Molecular characterization and seed germination of blue corn landraces with accelerated aging.

Abstract

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 laboratorie s of National Polytechnic Institute and National

University of México. See ds of four blue corn landraces

(Cuijingo, Cocotitlán, Puebla and Oaxaca), were subjected

to accelerated aging treatments: humid heat (HH, 41°C, 72

h, and 100% r. h.), and dry heat (DH, 60°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°C,

normal seedlings (NS ), abnormal seedlings (AS ), and dead

seeds (DS) were counted. The molecular characterization by

RA PD was also performed and the respective dendrograms

were constructed. In normal seedlings obtained from seeds

without accelerated ageing, the varie tie s 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, Cocotitlán and

Cuijingo. Differentiation of the band profiles among control

and deteriorated seeds occurred in the sequence: Oaxaca

(31,6%), Cocotitlán (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 abnormalitie

s in seedlings.