Molecular Characterization And Seed Germination Of Blue Corn Landraces With Accelerated Aging

The objective of this work was to determine the effect of accelerated aging on seeds of blue corn landraces. The study was conducted in the laboratories of National Polytechnic Institute and National University of Mexico. Seeds of four blue corn landraces (Cuijingo, Cocotitlan, Puebla and Oaxaca), were subjected to accelerated aging treatments: humid heat (HH, 41 degrees C, 72 h, and 100% r. h.), and dry heat (DH, 60 degrees C, 48 h. The parameters measured were: radicle protrusion (RP) in at 0 to 72 h of imbibition, and after seven days of incubation at 25 degrees C, normal seedlings (NS), abnormal seedlings (AS), and dead seeds (DS) were counted. The molecular characterization by RAPD was also performed and the respective dendrograms were constructed. In normal seedlings obtained from seeds without accelerated ageing, the varieties Oaxaca and Puebla were significantly superior. Seedling dry weight diminished with deterioration, being minimum under dry heat. The number of abnormal seedlings increased under both deterioration treatments, in the order Oaxaca, Puebla, Cocotitlan and Cuijingo. Differentiation of the band profiles among control and deteriorated seeds occurred in the sequence: Oaxaca (31,6%), Cocotitlan (25,8%), Puebla (19,6%) and Cuijingo (18,6%). These similarity values were inversely related to seed vigour, and irectly related to the presence of abnormalities in seedlings.