Evolution and adaptedness in a facultatively apomictic grass, Poa pratensis L.

Mazzucato, Andrea; Falcinelli, M.; Veronesi, F.

doi:10.1007/978-94-015-8806-5_2

Cited by 8 publications

(9 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Reproductive mode may furthermore be sensitive to environmental conditions (Barcaccia et al, 1997b;Mazzucato et al, 1997), and thus the induction of recombinant genotypes should be considered during cultivar selection and multiplication if the working environment is likely to differ from that of germplasm collection or cultivar constitution. For example, the Polish cultivar Topas, although characterised by a within-population genetic similarity higher than Italian ecotypes, was composed of multiclonal genotypes rather than being genetically uniform as expected.…”

Section: Patterns Of Evolution and Adaptednessmentioning

confidence: 99%

“…Since apomixis can lead to irregular embryo and seedling formation, unbalanced chromosome numbers, mutation accumulation and sterility, discrepancies observed between molecular polymorphisms scored within single populations and the relative proportions of seeds derived by apomictic or sexual processes may result from differential seed vitality and plant fertility. The relative fitness of sexually and apomictically derived embryos is furthermore correlated with the environment of evaluation (Mazzucato et al, 1997).…”

Section: Patterns Of Evolution and Adaptednessmentioning

confidence: 99%

See 1 more Smart Citation

Genetic diversity and reproductive biology in ecotypes of the facultative apomict Hypericum perforatum L.

et al. 2006

View full text Add to dashboard Cite

Apomixis is a mode of asexual reproduction through seed. Progeny produced by apomixis are clonal replicas of a mother plant. The essential feature of apomixis is that embryo sacs and embryos are produced in ovules without meiotic reduction or egg cell fertilisation. Thus, apomixis fixes successful gene combinations and propagates high fitness genotypes across generations. A more profound knowledge of the mechanisms that regulate reproductive events in plants would contribute fundamentally to understanding the evolution and genetic control of apomixis. Molecular markers were used to determine levels of genetic variation within and relationship among ecotypes of the facultative apomict Hypericum perforatum L. (2n ¼ 4x ¼ 32). All ecotypes were polyclonal, being not dominated by a single genotype, and characterised by different levels of differentiation among multilocus genotypes. Flow cytometric analysis of seeds indicated that all ecotypes were facultatively apomictic, with varying degrees of apomixis and sexuality. Seeds set by haploid parthenogenesis and/or by fertilisation of aposporic egg cells were detected in most populations. The occurrence of both dihaploids and hexaploids indicates that apospory and parthenogenesis may be developmentally uncoupled and supports two distinct genetic factors controlling apospory and parthenogenesis in this species. Cyto-embryological analysis showed that meiotic and aposporic processes do initiate within the same ovule: the aposporic initial often appeared evident at the time of megaspore mother cell differentiation. Our observations suggest that the egg cell exists in an active metabolic state before pollination, and that its parthenogenetic activation leading to embryo formation may occur before fertilisation and endosperm initiation.

show abstract

Section: Patterns Of Evolution and Adaptednessmentioning

confidence: 99%

Section: Patterns Of Evolution and Adaptednessmentioning

confidence: 99%

Genetic diversity and reproductive biology in ecotypes of the facultative apomict Hypericum perforatum L.

et al. 2006

View full text Add to dashboard Cite

show abstract

“…Furthermore, the polyploidy of most apomicts hinders genetic mapping studies and the building up of populations for reverse genetics. Even though apomixis may be variously influenced by environmental factors (Mazzucato et al, 1996), at least for facultative apomicts, it is generally accepted that apomictic behavior is under strong genetic control (Nogler, 1984;Savidan, 1990;Asker and Jerling, 1992;Savidan, 2000). An early theory regarding genetic control of apomixis proposed that the trait is regulated by a delicate gene balance (Mü ntzing, 1940) of recessive genes and that this might be disturbed after crosses.…”

mentioning

confidence: 99%

SERK and APOSTART. Candidate Genes for Apomixis in Poa pratensis

et al. 2005

Self Cite

View full text Add to dashboard Cite

Seed production generally requires the mating of opposite sex gametes. Apomixis, an asexual mode of reproduction, avoids both meiotic reduction and egg fertilization. The essential feature of apomixis is that an embryo is formed autonomously by parthenogenesis from an unreduced egg of an embryo sac generated through apomeiosis. If apomixis were well understood and harnessed, it could be exploited to indefinitely propagate superior hybrids or specific genotypes bearing complex gene sets. A more profound knowledge of the mechanisms that regulate reproductive events would contribute fundamentally to understanding the genetic control of the apomictic pathway. In Poa pratensis, we isolated and characterized two genes, PpSERK (SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE) and APOSTART. These full-length genes were recovered by rapid amplification of cDNA ends and their temporal and spatial expression patterns were assessed by reverse transcriptionpolymerase chain reaction and in situ hybridization, respectively. The expression of PpSERK and APOSTART differed in apomictic and sexual genotypes. Their putative role in cell-signaling transduction cascades and trafficking events required during sporogenesis, gametogenesis, and embryogenesis in plants is reported and discussed. We propose that, in nucellar cells of apomictic genotypes, PpSERK is the switch that channels embryo sac development and that it may also redirect signaling gene products to compartments other than their typical ones. The involvement of APOSTART in meiosis and programmed cell death is also discussed.

show abstract

“…Thus, plastid sequence characters can be especially meaningful for cultivars derived from one or a few maternal individuals, particularly those maintained vegetatively or apomictically. Poa pratensis spreads by rhizomes (Soreng and Barrie 1999) and produces seed mainly through aposporous apomixis (Mazzucato et al 1996).…”

Section: Discussionmentioning

confidence: 99%

The trnL-F plastid DNA characters of three Poa pratensis (Kentucky bluegrass) varieties

Holt¹,

Horová²,

Bureš³

et al. 2005

PLANT SOIL ENVIRON

View full text Add to dashboard Cite

The characterization of crop cultivars (varieties) will come to depend increasingly on molecular characters in addition to traditional morphological and agronomic characters. Three cultivars of Kentucky bluegrass (Poa pratensis L.), developed by the Plant Breeding Station Hladké Životice (PBHŽ), were characterized using sequences and PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism) patterns from the non-coding plastid trnL-F region (trnL intron, 549 bp, and trnL-trnF intergenic spacer [IGS], 344 to 364 bp). These characters could be readily and repeatably determined not only for mature plants, but also for seedlings (less than 12 weeks old), which are difficult to distinguish morphologically. The method is quick and sensitive. When restricted with a combination of BsaJ I and Bsm I, cultivar Slezanka has one major band, Moravanka has two, and Harmonie has three. When restricted with Alu I, the heaviest band migrates most slowly for Slezanka. It is expected that many Kentucky bluegrass cultivars will share the same trnL-F sequence, so these characters alone are not sufficient for variety identification.

show abstract

Evolution and adaptedness in a facultatively apomictic grass, Poa pratensis L.

Cited by 8 publications

References 33 publications

Genetic diversity and reproductive biology in ecotypes of the facultative apomict Hypericum perforatum L.

Genetic diversity and reproductive biology in ecotypes of the facultative apomict Hypericum perforatum L.

SERK and APOSTART. Candidate Genes for Apomixis in Poa pratensis

The trnL-F plastid DNA characters of three Poa pratensis (Kentucky bluegrass) varieties

Contact Info

Product

Resources

About