Germination of jojoba (Simmondsia chinensis L) seeds under the influence of several conditions

Our study indicates that jojoba is suitable plant for cultivation of the Egyptian marginal soils, in the desert area, where the seeds were germinated and grown in sandy soil of marginal fertility. To study the effect of NaCl and mannitol on seeds germination, jojoba seeds were placed on cotton layer flooded with solution containing different concentrations of them. Salinity stimulated seed germination, especially, when the seeds were subjected to relatively low concentration of NaCl (0.5 – 3 gm/l). Increase the concentration of NaCl over 3 gm/l resulted in inhibition of seed germination as well as radicle growth. Application of 2 or 3 gm/l mannitol in germination medium improved the seed germination, vice versa was detected under progressive increase of mannitol in germination medium. Mannitol as same as NaCl delayed seed germination of jojoba plant. On the other hand, jojoba seeds can be germinated in low frequency under high concentration of mannitol, up to 100 gm/l, when seeds were placed on three cotton layers just wetted by distilled water containing mannitol. Temperature may be the most critical factor during jojoba seed germination, therefore summer was the best season for seed germination; also, 30 oC was the best temperature degree for seed germination and emergence of radical in the shortest time.