Flowers as You Like Them

by S. L. EMSWELLER

FOR SOME reason or other the average gardener likes his flowers big. He boasts about his giant pansies and petunias, or gladiolus spikes 6 feet tall with flowers 6 inches across. At the flower shows the accolade goes to the mammoth amaryllis or the colossal zinnias. Vegetable gardeners also know this urge to achieve greater size—taller corn, giant radishes, 4-pound onions, turnips as big as pumpkins, and pumpkins as big as a house. The truth is that as a rule the very large vegetables are inferior in quality, but the public likes size, and size is what flower and vegetable seedsmen are trying to give them.

The size of a flower or vegetable is something over which the gardener has considerable control. The old discussion over heredity versus environment has been laid to rest, and now we talk of heredity plus environment, with each playing an important role in determining size and quality of both flowers and vegetables.

The good gardener is one who obtains the maximum of growth and yields from the seed and plants available to him. He accomplishes this by using the best growing practices: Adequate fertilizers, moisture, and good tillage. As a result of flower-breeding work by the seed companies, amateurs, and State and Federal workers, there has been a steady advance in the quality and quantity of varieties available to the gardener. Many of these improvements have resulted from hybridization between two varieties. Thus we have been able to reshuffle their characters and combine good qualities from both. The better of the new types are fixed (that is, made to come true from seed) by selection and then become available to the gardening public. It has also been found that when crosses are made between certain strains or varieties of flowers, the resulting hybrids exhibit greater vigor than either of the parents. We have taken advantage of this hybrid vigor to develop greater size and yield in corn, onions, tomatoes, squash, cucumbers, and snapdragons. The seed of such hybrids cannot be used since it will not produce plants like the hybrid parent—an important warning.

About 9 years ago A. F. Blakeslee and A. G. Avery, of the Carnegie Cold Spring Harbor Station in New York, and B. R. Nebel and M. L. Ruttle, of the New York Agricultural Experiment Station, described a method by which one type of mutation could be produced at will. They found that treatment of seed or young seedlings in a water solution of the drug colchicine usually produced increased vigor and larger flowers. Colchicine, by the way, is extracted from bulbs of the fall-blooming crocus and, strangely enough, has no effect on the crocus chromosomes. Examinations of the cells of such affected plants revealed striking changes from the normal. The plant cells were larger and the number of chromosomes had been doubled. The chromosomes are the carriers of the heredity of. a plant. They determine whether a plant will be tall or dwarf, perennial or annual, bear white, red, or some other colored flower. Such characters as size of flowers and fruits are also determined by them.

The chromosomes occur in pairs, that is, there are two of each type present. An Easter lily plant has 24 chromosomes, two each of 12 types. It is relatively easy to distinguishamong all 12 except those labeled in the illustration I and J, and K and L. All normal Easter lily plants have two each of the A, B, C, and the nine other types. No other plants so far studied by anyone have exactly the same types of chromosomes as the Easter lily. Thus, if we had only a small piece of a plant and found the chromosomes shown in the picture in its cells, we would know it was a piece of an Easter lily.