DEVELOPMENT AND TESTING OF F1 HYBRID PEACHES AS AN ALTERNATIVE PEACH PRODUCTION STRATEGY

Abstract

F1 hybrids have not been used in tree breading because 1) there have generally not been technologies for the production of homozygous lines; 2) in most species homozygosity leads to severe inbreeding depression and the inability to sustain inbred lines; and 3) in the case of tree fruits the long juvenile periods of most species makes it impractical to use F1 hybrid seed for fruit production. Unlike most species, the peach may be particularly suited to the development of F1 hybrid rootstock or scion varieties because it tolerates inbreeding and the juvenility period is relatively short (2-3 yrs). Doubled haploid peaches, including male sterile lines, were obtained from T.K. Toyama (Hortscience 9:187). Intercrossing male sterile and fertile lines, we produced seven F1 hybrid populations. F1 trees fruited in the third growing season. Flowering, fruit production and fruit quality were uniform within each F1 hybrid population. Fruit quality of the different F1 hybrid lines ranged widely. Productivity was high and tree growth vigorous. These observations suggest the potential for the use of F1 hybrids for peach rootstock and scion variety development.