Experiments on the Nutrition of Isolated Roots

• Main Author: Addicott, Fredrick Taylor
• Format: Others
• Published: 1939
• Online Access: https://thesis.library.caltech.edu/10645/8/Addicott_ft_1939.pdf; Addicott, Fredrick Taylor (1939) Experiments on the Nutrition of Isolated Roots. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/F2N6-4H73. https://resolver.caltech.edu/CaltechTHESIS:01232018-095827563 <https://resolver.caltech.edu/CaltechTHESIS:01232018-095827563>

<p>1. The history of plant tissue culture is outlined.</p> <p>2. The technique of root cultures is reinvestigated from several aspects and some changes are incorporated for the present work.</p> <p>3. The section of vitamin B₁ as a root growth hormone is examined, and its presence is found to be closely correlated with the growth rate, rate of cell divisions, and extent of meristem in isolated roots.</p> <p>4. A second growth factor of pea roots present in yeast extract is found not to be among the micorelements of plant nutrition nor among the amino acids.</p> <p>5. Nicotinic acid is found to be the second growth factor of pea roots. With vitamin B₁ it is capable of supporting a higher rate of growth for pea roots than can yeast extract.</p> <p>6. Evidence is presented to show that inositol, phosphate, and optimum hydrogen ion concentration may have promotice effects on the growth of pea roots.</p> <p>7. A number of experiments are described which indicate that it may be impossible to establish a clone of pea roots.</p> <p>8. Preliminary experiments on the culture of excised anthers are described, and the high activity of embryo extracts on anther growth is noted.</p>