The effects of chemical and physical mutagens on morphological and cytological characters of barley (Iranian cv. Nosrat)
Induced mutations are highly effective in enhancing natural genetic resources and have been used in developing beneficial variations for practical plant breeding. In the current study, dry grains of barley (Hordeum vulgaris L., cv. Nosrat, 2n = 2x = 14) were exposed to physical and chemical mutagens. The results of Duncan multiple rang test showed that treatments of gamma ray (control (0), 200 and 320 Gy) had highest germination percentage and formed class a. The lowest germination percentage belonged to ethyl methane sulfanate (0.7%). Mean comparison of radical length trait showed that the highest radical length belonged to gamma ray control, 200 Gy and sodium azide (SA) 0.5 mM and treatments of gamma ray 700 Gy, 1200 Gy and ethylmethane sulphonate (EMS) 0.7% had lowest radical length. Mean comparison of plumule length trait showed that treatment of SA 1 mM had highest plumule length. Cytogenetic studies have shown chromosome breakage in some induced barley seed by high dose of 700 and 1200 Gy. On the basis on growth traits analysis, sodium azide 0.5, 1 and 5 mM, ethyl methane sulfanate 0.1% and gamma ray 200 and 320 Gy are appropriate mutagens. However, it needs more consideration on mutagen, dose of mutagens and trait to have best breeding program by mutagenesis.
Key words: Barley, physical and chemical mutagen, gamma radiation, sodium azide, ethyl methane sulphonate.