International Journal of Agriculture: Research and Review. Vol., 2 (S), 1097-1105, 2012
Available online at http://www.ecisi.com
ISSN 2228-7973 ©2012 ECISI Journals
EFFECT OF PRIMING BY SALICYLIC ACID ON GERMINATION AND SEEDLING
GROWTH OF SAFFLOWER SEEDS UNDER CACL
2
STRESS
BAHAREH JAMSHIDI JAM
1
,FARID SHEKARI
2*
,MOHAMMAD REZA AZIMI
3
AND ESMAEIL ZANGANI
4
1- Dept. of Agronomy and Plant Breeding, Faculty of Agriculture, University of Zanjan, Zanjan, Iran.
2- Dept. of Agronomy and Plant Breeding, Faculty of Agriculture, University of Zanjan, Zanjan, Iran.
3- Dept. of Agronomy and Plant Breeding, Faculty of Agriculture, University of Zanjan, Zanjan,
4- Dept. of Agronomy and Plant Breeding, Faculty of Agriculture, University of Zanjan, Zanjan, Iran.
*Corresponding Author Email: shekari@znu.ac.ir , faridshekari@yahoo.com
ABSTRACT: Excess calcium in calcareous soils leads to some problems in germination and
subsequent growth of plants. The effects of priming by salicylic acid (SA) on safflower seeds,
cv. Goldasht, were examined under various levels of CaCl
2
. Factors were seven levels of SA
(including untreated seed as control, 0, 500, 1000, 1500, 2000 and 2500 μM) and CaCl
2
in
five levels (0, 80, 160 ,320 and 400 mM). Calcium stress reduced the percentage and rate of
germination, fresh and dry weight of cotyledons, cotyledonary leaf area, shoot and root dry
weight, root and shoot length, shoot to root ratio and specific leaf weight, but increased mean
time germination. Application of SA led to improve measured traits, both in control and stress
conditions. Seed priming with 2000 μM SA in the highest level of CaCl
2
led to increase in
shoot dry weight near to 90% compared to non-treated seeds. Root dry weight showed greater
decrease with increasing stress levels than shoot dry weight. The highest cotyledonary leaf
area was found in non-stress condition and in primed seeds with 2000 μM SA. It seems that
seed priming with 500 μM SA had most effects on measured traits both in stress and non
stress conditions. Results showed that both seed priming with SA or distilled water (0 μM
SA) improve safflower seedlings resistance to calcium stress.
Key words: germination rate, shoot and root dry weight, specific leaf weight.
INTRODUCTION
Among the oilseed crops, only
safflower (Carthamus tinctorius) originated
from Iran (Alyari et al., 2000) and had some
favorite traits such as resistance to salt and
drought stress, relatively high resistance to cold
stress and suitable oil with valuable unsaturated
fatty acids (AlYari et al., 2000; Sato et al.,
2005).
Environment stress reduces crop production
more than other factors in the worldwide
(Levitt, 1980). Soil and water salinity is one of
the limiting factors in plant growth (Tanji,
1990). The dominant cations in the most saline
soils are Na
+
, Ca
2+
, SO
4
2 +
, Mg
2 +
and K
+
. The
important soluble salts in this soils that restricts
growth and reduce plant productivity are NaCl
2
and CaCl
2
(Levitt, 1980). Plant growth and crop
production in calcareous soils and the soils with
high pH always had some problems. An
important part of these problems are caused that
in these soils due to high pH and concentration
of calcium, some nutrients such as phosphors
and micro elements, which their absorption
depend to pH, fixed and could not be absorbed
by plants. (Deluca et al., 1989). Although the
Ca salts present in soil had lower solubility, the
activity of the Ca
2+
in the soil is much higher
than other ions responsible for ionic stress. The
response of plant to calcium stress is not usually
due to the primary Ca stress, but to the
secondary stresses induced by the Ca, pH,
mineral deficiency, etc. For instance, lime
induces chlorosis in calcifuges plants due to an
iron deficiency. Calcareous soils have high
quantities of bicarbonate as well as calcium. In
early growth stages, and even higher amounts of
calcium is needed for plants, if Ca
accompanying with bicarbonate, plants injured
by this ions (Levitt, 1980). They can usually be
precipitated in the cell sap, commonly as
oxalates or carbonates, or neutralized in the
soluble from in the cell sap as malates or