This Small Business Innovation Research Phase I project addresses the scale up of a novel technology, the generation of periclinal chimeras. Tissue-Grown Corporation scientists have developed a novel method for combining the best characteristics of two varieties of potato by forming chimeras. The meristems of dicotyledous plants are organized into three distinct cell layers. Established in meristems, cell layers have set patterns of division and maintain their distinctive organization throughout the plant. Chimeric plants are composed of cell layers from different parents. Chimeras offer the ability to work with a much broader choice of genetic donor germplasm in new variety development. Chimeras provide a means for rapid incorporation of wild species epidermal traits onto commercial varieties, without changing the tuber characteristics of the original varieties. Breeders must use many generations of backcrossing, and must often begin with somatic hybrids from protoplast fusion, in order to bring a wild species gene into a commercial potato germplasm. Wild species contain a wealth of disease resistance genes and genes of horticultural interest, but they also come with a heavy burden of genes detrimental to potato tuber production, such as delayed tuber set, odd colors, shapes and sizes of tubers, and excessive tuber glycoalkaloids. Using chimeras, many well-established and valuable varieties can be enhanced without disturbing or damaging their primary tuber traits. This research is directed toward the development of methods for the mass production of new potato varieties. The specific germplasm targets would combine insect resistance from the wild Solanum species, S. berthaltii and the tuber qualities of a commercial potato variety, cv. Shepody. If successful this would result in rapid generation of new potato varieties that can take advantage of wild germplasm traits for pest resistance without the undesirable wild tuber traits. Pest resistance is often a multigenic trait with consequently complex inheritance patterns. Candidates for improvement include fresh market (table stock) as well as frozen and processed products (French fries, chips and dehydrated products). Successful market penetration could generate annual revenues exceeding $30 million.
