Data/hora: 14/06/2024 01:33:28

Biblioteca(s): | Embrapa Agropecuária Oeste; Embrapa Mandioca e Fruticultura; Embrapa Meio Norte / UEP-Parnaíba; Embrapa Meio-Norte; Embrapa Semiárido; Embrapa Unidades Centrais.
Data corrente: | 09/09/2004
Data da última atualização: | 18/05/2016
Autoria: | SOARES FILHO, W. dos S.; VILARINHOS, A. D.; ALVES, A. A. C.; CUNHA SOBRINHO, A. P.; OLIVEIRA, A. A. R.; SOUZA, A. da S.; LEDO, C. A. da S.; CRUZ, J. L.; SOUZA, L. D.; CASTRO NETO, M. T. de; GUERRA FILHO, M. dos S.; PASSOS, O. S.; MEISSNER FILHO, P. E.
Título: | Citrus breeding program at Embrapa Cassava & Fruits: development of hybrids.
Ano de publicação: | 2003
Fonte/Imprenta: | Cruz das Almas: Embrapa Mandioca e Fruticultura, 2003.
Páginas: | 39 p.
Série: | (Embrapa Mandioca e Fruticultura. Documentos, 107).
ISSN: | 1516-5728

Idioma:

Inglês
Português

Conteúdo: | In order to obtain new citrus varieties, better adapted to tropical conditions, the Embrapa - National Cassava & Fruits Research Center (CNPMF), as known as Embrapa Cassava & Fruits, has started in September 1988 a hybridization program based on its own Active Germplasm Bank, which shows a great genetic variability, represented for about 700 accesses, comprising several Citrus species and varieties, besides close relative genera, among which are inclused Poncirus, Fortunella, Microcitrus, Eremocitrus and Severinia, among others of smaller importance, under the point of view of genetic improvement. The program was set up due to the relatively low longevity of the citurs orchards, whose life span is around 15 to 18 years in the main producing areas of São Paulo State, that represents about 75% of the Brazilian production, and from 12 to 15 years in the North and Northeast regions of the country. As immediate objectives, the program aims at selection of genotypes, particularly rootstocks, tolerant to drought conditions and aluminum toxicity, resistant to diseases such as Phytophthora root rot and Citrus Tristeza Virus - CTV, and adapted to high density tree population. A multidisciplinary research group is involved in these studies and several research activities are underway,  mainly: a) hybridization, including varieties of high agronomic valoe and/or adaptive potential to grow in abiotic and biotic stresses; b) identification of hybrid embryos and early identification of zygotic seedlings by analysis of foliar morphology, isoenzymes, polymorphic DNA segments and chromosome banding; c) studies concerned to in vitro cultivation of citrus embryos, as well as to the complement of the embryogenesis of zygotic embryos starting from early stages, avoiding or restricting the presence of nucellar embryos, particularly in polyembryonic varieties, used as female parents in artificial hybridizations; d) identification of promising parents regarding to obtaining new hybrid varieties, rootstocks and scions; e) definition of methodologies for early selection of hybrids tolerant to drought and aluminum toxicity, as well as resistant to Phytophthora root rot and CTV; f) establishment of methodologies for early flowering induction, aiming at shortening the pre-reproductive period of selected hybrids; g) development of somatic hybrids by protoplast fusion.
Palavras-Chave: | Bandeamento cromossômico; Citros; Citrus trieza virus; Cultura de tecidos; Cultura dos tecidos; Early flowering induction; Florescimento; Fusão de protoplastos; Gomose de Phytophthora; Indução de florescimento; Marcadores moleculares; Molecular makers; Molecular markers; Phutophthora root rot; Phytophthora root rot; Tolerance to aluminum toxicity; Tolerance to alumium toxicity; Tolerância à seca; Tolerância ao alumínio; Tristeza dos citrus; Vírus da tristeza dos citros.
Thesagro: | Alumínio; Fruta cítrica; Hibridação; Indução; Marcador Molecular; Melhoramento; Poliembrionia; Seca; Vírus.
Thesaurus Nal: | breeding; chromosome banding; Citrus; Citrus tristeza virus; drought tolerance; hybridization; polyembryony; protoplast fusion; tissue culture.
Categoria do assunto: | --
URL: | http://ainfo.cnptia.embrapa.br/digital/bitstream/item/143115/1/Citrus-Breeding-Program-Doc-107-2003.pdf
Registro original: | Embrapa Mandioca e Fruticultura (CNPMF)

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