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The effects of genotype, culture medium, and explant on callus initiation
and plant regeneration were studied using a factorial experiment in a
complete randomized design with three replications. Cotyledon and hypocotyl
explants were excised from the seedling of each alfalfa cultivars and processed
for callus formation and regeneration according to procedures suggested by
Bingham and Saunders, Walker and Sato , and Meijer and Brown. Callus
volume, Percentage of somatic embryos and regeneration efficiency were
measured. Callus formed on all treatments but its volume was significantly
affected by each of the three factors and their interactions. Me,an comparisons
showed that the largest callus volume was obtained from cotyledon explant of
cultivar Shirazy in MSHI medium and the smallest callus volume from
hypocotyl explant of Moapa cultivar in MMS medium. In general, callus
produced from cotyledon explant was larger than that produced from
hypocotyl explants. Results of plant regeneration showed that only Walker
and Sato procedure regenerated plant via somatic embryogenesis. Effects of
explant, genotype and their interactions were significant at 0.01 level. Percent
of somatic embryos was between 0 to 20% with highest belonging to the
hypocotyl explant of cultivar Crisary and lowest belonging to coytledon explant
of cultivar Mohajeran. Hamadany, Crisary, Semirchankaya, and Moapa
cultivars were regenerated from hypocotyl explants while cultivars Mohajeran
and Semirchankaya were regenerated from cotyledon explants.