Ultrastructural and molecular study of plastid inheritance in Abies alba and some Abies hybrids

The ultrastructure of egg cells in Abies alba was examined to elucidate the lack of maternal inheritance of plastids. Before fertilization, maternal p lastids are absent in the perinuclar zone containing mainly mitochondria an d smooth endoplasmic reticulum. During egg cell development the maternal pl astids are transformed into large inclusions which are situated mostly towa rds the periphery of the egg cell, and finally disintegrate. As a consequen ce, they do not participate in zygote formation. RFLP analysis of cpDNA of parental trees and their F1 interspecific hybrids (A. albaxA. numidica, A. albaxA. nordmanniana, A. nordmannianaxA. Alba) us ing HindIII and BamHI showed a paternal mode of cpDNA inheritance. Paternal inheritance has also been found with PCR/RFLP analysis of cpDNA from paren tal trees and their hybrids (A. albaxA. pinsapo, A. pinsapoxA. alba, A. pin sapoxA. numidica) using ApaI and HaeIII digests, as well as in the crosses of A. cephalonicaxA. nordmanniana, A. nordmannianaxA, cephalonica, A. cepha lonicaxA. numidica using TagI digests.