Propagation of Ornamental Plants
23(3): 71-80, 2023
IN VITRO PROPAGATION OF DENDRANTHEMA × GRANDIFLORUM (RAMAT.) KITAM. THROUGH AXILLARY SHOOTS
Govindan Thamodharan1*, Paranjothi Mathankumar2, and Thangavel Veeramani1
1 Department of Crop Improvement, Vanavarayar Institute of Agriculture, Manakkadavu, Pollachi, Tamil Nadu - 642103 India, *E-mail: srigsiva852@gmail.com 2 Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural University, Lawley Road, Coimbatore, Tamil Nadu - 641003, India
Five Dendranthema genotypes viz., Co 1, Yellow, Pink marble, Snapper, and Super white, were evaluated for in vitro propagation. Nodal explants from healthy initial plants were cultured on Murashige and Skoog (MS) media for axillary shoot induction which comprised 1.5-2.0 mg l-1 BAP, 0.1 to 0.15 mg l-1 NAA, and IBA/IAA in five treatment combinations along with control. The tissue culture-raised plants were evaluated for seven growth-promoting traits to identify the effective protocol for rapid multiplication to promote the cut flower industry. At the earliest (26.5 days) shoot formation was observed in genotypes Co 1 and Super white, the highest rate of axillary shoot multiplication (92.0% and 90.0%) was found in Super white and CO 1, the highest mean number of shoots (36.0) in Snapper, and the highest mean shoot length (9.0 cm and 8.8 cm) in Co 1 and Super white when the culture grown on MS medium comprising 1.5 mg l-1 BA + 0.1 mg l-1 NAA + 0.1 mg l-1 IAA (T1). Excised axillary shoots in length of 7-9 cm were transferred to rooting media supplemented with 0.5-1.0 mg l-1 IBA/IAA and 0.05-0.5 mg l-1 NAA. The combination 1.0 mg l-1 IBA + 0.05 mg l-1 NAA (R3) appeared to induce the highest rooting (91.0%) in Super white and the highest mean number of roots (23.0) was for Pink marble. The highest acclimatization rate of the tissue culture-raised plants (56.5% and 49.5%) was found in Co 1 and Super white, growing soil substrate of Vermicompost + FYM + Red soil (Alfisol). The flowering of shoots derived from cominations 1.5 mg l-1 BA + 0.1 mg l-1 NAA + 0.1 mg l-1 IAA (T1) and 1.5 mg l-1 BAP + 0.5 mg l-1 NAA + 0.15 mg l-1 IBA (T4) registered a significantly reduced mean number of days for flowering at 58.5 and 59.3 days, respectively, observed for Snapper. While the genotypes Co 1, Yellow, and Super white showed delayed flowering in the same substrate.
Key words: axillary shoots, Dendranthema, flowering, rapid multiplication, regeneration
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