Effects of sodium nitroprusside on shoot multiplication and regeneration of Vanilla planifolia Andrews

Nitric oxide (NO) plays diverse roles in the growth and development of plants. The effects of a NO donor, sodium nitroprusside (SNP), on shoot multiplication and regeneration of Vanilla planifolia Andrews have been studied. Nodal segments of V. planifolia were used as explants to initiate shoots. The number of shoots per explant showed a significant increase in the presence of SNP and more than 93% of explants formed shoots. Supplementation of 10.0 mu M SNP to Murashige and Skoog (MS) basal medium containing 1.0 mg/L 6-benzylaminopurine (BAP) produced the highest number of shoots per explant (10.33) after 60 d of culture. However, in this treatment, shoot length (3.76 cm) was less than in the other treatments, except for the plant growth regulator-free MS medium. MS medium containing only 1.0 mg/L BAP produced the highest shoot length (4.49 cm) with a mean number of 6.26 shoots per explant. These findings indicate that NO stimulated shoot development and may be considered as an intermediary of adventitious shoot regeneration, as has been suggested for other plant species.