Establishment of Embryogenic Cell Suspension Culture and Plant Regeneration of Egyptian Cumin (Cuminum cyminum L.)

摘要

Embryogenic cell suspension (EGS) cultures were established from hypocotyl segments-derived embryogenic calli of Egyptian cumin (Cuminum cyminum L. cv. 'Balady'), the sole popular commercial variety of cumin in Egypt. After culture for 2-4 months on B5 solid callus induction medium supplemented with 0.88 mg/1 2,4-dichlorophenoxyacetic acid (2,4-D) plus 0.86 mg/1 kinetin (Kin), meristematic globules and yellow, friable ECS were induced from the explants of seedling hypocotyls. ECS were initiated fromthese embryogenic calli in the same liquid B5 callus induction medium. After selection of small aggregates and single cell cultures at 15-day intervals for 2 months, homogeneous and yellow ECSs, composed of single cells, small cell aggregates were established. Based upon the growth dynamic of ECS, the entire old medium was replaced weekly by an equal volume of fresh medium. Plating of ECS (1-12 months old) on 3 different solid B5 media (B5_Z, B5_K and B5_(ZK)) resulted in the induction and development of approximately six, two and six compact, organized calli/ml of ECS, respectively. Variation in callus induction ability was influenced by the time elapsed after subcultures and the medium used. Plated cells responded best 5 days after subculture; 11 calli/ml ECS were obtained while 8.2 shoots/ml ECS regenerated on B5_(ZK) medium containing 0.065 mg/1 Zeatin + 0.021 mg/1 Kin. A total of 230 plants were obtained, -75% of which were survived under ex-vitro conditions, flowered and produced normal seeds. Chromosome number of suspension cells ranged from 12-28 chromosomes, and the majority of cells (51%) had a normal (14) chromosome number, which was also observed in 63% of tested root tip cells of regenerated plants.