Thesis (Ph. D.)--University of Florida, 1974. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 93-98).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1980. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 84-87).

Hybrids between wheat and jointed goatgrass have long been presumed to be sterile; however, seed were found on hybrid plants in 1990. Field studies were conducted in 1995 and repeated in 1996. One to ten hybrid plants were planted in variable populations of wheat and jointed goatgrass to determine the rate of seed set and viability of seed produced on hybrids. An average of 2.3% of florets set seed in 1995 and 3.8% of florets set seed in 1996. Seed were set in all treatments. Hybrid population had no effect on seed set. The BC1 (first backcross) seed produced in the field studies were separated according to seed condition, full or shrivelled, and were tested for germination. Ninety-four percent of the full seed germinated in each year and 79% and 84% of the shrivelled seed germinated in 1995 and 1996, respectively. Field studies were conducted in 1996 and 1997 using seed set on hybrids grown in populations of 150 jointed goatgrass or 150 wheat plants in the previous year's field study. Ten BC1 plants were planted into plots containing 100 jointed goatgrass plants. From 0.25 to 20.29% of florets per plot set seed. Greenhouse studies were conducted in 1997 and repeated in 1998 using BC1 seed produced in the previous year's field study. Seed resulting from self-pollination occurred on 4.1% or 59 plants in 1997 and 2.1% or 16 plants in 1998. Percent seed set ranged from 0 to 80.22% on a per plant basis. Parental population and seed set on BC1 plants can not be predicted based on coleoptile color, germination day, leaf width, number of veins in the leaf, presence or number of hairs on leaf margin, plant posture, number of spikes produced, culm height, spike length, or resemblance to parents. / Graduation date: 1999

The main objectives of this thesis are: i) to assess the genetical variation in Nigerian oil palm (Elaeis guineensis Jacq.) populations with respect to the fatty acid composition of their oil; and ii) to assess the value of the Nigerian material to the breeder in oil palm improvement programmes. Two hundred families, the progeny of 200 (5 from each of 40 populations) individual palms from which seeds were collected in Nigeria were planted in a completely randomised design in two independent blocks of six seedlings per family. A set of fifty families were planted in another experiment at three locations in order to detect the presence of genotypeenvironmental interaction. Data on fatty acid composition from the above experiments is presented and compared with data for current breeding material, the related species (E.oleifera) and the interspecific hybrid (E.oleifera x E • guineens is) • There is substantial phenotypic variation for fatty acid traits in the Nigerian material. Part of the variation observed is genetically determined but heritability estimates are generally low and the populations studied do not differ greatly for these traits. Genotype-environment interaction was not detected with respect to fatty acid composition in the material studied. The Nigerian material offer much greater scope for breeding high yielding oil palms with modified fatty acid composition than the current breeding material. However, the interspecific hybrids (E.oleifera x E.guineensis) offer even better prospects for improvement of fatty acid composition.

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