Effect of leaf leachate of four species on sprouting behavior of rhizomes, seedling growth and diosgenin content of Costus speciosus.
Konar J., Kushari D. P.
Author Affiliation: Department of Botany, University of Burdwan, Golapbag, Burdwan 713?104, West Bengal, India.
Bulletin of the Torrey Botanical Club 116 : 339-343
Abstract : C. speciosus is widely grown in West Bengal under the shade of various plantation trees. Since it is known that substances leached from certain shade trees can have allelopathic or promotive effects on understorey species, the rhizomes of C. speciosus were treated with leaf leachates of Mangifera indica, Shorea robusta, Tectona grandis and Eucalyptus globulus. Treatment with leaf leachates of M. indica, S. robusta and T. grandis increased the percentage sprouting of rhizomes, shortened the sprouting time and promoted subsequent growth, while the leaf leachate of E. globulus inhibited rhizome sprouting and growth. Maximum growth promotion was obtained with a 4 × dilution of the M. indica leachate. The diosgenin concentration in C. speciosus rhizomes was increased by treatment with the M. indica leachate, unaffected by the S. robusta and T. grandis leachates, and decreased by the E. globulus leachate.