SciELO - Scientific Electronic Library Online

 
vol.20 número3A search for RFLP markers to identify genes for aluminum tolerance in maizeGenetics of resistance to the fungus Helminthosporium sativum in wheat: use of culture filtrates in tissue culture índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Brazilian Journal of Genetics

versión impresa ISSN 0100-8455

Resumen

GRANDO, Magali Ferrari  y  MORAES-FERNANDES, Maria Irene B. de. Two point deterministic model for acquisition of in vitro pollen grain androgenetic capacity based on wheat studies. Braz. J. Genet. [online]. 1997, vol.20, n.3 ISSN 0100-8455.  http://dx.doi.org/10.1590/S0100-84551997000300018.

This article discusses, from the standpoint of cellular biology, the deterministic and indeterministic androgenesis theories. The role of the vacuole and of various types of stresses on deviation of the microspore from normal development and the point where androgenetic competence is acquired are examined. Based on extensive literature review and data on wheat studies from our laboratory, a model for androgenetic capacity of pollen grain is proposed. A two point deterministic model for in vitro androgenesis is our proposal for acquisition of androgenetic potential of the pollen grain: the first switch point would be early meiosis and the second switch point the uninucleate pollen stage, because the elimination of cytoplasmatic sporophytic determinants takes place at those two strategic moments. Any abnormality in this process allowing the maintenance of sporophytic informational molecules results in the absence of establishment of a gametophytic program, allowing the reactivation of the embryogenic process

        · resumen en Portugués     · texto en Inglés