Plant Sciences Commons^™

Expression Analysis Of Plant Defense Responses During The Establishment Of Biotrophy And Role Of Abiotic Stress In The Infection Of Dyer’S Woad (Isatis Tinctoria) By Puccinia Thlaspeos, Elizabeth Thomas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The kinetics and amplitude of the salicylic acid-responsive pathogenesis-related (PR) genes and the cytochrome P450 gene ItCYP79B2 in the compatible interaction between Puccinia thlaspeos and dyer’s woad (Isatis tinctoria) during the first 72 hours of inoculation were examined. Immediately following penetration of the host by the rust pathogen, there was a modest up-regulation of PR genes but a significant down-regulation of ItCYP79B2 expression. During haustoria formation, a significant pathogen-mediated suppression of PR genes was observed with a corresponding up-regulation of ItCYP79B2. This potentially facilitates haustoria formation by P. thlaspeos. After haustoria formation, a more …

In Vitro Morphogenesis And Mutation Of Glycine Max L., Thomas Daniel Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soybean (Glycine max L. c.v. Consoy) tissue cultures were grown in synthetic media containing various concentrations and combinations of minerals, auxins, cytokinins, pH levels, and inorganic growth factors in a systematic procedure to establish optimum media for initiation and maintenance of callus. Further modification of the hormone level was employed to initiate callus morphogenesis. Normally toxic levels of atrazine were established in soybean calli media, and ethyl methanesulfonate (EMS) and X ray-induced mutant calli were selected for atrazine tolerance.

Optimal media for initiation and maintenance of soybean calli were developed and a defined medium was determined that consistently yields …

The Action Of Antibiotics And Antimetabolites On The Tobacco Mosaic Virus Infection Process In Bean Leaves, Virendra Nayyar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The action of 28 antibiotics and antimetabolites at varying concentrations was studied in coincidence with the bioassay of tobacco mosaic virus on detached bean leaves by using an ultrasonic method of inoculation developed by Lamborn, Cochran and Chidester.¹ All tested chemicals were classified, in regard to the virus infection process, as inhibitory or stimulatory and their optimal concentrations in the inoculum were determined. Of the 28 antibiotics and antimetabolites studied, eight were found to stimulate while twenty inhibited TMV infection in bean leaves. From the results of these experiments, an attempt was made to characterize the nature of the …

Overwintering Of Erwinia Amylovora Inside Living Host Tissue In Cache Valley, Utah, G. Doyle Morrill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Experiments were conducted to see if Erwinia amylovora (Burrill) Winslow et al. overwinters inside living host tissue in Utah. Bacteria, collected from apple, pear, mountain ash, chokecherry and Pyracantha, were used in the experiment. Isolates taken from buds and inner bark plated on nutrient yeast dextrose agar, we re tested by serological and bacteriophage techniques. Those showing positive tests were then inoculated into Bartlett pear seedlings to test virulence.

Both virulent and avirulent isolates were isolated from each species of plant in the experiment. Pathogenic bacteria were isolated from diseased tissue near cankers, as well as from apparently healthy inner …

Red Raspberry Root Rot In Northern Utah, Robert L. Powelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

During the last few years, red raspberry growers in Utah have been finding that plantings gradually lose vigor and are not profitable. In the largest raspberry growing area in Utah, Utah County, figures taken from the U.S. census from 1930 to 1950, show a decrease in acres of raspberries grown from 401 in 1930 to 190 in 1950 (2). In many instances this deterioration of raspberry plantings in Utah has not been definitely associated with known plant pathogenic fungi or virus infections. Neither can the expansion of suburbs account for this decrease. In certain cases it has been obvious that …

An Etiological And Host Range Study Of Celery Mosaic In Utah, Dennis H. Hall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Celery mosaic is a virus disease of major economic importance in Utah. In years of severe epiphytotics, it has been a limiting factor in celery production. In 1947 losses due to this disease were estimated to exceed 8 per cent of the total crop. This estimate does not include losses resulting from reduction in grade or from plants discarded in the packing sheds. The celery acreage in Utah dropped from a high of 950 acres in 1946 to 750 acres in 1947 and dropped again in 1948 to 420 acres. Leaders in the industry attributed this reduction in acreage, in …