TITLE:
Salinity Tolerance in Argentinean Population of Bromus catharticus. Variability and Direct and Indirect Effects on Seedling Characters
AUTHORS:
Monica Beatriz Aulicino, Monica Beatriz Collado, Hernan Barca, Maria del Carmen Molina
KEYWORDS:
Bromus catahrticus, Prairie Grass, Salinity Tolerance, Population Genetic Variability, Path Coefficient Analysis
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.11 No.12,
December
17,
2020
ABSTRACT: The aim of this research was to evaluate the salinity
tolerance in prairie grass populations at the seedling stage quantifying the
variability and the influence of physiological traits related to it. Salinity
tolerance, in Bromus catharticus Vahl (prairie grass) populations collected in different environments of the
Pampean Phytogeography region (Argentine) was evaluated at the seedling stage,
using controlled condition of temperature and light. It was adopted a
completely randomized design using 3 plots with three plants each one per
population and two levels of treatment: 0 mM and 100 mM NaCl. Morphological,
biomass and membrane stability root and shoot traits were studied. A factorial
ANOVA with interaction was estimated. Then one way ANOVA for all seedling
traits in both treatments allowed estimating variance components, coefficient
of genotypic determination (CGD) and variation index (VI). Comparisons between
populations were made using Tukey test (at 5% of probability). Phenotypic
correlations among traits were calculated and then a path coefficient analysis
separated direct and indirect effects at 100 and 0 mM NaCl. No significant
interactions “Population × Treatment” were found for any character. The saline
stress caused a pairing in the population means for the most traits.
Coefficients of variation were mainly higher when the seedlings grew without
stress (0 mM) because it allowed a greater potential genotypic expression. The
absence of significant interactions denotes a good homeostatic capacity of the
prairie grass facing that abiotic stress. Leaf length, shoot length and root
dry matter were the variables with the largest direct and indirect effects. Our
results showed an increase for them at salt and demonstrated intraspecific
variation, possibly in relation with the origin sites. Plants under stress
showed a marked resilience, in order to quickly restore the same biomass
allocation patterns that occur in non-stress environment.