Table 1.
The effect of various combinations of PGRs on callogenesis in Solanum lycopersicum cultivars irrespective of explant type.
Fig 1.
Steps of complete in vitro regeneration in S. lycopersicum cv. Riogrande.
(A) In vitro grown one week seedlings of cv. Riogrande. (B) Cotyledonary explants. (C) Hypocotyls explants. (D-E) Calli induced from cotyledons and hypocotyls. (F-G) shoot and root organogenesis. Scale bars for (A, B, C, D, E and G), 150 mm. Scale bars for (F) 20 mm.
Fig 2.
The effect of medium pH (4.0) on rhizoids production from cotyledon and hypocotyl explants of tomato (cv. Riogrande) with optimized concentration of NAA (0.5/2 mg/L).
(A-A2) Rhizoids induced on cotyledon explants after one-week incubation. (B-B2) Rhizoids induced on hypocotyl explants after one-week incubation. (C) Primary and secondary somatic embryogenesis with many proembryos after 2 weeks of incubation. Scale bars (A, A2, B, B2) 5 mm. Scale bars (C), 50 mm.
Table 2.
The effect of various concentrations of NAA and pH values on rhizoid induction in S. lycopersicum cv. Riogrande.
Fig 3.
Induction of RTBs from rhizoids on MS media supplemented with TDZ/BAP (5 mg/L) at pH 4.0.
(A) Individual rhizoids tuber excised from rhizoid cluster at pH 4.0. (B-C) Globular and heart shaped embryo development at pH 4.0. (D-F) In vitro germination of somatic embryos to multiple shoot and roots after 2 weeks of incubation at pH 5.8. Scale bar (A) 2 mm. Scale bars (B, C and E) 15 mm. Scale bar (D) 150 mm. Scale bar (F) 20 mm.
Fig 4.
Stages of whole plantlet development from cluster of somatic embryos development via RTBs formation on MS media supplemented with TDZ at pH 4.0.
(A-B) Induction of RTBs in light conditions, arrows showing development of club shaped structures. (C-D) Maturation of RTBs to pre-cotyledonary stage embryo at the tip of rhizoid cluster. (E) In vivo germination of somatic embryos to whole plantlet. Scale bars (A-E) 20 mm.
Table 3.
Effect of TDZ/BAP concentration on rhizoid tubers (RTBs) induction at low pH in S. lycopersicum cv. Riogrande (no distinction of explant type).
Table 4.
Effect of pH values on development of rhizoid tubers (RTBs) irrespective of explant type in S. lycopersicum cv. Riogrande supplemented with 5 mg/L of TDZ.
Table 5.
Effects of culture media and explant type on shoot regeneration in four S. lycopersicum cultivars.
Table 6.
Effect of auxins on rooting of in vitro regenerating shoots of four S. lycopersicum cultivars after 8–10 weeks of incubation.
Fig 5.
Light microscopic sections of rhizoid tubers (RTBs) stained with safranin stain on tuber induction medium supplemented with 5 mg/L TDZ at pH 4.0 from cotyledon explants of S. lycopersicum cv. Riogrande.
(A) Section of regenerating rhizoid tubers after 25 days of incubation showing globular and nodular embryos arising from aggregate of callus tissues, 40 X. (B) Enlarged view of T-section showing embryonic cells. (C) Transverse section of mature RTB, 20X automatic scanning system [ASS]. (D) Enlarged view of section under box showing multiple embryoids. Scale bars (A, C) 200 μm. scale bars (B, D) 50 μm.
Fig 6.
Histology of somatic embryos developed via direct somatic embryogenesis from cotyledons explants of S. lycopersicum cv. Riogrande.
(A) Section of explants with various stages of somatic embryos showing abundance of globular stage embryos, after one week on tuber induction medium. (B) Enlarged view of transverse section under red box. (C) Globular shaped embryos [nucleus not stained] (D) Heart shaped embryos. (E) Torpedo-shaped cells. (F) Longitudinal section of single RTB club shaped embryo attached to explant. (G) Safranin stained section showing different stages of SE scale bars (A, G) 200 μm. scale bars (C, D, E) 200 μm. Scale bar (B, F) 50 μm.
Fig 7.
Plant acclimatization and transferring to soil substrate.
(A) 2 months old, plants transferred to soil with plastic cover in growth room. (B-C) Plants transferred to natural environment. Scale bar (A, B, C) 2 cm.