Development of cormogenic nodules and microcorms by tissue culture, a new tool for the multiplication and genetic improvement of saffron

In order to develop a continuous system for saffron micropropagation by the induction of nodular cormogenic callus in vitro, different plant growth re gulators as well as organic supplements have been evaluated in relation to their capacity to regulate morphogenesis and plant regeneration in cultures of meristematic tissues from saffron corms. Microsurgery of the apical mer istematic bud in corms prior to culture increased the induction of cormogen ic nodules. High concentrations of BA (2 mg.L-1) and low of 2,4-D (0.1 mg.L -1) were found to be essential for development and proliferation:of cormoge nic nodules. The application of pachlobutrazol and imazalil increased the i nduction rate of adventitious shoots in the nodular cormogenic calli and th e growth of microcorms. The corms with adventitious shoots were rooted in m edium without growth regulators and were able to generate dormant microcorm s in vitro. This technique could be Of interest for the multiplication as w ell as the genetic improvement of saffron crop. ((C) 1999 Inra/Editions sci entifiques et medicales Elsevier SAS.)