Cytogenetic analysis of reciprocal hybrids and their parents between Larix leptolepis and Larix gmelinii: implications for identifying hybrids

We studied the parental taxa and the interspecific reciprocal hybrids between Larix leptolepis with Larix gmelinii, using classical cytogenetic methods, as well as fluorescence in situ hybridization (FISH) and genomic in situ hybridization. A high frequency (> 90%) of complete bivalent formation was observed in reciprocal hybrids. Less than 10% of pollen mother cells exhibited abnormalities. The most frequent abnormalities were bridges. Multivalent chromosome associations were also observed in both reciprocal hybrids, suggesting that some chromosome interchange events did occur, and introgressions from one to the other species were possible. Intergenomic recombination indicates that genes might be readily introgressed into one species from the other in the genus Larix. Interspecific hybridization may be a potential method for genetic improvement in larch. FISH markers documented that the recombinant genomes of reciprocal hybrids were strictly additive and stable, indicating that FISH also might be a useful tool in Larix breeding.ForestryGenetics & HeredityHorticultureSCI(E)3ARTICLE3405-412