Two types of molecular genetic markers were used for genetic identification of species and local stocks of palearctic coregonids (Coregonidae, Salmoniformes, Teleostei). Seven nominate species of whitefishes and ciscoes Coregonus spp. of Eurasia Arctic Sea basin and inconnu Stenodus leucichthys nelma represented by specimens from North America were studied. Using restriction analysis of PCR-amplified products of the ND-1 gene of mitochondrial DNA (mtDNA) and allelic composition at several allozyme loci discrimination was successful between C. lavaretus pidschian Siberian whitefish, C. nasus broad whitefish, C. autumnalis Arctic cisco, C. migratorius Baikal omul, C. peled peled, and C. sardinella least cisco. Muksun C. muksun was indistinguishable from Siberian whitefish. Creatine kinase (CK) isozyme patterns and Rsa I restriction patterns of ND-1 were the most effective markers allowing discrimination among species. Intra-specific differentiation in mtDNA was found in all species but was much less pronounced than inter-species variation. In several specimens composite haplotypes typical of another species were found that reflect probable gene introgression by hybridization. A combination of mtDNA and nuclear genetic markers is suggested for reliable identification of both typical species representatives and hybrids. 2000 The Fisheries Society of the British Isles

No abstract

No abstract

No abstract

No abstract

No abstract

Approximately 4000 mature seeds from 350 trees in nine populations (12-75 trees per population) of Siberian stone pine were investigated for multiple embryos (polyembryony). Haploid megagametophytes and embryos were genotyped for eight allozyme loci. Eight-yone seeds (2.11%) had more than 1 embryo. Of these, 71 seeds had 2 embryos (1.85%), 6 seeds had 3 embryos (0.16%), 3 seeds had 4 embryos (0.08%) and 1 seed had 6 embryos (0.026%). Allozyme comparison of megagametophytes and embryos could distinquish two types of polyembryony in 56 of the 81 seeds. In 28 seeds (50%) the polyembryony was polyzygotic (independent fertilizations of more than one egg cell in the ovule); 25 seeds (45%) had most likely monozygotic polyembryony (genetically identical embryos resulting from the cleavage of a single proembryo) and 3 seeds had both genetically different and genetically identical embryos. To the best of our knowledge, this is the first genetic evidence for the form of polyembryony in conifer seeds.

No abstract