3.4. Shoot regeneration
Shoot regeneration from the well-developed calli from different explants of the crocus species cultured on four different media has been summarized in Table 3. Specific ratios of NAA and TDZ supported callus induction (Table 1). A decrease in TDZ concentration with the addition of IAA into the media progressively increased the percent response and enhanced shoot formation in the crocus species (Fig. 1o-r). The majority of the responsive cultures producing shoots developed these from the basal portion of the callus (as shown in Fig. 1n) and very rarely from all over the surface (as shown in Fig. 1j). A maximum number of shoots per callus was observed for the (2 mg/L IAA + 2 mg/L TDZ + 2 mg/L BAP) combination in MS medium. Therefore, the reduction in TDZ concentration (from 4 mg/L to 2 mg/L) and the addition of (2 mg/L IAA + 2 mg/L BAP) proved to be more suitable for the production of distinct shoots (Table 3).