B-chromosomes are found in vertebrate and invertebrate animals, musci, gymnosperm and angiosperm plants [Moshkovich, 1979; Jones, Rees, 1982; Jones, 1995; Muratova, 2000; Camacho et al, 2000; Palestis et al., 2004; Vujošević, Blagojević, 2004; Jones et al., 2008, and others]. At present above 230 species with B-chromosomes are known among tree plants. There are more than 200 species angiosperms from 60 families and about 30 species gymnosperms from 4 families.

The presentation will deal with the results of own investigations and rewier of literature data on the karyology of the genus Picea A. Dietr. representatives and other conifers species. More than a half of conifer species with B-chromosomes belong to the genus Picea – 18 species including interspecific hybrid [Kruklis. 1971a, b; Moir, Fox, 1972; Rees et al., 1977; Teoh, Rees, 1977; Shershukova, 1978; Keen et al., 1982; Liu, Li, 1985; Lai et al., 1986; Medvedeva, Muratova, 1987; Hizume, 1988; Hizume et al., 1988, 1989, 1991; Broka, 1990; Il’chenko, Gamaeva, 1991; Gamaeva, 1992; Muratova, Frolov, 1995; Vladimiriva, 200, 2002; Li et al., 2001; Muratova, Vladimirova, 2001a, b; Butorina, Bogdanova, 2001; Muratova et al., 2001, 2002, 2004, 2005; Vladimirova, Muratova, 2003, 2005, 2006; Vladimiriva et al., 2003, 2007; Karpjuk, 2004; Karpjuk, Muratova, 2005; Karpjuk et al., 2007; Sedelnikova, 2006; Shibata, Hizume, 2008; Kvitko et al., 2009].

It is generally agreed that B-chromosomes are derived initially from members of the A-chromosome complement [Jones, Rees, 1982]. Genetic effects of supernumerary chromosomes have a polygenic nature. B-chromosomes don't affect the phenotype features but influence on the nuclear phenotype and genome function, on the duration of the cell cycle, genetic activity, nuclear DNA amount, behaviour of A-chromosomes during meiosis [Moir, Fox, 1975; Teoh, Rees, 1976, 1977; Jones, Rees, 1982; Broka, 1990]. Hereditary of B-chromosomes genes has not the Mendelian character. In many cases B-chromosomes have negative influence on fertility and viability.

Different species show availability of B-chromosomes in the central parts of area as well as in peripheral small isolated populations. Presence of B-chromosomes can be connected with unfavourable ecological factors and anthropogenous influence [Pravdin et al., 1976; Moir, Fox, 1977; Teoh, Rees, 1977; Jones, Rees, 1982; Medvedeva, Muratova, 1987; Broka, 1990; Vladimirova, 2000, 2002; Muratova, Vladimirova, 2001a, b; Muratova et al., 2001, 2002, 2004, 2005; Vladimirova, Muratova, 2003, 2005, 2006]. It is possible that plants including B-chromosomes are more polymorphic in contrast with plants without them, and more adaptive to changing environment.

The study is supported partly by Russian Foundation of Basic Research (Grant No 08-04-90001) and Integration project of SB and UB RAS No 49.

Note. Abstracts are published in author's edition