Central Tuber Crops Research Institute, Trivandrum, India
The effect of different culture media on pollen germination and tube growth has been studied in Dioscorea bulbifera. The pollen grains did not germinate in distilled water. In 5 per cent sucrose concentration, the pollen germination was found to be 34.5 per cent and the pollen tube length to be 42.8 microns. However, by adding 200 ppm boric acid to 5 per cent sucrose solution, the pollen germination increased to 85.4 per cent and pollen tubes attained on an average 271 microns in length. Further, in a medium of 5 per cent sucrose containing 200 ppm boric acid and 100 ppm calcium nitrate, the length of pollen tubes was observed to be 466.8 microns, which is more than thirty times the diameter of the pollen. However, the pollen grains did not show any favourable growth response with magnesium sulphate. The effect of sugar and chemicals in pollen germination and tube length and the implications of the results obtained have been discussed.
