Callus was initiated from one-week-old seedling roots on Linsmaier and Skoog's medium with 2,4-dichlorophenoxyacetic acid (2,4-D). Growth pattern was compared in haploid and diploid root callus cultures. Haploids were selected from crosses of C x C-I stocks. Growth was assessed by fresh and dry weight analysis after a month. Haploid callus growth was slow (0.5 + 0.05 g) compared to diploid (1.01 + 0.10 g). Rhizogenetic ability was greater in haploid calli as evidenced by profuse rooting, especially in suspension cultures under similar conditions. Diploid root was found to be superior over haploid for callus initiation and growth.

Effects of growth regulators GA3 and abscisic acid (ABA) were also studied using diploid root cultures. Callus was initiated from roots of one-week-old seedlings on LS media with 2,4-D plus different concentrations of either GA3 (10-40 mg/l) or ABA (1-4 mg/l). After one month, the fresh and dry weights of calli were analyzed. With increasing concentrations of GA3 and ABA, a decrease in callus growth was observed compared to control. It may be suggested that these growth regulators influence the growth of root callus cultures.

P. Suprasanna, K. V. Rao and G. M. Reddy
 
 

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