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RESULTS

Analysis of callus cultures

Establishing cell and tissue cultures of Lantana is a difficult task to accomplish because of the interference posed by phenolic compounds. The best treatment for callusing, in terms of number of explants showing callusing and the degree of callusing, was the combination of MS + 2,4-D (1 μM) + NAA (1 μM) + BAP (5 μM). On the responding medium, 100% of the explants callused, and the callus growth was profuse after the first subculture. On this medium, the leaf-disc explants first turned brown but after a week, bright-green, hard, compact calli started developing from the margins of the leaf-disc (Figure 11.4 A, B). These compact calli were dissected out and subcultured on the fresh medium of the same growth regulator composition. The rate and degree of callus proliferation increased with the subsequent subcultures, the nature of callus did not improve substantially. The callus was friable and soft but remained deep brown in nature (Figure 11.4 C, D). Until 10 th subculture, the cells in the callus were a mixture of green and brown cells (Figure 11.4 E). It took about 26 weeks of regular subculturing, at 4-week intervals, to obtain profusely growing fresh, friable, granulated and cream callus. (Figure 11.4 F) .