Nad1 b/c intron polymorphism reveals maternal inheritance of the mitochondrial genome in Picea abies

Our goal was to determine the mode of inheritance of Picea abies mitochondria. We studied four trees implicated in intraspecific controlled crosses. Based on a PCR-derived technique, one mitochondrial marker, the intron b/c of subunit 1 of NADH dehydrogenase (nad1 b/c), was informative in one of the available crosses. This fragment was sequenced and exhibited several features concordant with the group-II intron, as judged from its sequence evolution and organisation. All of the 96 offspring analysed from the two polymorphic parents present a maternal profile. We conclude that in P. abies the mitochondrial genome is maternally inherited. This result is congruent with the commonly observed pattern of mitochondrial inheritance in the other Picea species studied so far. The existence of mtDNA polymorphic markers that are maternally inherited should now facilitate the study of the population genetic structure of the Norway spruce.