Confirmation of Hybridity and Identification of Self-Fertile Genotypes of Tecoma Spp. (Bignoniaceae)

Tecoma Juss. is a genus of 14 species, primarily distributed in the neotropics, which is desired for its bright flowers including yellows, oranges, and reds.  The genus has been reported as self-incompatible but reports are conflicting.  Interspecific hybridization and self-pollination of several species of Tecoma were conducted to develop novel forms for the nursery industry.  Morphology and genomic in situ hybridization (GISH) were used to confirm hybridity.  We report the development of fertile hybrids from the cross between T. garrocha Hieron. and T. stans (L.) Juss. ex H.B.K. that were then successfully backcrossed to both parents and self-pollinated to produce F2 progeny.  Tecoma garrocha, T.stans, and T. guarume A. DC ‘Tangelo’ were identified as self-fertile. To our knowledge, we present the first report of three species hybrids in Tecoma with pedigrees of (T. garrocha x T. stans) x T. capensis (Thun.) Spach. and (T. garrocha x T. stans) x T. guarume ‘Tangelo’, respectively.  Leaf morphology of F1 hybrids of T. garrocha x T. stans were intermediate between the parents and we demonstrate the utility of GISH in identifying hybrids.  Furthermore, we verify that self-incompatibility is not ubiquitous in the genus.