Like mitochondria, chloroplats inherit from single parent. In general in gymnosperms it is paternal where as in angiosperms maternal. There are intresting reports if you surf. By the way what fern are you working. Just have look at the following they may give some idea
POPULATION-SPECIFIC GENDER-BIASED HYBRIDIZATION BETWEEN DRYOPTERIS INTERMEDIA AND D. CARTHUSIANA: EVIDENCE FROM CHLOROPLAST DNA
Maternal inheritance of chloroplasts in the horsetail Equisetum variegatum (Schleich.)
The seemingly strict maternal transmission of cpDNA in this species suggests that uniparental chloroplast inheritance preceded the evolution of heterospory in the seed-plant lineage.
Thank you very much! Normally I work with flowering plants.....this my firt with ferns. I would like cp-markers and I ask me...and the inheritance? So I use also this network to have more information.
VOGEL, J. C., RUSSELL, S. J., RUMSEY, F. J., BARRETT, J. A. & GIBBY, M. 1998. Evidence for maternal transmission of chloroplast DNA in the genus Asplenium (Aspleniaceae, Pteridophyta). Bot. Acta 111: 321-334.
When dealing with hybrids, and parents are out of doubt (for example, constructing artificial hybrids in gametophyte cultures, where you control male and female GFs), a simple comparison of cpDNA markers (distances, shared mutations, in silico RFLP, etc) can probe the origin of the plastid. We are doing that in some Iberian Asplenium complexes. 100% of the times we are detecting that the plastid is inherited from the mother.