Estimations on Trait Stability of Maize Genotypes

The purposes of this study were to define the kind of trait inheritance through stability estimations of various traits in maize, to define the relationship between different environments and maize hybrids, and to propose the best environments and hybrids for farmers. Field experiments were conducted in two years (2011 and 2012) at four different locations in Greece: Florina, Trikala, Kalambaka and Giannitsa which were selected as they represent different environments. The genetic materials tested in a Randomized Complete Block (RCB) design, were 15 F1 commercial maize hybrids and 15 open-pollination lines developed from 4-cycle Honeycomb evaluation. Materials were sown and harvested by hand at different dates according to local conditions. Trait stability index ( x ¯ ∕ s ) 2 across environments was computed for each maize trait studied: yield, specific weight, 1000-kernel weight, axis (spindle) weight, spike weight, number of kernels per spike, spike length and diameter, number of kernel rows, spindle diameter, main spike and plant height, prolificacy and number of kernels per row. The findings showed great differences in stability index between traits and also for the same trait across environments or between maize genotypes. GGE biplot for yield distributed genotypes in a different way for Florina on the basis of one main factor and managed to depict Trikala’s differential response on the basis of two factors. Almost the same trend was found for 1000-kernel weight and specific weight, where there was a wide core for similar responding genotypes. Basic conclusions of this research are summarized in great differences of various traits, indicating qualitative, medium or quantitative inheritance. Estimations for trait stability can be easily performed in a multi-genotype experiment using trait stability index. The most stable hybrids were proved to be 31Y43, COSTANZA and FACTOR. The environment favouring a general stable performance proved to be Florina.