title: The nature of apomixis in cassava (Manihot esculentum, Crantz).
abstract: Apomixis in cassava is formed by aposporic embryo sacs which arise from cells in nucellus or from cells in the sexual embryo sac. There is an association between sterility and apomixis. It seems that sterility caused by defected meioses triggers a specific gene for exhibiting apomixis. This apomictic mechanism is favoured by natural selection since it offers an escape from lethality and provides a perpetuation of the current genotype.
authors.affiliation: Departamento de Genetica e Morfologia, Universidade de Brasilia, Brazil. nagnassa@rudah.com.br
authors.forename: N M
authors.initials: NM
authors.lastname: Nassar
mesh_terms: D020732:Cytogenetic Analysis; D004171:Diploidy; D005298:Fertility; D007246:Infertility / Q000235:genetics; D002365:Manihot / Q000033:anatomy & histology / Q000196:embryology* / Q000235:genetics*; D008540:Meiosis; D008938:Mitosis; D011058:Pollen / Q000235:genetics*; D012100:Reproduction, Asexual / Q000235:genetics*; D012641:Selection, Genetic; D014314:Trisomy