%0 Journal Article
%T Germination Kinetics in Two Acacia karroo Hayne Ecotypes under Salinity Conditions
%A Abdenour Kheloufi
%A Abdelmalek Chorfi
%A Lahouaria-Mounia Mansouri
%J Open Access Library Journal
%V 4
%N 1
%P 1-11
%@ 2333-9721
%D 2017
%I Open Access Library
%R 10.4236/oalib.1103319
%X
Acacia karroo Hayne is the most important woody invader of grassland in South Africa,
and is one of the fastest-growing acacias, and produces high-density wood. This study
aims to compare the germinative behaviour
of A. karroo seeds collected from two ecotypes geographically and
climatically different (Coastal and Steppic area) in salt stress. The seeds
were exposed to saline stress conditions by increasing concentrations of sodium
chloride (NaCl) varying from 0 to 50, 100, 150, 200, 250, 300, 400 and 600 mM.
Germination was estimated by the daily rates and the final germinated seed rate
during a period of 21 days in Petri dishes at 25¡æ (5 replicates of 20 seeds).
The emergence of seedlings was appreciated by their overall length. The results
revealed the existence of a significant variation (p < 0.001) between
the two seed sources. Indeed, those collected from an arid ecotype were most
tolerant at higher sodium chloride concentrations. The response to salinity
stress varied in time with NaCl concentration and seeds origin which could be
attributed to intraspecific variations resulting from the natural selection of
the same species. Under 400 mM of NaCl, 20% of germination was obtained from
the coastal seeds against 66% from the steppic seeds. The repeated measures
analysis of variance also revealed a significant effect of factors ¡°Concentrations of NaCl,
ecotypes, time of germination and their correlation¡± on the kinetics of germination.
%K Acacia Trees
%K Seed
%K Salinization
%K Tolerance
%K Forestry
%U http://www.oalib.com/paper/5280789