Claire Federici (UC Riverside, Dept. of Botany and Plant Sciences) examines Olinda Valencia oranges, hoping to locate seedless fruit. This group of Valencia trees are part of a long-running plant breeding project at Lindcove that is headed by Dr. Mikeal Roose, and is the same project that has brought low-seeded mandarins to global markets. The Valencia trees were grown from irradiated budwood, which has the intended result of occasionally disrupting the genes that promote seed formation. If a tree is found to have low-seeded fruit, then its budwood is likely to produce low-seeded fruit, and a new low-seeded line of Olinda is created!
While several varieties of seedless or low-seeded Valencias are commercially available, notably Delta and Midknight, the popular seedy Olinda variety is favored by San Joaquin Valley growers for high productivity and tolerance of hot summers.