CYTOLOGICAL AND MORPHOLOGICAL VARIATIONS IN WILD POPULATIONS OF AVENA-CANARIENSIS FROM THE CANARY-ISLANDS

Three sorts of chromosomal variations, loss of satellite, cytomixis an d translocation, were observed in hybrids between different natural po pulations of Avena canariensis. A heteromorphic rod bivalent is freque ntly found in the hybrids between early and late flowering ecotypes of A. canariensis and one satellite chromosome has been lost in the earl y flowering ecotype of Lanzarote Island. Cytomixis was observed in a n umber of inter-population hybrids, and one genotype was shown to induc e cytomixis causing a great loss of chromatin. The plants showing cyto mixis were 70-80% fertile but cytomixis was considered to be an isolat ing mechanism. A quadrivalent (or trivalent) caused by a single recipr ocal translocation was observed in the populations which originated fr om a distinct geographic region i.e. the northern part of Lanzarote.