Articles
EFFECTS OF LASER BIOSTIMULATION ON GERMINATION OF ACACIA FARNESIANA (L.) WILLD.
Article number
854_4
Pages
41 – 50
Language
English
Abstract
Acacia farnesiana (L.) Willd. is a very important multipurpose species in Egypt and many other countries.
It is valued as forestry and as an ornamental tree.
Its flowers produce a perfume called cassie extensively used in European perfumery.
The present study aims to the determination of the effect of helium-Neon (He-Ne) light irradiation on accelerating the germination of A. farnesiana seeds, which have dormancy due to impermeability of seed coat of water.
The seeds were exposed to He-Ne laser light for 1, 3, 5, 7, and 9 minutes with different irradiance 0.03, 0.20, 0.61, 1.14, and 1.70 W/cm2. Gibberellic acid (GA), indole-acetic acid (IAA), abscisic acid (ABA) as well as phenols were determined after 48h in treated and untreated seeds.
Thin sections in the testa were also made.
Germination indices: the time to germinate, germination period, germination percentage and germination speed were determined.
The results showed that irradiation by the laser beam of the seed coat, (testa or pericarp, the envelope enclosing the seed embryo), succeeded in perforating the seed coat at one or more positions.
Generally, an increase in irradiance and exposure time of He-Ne laser light irradiation increased levels of endogenous promoting substances (GA and IAA), and decreased levels of endogenous inhibiting substances (ABA and phenol) in seed coats.
We conclude that irradiance of seeds with He-Ne laser light at 1.70 W/cm2 for 9 min. significantly affected germination indices when compared with control seeds.
It is valued as forestry and as an ornamental tree.
Its flowers produce a perfume called cassie extensively used in European perfumery.
The present study aims to the determination of the effect of helium-Neon (He-Ne) light irradiation on accelerating the germination of A. farnesiana seeds, which have dormancy due to impermeability of seed coat of water.
The seeds were exposed to He-Ne laser light for 1, 3, 5, 7, and 9 minutes with different irradiance 0.03, 0.20, 0.61, 1.14, and 1.70 W/cm2. Gibberellic acid (GA), indole-acetic acid (IAA), abscisic acid (ABA) as well as phenols were determined after 48h in treated and untreated seeds.
Thin sections in the testa were also made.
Germination indices: the time to germinate, germination period, germination percentage and germination speed were determined.
The results showed that irradiation by the laser beam of the seed coat, (testa or pericarp, the envelope enclosing the seed embryo), succeeded in perforating the seed coat at one or more positions.
Generally, an increase in irradiance and exposure time of He-Ne laser light irradiation increased levels of endogenous promoting substances (GA and IAA), and decreased levels of endogenous inhibiting substances (ABA and phenol) in seed coats.
We conclude that irradiance of seeds with He-Ne laser light at 1.70 W/cm2 for 9 min. significantly affected germination indices when compared with control seeds.
Authors
A. Soliman, M.A. Harith
Keywords
Acacia farnesiana, helium neon (He-Ne) laser, seed germination, gibberellic acid (GA), indole-acetic acid (IAA), abscisic acid (ABA), phenols
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