TITLE:
The Effects of Several Types of Induced Abiotic Stress on Cephalaria joppensis Germination under Controlled Conditions
AUTHORS:
Miriam Daklo-Keren, Waffa Abu-Aklin, Orit Cohen, Valantina Berger, Galina Sidan, Aharon Bellalou, Orit Amir-Segev, Ran Hovav, Shmuel Galili
KEYWORDS:
Cephalaria joppensis, Abiotic Stress, Seed Germination
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.7,
June
25,
2018
ABSTRACT: The recently domesticated species, Cephalaria joppensis (CJ), is emerging as a new alternative forage crop in Israel. It has high
biomass potential and nutritional values that are comparable to forage wheat.
However, CJ emerges slowly under cold conditions, which hinders its development
as a major winter crop. Additional tolerance for abiotic stress would improve its performance as a forage crop. We examined the effects of several
abiotic factors (i.e., cold, salinity,
drought and pH) on CJ germination under controlled conditions. The effect of
temperature was studied by incubating seeds at different temperatures between 7°C and 35°C. The effects of salinity, osmotic potential and pH were tested by incubating seeds at different NaCl,
PEG and pH levels, respectively. Temperature, salinity and osmotic potential
significantly affected germination; whereas pH did not. Temperature did not affect the final proportion of germinated seeds, but did
affect other germination-rate
variables, indicating that germination rate might be the limiting factor under
field conditions. Salinity also affected germination-rate variables, but not
the proportion of seeds that germinated. Notably, CJ was found to be relatively
resistant to high salt concentrations, with a 273 mM NaCl threshold for
germination, indicating its potential as a relatively salt-tolerant
forage crop. Both the proportion of germinated seeds and the germination rate
were highly sensitive to the osmotic-potential treatments, indicating that
drought resistance will remain the biggest challenge for CJ. This study
provides baseline data for a rapid and efficient system for further screening
for abiotic-stress tolerance among wild and cultivated lines of CJ.