Abstract :
Response of three Iranian salt tolerant wheat to immature and mature embryo culture, different treatment of salinity with NaCL (0, 70, 140, 210 and 280 mg/l-1) and different levels of ABA (0, 3, 6, 9 and 12 mg/l-1) was examined. Mature embryos and immature embryos placed in medium supplemented with 10 mg/l-1 and 2 mg/l-1 2.4-D, respectively. From the viewpoint of callus induction and callus volume, mature embryos represented more and bigger callus. Mature embryos entered progressive growth phase sooner than immature embryos. Significant difference observed among cultivars in callus induction and callus volume. Roshan and Nik-nezhad showed the best and the least amount of callus induction and callus volume, respectively. There was a high correlation between callus induction and callus volume in this examination. Control treatments represented the greatest callus volume and with increase in salt concentration, relative growth (RG) and relative fresh weight growth (RFWG) decreased because of sodium influx to explants and cell membrane damages. Roshan and Nik-nezad showed the best amount of RG and RFWG, respectively. Tabasi represented the least value of RG and RFWG. The hormone levels evaluation showed that with increase in hormone concentration, callus induction decrease because of retard in cell cycle but RG increased because of anti oxidation activation. In 3 mg/l-1and 12 mg/l-1 the best and the least amount of RG and RFWG were obtained. These observation shows that ABA donate resistance to environmental stresses especially salt stress at callus in vitro culture.
