INDUCTION OF ANDROGENIC EMBRYOIDS FROM ANTHER CULTURE OF <em>MADHUCA</em> <em>INDICA</em>

Abstract

The effects of anther development, sucrose and growth regulators on the embryogenic response of Madhuca indica anthers were studied. Anthers isolated from 8, 12 and 18 mm flower buds were cultured on Murashige and Skoog's medium supplemented with sucrose (30 and 60 g l^-1) and varying concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) (4.5 and 9.1 μM) in combination with N⁶-benzyladenine (BA) (4.4 and 8.9 μM) or kinetin (4.6 and 9.3 μM). Difference in response was observed between various developmental stages of anthers. Anthers taken from 12 mm flower buds (stage II anthers) were most responsive in terms of survival as well as callogenic differentiation. Stage III anthers (from 18 mm flower buds) were the least responsive in culture. Cytological observations showed that microspores in both stage I (from 8 mm flower buds) and stage II anthers were predominantly uninucleate. Optimum callus proliferation from stage II anthers occurred in low (30 g l^-1) sucrose medium supplemented with 2,4-D and BA. Embryoid induction took place exclusively from stage II anthers at a higher sucrose (60 g l^-1) concentration in the presence of high levels of 2,4-D and kinetin. Early embryonic segmentation in stage II microspores indicated androgenic origin of these embryoids. However, these embryoids failed to regenerate into complete plantlets, suggesting restricted morpho-organogenic competence of anthers in M. indica.