Discriminacion por electroforesis de isoenzimas en cuatro morfotipos del clon (MCol 2215) de yuca Venezolana (Manihot esculenta Crantz) de la Costa Atlantica

Four morphological types of cassava clone MCol 2215 (Venezolana) have been observed in El Carmen de Bolivar, Colombia. Therefore, tissues from leaf apical meristems and from root tips were assessed by electrophoresis using 4 isoenzymes as genetic markers (esterase, diaphorase, acid phosphatase, oxalic glutamate). The 4 morphological types presented similar electrophoretic patterns for the 4 isoenzyme systems tested, indicating that the different types of branching observed are not due to genetic factors but to environmental factors still unidentified. (CIAT)En El Carmen de Bolivar, Colombia, se han observado 4 morfotipos de yuca clon MCol 2215 (Venezolana); por tanto, se evaluaron tejidos provenientes de meristemas apicales foliares y de brotes o puntas radicales mediante electroforesis usando 4 isoenzimas como marcadores geneticos (esterasa, diaforasa, fosfatasa acida, glutamato oxalico). Los 4 morfotipos presentaron iguales patrones electroforeticos en los 4 sistemas isoenzimaticos probados, lo que indica que los diferentes tipos de ramificacion observados no se deben a factores geneticos sino a causas ambientales, hasta ahora desconocidos. (CIAT

New marker genes found in cassava

Five new marker genes in cassava are described; they control the following traits: chlorophyll production in seedlings, stem growth habit, stem collenchyma color, root parenchyma color, and leaf lobe shape (pandurate vs. normal). Names were proposed for each loci and dominant and recessive phenotypes described. In the case of parenchyma color, the dominant gene appears to have a dosage effect, resulting in more intense color in the homozygote as compared with the heterozygote. Pandurate leaf shape presents some unclear segregation patterns, suggesting epistatic effects of other genes. Reciprocal crosses studied for segregation of seedling albinism, stem collenchyma color, and root parenchyma color show identical ratios regardless of which parent was male or female, indicating that inheritance is not influenced by cytoplasmic effects. (CIAT