeny populations from a cross of 'Stephens'x 'Tibet dwarf' were grown in a spaced-planted experiment to obtain information concerning the nature of inheritance and possible associations between grain yield and the components of yield. Agronomic traits measured on an individual plant basis were: heading date, days to maturity,...
Physical properties of gluten and pigment content are of primary importance in determining quality in durum wheat (Triticum turqidum L. var. durum). The objective of this investigation was to evaluate the contribution of different -y-gliadin protein subunits in durum wheat pasta quality as measured by the sodium dodecyl sulphate microsedimentation...
The effects of some soil- and foliar-borne biotic factors on
grain yield and the components of yield were evaluated using five
winter wheat varieties sown at two dates. Within each planting date,
varieties were grown under four different combinations of two soil
treatments (fumigation and nonfumigation) and two foliar treatments...
Concerns about the genetic control and environmental influence
of various stages of development including the grain filling period,
and the relationship between early maturity and grain yield prompted
this study.
The experimental material consisted of two facultative and two
winter wheat cultivars. A dial!el cross, excluding reciprocals, was
also developed...
Three stem rust Puccinia graminis graminicola, resistant sources of perennial ryegrass, Lolium perenne, 4A, 48A, and 77A, were crossed in a partial diallel design with one susceptible source, MP-2, resulting in six crosses excluding reciprocals. The F1's and cloned parental populations were inoculated in the field and rated on a...
Four isogenic lines possessing different combinations of height
reducing genes Rht₁ and Rht₂ from 'Norin 10' were crossed to a short
stature, early maturing, septoria susceptible cultivar identified as the
'Tibet Dwarf'. The isogenic lines originated from the backcross
population of 'Itana'/3/'Norin 10'/'Brevor 14'//6*'Itana'. Parents, F₁
and F₂ generations provided...
Immature embryo explants taken eight days after anthesis were used
to establish callus cultures of spring barley. Two types of calli
were observed. A soft watery callus which produced a limited number
of shoots and a harder yellowish callus that gave rise to numerous
green primordia and shoots. Gamborg's B5...
Concerns about the possible reciprocal differences resulting from
systematic crossings of winter and spring wheat gene pools prompted
this investigation. If traits can be improved by simply reversing the
direction of a cross, then identification of the best female parent in
a cross would be helpful for breeding programs.
Two...
Ten wheat crosses (four winter x spring and six winter x winter)
involving F₃ and F₄ generations and their respective winter parents
were used to determine whether the early generation selection would
be effective for kernel hardness and grain protein content. In
1980, twenty individual F₂ plants were selected with...
Concerns regarding the most effective means of evaluating
segregating generations of spring barley prompted this investigation. Three methods of selection were considered: bulk, pedigree, and single seed descent. F₆ lines derived by each method
were grown in a replicated yield trial. The effectiveness of each
method was measured in terms...
The need to develop a shorter life cycle wheat cultivar which
would be more adapted to multiple cropping systems prompted this
study. Thus the following information was obtained.
Greatest variations in developmental patterns were found in the
stem elongation, booting, inflorescence emergence and anthesis for
five winter and five spring...
Three chemicals SD 55446, SD 55447 and WL 84245 were found to
induce male sterility in cultivars of wheat or triticale. Both SD 55446
and SD 55447 when applied at a concentration of 0.896 kg/ha resulted
in 90% male sterility. However, SD 55447 caused female sterility at
the same concentration...
The nature of the genetic variation associated with a cross involving winter and spring wheat parents for four quality factors was evaluated. Yamhill, a soft white winter wheat, and Inia 66, a hard red spring wheat, were selected as parents for this study. They represented distinctly different phenotypes for the...
This investigation was conducted to provide information regarding
1) the relationship between the nitrogen percentage in the vegetative
tissue of wheat and barley at various growth stages with grain protein
and 2) to evaluate the possible association between grain yield
and grain protein as influenced by different cultivars, nitrogen
levels...
Differential grain yield response of two winter wheat cultivars
('Yamhill' and'McDermid) when grown on acid soils prompted this investigation.
Root samples were taken at two soil depths at late
tillering and anthesis from plots established on an acid nonpareil
soil in Douglas County, Oregon. The soil pH was 5.2-5.3 and...
Concern regarding the lack of genetic variability and the apparent yield plateau reached in wheat breeding have prompted this investigation. The systematic crossing of spring and winter wheat types which have evolved to form somewhat different gene pools, may provide a source of additional usable genetic variability for future yield...
Wheat (Triticum aestivum) is the major food crop produced
on the Anatolian Plateau of Turkey where due to limited
rainfall the farmers follow the traditional system of fallow
farming. They are presently producing an average of 1.15
tons of grain per hectare during the crop year. This rate
of production...
Parental and segregating populations derived from four winter x
spring wheat crosses were investigated to obtain information concerning
the inheritance and association of earliness, grain yield and yieldrelated
traits. Feasibility of selecting in early generations for these
characteristics was also evaluated. Four winter wheat cultivars
(Hyslop, Yamhill, Bezostaia 1, and...
Laboratory studies were conducted under different temperature and moisture regimes to evaluate the effects of temperature and moisture on stand establishment and seedling characteristics associated with stand establishment. Percent stand and days to 25% emergence were used as indexes of stand establishment. Seedling characteristics analyzed were: shoot length, coleoptile length,...
Five genetically and morphologically different winter wheat
cultivars, Hyslop (H), Yamhill (Y), Paha (P), Luke (L), and Sprague
(5) were blended in all possible combinations. These composites
plus the five pure stands were planted in the fall of 1973 at three
environmentally diverse locations in Oregon: Hyslop Agronomy Farm,
Corvallis;...
Factors which influence the effectiveness of making early generation
selections within bulk populations were investigated. Material
utilized included the parents, F₁, and F₂ through F₅ bulk populations
resulting from a diallel cross. Information concerning the response
of two traits, plant height and grain yield, was obtained for these populations
at...
The response of two newly released cultivars of winter wheat
when grown under different row spacings, seeding rates and nitrogen
levels were investigated. Measurements made included grain yield,
tiller number per unit area, plant height, 300 kernel weight, bushel
weight and protein content of the grain. Hyslop and Yamhill cultivars...
Four, six-rowed, spring barley cultivars were used as
parental material in this study. The parents were distinctly different
in plant height. Washington-6124-62 is a standard height
selection while Short Wocus and Minn. 66-102 are intermediate.
The fourth parent was a dwarf selection obtained from India. The
two intermediate cultivars and...
Four agronomically and genetically diverse winter wheat parents
were utilized as the experimental organisms. Atlas 66 and NB 68513
were selected as cultivars with a high and stable protein content when
grown under different environmental condidtions. They are intermediate
for grain yield when grown in the Pacific Northwest. Yamhill
and...
The seeds of Douglas fir, a representative of the gymnosperm
flora, were studied at six stages of germination to discern the structures
of food reserves and to study ultrastructural changes occurring
during germination in the embryo and resulting seedlings.
The materials were fixed in three fixatives, dehydrated with
ethanol series,...
The purpose of this study was to determine the nature and amountof genetic variation and possible associations between winterhardinessand earliness in winter x spring wheat crosses.Four winter wheat cultivars selected for differences in earlinessand winterhardiness were crossed with a nonhardy, day length insensitivespring wheat cultivar. The following year, experiments containing...
