Morphological inheritance in selected Pinusechinata, P. taeda, and putative hybrids

Seedlings from loblolly (Pinustaeda L.), shortleaf (P. echinata Mill.), and morphologically intermediate pines (putative hybrids) were grown in greenhouse flats. Hybrid index scores based on morphological traits were calculated for parent trees and open-pollinated progeny. The scores of open-pollinated families were well correlated with those of their respective parents, indicating that parental hybrid index is a relatively accurate indicator of genotype.For several parent trees initially classed as putative hybrids, hybrid index scores tended toward shortleaf pine. Subsequent observations of progeny revealed that, except for one family, progeny were indistinguishable from shortleaf pines. This exception was intermediate to both species for both parent and progeny morphology and was concluded to be a natural hybrid.