) CICER ARIETINUM L.( بررسي تاثير خوسرمايي بر تحمل به يخ زدگي در سه رقم نخود

The effect of cold acclimation on freezing tolerance of three chickpea (Cicer arietinum L.) cultivars

It is necessary to alter temperature gradually when we have an intention for screening of plants to freezing tolerance so that it allows us to make active acclimation mechanisms and reveal impression of efficient genes. In order to asses manners of applying these temperature alternations on chickpea in vitro, in this study seeds of two genotypes `ILC533ʹ and `ILC482ʹ and a variety of Qazvin were grown in the relatively steril condition and 1 cm explants from second and third nods of those plants were prepared and grown on an agar medium in vitro. Acclimation treatments were done 10 days and/or 20 days at 4°C. After acclimation, those cultures as well as control (no acclimation) were frozen at -4, -8, -12, -16 and -20°C for lh and on the basis of peresent injury, probit analysis was accomplished to identify LT50 for each treatment. Evaluation of freezing tolerance by LT50 showed that the cold acclimation increased freezing tolerance and 20 days cold acclimation had better effect on cold hardiness and viability. Freezing tolerance of `ILC533ʹ induced by cold acclimation was more than other cultivars. Also acclimation for 20 days allowed satisfactory discrimination between the hardy cultivars ʹ1LC482ʹ and `Qazvinʹ and less cold hardy `ILC533ʹ. The results suggest that acclimation treatment for 20 days at 4°C can be used for in vitro screening of chickpea to decline freezing injury. So it seems to prepare the possibility of autumn culture by screening of tolerant chickpea.