Tissue Culture Studies on Aerides multiflora
In the present study, different nutrient media viz., Murashige and Skoog (full strength and half strength), (Mitra et al.), with and without coconut water were evaluated for seed germination and early protocorm development of Aerides multiflora, a medicinally important orchid. Varied responses were observed in different media. Early spherule formation was first observed in full strength MS medium supplemented with 10% CW (after 4 week of culture) followed by full strength basal MS medium (4.5 week of culture). The protocorms further used in this study were obtained from in vitro seed germination of A. multiflora. Protocorms were cultured on Murashige and Skoog basal medium fortified with Activated Charcoal (AC) and different growth additives viz., peptone, yeast extract (YE), casein hydrolysate (CH), coconut water (CW) and plant growth regulators viz., 6-benzylaminopurine (0.5-1.0 mg/L) and 1-naphthalene acetic acid (0.5-1.0 mg/L) alone and in combinations. Maximum protocorm proliferation was observed on medium supplemented with 1.0 mg/L BAP followed by development of leaf primordia within 40 DAC, whereas complete seedling with 2-3 leaves and 1-2 roots was developed in medium fortified with 0.1% peptone. In medium supplemented with yeast extract only leaf primodia was observed while in medium containing CH tissue drying was observed after 10 DAC. Several attempts have also been made to reduce the cost of tissue culture raised plants. The efforts have largely concentrated around using low cost alternatives to gelling agent (agar). In the several alternatives tried viz., coconut coir, cotton, filter paper, isabgol, sago and corn starch, formation of leaf primordial from protocorm was observed after 3 weeks in cotton based medium followed by medium gelled with 13% sago after 3.5 weeks. Slow growth and development of protocorm was observed in medium gelled with isabgol. Further experiments are underway.
Keywords: Aerides multiflora, protocorms, leaf primordia, low cost alternatives, DAC