Browsing by Author "Walker, Paul N."

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Citation - Scopus: 1
Effect of Atrazine on Algal Contamination and Sugarcane Shoots During Photoautotrophic Micropropagation
(American Society of Agricultural Engineers, 2003-01) Ertürk, Handan; Walker, Paul N.; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
A laboratory procedure was developed for obtaining and maintaining photoautotrophic cultures ofsugarcane shoots in vitro for three generations. Algae contamination in vessels was a problem for photoautotrophic growth under septic conditions. Atrazine, a herbicide, was effective in controlling algae at a concentration of 10 ppm, but the growth of shoots in herbicide-treated sugarless Murashige and Skoog (MS) medium decreased to about half of the growth in untreated medium. As a result, atrazine was not considered to be a practical solution for algae control. Additional work is needed to optimize photoautotrophic micropropagation of sugarcane for both septic and aseptic conditions. Photoautotrophic micropropagation of sugarcane may be economical only if culture can be perfected under septic conditions.
Citation - WoS: 7
Citation - Scopus: 11
Effects of Light, Carbon Dioxide, and Hormone Levels on Transformation To Photoautotrophy of Sugarcane Shoots in Micropropagation
(American Society of Agricultural Engineers, 2000) Ertürk, Handan; Walker, Paul N.; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Sugarcane (Saccharum spp.) shoots were transferred from a heterotrophic micropropagation environment and cultured on sugar-free Murashige and Skoog (MS) salts medium in the controlled atmosphere of a growth chamber. The purpose was to achieve photoautotrophic shoot culture to be used for micropropagation. Effects on the shoots were tested for three factors: Carbon dioxide concentration, light level, and the hormone concentration of the growth medium. Factorial design was applied for the experiment such that all combinations of high and low factor levels were utilized, and the medium level of each factor level constituted the middle point of the design. All shoots were observed to become yellowish in color and lose vigor in the sugarless environment, although the successful treatments regained their color and vigor. Average dry weights of shoots per vessel were recorded at the end of two weeks as a quantitative measure of transformation of shoots to photoautotrophy. Light and CO2 levels were found to have statistically significant and positive effects. The negative effect of hormone concentration was insignificant.
Citation - WoS: 4
Citation - Scopus: 7
Effects of Rooting Period, Clump Size, and Growth Medium on Sugarcane Plantlets in Micropropagation During and After Transformation To Photoautotrophy
(American Society of Agricultural Engineers, 2000-03) Ertürk, Handan; Walker, Paul N.; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
Experiments were conducted to improve the conditions for growth of sugarcane (Saccharum spp.) plantlets during and after transformation to photoautotrophy. The experimental treatments included different rooting periods, media, and clump sizes. Photomixotrophic (sugar-containing medium) and photoautotrophic (sugar-free medium) cultures were also compared. The presence of roots was concluded to be essential for plantlet survival during transformation from photomixotrophic to photoautotrophic culture. Six-week rooted plantlets were fully capable of surviving photoautotrophic conditions after transfer whereas three- and four-week rooting periods were insufficient. The test of clump size during transformation to photoautotrophy showed that two plantlets per clump resulted in the highest growth, but insignificantly so, when tested against four plantlets per clump and individual plantlets. Comparison of different sugarless medium types for the photoautotrophic growth of plantlets showed that liquid Murashige and Skoog (MS) medium had the highest growth among other liquid media tested but the differences were not statistically significant. Similarly, gelled MS medium gave insignificantly higher growth rates when compared with liquid MS media. Liquid MS medium was concluded to be suitable for photoautotrophic growth of sugarcane plantlet cultures. The experiments of this study achieved photoautotrophic cultures growing in weight and in number of plantlets, though at a much slower rate than for photomixotrophic cultures. This study is the first time photoautotrophic multiplication of any plant has been demonstrated in micropropagation and further optimization of culture conditions is needed.
Photoautotrophic and Heterotrophic Micropropagation of Sugarcane Shoots in Controlled Environments
(2000) Ertürk, Handan; Walker, Paul N.; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
We achieved successful growth and multiplication of sugarcane shoots in vitro under photoautotrophic conditions aseptically for three generations in our laboratory and proposed an experimental procedure for photoautotrophic micropropagation of sugarcane in controlled environment. The growth rate of photoautotrophic cultures in sugarless MS medium was found to be half of the growth rate of heterotrophic cultures in multiplication medium after a two-week period in the same environment. Contamination with algae in some vessels was recognized as a problem for septic photoautotrophic growth. Atrazine was found to be effective in controlling algae at a concentration of 10 ppm. But, atrazine in total was not considered to be a practical solution for the algae problem as it had a negative affect on the growth of shoots.