DEVELOPMENT OF TETRAPLOID HYBRID PASSION-FRUIT CLONES WITH POTENTIAL FOR THE NORTH TEMPERATE ZONE

When Passiflora incarnata L. was crossed with P. edulis f. flavicarpa Degener, all plants of the diploid hybrid were pollen-sterile and nonfruitful. Doubling the chromosome number of emergent F1 seedlings with colchicine restored fertility in some individuals, but all plants were strongly self-incompatible and many showed low pollen viability. Crossing colchicine-treated plants that had been converted to amphiploids produced a tetraploid hybrid group of four seedling progenies that had some degrees of cross-compatibility. Juice of the amphiploid hybrid is lighter in color than that of P. edulis, but is sweet, strongly aromatic, and may have use alone or, typically, as a blend with other juices.