aliakbar ehsanpour; Behrokh Shojaie; Mohammad Reza Abdi
Abstract
In this study, the effects of gamma rays on changes of proline, sodium and potassium in potato calli
(Solanum tuberosoum L.) cultivar "White Desiree" were investigated. After irradiation of calli by 60 and 80 Gy
of gamma radiation, irradiated and non irradiated calli were transferred to a callus production ...
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In this study, the effects of gamma rays on changes of proline, sodium and potassium in potato calli
(Solanum tuberosoum L.) cultivar "White Desiree" were investigated. After irradiation of calli by 60 and 80 Gy
of gamma radiation, irradiated and non irradiated calli were transferred to a callus production medium
containing 0, 30, 60, 90, 120 and 150 mM NaCl. After 26 days post treatment amounts of proline, Na+ and K+
were measured. The results showed that generally in each of gamma ray treatment, amounts of proline at 120
and 150 mM NaCl were significantly more than 0, 30, 60 and 90 mM salt. A significant difference observed
only at 150 mM NaCl between irradiated and non irradiated calli. This result could be related to the proline
role in osmotic adjustment at high concentration of salt. The amounts of sodium increased by increasing salt
the concentration but the amount of potassium decreased. These results showed that the sodium influx
inhibited the potassium uptake, and may be because of strong inhibitory effect of sodium on the potassium
uptake system or efflux potassium from the cells. The Na+/K+ ratio decreased at 150 mM by 60 and 80 Gy of
gamma radiation.
Akram Zia; Farkhonde Rezanejad; Abbas Safarnejad
Abstract
Thyme (Thymus vulgaris L.) is an aromatic and medicinal plant which is very important for the herbal
industry. In this research, in vitro selection for NaCl tolerance was investigated in this plant. Hypocotyl and
shoot explants (apical meristem and cotyledonary leaves) of sterilized seedlings were ...
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Thyme (Thymus vulgaris L.) is an aromatic and medicinal plant which is very important for the herbal
industry. In this research, in vitro selection for NaCl tolerance was investigated in this plant. Hypocotyl and
shoot explants (apical meristem and cotyledonary leaves) of sterilized seedlings were cultured in MS medium
supplemented with different combinations of 2, 4-dichlorophenoxyacetic acid (2, 4-D), napthaleneacetic acid
(NAA), kinetin (KIN) and N6-benzyladenine (BA) for callus induction. Results showed that the maximum
frequency of callus induction was obtained on MS medium containing 1:0.5 ratio of 2, 4-D:Kin (mgl-1), while
optimal callus induction with the best quality and regeneration potential was achieved in 1:1 ratio of NAA:BA
(mgl-1). The calli grown in 1:1 ratio of NAA:BA (mgl-1) were transferred to NaCl supplemented medium at 50,
75 and 100 mM concentrations. Fresh and dry weights, percentage of necrosis and regeneration of calli were
determined after 4 weeks. There were significant differences between fresh and dry weights of calli in different
concentrations of NaCl. The highest and the lowest of fresh and dry weights of calli from hypocotyl explants
were observed in 0 (control) and 100 mM NaCl concentrations, respectively. But fresh weight of shoot-derived
calli induced from shoots reduced only in 100 mM NaCl and the dry weight of them was not significantly
different. The necrosis percentage increased by increasing the salt concentration. Callus regeneration just
occurred at the concentration of 50 mM of NaCl and all regenerated shoots well rooted on half strength MS
medium, with 0.8% (w/v) sucrose and without growth regulators.
