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...
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...
Crossover frequencies for seven selected regions on five
chromosomes of maize were measured to ascertain the effect of
chelating agents on recombination. Ethylenediamine tetraacetic acid,
EDTA, and dimethyl sulfoxide, DMSO, were used in three concentrations
singly, and in all combinations. Plants heterozygous for
for linked genes governing seed and seedling...
A great potential for increasing upland rice production exists in
the savanna soils of Colombia. These vast areas are currently
underutilized. However, they have good soil structure, flat
topography, coupled with sufficient and well distributed rainfall,
making savanna soils ideal for upland rice cropping system. The major
constraints to upland...
A higher level of efficiency in the production of doubled-haploids must be achieved if
this procedure is to be beneficial in plant improvement. Of equal importance is the
development of protocols, which are not genotypic specific and result in progeny that represent
a random sample of gametes from the parental...
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...
Responses to two cycles of mass selection for heading date,
followed by selfing or intermating, were studied in two diverse
winter wheat (Triticum aestivum L. em. Thell) crosses. Selection
was bidirectional, resulting in early and late populations for
each mating system, cycle, and cross. The influence of mass
selection for...
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...
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...
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...
A set of genes which show developmental and tissue
specificity are expressed late in embryo maturation during
grain formation in wheat (Triticum aestivum). Two members
of this maturation gene set (MGS) are Em and triticin, a 7S
globulin. Results presented here show that during
embryogenesis, the expression of Em mRNA...
To study the grain filling traits in wheat, two winter cultivars
and four spring cultivars were selected. The resulting Fl, F2, F3 and
backcrosses were tested. The following measurements were made:
a) Visual traits for physiological maturity (PM),
b) Grain dry weight accumulation,
c) Regression models for grain filling period,...
Five winter wheat cultivars and their diallel crosses were evaluated for plant height, harvest index, deading-maturity duration, the components of yield, (spikes per plant, spikelets per spike, kernel weight and kernels per spikelet)and total plant yield. Two diverse locations, Moro, a dryland site (250 mm annually) located in central Oregon...
A major factor limiting the efficiency of plant improvement programs is the lack of knowledge as to which parental combinations to make when working with quantitatively inherited traits. The primary objective of this study was to provide information regarding the use of combining ability analysis to predict which cross combinations...
The lack of information regarding the inheritance of the duration and rate of
grain filling, and the possible relationship between grain fill and grain protein
content in wheat prompted this study.
Early maturing Chinese cultivars, 'AI Feng 2' and 'CB 83-52', and late
maturing cultivars adapted to Oregon, 'Stephens' and...
Strawbreaker foot-rot is a major limiting factor to cost efficient winter wheat
production in the Pacific Northwest. Development of resistant cultivars has been
hindered by the lack of adequate levels of genetic resistance and screening techniques
which can consistently detect desired genotypes.
Studies were conducted to determine if the reported...
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...
Attempts to develop dual-purpose durum wheat cultivars for both pasta and bread-making
have been unsuccessful. To better understand this limitation, thirty durum
genotypes, selected based on their diverse geographical origin, and five bread wheat
cultivars were compared as to their flour mixing properties, dough physical characteristics
and baking performance. The...