Efficient interspecific hybridization in the genusHelianthus via "embryo rescue" and characterization of the hybrids.

With the aid of the "embryo rescue" technique, interspecific hybrids in the genusHelianthus could be raised with a recovery rate of 41%. Altogether, 33 different hybrid combinations were realized using the cultivated form, both as a female and male parent. The hybrids obtained have been identified by different methods, i.e., by comparison of leaf morphology, pollen stainability, chromosome number and by RFLP analysis. The former three methods are useful to obtain global information, while the RFLP analysis allows a rapid and safe characterization in early developmental stages of the hybrids.