Hybridization and Self-Compatibility in Controlled Pollinations of Eastern North American and Asian Hemlock (TSUGA) Species    (View PDF)

S.E. Bentz, Louise G.H. Riedel , Margaret R. Pooler, and A.M. Townsend

Abstract: Controlled pollinations were made between five hemlock (Tsuga) species from eastern North America and Asia. Resulting seeds were collected and planted, and more than 5,700 seedlings germinated. A selected number of putative hybrids from each cross were tested for authenticity by DNA fingerprinting. Attempts to hybridize T. canadensis (eastern hemlock) with three Asiatic species were unsuccessful. However, 59 authentic hybrids from crosses between T. caroliniana (Carolina hemlock) and T. chinensis (Chinese hemlock) were identified. Crosses between the Asiatic species also were successful. Selfing was demonstrated in all species. Further studies are needed to determine the nature of the crossability barrier between T. canadensis and the Asiatic species. Because eastern native hemlocks are suffering injury from the introduced pest hemlock woolly adelgid (Adelges tsugae), fundamental information of this type may enable plant breeders to successfully hybridize adelgid-tolerant species with the susceptible native hemlock species to create new trees that are both tolerant to the adelgid and horticulturally desirable.

Keywords: AFLP; controlled pollination; hemlock; plant hybridization; hemlock woody adelgid; Tsuga.

https://doi.org/10.48044/jauf.2002.029