Abstract
The present paper deals with the results of investigation on the change of physiological properties due to the chromosome doubling in tomato, Lycopersicum esculentum, which was induced by the decapitation-callus method. A retardation of growth appeared always at the beginning of development in tetraploids, but thereafter, no peculiarity was shown in the type of growth, except the case of fruitless, in which they were extraordinarily vigorous. The late and poor blooming was also the ordinary characteristic of tetraploids. Such special variations were found in the percentage of dry matter in tetraploid plants as low in the vegetable organs and high in the fruits, though tetraploids surpassed diploids in the total weight of plants, both the fresh and dry. It may be caused by the reduction of cell sap concentration in the vegetable organs. Much nitrogen was contained in the vegetable part and less in the fruit in tetraploids. The increase of sugar and organic acid occured in the tetraploid fuits and the addition of vitatin C content in them could be obtained by means of crossing with tetraploids of L. pimpinellifolium. The tetraploids were also very much superior in regard to the resistance to Fusarium lycoperici and mosaic disease.
