THE EFFECT OF MUTATION ON MICRO PROPAGATION OF Crocus sativus L.

Abstract

Saffron is an important medicinal plant widely cultivated for nutrition and economic properties.<br><br>The mutation can be used to increase the variation in this plant. The aim of this study was to<br><br>evaluate of the effect of gamma radiation on the in vitro cormogenesis and the corm size and then<br><br>acclimatization of the corms. Three ecotypes of the saffron corms were collected from Mashhad,<br><br>Torbat-e Heidarieh and Sarayan provinces in Iran. Gamma radiation with the intensities of 2.5, 5,<br><br>7.5 and 10 Gray were used for corm treatment. Then, for In vitro propagation, the SH medium<br><br>containing 3 mg/L BAP and 1 mg/L NAA was applied. The highest survival rate was observed in the<br><br>2.5 Gray treatment of apical buds, in Torbat-e Heydarieh ecotype with 90% survival. After two<br><br>months, the bud number on each explant was determined. The highest bud number was observed in<br><br>2.5 Gray dose in the Sarayan ecotype with 11.03 buds per explant. The buds were transferred to a<br><br>room with the temperature of 15°C and a photoperiod of 10/14 hrs (light/dark). The Rooting was<br><br>done on a SH medium containing 2 mg/L BAP with 9% sucrose. The best treatment for<br><br>cormogenesis induction was 1 mg/L IBA in ½ SH medium. Then, the MS medium with 6% sucrose<br><br>was used to increase the size of corms in the dark condition at 25°C which led to a mean diameter<br><br>increase of 1.22 cm. Finally, the corms were transferred to cocopit-perlite pots to check the survival<br><br>rate. The acclimatization percentage was 91.66%. This study showed that the lower dose of Gamma<br><br>ray can increase the number of sprouts and thereby the number of corm production.