14
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Marker-assisted screening of breeding populations of an apomictic grass Cenchrus ciliaris L. segregating for the mode of reproduction

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Abstract Cenchrus ciliaris L. is an apomictic forage grass grown in pastures and rangelands of the semi-arid tropics. It reproduces predominantly through apomixis; rarely, obligate sexual plants have also been reported. Absence of sexual reproduction limits the possibility of genetic improvement through hybridization. This study reports on hybridization of an obligate sexual, self-incompatible buffelgrass with pollen from apomictic plants towards development of an F2 population segregating for mode of reproduction and use of sequence characterized amplified region (SCAR) markers for screening the population. The segregation ratio of 3:1 (facultative: apomictic) was observed in the F1 generation, whereas it was 1:2:1 (apomictic: facultative: sexual) in the F2 generation. A number of obligate sexual F2 progenies with desirable agronomic traits were obtained. The SCAR markers were able to screen out apomictic plants from sexual ones, but failed to discriminate between facultative and sexual. Marker-assisted screening could be useful for introgression of desirable trait(s) in the apomictic genotype through hybridization.

          Related collections

          Most cited references35

          • Record: found
          • Abstract: found
          • Article: not found

          A parthenogenesis gene of apomict origin elicits embryo formation from unfertilized eggs in a sexual plant.

          Apomixis is a naturally occurring mode of asexual reproduction in flowering plants that results in seed formation without the involvement of meiosis or fertilization of the egg. Seeds formed on an apomictic plant contain offspring genetically identical to the maternal plant. Apomixis has significant potential for preserving hybrid vigor from one generation to the next in highly productive crop plant genotypes. Apomictic Pennisetum/Cenchrus species, members of the Poaceae (grass) family, reproduce by apospory. Apospory is characterized by apomeiosis, the formation of unreduced embryo sacs derived from nucellar cells of the ovary and, by parthenogenesis, the development of the unreduced egg into an embryo without fertilization. In Pennisetum squamulatum (L.) R.Br., apospory segregates as a single dominant locus, the apospory-specific genomic region (ASGR). In this study, we demonstrate that the PsASGR-BABY BOOM-like (PsASGR-BBML) gene is expressed in egg cells before fertilization and can induce parthenogenesis and the production of haploid offspring in transgenic sexual pearl millet. A reduction of PsASGR-BBML expression in apomictic F1 RNAi transgenic plants results in fewer visible parthenogenetic embryos and a reduction of embryo cell number compared with controls. Our results endorse a key role for PsASGR-BBML in parthenogenesis and a newly discovered role for a member of the BBM-like clade of APETALA 2 transcription factors. Induction of parthenogenesis by PsASGR-BBML will be valuable for installing parthenogenesis to synthesize apomixis in crops and will have further application for haploid induction to rapidly obtain homozygous lines for breeding.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Apomixis technology development-virgin births in farmers' fields?

            Apomixis is the process of asexual reproduction through seed, in the absence of meiosis and fertilization, generating clonal progeny of maternal origin. Major benefits to agriculture could result from harnessing apomixis in crop plants. Although >400 apomictic plant species are known, apomixis is rare among crop plants, and the transfer of apomixis to crop varieties by conventional breeding has been largely unsuccessful. Because apomictic and sexual pathways are closely related, de novo engineering of apomixis might be achieved in sexually reproducing crops. Early consideration of issues relating to biosafety and intellectual property (IP) management can facilitate the acceptance and deployment of apomixis technology in agriculture.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Tight clustering and hemizygosity of apomixis-linked molecular markers in Pennisetum squamulatum implies genetic control of apospory by a divergent locus that may have no allelic form in sexual genotypes.

              Apomixis is a naturally occurring mode of reproduction that results in embryo formation without the involvement of meiosis or fertilization of the egg. Seed-derived progeny of an apomictic plant are genetically identical to the maternal parent. We are studying a form of apomixis called apospory that occurs in the genus Pennisetum, a taxon in the grass family. A cultivated member of this genus, pearl millet (Pennisetum glaucum), reproduces sexually. A wild relative of pearl millet, Pennisetum squamulatum, that is an obligate aposporous species, is cross-compatible with pearl millet when used as a pollen donor in the interspecific cross. We present herein the genetic mapping of 13 molecular markers in an interspecific hybrid population of 397 individuals that segregates for apomixis and sexuality. Surprisingly, 12 of the 13 markers strictly cosegregated with aposporous embryo sac development, clearly defining a contiguous apospory-specific genomic region in which no genetic recombination was detected. Lack of or suppression of recombination may be coincidentally associated with the chromosomal context of the apomixis locus or it may be a consequence of its evolution that is essential for preservation of gene function as has been previously shown in studies of complex loci in both plant and animal species.
                Bookmark

                Author and article information

                Contributors
                Role: ND
                Role: ND
                Role: ND
                Journal
                cbab
                Crop Breeding and Applied Biotechnology
                Crop Breed. Appl. Biotechnol.
                Crop Breeding and Applied Biotechnology (Viçosa, MG, Brazil )
                1518-7853
                1984-7033
                March 2017
                : 17
                : 1
                : 10-17
                Affiliations
                [2] New Delhi orgnameICAR - Indian Agricultural Research Institute orgdiv1Division of Biochemistry India
                [1] orgnameICAR - Indian Grassland and Fodder Research Institute orgdiv1Division of Crop Improvement India
                Article
                S1984-70332017000100010
                10.1590/1984-70332017v17n1a2
                3fe8537c-536a-4b22-add6-d21a47d9ead5

                This work is licensed under a Creative Commons Attribution 4.0 International License.

                History
                : 23 March 2016
                : 25 August 2015
                Page count
                Figures: 0, Tables: 0, Equations: 0, References: 35, Pages: 8
                Product

                SciELO Brazil


                SCAR,apomixis,molecular marker,sexual reproduction
                SCAR, apomixis, molecular marker, sexual reproduction

                Comments

                Comment on this article