Thesis (Ph. D.)--University of Wisconsin--Madison, 1962. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 87-92).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1962. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1968. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references. Also available via the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 175-205). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 175-205). Also available on the Internet.

Thesis (M.S.)--Virginia Polytechnic Institute and State University. / Vita. Abstract. Includes bibliographical references (leaves 66-72). Also available via the Internet.

Potato leafhopper causes considerable damage in red clover. The main objectives of this study were to clarify the inheritance of pubescence and to evaluate the relationship between pubescence and potato leafhopper (Empoasca fabae (Harris) resistance. Thirteen red clover clones of diverse origin, including both pubescent and non-pubescent types were used as parents. A series of crosses were made in all possible combinations among the 13 parental clones. Seedlings of F$ sb1$ progeny and stem cuttings from parents were planted in the field in the summer of 1993 in a randomized complete block design. Based on the results, the inheritance of pubescence type on red clover stems, petioles and abaxial leaf surfaces was best explained individually by two-locus models showing dominant and recessive interaction. A two locus model with recessive epistasis was proposed for pubescence on stipules and basal internodes, but there were a number of crosses that deviated from expected ratios. There was quantitative variation for trichome density on red clover and it appeared to be inherited as a quantitative trait. Based on mid-parent offspring regression, the heritability estimates of trichome density on petioles, stems, abaxial leaf surfaces, and adaxial leaf surfaces were 0.16, 0.77, 0.50 and 0.48, respectively. Pubescence was apparently associated with potato leafhopper resistance. Visual ratings of feeding injury, the numbers of leafhopper nymphs per plant and the numbers of nymphs per gram of dry plant material were higher on glabrous plants than on pubescent plants. (Abstract shortened by UMI.)

No description available.

Bacillus subtilis Stämme vom FZB - FZB24, FZB37 und FZB38 des FZB Biotechnik, Berlin - und ihre Stoffwechselprodukte wurden als Agenzien für eine Resistenzinduktion gegen Schädiger in drei Wirtspflanzen-Erreger-Systemen, Vicia faba - Uromyces appendiculatus, Vicia faba - Aphis fabae und Triticum aestivum - Rhopalosiphum padi untersucht. Prä-inokulativ wurden Blätter und Saatgut der Pflanzen mit den Testsubstanzen behandelt. Zur Testung gelangten Bakterien-Kulturfiltrat (KF), KF-Zenrifugationsüberstände, die vegetativen Zellen und Sporen der B. subtilis Stämme. Nach lokaler Applikation der KF-Überstände von B. subtilis auf die Wirtspflanzenblätter konnte eine erhebliche Breite antibiotischer (entwicklungshemmender) Wirkungen auf A. fabae und R. padi beobachtet werden. Eine Untersuchung der freien Aminosäuren im Phloemsaft von Vicia faba zeigte, daß sich nach Befall von Aphis fabae speziell bei den zuvor mit bakteriellem Kulturfiltrat und KF-Überstand behandelten Pflanzen im Vergleich zu der nur mit Wasser behandelten Kontrolle, die Konzentration von neun Aminosäuren änderte. / In topical and systemic plant treatment, in three host–parasite systems, i.e. Vicia faba - Uromyces appendiculatus, Vicia faba - Aphis fabae and Triticum aestivum - Rhopalosiphum padi the culture filtrate and supernatant of Bacillus subtilis (FZB24, FZB37 and FZB38 from FZB Biotechnik Berlin) was shown to inhibit the development of urediospores produced by Uromyces appendiculatus. The performance of Aphis fabae and Rhopalosiphum padi was evaluated using life table tests where the aphids'' development time (tD), pre-reproduction time (td), relative growth rate (RGR) and intrinsic rate of natural increase (rm) were assessed. A wide range of antibiosis effects in Aphis fabae and Rhopalosiphum padi was observed when the supernatant of Bacillus subtilis was used as foliar topical treatment. The tested aphids presented longer development and pre-reproduction time; conversely a lower relative growth rate and intrinsic rate of natural increase was observed. The investigation of the free amino acids of the phloem sap of V. faba plants, showed the concentration of the amino acid serine remained unchanged in the supernatant induced plants in this study, which was interpreted as the major reason for the observed antibiosis effect on the tested aphids.