Direct organogenesis from shoot tip of Egyptian New Valley date palm cultivars

Shoot tip explants of superior date palm cultivars Sewi, Tamr El wady, Hegazi and one individual unknown female from El-Kharga city (called Faleg or Meghel) were grown in the New Valley region and cultured on three different starting culture media MS+10mg/l 2,4-D+3.0mg/l 2iP ( M1), MS+ 10mg/l NAA+ 3.0mg/l 2iP (M2) and MS+30 mg/l NAA+20mg/l 2iP(M3) for eight months (two months interval). All culture media were supplemented with 40g/l sucrose, 2.0 g/l PVP, and 3.0 g/l activated charcoal and solidified with gelrite at 2.0 g/l. After eight months, some morphological responses were noticed as direct shoot buds, direct embryogenesis and callus. Depending on these responses, different culture media with different combinations of auxin and cytokinin were used to differentiate and multiply these cultures. Results indicated that the highest direct shoot bud percentage was formed on M1 medium while the highest direct embryo percentage was formed on M2.Induced direct shoot buds that transferred to the half strength of 2,4D then transferred to auxin free medium showed the highest multiplied rate as clusters. Maximum shoot number was obtained when transferring these clusters to a modified medium supplemented with 3/4 MS salt + 2.0 mg/l BA+ 0.5 mg/l Kinetin+ 0.25 mg/l 2iP+ 1.0 mg/l IAA. Meanwhile, induced direct embryos transferred to a modified medium supplemented with 1/2 MS+ 0.25 mg/l ABA + 0.5 mg/l Kinetin+ 0.25 mg/l 2iP showed the highest secondary embryo number. All induced shoots were rooted successfully and transferred to the greenhouse.