Factors affecting in vitro culture initiation and shoot multiplication in male sterile African marigold (Tagetes erecta L.) lines

A study was undertaken to establish cultures from field-grown, male sterile MS₇ and MS₅ marigold lines to utilize them in F₁ hybrid seed production. Culture initiation was better with nodal segment at the appearance of first flower from male sterile plants, using 0.1% HgCI₂ for 5 min. on MS medium supplemented with 500 mg/l gentamycin in both the genotypes. Shoot proliferation was registered best on MS medium supplemented with 10.0 mg/l BAP, 0.5 mg/l IAA and 40 g/l sucrose. High shoot proliferation, i.e. over three shoots per explant was obtained in MS₅ compared to MS₇ lines. The rooted plantlets could successfully be hardened and transferred to glasshouse conditions.