SBICafé
Biblioteca do Café

Observações citológicas em Coffea. XIV - Microsporogênese em Coffea arabica L. Var. rugosa K.M.C.

Mostrar registro simples

dc.contributor.author Medina, Dixier M.
dc.date.accessioned 2019-01-21T10:56:03Z
dc.date.available 2019-01-21T10:56:03Z
dc.date.issued 1950-02
dc.identifier.citation MEDINA, D. M. Observações citológicas em Coffea. XIV - Microsporogênese em Coffea arabica L. Var. rugosa K.M.C. Bragantia, Campinas, v. 10, n. 2, p. 61-66, 1950. pt_BR
dc.identifier.issn 1678-4499
dc.identifier.uri http://dx.doi.org/10.1590/S0006-87051950000200003 pt_BR
dc.identifier.uri http://www.sbicafe.ufv.br/handle/123456789/11000
dc.description.abstract Only one plant of Coffea arabica L. var. rugosa K.M.C., is available for study Its fruit production is very low. Of the progeny observed, none has reproduced th rugose condition of the leaves characteristic of the parent plant. Previous study ha shown that the rugose condition of the leaves could not be considered a somatic chimer because the tissues have a normal number (2n=44) of chromosomes. The present cytological study was undertaken in order to find out if the low yiel of the rugose variety could be related to abnormalities in microsporogenesis. The structure of the chromosomes in early prophase is difficult to study. In diaki nesis two pairs and sometimes three pairs of chromosomes appear to be attached to th nucleolus. Also in diakinesis it is possible to locate the centromere in the chromosoni pairs and to count the chiasmata. It was observed that an average of 6.6 bivalent show one single chiasma, 12.3 bivalents show two chiamata and 3.0 bivalents shoM three chiasmata. The average total number of chiasmata per cell at this phase is o 40.0, while at metaphase this number is reduced to 34.7. The first division in the mi crospore is normal and the resulting two nuclei differ in size and also in the size o their nucleolus. The polen grains are normal, giving 69% germination on a medium containinj 0,5% of agar and 15% of sucrose. It is concluded that microsporogenesis is normal and would not appear to be relate< to the low production of fruits of the rugosa variety. The fact that none of the progen1 has reproduced the rugose condition might be due to the limited number of plants observed. pt_BR
dc.format pdf pt_BR
dc.language.iso pt_BR pt_BR
dc.publisher Instituto Agronômico (IAC) pt_BR
dc.relation.ispartofseries Bragantia;v. 10, n. 2, p. 61-66, 1950;
dc.rights Open Access pt_BR
dc.subject.classification Cafeicultura::Genética e melhoramento pt_BR
dc.title Observações citológicas em Coffea. XIV - Microsporogênese em Coffea arabica L. Var. rugosa K.M.C. pt_BR
dc.type Artigo pt_BR

Arquivos deste item

Arquivos Tamanho Formato Visualização
Bragantia_v. 10_n. 2_p. 61 - 66_1950.pdf 454.1Kb application/pdf Visualizar/Abrir ou Pre-visualizar

Este item aparece na(s) seguinte(s) coleção(s)

  • Bragantia [359]
    Artigos relacionados a Cafeicultura

Mostrar registro simples

Buscar em toda a Biblioteca


Sobre o SBICafé

Navegar

Minha conta