Resumo
A study has been made of the embryo sac in self-sterile Coffea canephora flowers of different ages. The process was observed to be normal and included the formation of two synergides and one egg cell in the micropilar region, three antipodals at the chalazal region and two polar nuclei lying in the middle of the sac. It is known that in the species C. arabica the embryo sac formation is complete at the time the flowers open. Embryo sac formation in C. canephora is slightly delayed and it is not complete until the day following opening of the flowers. It was also determined that in C. canephora shedding of pollen begins shortly after the flowers open and the pollen was functional at least for two days. Thus the results of the present study indicate that the self-sterility of C. canephora flowers is not due to the delay in formation or abnormal development of the embryo sac.
Observações citológicas em Coffea. XVII - O saco embrionário em Coffea canephora Pierre ex Froehner
Cândida H. T. Mendes
Engenheiro agrônomo, Secção de Citologia, Instituto Agronômico de Campinas
SUMMARY
A study has been made of the embryo sac in self-sterile Coffea canephora flowers of different ages. The process was observed to be normal and included the formation of two synergides and one egg cell in the micropilar region, three antipodals at the chalazal region and two polar nuclei lying in the middle of the sac.
It is known that in the species C. arabica the embryo sac formation is complete at the time the flowers open. Embryo sac formation in C. canephora is slightly delayed and it is not complete until the day following opening of the flowers.
It was also determined that in C. canephora shedding of pollen begins shortly after the flowers open and the pollen was functional at least for two days. Thus the results of the present study indicate that the self-sterility of C. canephora flowers is not due to the delay in formation or abnormal development of the embryo sac.
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LITERATURA CITADA
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Datas de Publicação
-
Publicação nesta coleção
31 Maio 2010 -
Data do Fascículo
Abr 1950
