Interaction of Growth Regulators and Arbescular Mycorrhizal Fungi on In Vivo Micrografting of Pistachio (Pistasia vera L.)

Micrografting is an important technique supporting the micropropagation of a range of plant species, particularly woody plant species. In the past decade, in vivo and in vitro micrografting has become a strategy to facilitate shoot recovery and acclimatization of horticultural species. This experiment was conducted to study pistachio (P. vera L.) micrografting under in vivo condition and interaction of growth regulator and arbescular mycorrhizal fungi on micrografting success and stablishment. The scions were prepared from shoot tips of 6-7 years- old mature trees of " Ahmad Aghaie" cultivar and were micrografted on 14-deys- old "Qazvini" under controlled conditions. In order to examine the effect of mycorrhizal symbiosis on micrografting success and stablishment, inoculation of rootstooks with mycorrhizae (Funneliformis mosseae) was performed at the time of seed sowing. After floating the scions in ascorbic acid (0 and 400 mg L-1) for 60 min, they were treated with IBA (0, 50 and 100 mg L-1) and BA (0, 40 and 80 mg L-1). The results showed that, mycorrhizal inoculation had a positive influence on graft success percentage, survival percentage, scion growth, scion dry weight and leaf number. With the use of growth regulator, the success rate of micrografting increased so that the level of 100 mg L-1 of indolebutyric acid and 40 mg L-1 of benzyl adenine was observed to be more effective than other levels. In this study, ascorbic acid treatment had different effects, but in most cases it did not have a significant effect on micrografting, even in combination with growth regulators, the treatment had a negative effect. According to the results obtained from this study, it seems that the use of growth regulatorse and AM fungi had a positive effect on the survival rate of micrografted plants and these plants had a longer survival.