Masters Theses


Gary N. Duren

Date of Award


Degree Type


Degree Name

Master of Science


Plant Sciences

Major Professor

Bill Pickett

Committee Members

W. E. Roever, R. B. Thompson, H.D. Swingle


The cultivated tomato, Lycopersicon esculentum, although a relatively new addition to the American diet, has rapidly gained a place as one of our more important vegetables.

The origin of the tomato is obscure, but it seems likely that it is native to the Peru-Bolivia-Ecuador area of the Andes (20). The cultivated tomato was probably carried northward into Central America and Mexico by prehistoric migrations of Indians. For centuries it has been a staple food in the Mexican diet (1).

Although Spanish explorers had found the tomato being used as a food, there was considerable reluctance in most of Europe to its use as anything but an ornamental. It was frequently said to be poisonous. The earliest record of tomatoes being used as a food in this country was in 1812 (20).

Work is going on continually in the United States as well as other countries to breed better varieties of tomatoes. Probably the first American contribution toward tomato improvement was the introduction of Tilden by Henry Tllden of Davenport, Iowa in 1865. The next notable advance occurred in 1870 with the introduction of Trophy, a result of hybridization and selection by Dr. Hand, of Baltimore County, Maryland (20), Today there are over 350 horticultural varieties, most of which are only slightly different from each other (15).

To combine into one -variety such factors as: bright red color, good fruit size, productiveness, quality, and good foliage cover, as well as resistance to disease, cracking and heat seems to be a very difficult task. Nevertheless, progress has been made. There are many genetic differences among these varieties. Therefore a variety could be quite desirable under one set of conditions; yet under another set, a complete failure. In order for one to make an intelligent selection of a variety for his growing and market conditions he must know the genetic factors the variety possesses. One should also know how these factors affect productivity under different conditions (4). Descriptions found in commercial catalogs are often insufficient for selection of varieties.

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