Producing "Seedless" Watermelons:
A Biotechnology Virtual Tour
After nearing completion of his Ph.D. in Plant Breeding, Vegetable Crops, and Plant Physiology in 1949, Warren Barham started a research and development program and became interested in modifying the size of seeds found in watermelons. He reasoned that seeds took up too much space and consumed more plant energy. Beginning with seeds provided by
a North Carolina State student who graduated in 1897, and who claimed the variety had been long grown by his family, Barham started his research with a plant that expressed the trait for small seeds but produced an unacceptable quality fruit. Seed size is only one of many characteristics important in the marketing of watermelons. Out of Barham's initial interest in watermelons, a thriving family owned business, Barham Seeds, Inc., evolved. His business has produced over twenty seedless and seeded watermelon hybrids. He uses ancient methods along with modern technology to add specific traits to seeds and plants for variety and hybrid development.
Barham began his research by performing hand pollinations using different, larger seeded diploid parents crossed with the small seeded variety to study how seed size was inherited. What he discovered is that in inbred line (plants whose desirable characteristics are expressed consistently from generation to generation) crosses small seed size is inherited as a Mendelian dominant and in other combinations, he produced a hybrid fruit containing seeds in between those of the parents. The pattern of inheritance was varied.
Over the years, Barham has continued to refine other traits desired in watermelons. His goal has been to develop inbred lines of plants with specific characteristics. When crossed, the appropriate parents produce seed for plants that set a "seedless" fruit, or with different parents have other traits determined desirable by growers and the general public. Barham licenses these hybrids to commercial seed brokers and/or growers, who generate hundreds of pounds of seed for sale to watermelon farmers. Barham Seeds, Inc. does not sell seed, plants for transplantation or watermelon fruit. Barham deals directly with seed growers and/or brokers who assume responsibility for the "scaling-up" process after purchasing a license for the hybrids developed in test fields operated by the Barham family.