Apomixis is a means of asexual reproduction by which plants produce embryos without fertilization and meiosis,therefore the embryo is of clonal and maternal origin.Interspecific hybrids between dip-loid B.vulgaris(2n=...Apomixis is a means of asexual reproduction by which plants produce embryos without fertilization and meiosis,therefore the embryo is of clonal and maternal origin.Interspecific hybrids between dip-loid B.vulgaris(2n=2x=18)and tetraploid B.corolliflora(2n=4x=36)were established,and then back-crossed with B.vulgaris.Among their offspring,monosomic addition line M14(2n=2x=18+1)was se-lected because of the apomictic phenotype.We documented chromosome transmission from B.corol-liflora into M14 by using genomic in situ hybridization(GISH).Suppression of cross-hybridization by blocking DNA was not necessary,indicating that the investigated Beta genome contains sufficient species-specific DNA,thus enabling the determination of genomic composition of the hybrids.We analyzed BAC microarrays of B.corolliflora chromosome 9 by using fluorescence-specific mRNA of B.vulgaris and Beta M14.BAC clones 16-M11 and 26-L15 were detected as fluorescence-specifics of BAC DNA of Beta M14.Then both BAC clones 16-M11 and 26-L15 were in situ hybridized to M14 chromo-somes.The two hybridized BAC clones were located close to the telomere region of the long arm of a single chromosome 9,and showed hemizygosity.The results of BAC microarrays showed that these developments of embryo and endosperm have conservative expression patterns,indicating that sexual reproduction and apomixis have an interrelated pathway with common regulatory components and that the induction of a modified sexual reproduction program may enable the manifestation of apomixis in Beta species.It would be sufficient for the expression of apomixes with those apomictic-specific genes on chromosome 9 of B.corolliflora.展开更多
基金the National Transgene Scientific Program (Grant No. JY03A2402)the Postdoctoral Science Foundation of Heilongjiang Province
文摘Apomixis is a means of asexual reproduction by which plants produce embryos without fertilization and meiosis,therefore the embryo is of clonal and maternal origin.Interspecific hybrids between dip-loid B.vulgaris(2n=2x=18)and tetraploid B.corolliflora(2n=4x=36)were established,and then back-crossed with B.vulgaris.Among their offspring,monosomic addition line M14(2n=2x=18+1)was se-lected because of the apomictic phenotype.We documented chromosome transmission from B.corol-liflora into M14 by using genomic in situ hybridization(GISH).Suppression of cross-hybridization by blocking DNA was not necessary,indicating that the investigated Beta genome contains sufficient species-specific DNA,thus enabling the determination of genomic composition of the hybrids.We analyzed BAC microarrays of B.corolliflora chromosome 9 by using fluorescence-specific mRNA of B.vulgaris and Beta M14.BAC clones 16-M11 and 26-L15 were detected as fluorescence-specifics of BAC DNA of Beta M14.Then both BAC clones 16-M11 and 26-L15 were in situ hybridized to M14 chromo-somes.The two hybridized BAC clones were located close to the telomere region of the long arm of a single chromosome 9,and showed hemizygosity.The results of BAC microarrays showed that these developments of embryo and endosperm have conservative expression patterns,indicating that sexual reproduction and apomixis have an interrelated pathway with common regulatory components and that the induction of a modified sexual reproduction program may enable the manifestation of apomixis in Beta species.It would be sufficient for the expression of apomixes with those apomictic-specific genes on chromosome 9 of B.corolliflora.
