Microspore culture in <i>Corchorus olitorius: </i>Effect of growth regulators, temperature and sucrose on callus formation*

Abstract

Culture of isolated microspores and of anthers on media containing IAA directed free microspore development to an embryogenic pathway in <i>C</i>. <i>olitorius. </i>The first division of microspores on transfer to culture media was symmetrical in contrast to the asymmetrical division seen in normal development <i>in vivo. </i>Initially, 10-30% microspores divided

symmetrically, but only 0.2-1% of the dividing microspores continued dividing and produced multicellular microcalli. About 30% of these microcalli produced callus but only on medium with 2.0 mg/L zeatin and 0.1 mg/L IAA. Incubation in the dark at temperatures of 35^o C for 1 day and then 25^o C was found effective for induction of first embryonic division in <i>Corchorus. </i>The frequency of microspore callus formation was higher on medium containing either 3% or 5% sucrose. Addition of colchicine and addition of activated charcoal to the above medium did not enhance microspore division in <i>Corchorus olitorius. </i>On transfer to different media most calli produced roots but regeneration of shoots and embryos was not induced.