TITLE:
Generational Mean Analysis of Salt Tolerance during Osmotic Phase in Maize Seedling
AUTHORS:
Mónica B. Collado, Mónica B. Aulicino, Miguel J. Arturi, María del C. Molina
KEYWORDS:
Maize, Salinity, Osmotic Stress Tolerance, Genetic Effects, Generation Means Analysis
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.10 No.4,
April
22,
2019
ABSTRACT: This study details the nature and magnitude of the
genetic effects associated with various quantitative characters (morphological
and hydric relations) measured in maize seedlings during the osmotic phase of
saline stress (100 mM NaCl). Three lines with differential behavior in salt
stress: SC2 (tolerant), AFE (susceptible) and LP3 (moderately tolerant) were
used to obtain contrasting crosses (SC2 × AFE) and (SC2 × LP3). An analysis of
six generational means (P1, P2, F1, F2, BC1 and BC2)
was applied for each cross. First a
scaling test was applied and then a three and six-parameter
genetic models were used to estimate various genetic components. In none of the
traits studied there was evidence of adequacy to the three parameter model,
which indicates important epistatic effects in genetic expression. The dominant
genetic effects were greater than the additive ones for all the characters
evaluated. LG showed positive and significant differences for [h] in both crosses, indicating the presence
of hybrid vigor and its possible use in the improvement. Low value of [d] and high of [h] both
significant in SC2 × AFE, indicates existence
of genes dispersion between the parental lines. While, for the cross SC2 × LP3,
the low and significant value of [d] and not significant value of [h], indicate greater genetic
similarity. In the SC2 × LP3 cross, the negative interaction [l] confirms ambidirectional dominance, while for SC2 × LP3 the positive sign
indicates directional dominance. The analysis of tolerance to salinity in the
osmotic phase showed a complex polygenic inheritance for the traits used,
determined by simple and interaction effects of different magnitudes and
significance according to the cross considered.