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...
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...
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...
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...
Barley Yellow Dwarf Virus (BYDV) is a major disease of wheat. Unfortunately, unlike barley where the Yd2 gene provides adequate levels of resistance, the situation in wheat is more complex. This study was designed to provide information regarding: 1) evaluation of methods of measuring resistance among selected cultivars; 2) identification...
The nature of inheritance and possible associations for traits
influencing earliness and grain yield were investigated using a four
parent diallel of winter and spring wheat cultivars.
More genetic variability was observed for the traits measured in
segregating populations resulting from crosses between winter and spring
type wheats in contrast...
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...
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...
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...