Full Length Research Paper

Effect of water stress on growth of colchicine induced polyploid Coccinia palmata and Lagenaria sphaerica plants

Nontuthuko Rosemary Ntuli and Alpheus Mpilo Zobolo*

Department of Botany, University of Zululand, Private Bag x1001, KwaDlangezwa, 3886, South Africa.

*Corresponding author. E-mail: azobolo@pan.uzulu.ac.za.

Accepted 29 September, 2008

Polyploid induction was conducted by different colchicine concentration with seedlings of Coccinia palmata and Lagenaria sphaerica. Colchicine induced polyploid seedlings were grown in pots and subjected to varying levels of irrigation until they reached a flowering stage. The survival rate was best at colchicine concentration of 0.001 g/L in seedlings treated after three days of germination. Polyploidy induction was best at colchicine concentration of 0.01 g/L in seedlings treated after three days of germination. The induction rates for C. palmata and L. sphaerica were 90 and 86%, respectively. Compared with normal diploid plants, the polyploid plants of C. palmata and L. sphaerica inducted in our experiments had short stems. The polyploid induced plants had many active shoot apices, increased leaf chlorophyll content and were more drought resistant compared with normal diploid plants.

Key words: Colchicine, Coccinia palmate, Lagenaria sphaerica, water stress.