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Full-Text Articles in Physical Sciences and Mathematics
Seasonal Expression Of Apospory In Bahiagrass, Esteban F. Rios, Ann R. Blount, Kevin E. Kenworthy, Carlos A. Acuña, Kenneth H. Quesenberry
Seasonal Expression Of Apospory In Bahiagrass, Esteban F. Rios, Ann R. Blount, Kevin E. Kenworthy, Carlos A. Acuña, Kenneth H. Quesenberry
IGC Proceedings (1997-2023)
Flowering plants can reproduce sexually (outcrossing and/or selfing) and/or asexually. Sexual reproduction implies the successful completion of meiosis and double fertilisation for the formation of both the embryo and the endosperm. In contrast, gametophytic apomixis is an asexual mode of reproduction through seeds that involves parthenogenetic embryo development from a cytologically unreduced egg cell (2n). Apospory is the process by which unreduced gametophytes are formed after a series of mitotic divisions of somatic cells (2n) in the ovary. This occurs independently from the sexual meiotic process; and therefore, both sexual and apomictic pathways may coexist simultaneously. Apospory is inherited in …
Breeding Strategies For Brachiaria Spp. To Improve Productivity–An Ongoing Project, Geovani F. Alves, Ulisses J. De Figueiredo, Antônio D. Pandolfi Filho, Sanzio C. L. Barrios, Cacilda B. Valle
Breeding Strategies For Brachiaria Spp. To Improve Productivity–An Ongoing Project, Geovani F. Alves, Ulisses J. De Figueiredo, Antônio D. Pandolfi Filho, Sanzio C. L. Barrios, Cacilda B. Valle
IGC Proceedings (1997-2023)
Two strategies have been used in the breeding of Brachiaria (syn. Urochloa) to produce new cultivars. The first involves exploring the natural variability existing in nature, which is the selection of ecotypes, mostly apomicts, from the diversity in germplasm banks. This strategy proved efficient originally and the cultivars in use in Brazil were derived in this way, but progress with this strategy is limited in the medium to long term.
Agronomic Evaluation Of 324 Intraspecific Hybrids Of Brachiaria Decumbens In Brazil, Rogério G. Mateus, Sanzio C. L. Barrios, Ulisses J. De Figueiredo, Cacilda B. Valle
Agronomic Evaluation Of 324 Intraspecific Hybrids Of Brachiaria Decumbens In Brazil, Rogério G. Mateus, Sanzio C. L. Barrios, Ulisses J. De Figueiredo, Cacilda B. Valle
IGC Proceedings (1997-2023)
Brachiaria decumbens cv. Basilisk is the most planted pasture grass in the tropics owing to its adaptation to poor and acid soils, typical of the tropics, plus good animal performance. This cultivar was responsible for a radical change of scenario in central Brazil in the early 1970s and is the only cultivar available commercially. Efforts to breed this species have been recent, as the successful somatic chromosome duplication of sexually reproducing diploid plants of B. decumbens was accomplished only in 2009 (Simioni and Valle 2009). Subsequently, intraspecific crosses with natural apomictic tetraploid accessions were carried out. Breeding is needed since …
Agronomic And Nutritional Evaluation Of Intraspecific Crosses In Brachiaria Decumbens, Simony A. Mendonça, Sanzio C. L. Barrios, Ulisses J. De Figueiredo, Geovani F. Alves, Cacilda B. Valle
Agronomic And Nutritional Evaluation Of Intraspecific Crosses In Brachiaria Decumbens, Simony A. Mendonça, Sanzio C. L. Barrios, Ulisses J. De Figueiredo, Geovani F. Alves, Cacilda B. Valle
IGC Proceedings (1997-2023)
Brachiaria decumbens cv. Basilisk is the single most important forage grass used for pastures in the tropics. This cultivar has exceptional adaptation to acid soils, vigorous growth, ease of establishment, and good forage value throughout the year, but these favourable characteristics are counteracted by its susceptibility to insect pests such as spittlebug. Breeding to produce improved cultivars within this species was impossible until 2009 due to the lack of compatible sexual ecotypes. With the success of somatic chromosome duplication of sexually reproducing diploid plants of B. decumbens (Simioni and Valle 2009), intraspecific crosses with natural apomictic tetraploid accessions were finally …
Reciprocal Recurrent Selection In The Breeding Of Brachiaria Decumbens, Sanzio C. L. Barrios, Cacilda B. Valle, Geovani F. Alves, Rosangela M. Simeão, Liana Jank
Reciprocal Recurrent Selection In The Breeding Of Brachiaria Decumbens, Sanzio C. L. Barrios, Cacilda B. Valle, Geovani F. Alves, Rosangela M. Simeão, Liana Jank
IGC Proceedings (1997-2023)
Pastures of Brachiaria decumbens cv. Basilisk radically changed the scenario of livestock production in central Brazil in the early 1970s and in fact, promoted the development of this vast region. However, despite the reasonable biomass yields and nutritional value when grown on these tropical acid soils, its susceptibility to grassland spittlebugs has limited its use. The breeding of B. decumbens in Brazil has been restricted to interspecific crosses using cv. Basilisk as a pollen donor due to the lack of compatible sexual ecotypes within this species. Recently, the successful chromosome duplication of a sexually reproducing diploid accession produced 3 successful …