Articles

Phenotyping the ideotypes of two maize landraces from Madeira archipelago using morpho-agronomic traits and zein pattern


Abstract


Madeira Archipelago holds specific maize genetic resources whose populations, representing field diversity, were
previously classified into four main landrace groups. The ISOPs 0061 and 0070, with common names of “Milho
Sequeiro” and “Milho Branco” yellow and white maize, respectively, represent the ideotypes of two of these landraces.
These ideotypes have now been analyzed using morpho-agronomic and biochemical traits, to phenotype
these landraces. The variation of nine of the ten morpho-agronomic traits was used to separate the landraces
ideotypes. However, the seven traits of seed biochemical composition did not allow to segregate the landraces
ideotypes. This is not the case of zein pattern, which polymorphism shows to be specific for each ideotype. The
original ideotypes populations were regenerated twice under low input conditions. Zein patterns of the original
and regenerated accessions were compared, using two electrophoresis techniques. The lab-on-a-chip electrophoresis
showed that the standard SDS-PAGE zein pattern with six fractions could be separated into eighteen (ISOP
0061) and twenty (ISOP 0070) protein bands. In contrast, no significant changes were detected in the zein pattern
structure of the initial and regenerated accessions of both landraces ideotypes. The chip electrophoresis showed
to be a suitable technique to screen and characterize a large number of individuals and accessions of the germplasm
collections, due to its reproducibility. In particular, the zein patterns can be used to phenotype ideotypes
and establish a formula representing their structure, allowing to detect changes in landrace structure, occurring
as a result of gene bank management actions.

Keywords

chip electrophoresis; genotype; landraces; Zea mays L.; zein pattern.

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Maydica - A journal devoted to maize and allied species

ISSN: 2279-8013