Fecundity of Tetraploid × Diploid Crosses and Fertility of the Resultant Triploids in Salpiglossis sinuata

Abstract

Mean seed production in tetraploid × diploid crosses of Salpiglossis sinuata R et P. was similar to that in diploid × diploid crosses, but germination of the resultant triploid seeds was low (8%). Parental line selection resulted in some germination improvement. Triploid hybrids from these crosses were vigorous, with floral characteristics resembling tetraploids. The fertility indices of self-pollinations of triploids and pollinations by diploid and tetraploid plants were <1, 22, and 6, respectively, compared with 176 for diploid × diploid crosses. Thus, the self-pollinated triploids were virtually sterile.